EPA-600/2-76-090
April 1976
Environmental Protection Technology Series
              CLEAN  FUELS  FROM AGRICULTURAL  AND
                                         FORESTRY  WASTES
                                    Industrial Environmental Research Laboratory
                                          Office of Research and Development
                                         U.S. Environmental Protection Agency
                                   Research Triangle Park, North Carolina  27711

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                RESEARCH REPORTING SERIES

 Research reports of the Office of Research and Development, U.S. Environmental
 Protection Agency, have been grouped into five  series  These five broad
 categories were established to facilitate further development and application of
 environmental technology. Elimination of traditional  grouping was consciously
 planned to foster technology transfer and a maximum interface in related fields.
 The five series are:

     1.    Environmental Health Effects Research
     2.    Environmental Protection Technology
     3.    Ecological Research
     4.    Environmental Monitoring
     5.    Socioeconomic Environmental Studies

 This report has  been  assigned to  the ENVIRONMENTAL PROTECTION
 TECHNOLOGY series. This series describes research performed to develop and
 demonstrate instrumentation,  equipment,  and methodology to repair or prevent
 environmental degradation from point and non-point sources of pollution. This
 work provides the new  or improved technology required for the control and
 treatment of pollution sources to meet environmental quality standards
                    EPA REVIEW NOTICE

This report has been reviewed by  the U.S.  Environmental
Protection Agency, and approved for publication.  Approval
does not signify that the contents necessarily reflect the
views and policy of the Agency, nor does  mention of trade
names or commercial products constitute endorsement or
recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield. Virginia 22161.

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                                       EPA-600/2-76-090
                                       April 1976
                  CLEAN  FUELS

                        FROM

  AGRICULTURAL AND FORESTRY  WASTES
                          by

J.W. Tatom, A.R. Colcord, J.A. Knight, andL.W. Elston

             Engineering Experiment Station
             Georgia Institute of Technology
                Atlanta, Georgia 30332


                Contract No. 68-02-1485
                  ROAP No. BJV-012
              Program Element No. 1AB013


           EPA Project Officer:  J.D. Kilgroe

      Industrial Environmental Research Laboratory
        Office of Energy, Minerals, and Industry
           Research Triangle Park, NC 27711


                     Prepared for

     U.S. ENVIRONMENTAL  PROTECTION AGENCY
           Office of Research and Development
                 Washington, DC 20460

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                            ABSTRACT
An experimental investigation of the operating parameters for a mobile
waste conversion system based on the Georgia Tech Engineering Experiment
Station partial oxidation pyrolysis process has been made.  The object
of the testing was to determine that combination of parameters producing
the greatest amounts of char and oil and the least gas from agricultural
and forestry wastes.  From the tests, the dominant influence of air/feed
on char and oil yields is apparent and the desirability of low values of
this ratio is clear.

In addition to the testing, a preliminary design of a 200 ton/day (assuming
a 50 percent moisture feed) mobile pyrolysis system for conversion of
agricultural and forestry wastes into clean fuels was made and a simpli-
fied economic analysis conducted.  The results of this work indicate the
technical feasibility and the economic profitability of such a system.

This report was submitted in fulfillment of Project Number A-1653, Contract
Number 68-02-1485, by the Georgia Tech Engineering Experiment Station under
the sponsorship of the Environmental Protection Agency.  Work was completed
as of March 1975.
                                     ii

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                             CONTENTS






Abstract




List of Figures	iv




List of Tables	vi




Foreword	viii




Sections




I     Conclusions   	 	  1




II    Recommendations	3




III   Introduction  	  4




IV    EES Experience in Pyrolysis	10




V     Testing	23




VI    Mobile Pyrolysis System Preliminary Design  	 -^




VII   References	71




iVIII  Appendices	72
                                iii

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                             FIGURES


No.                                                                Page

1   EES Waste Converter Schematic                                   8

2   First Generation EES Pyrolytic Converter                       H

3   Wood Wastes Field Demonstration Unit—Overall View             !3

4   Wood Wastes Field Demonstration Unit—Char Handling            13
    and Storage System

5   New EES Pyrolytic Converter                                    15

6   Pyrolysis Tube Furnace for Bench Scale Experiments             17

7   Condensation Train for Pyrolysis Experiments                   18

8   Mass Balance for Pyrolysis of Pine Sawdust and Bark            19

9   Heat Available from Pyrolysis of Pine Sawdust and Bark         21

10  EES Pyrolysis Unit Process Flow Diagram                        24

11  EES Pyrolytic Converter—Feed Bin and Feed Conveyor            25

12  EES Pryolytic Converter—Close-Up of Feed System               25

13  EES Pyrolytic Converter—View of Condenser Train               25
    and Afterburner

14  EES Pyrolytic Converter—Close-Up of Condenser Train and       26
    Afterburner Showing Particulate Material Separator

15  EES Pyrolytic Converter—Close-Up of Unit                      26

16  EES Pyrolytic Converter—Feed System Showing Pneumatic Valve   26

17  Schematic of Agitator                                          29

18  Mass and Chemical Balance Calculation Procedure                40
                                  iv

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Figures Continuted

No.

19  Fractional Char Yields Versus Air/Feed Rate                         46

20  Percent Available Energy in Char-Oil Mixture                        47

21  Energy Breakdown of Pyrolysis Products                              ^

22  Heating Value of Noncondensible Gas                                 50

23  Effects of Feed Moisture on Available Energy                        51
    from Char-Oil Mixture

24  Mobile Pyrolysis System Concept                                     53

25  Mobile Pyrolysis Unit Process Flow Diagram                          "

26  Plan and Elevation Views of Trailer I                               ^6

27  Plan and Elevation Views of Trailer II                              57

28  Plan View of Deployed Mobile Pyrolysis System                       58

29  Elevation—Crossection Views of Mobile Pyrolytic Converter          60

30  Net Income of a Mobile Waste Converter with Varying                 67
    Capacity—Fuel Price $20/ton

31  Net Income of a Mobile Waste Converter with Varying                 68
    Capacity—Fuel Price $35/ton

32  Net Income of a Mobile Waste Converter with Varing                  69
    Capacity—Coal Price $50/ton

33  Net Income of a 100 Ton/Day (Dry) Waste Converter                   70
    with Varying Fuel Prices
                                                                        QO
A-l Viscosity of Pine Wood Waste Pyrolysis Oil                          3U

A-2 Weight Loss Versus Temperature for Pine Wood Waste                  91
    Pyrolysis Oil

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                              TABLES


No.                                                         Page

1    Analysis of Combustion Stack Effluent of                 14
     Wood Wastes

2    Summary of Results of Run 2                              36

3    Operating Conditions                                     38

4    Overall Mass Balance                                     43

5    Overall Energy Balance                                   44

6    Summary of Test Results                                  45

7    List of Equipment for Portable Pyrolysis System          61

A-l  Laboratory Analysis—Run 4                               75

A-2  Laboratory Analysis—Run 5                               76

A-3  Laboratory Analysis—Run 6                               77

A-4  Laboratory Analysis—Run 7                               78

A-5  Laboratory Analysis—Run 8                               79

A-6  Laboratory Analysis—Run 9                               80

A-7  Laboratory Analysis—Run 10                              81

A-8  Laboratory Analysis—Run 12                              82

A-9  Laboratory Analysis—Run 13                              83

A-10 Laboratory Analysis—Run 15                              84

A-ll Laboratory Analysis—Run 16                              85

A-12 Laboratory Analysis—Run 17                              86
                                    vi

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Tables Continued




No.                                                         Page






A-13 Laboratory Analysis—Run 18                             87




A-14 Laboratory Analysis—Run 19                             88




A-15 Trace Element Analyses                                  89
                                     vii

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                            FOREWORD
This effort was supported by the Environmental Protection Agency,
Industrial Environmental Research Laboratory, Research Triangle Park
(IERL-RTP), under Contract 68-02-1485.  We wish to express our appreciation
to Mr. James Kilgroe and Dr. Max Samfield of IERL-RTP for their many
contributions and suggestions.  And a special note of thanks is offered
to Ms. Eleanor Hancock and Ms. Beth Lanier for their invaluable assistance
in the preparation of this document.

It is EPA's policy to report numerical data in metric units.  However,
for the convenience of the readers, data reported herein is expressed in
units normally used in U.S. engineering practice.  A table for conversion
of these units into the international system of metric units is presented
in Appendix D.
                                   viii

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                            SECTION I

                           CONCLUSIONS


From the results of the testing, the following conclusions can be drawn:

        The effect on char-oil yields of air/feed is very important;
        the lower the air/feed the greater the yields.

        Bed depth may have an influence on oil yields but little effect
        on char yields.  Thus larger bed depth may be desirable to
        maximize char-oil yield.  (Larger bed depth would also allow
        use of a minimum number of air tubes and offers minimum
        obstruction to flow and agitator operation.)

        The effects of agitation (using the particular agitator geometry
        and feed tested) are not significant in influencing char-oil
        yields.  Agitation would probably allow greater throughputs,
        however.

        The effect of tube geometry on char-oil yields is apparently
        not significant.

        The overall mass, energy and chemical balances appear to be
        satisfactory; thus giving confidence to the results of the
        testing.

From the results of the design study, the following conclusions can be
drawn:

        A 200 gon/day (assuming 50 percent moisture) portable system
        appears feasible technically, and economically profitable.

        The system economics are strongly governed by the fuel price
        which can be obtained for the char-oil mixture.

        To obtain a maximum economic benefit, the system should operate 24
        hours a day, 250 days a year.

        Credits for disposal make the system especially profitable but
        are not necessary for economic justification.

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Uprating the system capacity would have a large impact on profit.

The travel and down time between operations at separate locations
have only a minor influence on productivity since typical operations
will last two to three weeks.

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                           SECTION II

                         RECOMMENDATIONS
The results of this study indicate the desirability of proceeding with
the development of the mobile converter concept.  More specifically, a
study of the effects of scale and of using a different feed material is
suggested.  Further development work in the utilization of the pyrolysis
gases for operating a modified gasoline engine is also felt desirable.
More work in the area of mechanical agitation should be made.  A test
of the burning characteristics of the char-oil mix would be useful.
And finally, the design, fabrication and test of the mobile converter itself
is a necessary step before construction of the complete mobile system
can be accomplished.

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                          SECTION III

                          INTRODUCTION
Each year the United States produces hundreds of millions of tons of
agricultural and forestry wastes.  These wastes, which represent a serious
disposal problem, also offer a potential source of a perpetually renewable
low sulfur fuel which could be used to help relieve domestic dependence
on foreign oil and gas supplies and thereby reduce our severe balance
of payments problem.  Therefore, if a practical technique for converting
even a fraction of these wastes into fuels could be developed, a signi-
cant step toward the solution of our nation's energy shortage would be
accomplished.  On a regional basis, the effect of such a development could
be dramatic since there are many areas which would become largely energy
self-sufficient if available wastes could be converted into fuels.  In
addition to the obvious advantages, a program for conversion of wastes
into clean fuels could produce an entirely new industry and generate many
new job openings in areas presently depressed both economically and
technically.

Such an energy development program would provide not only an ecologically
desirable method for disposing of wastes and producing fuels, but would
avoid the hazards, such as nuclear accidents and oil spills and the
unsightly blemishes from strip mining, that are associated with other
energy production methods.  Because the fuels produced would have a low
sulfur content, they could be burned directly or blended with high sulfur
coals to produce a low sulfur fuel with emissions acceptable to air quality
standards without the need for costly flue gas desulphurization equipment.

There is no doubt that some of the wastes produced are unavailable or
unuseable for such a program.  This is because, for example, current
agricultural harvesting equipment often leaves a large amount of crop
residue in the field where it is used as a soil conditioner.  While such
wastes could be feasibly collected, there is a question as to the desir-
ability of so doing because of the current high cost of fertilizer and
the wide-spread depletion of the organic content of our soil.  However,
much of the wastes are produced at processing plants such as sawmills,
sugar mills, rice mills, peanut shellers, cotton gins, etc., which
because of the availability and the concentrated form of the wastes, are
especially attractive as sources for energy production.  It should be
recognized that the recovery potential at these sites is based not only
upon the annually produced wastes but on the accumulated wastes from
many years of prior operation.  Indeed, there are canyons filled with

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wood residue in northern California and individual sawdust piles sixty-
feet deep and covering dozens of acres in the Southeast.  Therefore,
while the total available agricultural wastes are clearly only a portion
of that produced, the amounts are none the less staggering and the energy
potential is significant in terms of our national energy requirements.

Another concept related to producing energy from wastes is the "energy
plantation" (1 - 2) in which "biomass" would be grown entirely for the
purpose of producing energy.  It has been estimated (1) that an area
of less than one third of that involved in farming in the United
States could meet the entire energy requirement of all the installed
electric generating capacity in the country.  The nonagricultural area
classified as forest grazing land and grassland ranges, with proper
climate and rainfall suitable for energy plantations, is several times
that area.  Therefore the availability of land for energy plantations
is no impediment to its development.

From the above it appears that there is a significant argument that can
be made for the production of energy from "bioconversion," whether the
energy is a by-product or the principal product of agriculture.  However,
there are some obvious problems; e.g. :

     .  Agricultural waste (organic matter) is typically quite wet,'
        containing 30 to 70 percent water and therefore relatively
        low in heating value per pound.

        Since these materials would be scattered all over the country-
        side, the transportation costs per Btu to large thermal
        conversion plants would be very high.

        Because of the water content of these raw materials, the use
        of existing thermal conversion equipment is doubtful, at least
        at its rated capacity.  Most likely new or modified facilities
        would be required. (The overall steam side efficiency of boilers
        utilizing wet organic fuels such as bagasse and bark, is typically
        60 to 65 percent.  Thus there is a serious conversion penalty
        using these as-received, wet materials.)

        The particulate emissions from boilers operating on raw organic
        fuels would likely require the installation of expensive flue
        gas clean-up equipment.

        Agricultural wastes with a few exceptions are produced seasonally,
        not continuously.  Thus a steady supply of fuel from these wastes
        is not available and also it is impractical to tie-up capital
        equipment that cannot be used year round.

     .  Associated with the construction of a waste conversion facility
        dependent upon an adjacent, fixed supply of wastes over a long
        time period are contractual problems between the producer of the
        wastes and the waste utilizer.  While initially the waste producer

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        may be spending two to five dollars per ton of raw wastes for
        disposal, he may hesitate or refuse in a long term contract to
        giveaway, or perhaps pay a disposal charge for his wastes.  And
        clearly, once a facility for waste utilization has been
        constructed, the waste producer, upon termination of the original
        contract, has the waste utilizer in an uncomfortable economic
        position.

The above considerations have limited the development of the concept of
energy production from agricultural wastes in the past, and unless solutions
to the problems described are forthcoming, they will likely curtail future
developments.  In reviewing these factors, it should be realized that at
the heart of the operational problem is the high moisture content of the
wastes and the associated high transportation costs.  If some means could
be provided to eliminate or minimize these problems, then a major step
would be taken toward the practical development of the concept.

One apparent solution would be to simply dry the wastes before they are
transported; thus avoiding the transportation of all that water.  But
the question first arises as to the source of energy required to dry the
wastes.  Secondly is the fact that even wet agricultural wastes are
typically quite bulky and drying them will make them even more so.
Therefore while the weight of these materials could be reduced by drying,
their volume would be hardly affected.  Thus the transportation cost
benefit would be small or insignificant since the vehicles moving the
wastes would be volume limited.  Baling these wastes, or compacting them
somehow to a greater density is a relatively expensive operation, and
not believed to be practical.

Another concept is to utilize a mobile pyrolysis system that could be
transported to the site of the waste production and there convert the
wastes into a char, an oil and a low Btu gas.  The gas could be used to
dry the wet feed and to operate the associated equipment and the oil and
char could be mixed together to produce a single dense, free-flowing
solid.*  The weight reduction and the associated transportation costs
thereby affected would be very substantial.  A further benefit to be
derived is that since the system is portable it would provide greater
leverage for the waste utilizer in contract negotiations with the waste
producer, since the unit could always be moved to a new location.  The
portability feature would also guarantee greater equipment utilization
and through proper scheduling between seasonal agricultural wastes and
continuously available forestry wastes could provide an almost constant
supply of fuel.
*Mixing the oil and char is not an essential step but in many circumstances
would be advantageous since it would remove the necessity for a second
materials handling system.

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Finally, since the portable system could be assembled in factories, using
mass production techniques it would likely be less expensive than a
comparable fixed installation.

Therefore it appears that the concept of a mobile pyrolysis system has
merit, but there are still practical problems associated with operating
such a unit in the rural environment.  For example, most pyrolysis units
emphasize the production of gas, not char and oil; clearly there is
little practical use for an intermittantly available low Btu gas out in
the countryside.  Many pyrolysis units also require expensive front end
systems or elaborate auxiliary equipment.  And finally most pyrolysis
systems operate at elevated temperatures, require expensive insulating
materials,and are not easily moved.

The Engineering Experiment Station (EES) at Georgia Tech over the last
eight years has developed a simple, steady-flow, low temperature,
partial oxidation pyrolysis system which is completely self-sustaining.
In the EES design the pyrolysis occurs in a vertical porous bed.  A
schematic of this unit is shown in Figure 1.  From the figure its operating
features can be seen.  This unit requires no special front end system, has
very few moving parts, and depends upon a relatively small blower to
provide the air supply necessary to maintain the partial oxidization of
the feed.  The system typically converts a pound of dry organic wastes
into about a half pound of oil and char and one quarter pound of water
and one half pound of gas (allowing for the process air itself).

Typically a ton of as-received wastes would be converted, using the EES
process, to about 450 pounds of a powdered fuel, similar to coal, with
a heating value of 11,000-13,000 Btu/lb.  Thus, depending upon the feed
moisture content, the energy available for use at the central thermal
conversion plant could be 75 to 80 percent of that theoretically available
from the original dry waste; and, using a boiler conversion efficiency of
80 to 85 percent, the overall steam-side efficiency of the process could be
65 to 70 percent.  Hence the percent of useable energy could be as large as
and perhaps larger than that available with direct burning but with
avoidance or significant reduction of the problems of:

        Transporting the wastes.

     .  Modification or construction of new facilities compatible with
        fuels derived from organic wastes.

        Emissions resulting from unburned fuel particles.

The powdered char-oil fuel could be burned in either suspension fired
or in stoker fired boilers with esentially no modification.  It could
be blended with cheaper high sulfur coal to produce an additional economic
advantage.  The EES system thus appears to have many features desirable
for a portable unit.

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Non-Condensible
Gas & Steaa
Pyrolysis
   Oil
                           Waste Feed
                       (V.                N  .
                          Decomposing     I  J
                        C.  vJJas^te       '
                     ^               j    ^
               -\7—V
                                                        \
                                                           Process Air
                                       A     7\      TV
                                                           "1
                                                             Char
                                  Figure 1

                     EES Waste Converter Schematic

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This report then describes a program directed toward the development
of a portable pyrolysis system for conversion of organic wastes into
clean fuels using the EES waste converter design.  The program has two
main objectives which are:

     1.  "to conduct a parametric study of pyrolytic waste converter
         performance as a function of system parameters such as feed
         flow rate, bed depth, air flow rate and air tube location.
         The purpose of the tests is to optimize the production of
         char and oil and minimize the production of gas, and to
         obtain data for integrating the pyrolysis sections with other
         sections of a portable system.

     2.  Using the test data obtained, to perform a preliminary design
         of a transportable agricultural waste conversion system having
         a nominal feed rate of 200 tons/day, assuming 50 percent
         moisture."

The report is divided broadly into two sections describing the test
program and the design study.  However, a brief description of previous
EES work in pyrolysis is also presented to put the results of the study
in a wider perspective.

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                           SECTION IV

                   EES EXPERIENCE IN PYROLYSIS
GENERAL

The involvement of the EES in the area of conversion of solid wastes by
pyrolysis began with work eight years ago to develop a means to dispose
of peanut hulls without producing the pollution problems associated with
incineration.

The first pilot plant system, approximately five feet tall, was designed
to reduce peanut hulls to a char and a combustible gas.  The system built
in 1968 was operated on a batch basis at first and then on a continuous
basis with a manual input feed.  Hundreds of pounds of peanut hulls were
converted to char and off-gases during several months of testing with
this equipment.  Enough data were obtained to demonstrate the feasibility
of developing an automated prototype converter with the vertical, porous
bed design.

The large prototype, constructed in 1971 and shown in Figure 2,was built
to operate continuously at an input feed rate of 4,000 pounds per hour.
The unit was approximately 11 feet in height, and the reaction chamber
was mounted on top of a water-cooled collection chamber.  The feed-out
was accomplished by a horizontal screw at the base of the chamber.  The
off-gases were treated as potentially explosive in these tests,  and
consequently, a system was constructed to burn the gases in an unconfined,
diffusion controlled flame.  Experience with these gases showed that they
could be burned easily and safely by premixing and igniting in a conven-
tional fashion.  This system was operated over a period of many months,
while processing thousands of pounds of feed.  The reaction chamber of
this converter was designed to have a minimum weight and only enough
operating life to demonstrate the automatic operation of the process.
This was done to reduce the overall cost of this experimental prototype.
Consequently, the test program started with low temperature operation
and on succeeding tests the temperature was raised.  The internal structure
of the reaction chamber eventually failed after approximately six months
                                 10

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Figure 2.  First Generation EES Pyroltic Converter,


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of testing as a result of the elevated temperature.

Based on the data and results from the first pilot plant unit and the
experimental prototype, an improved pilot plant unit, used in the
present study and described in Section V, was designed and built.  In
addition a large 50 dry ton/day demonstration plant was built by the
Tech-Air Corporation, 2231 Perimeter Park, Atlanta, Georgia, who is the
licensee for the EES process.

The demonstration plant is located in a wood yard  in Cordele, Georgia,
and operates on wastes from the sawmill.  This system has been in
successful operation now for more than three years and was field tested
for two years prior to that.  The char produced is sold, the pyrolytic
oil produced is used in an oil-fired kiln drier, a portion of the gas
is used to dry the feed and the remaining gas is flared.  Plans are
to construct a process steam boiler which will utilize the remaining
gases.  The system is pictured in Figures 3 and 4.  An idea of scale
can be obtained by noting the control shed in the lower right hand
corner of the overall view, Figure 3.  A drier which utilizes hot
combustion gases from the off-gas burner reduces the water content
of the initially wet wastes down to four percent.  The input feed material
varies in moisture content from 20 to 55 percent, depending on weather
conditions, season of year, and the amount of sawdust in the feed.

Another attractive feature of this system is the cleanliness of its
exhaust which is completely invisible to the eye.  A recent analysis of
the combustion stack gases was made and the results are presented in
Table 1. These uncontrolled emissions are lower  than existing federal
and state standards for incinerators.

Recently, a new, larger (one ton/hour) more sophisticated pilot plant,
with improved instrumentation, and located near the smaller EES pilot
plant, has been constructed.  This system is primarily designed to
investigate in greater detail the parameters of the pyrolysis process at
a larger scale than previously possible.  A photograph of this system
is shown in Figure 5.
EXPERIMENTAL WORK

The EES work has involved both laboratory bench scale and pilot plant scale
studies of pyrolysis.  In both of these complementary efforts, a wide
variety of waste materials have been studied.


Laboratory Bench Scale Pyrolysis Experiments

These tests have been made to determine the general feasibility of a
particular feed for pyrolysis, to analyze the products, and to determine
                                 12

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 Figure  3.   Wood  Wastes  Field  Demonstration Unit-
            Overall  View.
Figure 4.  Wood Wastes Field Demonstration Unit-
           Char Handling and Storage System.


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                                   Table 1
                         Analysis of Combustion Stack
                           Effluent of Wood Wastes

Component
Water
Oxygen
Nitrogen
Carbon Dioxide
Carbon Monoxide
Particulates
A.
Composition
by Volume

14%
9.0%
69%
7.7%
30 ppm
14 micro
gms/f t^
COMPONENTS DETECTED
Test Method

Liquid Impinger collection
GCTC1
GCTC
GCTC
MSA2
Liquid Impinger collection

Mass Rate of
Pollutants
(pounds/minute)
NA7
NA
NA
NA
6.5 x 10~2
9 x 10~4
                      COMPONENTS TESTED FOR BUT NOT DETECTED
                            Threshold Sensitivity
Component

Hydrogen
Methane
Sulfur Dioxide
Nitrogen Dioxide
Ammonia
Hydrogen Sulfide
of Tests6
(ppm)
0.0009
0.0009
0.4
0.04
0.09
0.009
Test Method

GCTC
GCFID3
MSA4
MSA5
Odor
Odor
 Gas chromatography—thermal conductivity detector

 MSA—Mine Safety Appliance Co.  Test Part No.  91229
 Gas chromatography—Flame ionization detector
A
 MSA—Mine Safety Appliance Co.  Test Part No.  92623
 MSA—Mine Safety Appliance Co.  Test Part No.  83099

 These components would have to  be present in  concentration shown to  be
 detected; therefore, these results represent  the maximum amounts of  these
 components which could be in the stack gas

7NA—Not Applicable
                                       14

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Figure 5.  New EES Pyrolytic Converter,


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the theoretical yields available.  The general technique employed for the
pyrolysis of a particular material is as follows:  the material to be
pyrolyzed is placed in the metal pyrolysis tube either two inches I.D. or
six inches I.D. (see Figure 6).  The ends are capped, and the closed
unit is placed in the appropriate Lindberg tube furnace.  The downstream
end of the metal tube is connected to a condensation train as shown in
Figure 7.  The material in the tube is heated to, and held at, the desired
temperature for a predetermined time.  Spacers inside the pyrolysis
tube confine the charge to a uniformly heated zone in the furnace.
Internal temperatures are monitored with thermocouples.

The condensation train is arranged so that the high-boiling condensate
is collected mainly in one trap, while the water and low-boiling organic
material is collected in another trap.  The non-condensible gases, after
passage through a glass-wool scrubber and a cold trap, are measured with
a wet test meter and then collected in a large plastic bag for subsequent
analysis by gas chromatography.

On completion of a pyrolysis experiment, the exit from the pyrolysis tube
is closed to prevent air from entering the tube and reacting with the hot
char while the system cools.  After cooling, the system is disassembled,
and the char is collected, dried, and weighed.  The organic material and
water from the condensation train is collected and stored for further
analysis.  The gas sample is analyzed immediately after collection by
use of various gas chromatographic columns and techniques to determine
the composition.  The pyrolytic gases are predominantly hydrogen, carbon
monoxide, carbon dioxide, methane and lesser amounts of gaseous hydro-
carbons.  The analyses on the char include total ash, acid insoluble ash,
elemental composition, volatiles, heating value, and density.  The con-
densible organic material is usually characterized by a determination of
percent water, heating value, and elemental composition.  Pyrolysis
studies have been made with a variety of different materials including
pine bark, pine sawdust, mixtures of pine bark and sawdust, cotton gin
waste, bagasse, hardwood bark, hardwood chips, peanut shells, carpet
waste, nonmetallic automobile waste, municipal waste, dried sewage sludge,
and dried chicken manure.

To illustrate the type of results which were obtained from these laboratory
experiments, normalized yields (pounds of pyrolytic product per pound of
feed) for a mixture of pine sawdust and pine bark are plotted in Figure
8 as a function of temperature.  The figure shows that the char yields
decrease with increasing temperature, and this can be attributed to the
fact that the volatile content of the char decreases as the operating
temperature is increased.  The non-condensible gases increase with
increasing temperature and begins to show a leveling-off at the higher
temperatures.  This increase can be attributed to the formation of
condensible oil from the volatiles liberated from the char as the temper-
ature increases.  The aqueous yield decreases with increasing temperature.
                                  16

-------
Figure 6.   Pyrolysis Tube Furnace for Bench Scale Experiments

-------
                                                             LEGEND
                                                         1.   Pyrolysis tube
                                                         2.   Heated condenser
                                                         3.   Heated scrubber
                                                         4.   Heated trap
                                                         5.   Ice bath
                                                             Water cooled condenser
                                                             Water cooled scrubber
                                                             Chilled  trap
                                                             Glass wool scrubber
                                                             Dry Ice  trap
                                                             Siphon breaker
                                                             Wet test meter
                                                              to gas
                                                              collection
                                                              bag
Figure 7.   Condensation Train for  Pyrolysis Experiments

-------
!i
i
8
I
s
        0.40-
        0.35
        0.30
        6.25
0.20
        0.15
            400
                                               Char
                 I
                600
 I
800
                                                I
                                             1000        1200

                                 Pyrolysis  Temperature *F
                                                              Condensible
                                                              Organic
                                                              Material  (Oil)
                                  Non-Condensible
                                  Gas
                                                                     Aqueous
                                                             1400
            Figure  8.    Mass Balance for Pyrolysis of Pine  Sawdust and  Bark
                                               19

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As the temperature increases, the formation of water is evidently a less
dominant reaction while the reaction leading to the formation of more gases
and oil became more important.  These data are useful in predicting the
effects of temperature on yields in pilot plant experimental work.

The heat available from the pyrolysis of pine sawdust-pine bark mixture
is presented in Figure 9.  The significant information to be obtained
from this graph is that the sum of the heat values at each pyrolysis
temperature is very close to the heat value of the dry input feed material.
These data show that the total heat content of the input material over a
fairly wide temperature range can be accounted for in the pyrolytic
products (the external heat required to pyrolyze the feed being negligible).

Also shown in Figure 9 is a plot of the ratio of the energy available in
a mixture of the char and oil to the total energy in the wood waste.  It
appears that to recover the maximum energy in the char-oil mixuture the
pyrolysis should be conducted at as low a temperature as practical.


Pilot Plant Pyrolysis Experimental Work

The overall objective of the previous pilot plant experimental work has
been to determine the operating characteristics and parameters with
specific materials.  One important question that has been answered with
each material is how well the material feeds through the pyrolytic
converter.   Many materials are dense enough and are of such a physical
shape and size that they are essentially free-flowing and feed easily
through the converter.  Some examples are macadamia nut shells, hardwood
chips, and pine sawdust.  Pine bark must be hogged before it is suitable
as a feed material.  Peanut hulls, on occasions, have bridged in the
converter and hence some agitation is needed to break the bridge.   Other
materials,  such as bagasse, nonmetallic automobile waste, and cotton gin
waste present some problems with feeding.  With cotton gin waste,  for
example, it has been found necessary to use mechanical agitation in the
converter to keep the material from bridging in the pyrolysis zone.

The testing has indicated that the moisture content of the feed material
should be less than 10 percent.  If the moisture content is in the range
of 35 to 50 percent, as is the case with pine bark and sawdust, then the
material must be predried.  Other data and information obtained from
pilot plant pyrolysis experiments include throughput feed rates, yields of
char and condensible organic material, and composition of non-condensible
off-gases.   Ratios of process air to feed material rates are obtained
and correlated with yields and quality of products.  Materials that have
been processed in the EES pilot waste converter include peanut hulls, pine
bark, pine sawdust, mixtures of pine bark and sawdust, macadamia nut shells,
nonmetallic automobile waste, hardwood chips, cotton gin waste, and
municipal garbage.

In summary, the EES pyrolysis work conducted prior to this study has
indicated that there may be material handling problems associated with

                                  20

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    9000-
ii
    8000-
    6000-
    5000-
     3000-1
         I .
     2000-
     1000-
        400
                              0  measured heating value

                      Sum of Heats
                                                    Percent
                                               Available Energy
                                               in Char and Oil
Condensible
Organic
Material (Oil)
                                                                              _ 100
                                                                                -90
                                                                -80
             Latent Heat
             of Oil	
                                                                -70
                                                                              _60
                                                   Non-Condensible
                                                   Gas
                                                                -50

                                                   Sensible Heat

                                                   Latent Heat
                                                     of Aqueous
      I
     600
 \            \           I
800        1000        1200

 PYROLYSIS TEMPERATURE °F
                                                                  I
                                                                1400
160C
                                                                                      ?
                                                                                      0)
                                                                                      w
                                                                                      cr
                                                                                     M
                                                                                     It
                                                                                     l-t
      Figure 9.   Heat Available from  Pyrolysis of Pine  Sawdust and Bark
                                       21

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bulky wastes, in which case some form of mechanical agitation may be
required.  Further, it appears that the pyrolysis temperature has a
significant effect on product yields.  Since the bed temperature is
controlled by the air/feed ratio, it follows that in the pilot plant
work this latter ratio should have a major influence on the system
output.
                                 22

-------
                             SECTION V

                              TESTING
The object of the testing in the current study was primarily to determine
the optimum operating conditions for maximum production of char and oil
and for minimum production of gas using the EES pyrolysis system.  With
this in mind, the test instrumentation, the test operation and the selection
of the test parameters were made, within practical limits, to shed as much
light as possible on those conditions most favorable for application to
the portable converter concept.  The primary test parameters were:  the
air/feed ratio, the depth of the porous bed, the geometry and number of
air tubes, and the use of mechanical agitation.  A total of 19 runs were
made.  This included an initial shakedown run, a test run of the effects
on production rates and yields of changing the feed from a fifty-fifty
mixture of bark and sawdust to pure sawdust, three aborted runs, and
fourteen successful runs.

In the following sections a description of the facilities utilized, the
test and calibration procedure, the laboratory procedure and the results
of the testing are presented.
FACILITIES

The testing was conducted in the six ton/day EES pilot plant.  A process
flow diagram of the pilot plant is shown schematically in Figure 10.
Photographs of the unit showing views of the separate components involved
are presented in Figures 11 through 16.

The system operates as follows:  the wet sawdust is first dried in a  propane
fueled crop drier, then weighed and stored in drums.  During a test the
drums are emptied into a receiving bin and from there the feed passes onto
a conveyor which transports it to the pyrolysis unit.  The pyrolysis  unit
is 10 feet tall and is four feet on each side.  The average inside
dimensions of the bed are two feet by two feet and it is four feet deep.
The feed enters the converter through a gate valve and passes down through
the vertical bed.  Process air tubes are located in the lower portion of
the bed.  These water cooled tubes supply enough air to oxidize the feed
in their immediate vicinity and thereby produce sufficient heat for
pyrolysis of the remaining bed material.  The char at the bottom of the
                                 23

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      Wet
     Sawdust
             Dryer
Hot Water
to Dump
      Cold Water.
                                 Air
                                 Compressor
                                       ) Orifice

                                     _f	 (—Cyclone
                  JL-j >Cooling
                     , Fan
                                              Hot  Gas  to

                                              Atmosphere
                               Converter
      r
         Hot Gas
                                             •Jaste
                                             Particles
                                                         r  A
                                                         Condenser
Charcoal
                     Oil
                      Totalizing
                      Flow Meter
r-Orifice

S~\ Warm
                                 O{
                                    V __ x
                                                                      Sample  port
            Burner
                                                                                             —-Blower
              Air
                              EES Pyrolytic Unit Process Flow Diagram
                                             Figure 10

-------
                                                     Figure 11.
                                                     EES Pyrolytlc
                                                     Converter—
                                                     Feed Bin and
                                                     Feed Conveyor.
Figure 12.
EES Pyrolytic
Converter—
Close-up of
Feed System.
                                                     Figure 13
                                                     EES Pyrolytic
                                                     Converter—
                                                     View of Con-
                                                     denser Train and
                                                     Afterburner.


-------

Figure 14.  EES Pyrolytic Converter—
            Close-up of Condenser Train
            and Afterburner showing
            Particulate  Material
            Separator.

Figure 15.  EES Pyrolytic Converter-
            Close-up of Unit.
                      Figure 16.   EES Pyrolytic Converter-
                                  Feed System Showing
                                  Pneumatic Valve.
                                        26

-------
 bed passes into a screw conveyer that transports it to a valve assembly
 where it is emptied into receiving drums.

 The gases produced during decomposition of  the  feed pass upward through
 the downward moving feed and leave the unit near its top.  The gases
 then pass through a cyclone where particulates  are  removed  and then
 to an air cooled condenser which operates at  a  temperature  above the dew
 point of the mixture.   The condenser  removes  the higher boiling point
 oils which are collected and weighed.   The  remainder of the uncondensed
 oils, the water vapor  and the non-condensible gases pass into  a vortex
 burner which incinerates the mixture.

 The instrumentation utilized in  the study includes:

      1.   an in situ calibrated orifice to measure process air  flow rate

      2.   an in situ calibrated orifice to measure off-gas flow rate

      3.   scales used to weigh the dry input feed, the char, and the oil
          yields

      4.   a water meter to measure total cooling water flow

      5.   dial thermometers to measure inlet and exit cooling water
          temperatures

      6.   various thermocouples to measure:  pyrolysis gas temperatures
          at several points in the system, internal  bed temperatures,
          external surface temperatures and  the  vortex burner temperatures

      7.   a multiple channel recorder  to provide continuous  data as to
          various thermocouple outputs

      8.   a gas sampling system for laboratory analysis of the  off-gas
          composition

 The system operates at a pressure of  a few  inches of water  above ambient.
 Thus there is some gas lost when the  inlet  feed gate valve  operates.  As
 the process rate of the unit increases,  the gas production  increases and
 the pressure consequently rises.   The unit  has  pressure relief doors
 which operate at about 10-12 inches of water.   These doors  place an upper
 limit to the allowable processing rate and  provide  a safe means of
 relieving overpressures for any  system malfunction.

 The process rate of the system is governed  by the rotational speed of the
;char output mechanism.  A level  indicator senses the need for  additional
 feed and activates the gate valve and conveyor  system to provide the
 necessary input.  Thus, the gate valve cycles only  upon demand,  not
 continuously; hence the gases lost through*  this valve do not represent  a
 significant energy loss or pollution  problem.


                              "27

-------
The condenser is of a relatively simple design having a series of air
cooled vertical tubes through which the hot pyrolysis gases pass.  It
has been observed that oil droplets are frequently stripped off the inner
tube walls by the fast moving gases and carried in suspension through
the off-gas system, past the off-gas flow orifice and into the burner.
This results in some loss of oil; however, data analysis techniques are
used to account for this loss.

In several of the tests a mechanical agitation system was utilized to
enhance the flow of material through the waste converter and to prevent
the formation of bridges or arches which can obstruct the downward
moving feed.  A schematic view of the agitator used in these tests is
shown in Figure 17.  The system was constructed of heavy walled steel
tubing and was water cooled.  It was powered by an automatic piston-
cylinder system which provided a continuous reciprocating motion.  A
helical cam provided approximately 150 degree rotation of the agitator
on each forward and reverse stroke.
CALIBRATION AND TEST PROCEDURE

Prior to the testing many elements of the system instrumentation were
carefully calibrated.  The accuracy of some components such as the
thermocouples, however, was not checked since the required precision did
not demand temperature measurements of greater accuracy than the nominal
values of the manufactured wire.  Also the accuracy of the cooling water
meter was taken at face value from the name-plate data.  However, care-
ful attention was given to calibrating the process air orifice and also
the off-gas orifice against a known reference laminar flow element.
Both these ASME sharp-edged orifices were calibrated in situ to insure
accuracy.  An input feed rate back-up system, which measured the number
of rotations of a screw in the receiving bin, was calibrated directly by
weighing a number of drums of feed passing through the bin.  (This was
later used as a check to be certain that all input drums were recorded
properly.)  Tares were individually determined for all the drums  in
which the dried feed was stored.

The procedure during the tests was relatively straightforward:  the unit
loaded with feed or char the previous day, was heated-up by use of an
external gas fired burner.  When the temperature was sufficiently elevated,
the process air was introduced slowly and the burner turned off.  Normally
the bed temperature would begin to rise sharply after introduction of
the process air; however, if the air was added too soon, erratic operation
occurred and it was necessary to turn the gas fired burner on again for
additional heat.  Once it was apparent that the system was operating in
a self-sustaining mode, the output system was activated and slowly brought-
up to the operating capacity chosen for the test.  Likewise the process
air feed rate was adjusted to correspond to the desired ratio of air-to-feed
for the test.  The system was then allowed to come to a steady-state
condition, which required a nominal four hours.  Constant checks and
adjustments were made during this period to insure that the actual
operating conditions were those desired; however, it was found that the
                                 28

-------
        Figure 17
-SCHEMATIC OF AGITATOR
                                               Off Cu
          Oi«r Output
              29

-------
ability to establish a given feed process rate and a given air-to-feed
ratio was limited to a tolerance of plus or minus about 10 percent.

Upon initiation of the test run, continuous records of time, feed input,
char output, oil output, orifice manometer readings, and the various
temperatures were made.  In addition a continuous sample of the pyrolysis
off-gases was taken.  Every effort was made to insure that the unit
remained in a steady-state operating mode by continuous surveillance and
adjustment of the various instruments measuring and controlling the inputs
of the system.  "Grab samples" of the feed from each drum were taken
throughout the run.  Each run lasted four hours.  At its completion all
of the char and oil produced were collected and representative samples
of each were obtained.  The char sample was obtained by sequential use
of a riffle splitter to cut the total char yield down to, typically, a
five pound specimen.  The oil which was collected in a 55 gallon drum was
mixed thoroughly and a sample of about one pint was taken.  All of the
feed grab samples were mixed and cut using the riffle splitter to obtain
a composite sample of about five pounds.
LABORATORY PROCEDURE

The laboratory played a vital role in the determination of the feed and
products characteristics and in the subsequent analysis of the data.  Thus
the work was checked carefully and every precaution made to insure the
accuracy of the results.  However, despite these efforts there are
occasional instances where inconsistencies did arise.  While inherent
errors associated with the specific test procedures themselves clearly
contributed to the problem, it is believed that the principal explanation
for these occasional inconsistancies lies in the difficulty of sampling.
Frequently and of necessity a few grams sampled from a run were taken to
represent the entire production of the oil or char in some piece of
sensitive, chemical analysis laboratory equipment.  Thus even though
duplicate tests were usually made, there are some occasional problems
with repeatibility of results.  While inspection of the data reveals that
these variations are predominantly less than one percent and that the
overwhelming impression is of good repeatability, the presence, especially
in the elemental carbon, hydrogen, nitrogen and oxygen (CHNO) analysis,
of even small inconsistancies in oxygen content was found to have a
significant effect on the test results.  Thus, while these data, by
ordinary standards, stand up well, the sensitivity of the overall test
results to some of these data make close scrutiny necessary.
 It might be noted that conventional practice in coal analysis involves
obtaining oxygen percentage by difference, once the CHN analysis is complete.
This is apparently done because the oxygen percentage must be obtained
from analysis of a separate sample, while the C, H, and N analyses are
made with a single sample.  In the tests reported, the oxygen was measured
separately, but because of the sampling difficulties mentioned, there are
occasional inconsistencies and caution should be exercised in the casual
use of these numbers.  Clearly, the calculation of oxygen content by
differences is a respectable alternative.

                                 3
-------
 A review of the breadth of the laboratory work done  reveals  a wide
 assortment of different analytical procedures.   These  procedures  include
 analysis of the:

      1.   Feed for:

             percent moisture
             percent ash
          .  percent acid-insoluble ash
             percent carbon
          .  percent hydrogen
             percent nitrogen
             percent oxygen
             heating value

      2.   Char for:

             percent moisture
             percent ash
             percent acid-insoluble ash
             percent volatiles
             percent carbon
             percent hydrogen
             percent nitrogen
             percent oxygen
             heating value

      3.   Oils for:

             percent moisture
          .  percent carbon
             percent hydrogen
          .  percent nitrogen
             percent oxygen

 The  composition of  the  off-gas was determined by gas chromatography and
 reported as:

             percent nitrogen
          .  percent carbon monoxide
             percent carbon dioxide
             percent hydrogen
             percent methane
          .  percent C?  components
             percent C   components
             percent C.  components

jIn addition to the  above,  analysis of  selected  samples of feed, char and
joil  were made to determine the quantities  of trace elements such as:

                                   31

-------
            zinc
            copper
            colbalt
            nickel
            iron
            vanadium
            chromium
            manganuse
            sulfur
            chlorine

The laboratory also provided data  regarding the oil viscosity over a
range of boiling points.  And finally, analysis of the stack gas
emissions for a selected test was made.  Presented in the following
sections are brief descriptions of the laboratory procedures followed
to obtain all these data and estimates of the accuracy limits intrinsic
to the tests themselves.  The data itself is presented in Appendix A.
Solid Samples

Sample Preparation - The solid samples examined consisted of the dried
pine sawdust used as feed material for the waste converter and chars
produced by the convertor.  The sample size received in the laboratory
ranged from one to eight liters for the sawdust feeds and from one to
two liters for the char products.

The samples were thoroughly mixed and divided by quartering or by a
riffle splitter to produce a representative one liter sample, which
was passed through a Wiley Model 4 mill using a six millimeter screen.
The ground sample was again mixed and divided into approximately equal
parts.  One part was again passed through the Model 4 Wiley mill using a
two millimeter screen.  This material was then mixed and reduced by
quartering to approximately 100 grams.  The 100 gram sample was then
passed through a Wiley intermediate mill using a 40 mesh screen, remixed,
and quartered.  The larger portion of the -40 mesh sample was stored
in a tightly closed glass bottle for use in laboratory analysis.  The
remaining quarter of the material was again passed through the Wiley
Intermediate mill using an 80 mesh screen, remixed, and stored in a
tightly capped vial for elemental analysis.

Analytical Procedures - 1.  Percent Moisture in Sawdust Feeds:  Duplicate
1.000 gram samples were placed in aluminum dishes and dried for one hour
at 105°F in a forced air oven.  The dried samples were cooled in a
desiccator  and weighed.  The estimated error is + 0.6 percent (absolute).

     2.  Percent Moisture and Percent Volatiles in Chars:  These analyses
were performed by ASTM Method D-271.  The estimated error is + 0.3 percent
(absolute).

     3.  Percent Ash and Percent Acid-Insoluble Ash in Feeds and Chars:
Duplicate 1.000 gram samples of the feed or char were weighed into tared


                                  32

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porcelain crucibles, ignited to constant weight in a muffle furnace at
600°C, cooled in a desiccator, and reweighed.  The ash was digested in
a 1:3 mixture of hydrochloric and nitric acids for 30 minutes.  The
mixture was then diluted to approximately 100 ml. and filtered through
a Whatman No. 40 paper.  After thorough washing with distilled water
the filter paper and undissolved ash was returned to the crucible used
for the original ash determinations, ignited to constant weight at 600°C
cooled in a desiccator, and weighed.  The estimated error is + 0.2
percent (absolute).                                          ~~

     4.  Heating Values:  The heating values of the feeds and chars
were determined in a Parr Plain (Isothermal Jacket) oxygen bomb calorimeter,
following the procedures described in pp. 33-38 of Oxygen Bomb
Calorimeter and Combustion Methods, Technical Manual No. 130, Parr
Instrument Company, Moline Illinois (1960).  Agreement among replicate
samples was better than 2.5 percent (absolute) for the feeds and 3.5
percent (absolute) for the chars.

     5.  Elemental Analysis:  Carbon, hydrogen, nitrogen, and oxygen
were determined using a Perkin Elmer Model 240 Elemental Analyzer.  The
manufacturer claims a precision of + one percent (relative) for pure,
crystalline materials.  Because of the heterogeneous nature of the .
samples, and the resulting difficulty of selecting a representative
three milligram sample, and due to loss of volatiles from the chars in
the purge fraction of the analytical cycle, occasional variations as
high as 12 percent (absolute) have been observed in the carbon and
oxygen determination on char samples.  In most cases, however, the
agreement was better than six percent (absolute) for carbon and oxygen
in the feeds and chars.  Agreement among replicate hydrogen or nitrogen
determinations was better than one percent.

     6.  Trace Metals Analysis:  Five gram  samples of sawdust feeds and
chars were ashed at 600°C and the ash was digested in aqua regia.  The
mixture was diluted and filtered through glass filter paper, which was
then washed with distilled water.  The filtrate and washings were combined
and diluted to a known volume in a volumetric flask.  Trace metals were
determined on an Instrument Laboratories Model 251 Atomic Absorption/Flame
Emission Spectrophotometer, according to the Instrumentations Laboratories
Manual.  Copper, chromium, cobalt, iron, manganese, nickel, and zinc were
determined by atomic absorption.  Vanadium was determined by flame emission.
The occasional high level vanadiums were rechecked on separately ashed
samples.  Since the rises in vanadium levels were accompanied by rises in
the levels of iron and manganese it was believed that the relatively high
level of metals arose from tool steel introduced during materials preparation
or sample grinding.
Oil Samples

Sample Preparation - The oil samples received in the laboratory were
stored in tightly closed glass bottles and stirred before each analysis.

                                  33

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Analytical Procedures - Percent Moisture in Oil:  The percent moisture
in the oil was determined by the method of Dean and Stark.  The error
is believed to be + five percent (relative), although the oil is known
to begin to decompose partially with liberation of additional water at
the temperature of the toluene-water azeotrope, and that acetone and
other water soluble compounds have been detected in the head space over
stored oil samples.
Non-Condensible Gas Samples

Sample Preparation - Gas samples were drawn continuously from the head
space in the waste converter or from the upstream end of the condensers.
The sample stream was passed through a series of water cooled condensers,
a glass wool demister, an ice cooled trap, a chemical drying tube, and
a dry test meter to a tee in the sampling line.  From the tee the major
portion of the sample was exhausted to the atmosphere through a vane
type pump.  A smaller portion of the stream was led from the tee through
a tubing pump and a wet test meter into a 96 liter "Saran" gas collection
bag.  The flow rate in the gas streams was held constant throughout the
sampling periods.  At the end of the test the waters and oils from the
condenser train were measured and the gas collection bag was closed and
returned to the laboratory for analysis.

Analysis of Non-Condensible Gas Samples - The gases were mixed by kneading
the sample collection bag and their concentrations were determined by
gas chromatography.  Oxygen and nitrogen were determined using a Perkin
Elmer Model 990 Gas Chromatograph using helium carrier gas, a Molecular
Sieve 5A column, and a thermal conductivity detector.  Hydrogen was
determined in a similar manner using argon as the carrier gas.  Carbon
monoxide, methane, and carbon dioxide were determined in the same
instrument using helium carrier gas and an activated carbon column.
Hydrocarbons containing two or more carbon atoms were determined in a
Perkin Elmer Model 154 instrument using helium carrier gas, a Perkin
Elmer "R" column, and a flame ionization detector.  The estimated error
was + five percent (relative).

Stack Gas Analysis - Gases were drawn from the exit of the vortex burner
through a stainless steel probe then through a "Tygon" connecting tube
into a glass gas collection bottle equipped with a rubber septum and
glass stopcocks.  After thoroughly purging the bottle with stack gases,
the bottle was closed and returned to the laboratory for analysis by
gas chromatography, as described in the preceding section.
RESULTS OF EXPERIMENTAL PROGRAM

General

The importance to the conduct of the tests of rapid-feed-back of the
laboratory results was one of the major lessons learned from the test


                                 34

-------
program.  Without the rapid turn-around of the data, the testing would
have been practically conducted in an information vacuum.  Thus it was
essential that the overall test results be computed as they were
generated to maximize the useful information from the experimental
work.  Hence while in this study it was not always possible to get
written laboratory results in the time desired, continuous verbal
communication with the laboratory personnel provided sufficient
information to adequately guide the testing.

In the testing, a total of 19 runs were made, however the data for only
14 are presented in detail here.  These are runs 4, 5, 6, 7, 8, 9, 10,
12, 13, 15, 16, 17, 18, and 19.  The detailed results from runs 1, 2, 3,
11, and 14 are not reported for the following reasons:

        Run 1 was basically a shakedown to check out newly installed
        instrumentation and modified test procedures.

        Run 2 was only a preliminary test and conducted to determine
        the difference in the char and oil yields between operation
        with feeds of pure sawdust and a fifty-fifty mixture of sawdust
        and pulverized bark.  In the run, separate two hour tests were
        made at a constant feed rate and air/feed ratio.  Table 2
        presents the test conditions and the results of this run.
        From this table it appears that the yields are essentially
        equivalent and for this reason and because a local convenient
        supply of pulverized bark was not available, all further
        testing was conducted using sawdust alone.

        Run 3 was aborted because of a small leak in one of the
        cooling water lines.

        Run 11 was an attempt to duplicate run 7 but because of an
        inability to establish close enough correspondence to the
        desired test conditions, it was terminated.

        Run 14 was an attempt to test at low air/feed and at a very
        low feed rate.  The test was terminated because the unit
        operation became unstable and the output became intermittant.

One of the parameters to be investigated in the test program was that
of mechanical agitation.  The use of agitation has as its objective the
increase in process rate and the prevention of blockages-to-flow which
sometimes can occur with bulky feeds.  To evaluate the effects of
agitation on yield, a comparison should be made of the effects on
maximum throughput with and without agitation.  This was tried but in
was found that at a certain process rate without agitation the operating
pressure rose to near the maximum allowable.  There is little doubt that
had the maximum allowable unit pressure been higher, then greater process
rates would have been possible without the need for agitation.  Clearly
with agitation the process rate and pressure would have increased even
further.  Thus the limitations of the unit operating pressure prevented
the evaluation of the effects of agitation on maximum process rate.

                                  35

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                                TABLE  2
                      SUMMARY OF RESULTS OF RUN 2
                                  Sawdust                 Sawdust/Bark




Feed Rate (pound/hour)             368                          385




Air/Feed (pound/pound)             0.36                         0.35




Char (pound)                       143                          166




Char Yield  (percent)              19.4                         22.5




"Oil"  (pound)                     92                           93




"Oil" Yield  (percent)             12.5                         12.1
                                       36

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Only the influence on product yields could be tested.  Had the unit been
drafted, rather than pressurized, then the draft fan might have been
operated at a higher rpm and the problem avoided.  However with sawdust,
which is a relatively free-flowing material with a small angle of
repose, it might be expected that the influence of agitation on process
rate would not be strong in any case and therefore the effects on
maximum process rate would likely be unimportant.

Thus while the original objective to evaluate the effects of agitation
could not be completely met, the other test parameters were studied
with no difficulty and the conduct of the tests, as subsequently
described, was relatively straightforward.

Presented in Table 3 is a summary of the test conditions for the 14
reported runs.  The table shows the values of bed depth, air/feed ratio,
feed rate and the number of air tubes utilized.  Also indicated is
whether or not the mechanical agitator was operated and also the air
tube configuration investigated.  Clearly there are a large number of
tests that could be conducted with even two values of each of these
parameters.  With a program of only 14 tests, some discretion had to
be applied in selection of the test conditions.  Therefore the choice
of the parameters used in the tests was substantially influenced by
experience from previous tests and when a parameter was seen to have
little effect on the results, further investigation of its influence
was abandoned.

In considering the test parameters, it was anticipated at the outset
that the most desirable results were to be obtained at low air/feed
ratios (since this corresponds to low temperatures) and at maximum
bed depth.  Therefore the amount of testing at the greatest depth
given equalled all that at the two lower levels combined, with the
minimum depth given least.  It was also anticipated that with sawdust
the effects of agitation would be unimportant on yields; therefore
these tests were performed early in the program, verifying the expected
results.  Likewise the effects of air tube geometry and the number of
air tubes was not expected to be significant, so only a few tests at an
intermediate bed depth where the tube geometry could be varied easily
were made.

Therefore in the test program emphasis was placed on the effects of
air/feed ratio and feed rate on the product yields at a maximum bed
depth.  In the tests at maximum bed depth the practical operating limits
of the unit at minimum and maximum process rates and at minimum air/feed
ratios were also investigated.  Because these limits were reached in
runs 6 and 13 and because the existence of these limits influenced the
oil yields, especially, care must be exercised interpreting the results
from these two runs.  Otherwise the data from the runs at the greatest
bed depth appear consistent with the general trends of the overall test
results.

                                  37

-------
                                 TABLE 3
                             Operating Conditions
lun
lumber

4
5
9
10
17
18
19
6
7
8
12
13
15
16
Bed
Depth
(in.)
18
18
27
27
27
27
27
39
39
39
39
39
39
39
Number
Agitation Air Tubes-

no 4
yes 4
no 3
yes 3
no 3
no 2
no 2
no 2
yes 2
no 2
no 2
no 2
no 2
no 2
Air Tube*
Configuration

A
A
B
B
B
C
C
D
D
D
D
D
D
D
Air/Feed
(Ib/lb)
.47
.53
.70
.64
.38
.58
.42
.27
.56
.35
.45
.38
.22
.49
Feed/Rate
(Ib/hr)
291
246
184
184
195
189
186
491
202
226
237
118
346
222

* Configuration A involved  four  tubes,  2  at a depth of  16 inches, and
  two at a depth of 20 inches.
  Configuration B involved  3  tubes  at a depth of 27  inches.
  Configuration C involved  2  tubes  at a depth of  27 inches.
  Configuration D involved  2  tubes  at a depth of  39 inches.
                                 38

-------
Data Analysis

Before discussing the results of the runs specifically, the procedure
used to analyze the raw data should be described.  The raw data comprised
the basic information concerning feeds, temperatures, product yields,
etc. from the tests; but the feed, the oil and the off-gases contained
water, for example, which had to be accounted for.  Therefore, the
laboratory analysis of these samples was used to correct the data to a
dry basis.  Hence for this reason and for others there was a continuous
interplay in the data reduction between the laboratory results and the
basic test results.  Moreover, in the reduction of the data and the
computation of the mass and energy balances, additional chemical balances
were made to complement and correct the basic relationships.  The
following is offered to illustrate why this was necessary:

     Throughout the test program it was observed on numerous
     occasions that oil was collecting in and dripping from a
     flange upstream of the burner but downstream of the condenser
     and the off-gas flow orifice.  This oil was apparently passing
     through the orifice in the form of droplets and had its origin
     in the condenser where it was picked up by the off-gas stream.
     Several efforts to prevent this from occurring proved futile
     and it was finally concluded that the design of the condenser
     itself was primarily the cause.  Because of this.occurrence
     the basic orifice measurements were considered suspect and,
     the use of a nitrogen balance was employed to determine the
     off-gas flows.  Moreover because of the loss of oils, the
     resulting oil yields were significantly lower than anticipated
     from the laboratory results but again a back-up technique, a
     carbon balance, allowed an estimate of the amounts lost to be
     made.  In terms of the total feed flow rate, the amount of oil
     passing through the orifice did not represent a significant
     mass loss, however in terms of the energy flow, it represented
     a substantial proportion and corrections were necessary to
     obtain an adequate energy balance.

Thus in the mass and energy balances, a number of additional chemical
balances and checks were made.  To illustrate this procedure, the complete
data reduction process for the various chemical and mass balances is
presented schematically in Figure 18.  Study of the figure indicates that
it is divided into two sections, e.g., Inputs and Outputs.  Concerning
Inputs, the figure shows that the feed was analyzed for its water content,
and C, H, N and 0 analyses were performed.  This then allowed computation
of the amounts of dry feed processed and the corresponding amounts of
water, carbon, hydrogen, nitrogen, and oxygen.  The process air flow
rate and the chemical composition of atmospheric air allowed calculation
of the amounts of nitrogen and oxygen utilized.

The output char contained a small volatile or moisture content and this
was determined in the laboratory along with the elemental composition
which was found by use of a CHNO analysis.  These procedures allowed


                                    39

-------
                                                                                         rifura 1*

                                                                       Man and chraleal lalanca Calculation Procedure
                                                                                                                                             OUTPDT
Heamre
Tachnleuea
                             Laboratory
                             Determination
                             Method
                                             leaultlnf.
Ccwpatatlou
4
favduat
   IP
Moletura
Corresponding
Weight par
100 pound* of
Dry Feed
Percent:
Savduat
B20
CHKO


Pound a of:
Sawduit
"/
a *°2
Hj Z
M2

Or I flea


Percant of
»2
°2


Measuramane     Laboratory      Resulting      Computation     Corresponding
Technique       Determination   Coapoaitloa    t Analy*!*      Ueljht  per 100
                Method                                         Pounds  of Dry
                                                               reed
Char
&
Moiatura

Oil
&
Kolature

Dry
Ctt

Oll-Cmt
Water

Oxrtao

"Loit
Carkon"


	
Welsh
&
Sanpla

Weigh
&
Sa«pla

Caapla



	
H20
Analyaia
t
CHNO
Analysis

H20
Analyala
&
CHSO
Analysis

Chroaiaco*
graph



	
Percent of:
C
H20
CHNO

Percent of!
Oil
H.O
CHNO

Percent o£:
-2 'CH4
*> C
rz c'
2 C4



	




Nitrogen
Balance

Hydro Ren
Balance

Oxynen
Balance

Carbon
Balance
                                                                                                                                                                                    Pounds  of:
                                                                                                                                                                                    C
                                                                                                                                                                                    Pound*  of:
                                                                                                                                                                                    Oil
                                                                                                                                                                                    H,0 I X
                                                                                                                                                                                    c;
                                                                                                                                                                                    Poundc dry
                                                                                                                                                                                    Pound* H.O

                                                                                                                                                                                    in 0(f-(j.
                                                                                                                                                                                     rounds  C

-------
determination of the weight of carbon, water, hydrogen, nitrogen and
oxygen in the char for each run.  Similar procedures allowed computation
of the amounts of water, carbon, hydrogen, nitrogen, and oxygen in the
condensed oil.

The dry non-condensible gas composition was obtained from gas chromato-
graphic determinations.  Using the percent nitrogen found in the off-gas
and the total nitrogen input from the process air the amount of dry
pyrolysis gas was calculated.  Investigations indicated that the nitrogen
in the feed, the char and the oil is  small and can be ignored when
performing elemental mass balances.

The water content of the off-gas was obtained from a hydrogen balance.  In
this calculation the difference between the sum of the input hydrogen from
the sawdust and associated moisture and the sum of the hydrogen in the
output char, oil and dry gas, (including the char and oil moisture) was
determined.  Then this hydrogen was assumed to be associated with a
corresponding quantity of water and this value taken as the water content
of the off-gases.  As a check on this procedure an oxygen balance was
made using that oxygen associated with the measured input feed and process
air, the measured char, oil and gas outputs and that calculated for the
water.  The difference between the input oxygen and the output oxygen
was found to be never more than a few percent with an average for all
14 runs of only 0.8 percent.  This then confirmed the assumptions inherent
in the hydrogen balance and gave confidence to the overall mass balance
procedures.

Upon summing up the weights of the carbon, oil, water, and dry gas in a
mass balance it was typically found that seven to 10 percent of the
output products were unaccounted for.  Because of the confidence held in
the char measurements and the computed values of water and dry gas it
was felt that this lost material most likely was oil.  While this loss
did not appreciably affect the mass balance it had a major impact on the
energy balance.  This led to an additional computation, a carbon balance
to determine the "lost carbon."+  From the carbon balance it was found
that the amount of carbon missing from the products was on the average
very near that missing from the calculated mass balance; thus the surmise
that the "lost carbon" and the lost oil were the same was substantially
strengthened.  This then was taken as fact in further analyses and the
mass and heat balances calculated with the computed values of "lost carbon."
Presented in Appendix B is a sample calculation for the results of run 7
illustrating the preceding discussion.
•fSince the carbon content of the dry pyrolysis oil is so large, it can be
considered for practical purposes as "liquid carbon."  It was known from
the testing that considerable quantities of the oil were unaccounted for
and that the yields were well below those expected from the laboratory
results; therefore the suspicion that the lost carbon and the lost oil
were essentially the same was based on substantial but indirect evidence.


                                   41

-------
Discussion of Results

The results of the experimental work are shown in Tables 4 and 5.  A
summary of the most important data upon which the conclusions from this
investigation are derived is presented in Table 6.  Study of the results
from run 4 and 5, 9 and 10, 7 and 16, shows conclusively that the effects
of agitation on product yields are unimportant.**

Comparison of the data from runs 10 and 18 indicate that tube geometry
probably has little effect on product yields, although a comprehensive
study of this parameter was not made.

From a study of the data from all the tests it appears that the effect
of bed depth on char yields is unimportant; however the deeper beds may
result in greater oil yields and therefore may be more desirable in
maximizing the production of the char-oil mixture.

The most dramatic effect and the one which overrides the importance of
any of the other test parameters is the air/feed ratio.  This is illustrated
in Figure 19 which shows a plot of char yields as a function of air/feed
and Figure 20 which presents a graph of the percent of the available
energy in the char-oil mixture as a function of air/feed.  These figures
are plots of all the test data at various bed depths,tube geometries,
feed rates, and with or without agitation.  Clearly the air/feed ratio
is the dominant parameter and small values are the most desirable.

It is interesting to note in Figure 20 the value of the available energy
fraction extrapolated to zero air/feed.  This value is nearly identical
with that obtained from the tube furnace tests at a minimum pyrolysis
temperature and shown in Figure 9.  Since the pilot plant operating
conditions and those of the tube furnace become  more nearly comparable
at zero air/feed this result strengthens the test findings and provides
a possible means of correlating the laboratory and the pilot plant test
data.

Presented in Figure 21 is an energy breakdown of the pyrolytic products,
including losses, as a function of air/feed.  The data are plotted using
the results shown in Table 5 and no consideration is given to the various
values of bed depth, tube geometry, etc.  The graph reinforces the earlier
results which indicate the primary influence of the air/feed ratio on
product yields.  The figure graphically illustrates how the various energy
forms change with increasing air/feed and also demonstrates the generally
good closure of the energy balance.
**It is important to note that mechanical agitation has been shown in
previous studies with bulky wastes to have a pronounced effect on the
outcome of the testing.  Thus the fact  that in these tests with this
feed and this agitator the effects were unimportant  should not be
generalized to less free-flowing solids.


                                  42

-------
      TABLE 4




OVERALL MASS BALANCE*
OUTPUT
Run
Number


4
5

9
10
17
18
19

6
7
8
12
13
15
16



Average
it
*A11 res

Char
Yield
(lb)

18.7
20.7

11.6
10. A
28.1
10.2
27.8

25.8
16.1
22.5
26.3
28.9
32.7
17.4





ilts are

Oil
Yield
(lb)

6.3
6.7

14.4
11.3
8.1
11.3
14.3

7.8
10.1
12.0
5.9
15.0
12.1
13.8





present

Off-Gaa
Yield
(lb)

70.4
84.2

110
92.0
60.2
89.0
61.6

57.2
102
53.6
82.9
61.5
40.5
78.9





id on a

Char
& Oil
(lb)

25.0
27.4

26.0
21.7
36.2
21.5
42.1

33.6
26.2
34.5
32.2
43.9
44.5
31.2





Dasis of

Water
(lb)

45.4
42.4

27.1
40.3
30.0
39.9
32.7

39.4
28.8
41.5
39.9
32.9
32.4
33.0





100 lb

Total
Output
(lb)

141
154

160
152
126
151
136

130
157
130
155
138
117
143



142

dry sawc

INPUT
Feed
(lb)

^100
100

100
100
100
100
100

100
100
100
100
100
100
100





ust.

Air
(lb)

47.4
53.1

70.4
63.8
38.2
58.0
41.6

27.2
55.8
34.9
45.3
37.8
22.0
49.2







Water
(lb)

7.8
8.3

6.4
6.4
3.9
6.1
7.9

5.8
5.8
6.8
6.6
7.3
3.6
4.7







Total
Input
(lb)

155
161

177
170
142
164
150

133
162
141
152
145
126
154



*" 152



Dif-
ference
(lb)

14
7

17
18
16
13
14

3
5
16
-3
7
9
11



10



OXYGEN BALANCE
Input
(lb)

58.7
59.6

63.8
60.5
54.5
58.8
56.9

54.2
60.5
55.5
57.3
55.8
50.4
52.5



56.8



Output
(lb)

61.8
63.0

59.0
59.1
52.1
58.8
46.3

58.8
59.4
53.1
65.0
Dif-
ference
(lb)

-3.1
-3.4

-4.8
-1.4
2.4
0
10.6

-4.6
7-1
2.4
-7.7
51.2 4.6
48.4 2.0
55.6

-3.1



56.3



.4



CARBON BALANCE
Input
(lb)

45.7
45.6

45.6
47.1
48.2
47.5
45.8

45.3
48.2
46.3
46.5
46.3
48.4
46.5



46.5



Output
(lb)

28.7
35.0

38.4
33.5
35.3
35.2
45.0

37.9
46.1
37.9
40.8
44.6
42.5
38.7



38.4



Dif-
ferencE
(lb)

17.0
10.6

7.2
13.6
12.9
12.3
.8

7.4
2.1
8.4
4.3
1.7
5.9
7.8



8.1




-------
      TABLE  5




OVERALL ENERGY BALANCE *
OUTPUT*
Run
Number


4
5

9
10
17
18
19

6
7
8
12
13
15
16



Average

*A11 res
lln thou
C
Char


221
214

147
131
284
133
304

338
216
2.95
334
336
363
235





ults are
sands of
1 "
lemical
Oil


72.7
106

226
181
132
172
229

106
I 172
198
97.4
252
197
203





presen
Btu's.

Energy
Off-Gas


159
191

259
197
118
221
146

166
288
117
167
126
122
200





ed on a


"Lost"
Carbon


247
154

104
197
187
178
11.6

107
30.5
122
62.4
24.7
85.6
113





basis o


Le
Water
Vapor


51.8
50.2

31.3
46.4
34.3
47.1
38.7

45.0
32.9
47.4
46.8
37.0
37.1
38.4





: 100 Ib


tent & !
Off-Gas


3.2
4.2

5.7
4.4
2.4
5.6
4.3

2.6
4.7
2.5
5.6
2.0-
1.8
4.6





dry saw


Sensible
Char


5.3
3.0

3.3
2.1
7.3
2.7
8.3

7.4
5.0
6.6
7.0
7.4
8.5
6.5





lust.


Energy
Oil


1.3
1.3

2.9
2.3
1.6
2.3
2.9

1.6
2.1
2.4
1.2
3.0
2.4
2.8








Con-
Coolingi vective
Water Losses


18.7
17.3

22.0
26.6
20.3
14.0
16.6

5.6
20.0
15.7
13.0
15.3
5.5
12.8










6.7
6.5

6.5
6.6
6.7
6.6
6.7

6.5
6.5
6.6
6.6
6.5
6.6
6.7








Total
Output


787
747

807
794
794
782
768

786
778
797
742
810
828
823



789




INPUT1 Product Heatine
Feed


831
814

811
820
832
827
832

814
814
823
820
818
825
842



823




DIF-
FERENCE


44
67

4
26
38
45
64

28
36
26
78
RATIO
HEAT Otq
HEAT IN


.947
.918

.995
.968
.936
.946
.923

.966
.955
.968
.905
8 i .990
-3 , 1.004
19

.977



34





.959































Value
Oil


























Char plus
(BTU/lb)


12.873
12r473

14,367
14.419
12.231
14,289
1?,fiQ4

13,439
14,788
14,335
13.528
12.711
12,733
14,128









-------
                                                       TABLE -6
SUMMARY OF TEST RESULTS
Run
Number

4
5
9
10
17
18
19
6


7
8
12
13
15
16
Bed
Depth
(In.)
18
18
27
27
27
27
27
39


39
39
39
39
39
39
Agi-
tation

no
yes
no
yes
no
no
no
no


yes
no
no
no
no
no
Number
Air
Tubes

4
4
3
3
3
2
2
2


2
2
2
2
2
2
Air/
Feed
(Ib/lb)
.474
.531
.704
.638
.382
.580
.416
.272


.558
.349
.453
.378
.220
.492
Feed
Rate
(Ib/hr)
291
246
184
184
195
189
186
491


202
226
237
118
346
222
Char*
Yield
(lb)
18.7
20.7
11.6
10.4
28.1
10.2
27.8
25.8


16.1
22.5
26.3
28.9
32.4
17.4
Oil*
Yield
(lb)
6.3
6.7
14.4
11.3
8.1
11.3
14.3
7.8


10.7
12.0
5.9
15.0
12.1
13.8
Lost*
Carbon
(lb)
17
10.6
7.2
13.6
12.9
12.3
.8
7.4


2.1
8.4
4.3
1.7
5.9
8.0
Mass:
Output/
Input

1.02
1.02
.94
.977
.98
.99-
.91
1.03


.95
.98
1.05
.96
.975
.98
Energy:
Output/
Input

.947
.918
.995
.968
.936
.946
.923
.966


.939
.968
.905
.990
1.004
.977
Available**
Energy Comments
(Percent)
65.1
58.2
58.8
62.1
72.5
58.4
65.6
67.7


50.6
74.7
60.1
74.9
78.3
65.4







The oxygen balance
was not good.
Due to the high pro-
cess rate there was
a significant loss
of oil from the con-
denser.


The oxygen balance
was not good.
At this low through-
put, there was a
significant amount of
oil condensing in the
unit with resulting
eratic flow.


*A11 results are presented on a basis of 100 lb dry sawdust.
**Energy available in char/oil divided by total available from sawdust feed.

-------
.40.


.35 -


.30


.25 .


.20
  •o
  0)
2
    .10



    .05


      0
                                                                              SYMBOL NOMENCLATURE
                                                                               Bed
                                                                              Depth
                                                                             (inches)

                                                                                18
                                                                            Agitation

                                                                            Yes    No
                                       A6D
*Test Number and Air Tube
 Configuration (see Table 3)
                  ,10
                 .20
                                      .30         .40
                                      Air/Feed  (Ib/lb)
.50
.60
70
                                             Figure 19
                            Fractional Char Yields Versus Air/Feed Ratio

-------
         Closely corresponds to tube
         furnace tests (see Figure 9)
    90
    80
    70
 2.
    60
    50
u
  oo
    40
    30
    20
    10
 SYMBOL NOMENCLATURE

  Bed
 Depth  Agitat^n
(inches) Yes    No
   18      •

   27      |

   39      A
                             D
                             A
                                     8DA A13D
                                          D
                                          17B
                                                                  10B
           *Test Number and Air Tube
             Configuration  (see Table 3)
                        .2        .3        .4
                                  Air/Feed (Ib/lb)
                                       .5
.6
.7
                                  Figure 20
                              Percent Available

                         Energy in Char-Oil Mixture
                                      47

-------
oo
          10Q
           90
           80
         
-------
Figure 22 shows a plot of the non-condensible gas heating value as a
function of air/feed.  The scatter in the data is greater than experienced
elsewhere but there is a definite trend toward a reduced heating value
as the air/feed increases.  Check of the nitrogen content of the gas
shows a corresponding increased percentage which helps explain the lower
heating values.  Thus while the total heat available from the gas per
pound of dry feed increases with increasing air/feed, the heat content
of the gas is diminished.

Figure 23 presents a combination of data from Table 5 together with
computed heat energy requirements for processing and drying the feed.  The
computed curve is based on an assumed 1500 Btu required to evaporate each
pound of water in the feed and 360 Btu/lb dry feed of raw heat energy
required to process the dry feed.  This latter figure arises from an
assumed 50% derating of the engine power plant for the portable unit, a
requirement for 170 hp (see Table 7) and an assumed thermal efficiency
of 15 percent.  Since the energy required to dry and process the feed
must be supplied by the non-condensed gas, the figure provides a means of
determining the required air/feed ratio and the available energy in the
char-oil mixture for a given feed percent moisture*.   To  illustrate,  at a
50 percent moisture composition, 1860 Btu/lb dry feed would be required
for drying and processing.  At an air/feed ratio of approximately .47,
the available energy in the non-condensible gas would meet these energy
requirements and at this same air/feed value the heat available in the
char-oil mixture would be approximatley 5500 Btu/lb dry feed with an
overall conversion efficiency of about 65 percent.

Clearly as the feed moisture percent becomes much greater than 50 percent
the energy available in the char-oil mixture drops off sharply.
*Moisture composition is defined as pounds of water per pound of mixed feed.
                                 49

-------
        250
        200
Ul
o
        150
      (1)
      J-l
      OJ
         50 r
  LEGEND
O Bed Depth=18 inches
D Bed Depth=27 inches
A Bed Depth=39 inches
           .1
                  .3           .4           .5
                               Air/Feed (]b/lb)
                               Figure 22
                 Heating  Value of Non-Condensible Gas
.6
.7
.8

-------
JO'  .8    .6
   Air/Feed (drfc) Ib/lb
.2
                          XI J
                           4J
                           m
            20   40    60    80   IOC
           Feed Percent Moisture
       1,000
                             2,000
                                   Assumptions:
                             ,       1) Gross heat energy
                             ),000  required to  process
                                    one  pound dry feed=
                                    360  Btu
                              ,000
                                    2)   1500 Btu required
                                    in drier to  evaporate
                             5,000  one  pound of water
                             5,000
                         Figure 23

          Effects of Feed Moisture on Available
              Energy from Char-Oil Mixture
                             51

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                            SECTION VI

            MOBILE PYROLYSIS SYSTEM PRELIMINARY DESIGN
Presented in this section is a preliminary design of a 200 ton/day
(assuming 50 percent moisture) mobile pyrolysis system.  In addition
to the design, the results of a simplified economic analysis are also
shown.  But before discussing this work, the overall concept of the
portable system should be described.  Figure 24 presents a schematic view
of the proposed manner of operation of the system.  As pictured, several
mobile units would operate in zones with a large thermal conversion plant
at their center.  The several units would convert various agricultural
and forestry wastes into the  char-oil fuel which would be transported
to the thermal conversion plant.  By proper scheduling and by using the
constantly produced wood wastes as a means of leveling out the seasonal
fluctuations in the agricultural waste production, a fairly constant
supply of wastes could be provided.

As conceived, one char truck could service three or four pyrolysis units
and likewise only one tractor for perhaps seven or eight complete systems
would be required to move them from site to site.  The char trucks would
have a closed trailer which would also serve as a char-oil storage container
and be exchanged twice daily.

The portable system was designed with certain basic ground rules which
are listed below:

        It must be completely self-sustaining

        It must produce no land, water or air pollution

        It must be transported readily and with no special highway
        permits, i.e., its length should not be greater than 55 feet,
        its width is eight feet, its height is not more than 13 feet
        six inches and its weight is less than 73,000 pounds.

In addition to these basic limitations, it was assumed that:

        System does not require any outside source of water for cooling

        The system would comprise two trailers
                                  52

-------
        Figure 24





Mobile Pyrolysis System Concept
             53

-------
        The start-up would be accomplished using propane

        The oil condenser would operate at a temperature greater than
        the off-gas dew point to avoid moisture condensation

        A 50 percent derated gasoline engine operating on the low Btu
        pyrolysis gas would provide the power required to operate the
        system

        The design rated capacity of the system would be based upon the
        experience gained with the Cordele, Georgia, demonstration
        unit.
        The feed, and the resulting char, because of its typically low
        thermal conductivity, would serve as an insulator on the sides
        of the unit.  This would prevent not only the necessity for
        and associated weight of a ceramic insulator but also avoid the
        problems of transporting such a brittle, fragile system
SYSTEM DESCRIPTION AND DRAWINGS

The overall portable pyrolysis system is shown schematically in Figure 25.
Examination of the figure indicates that after leaving the hammer mill,
the pulverized wet bark, together with the sawdust enters the drier and
from there the mixture is conveyed to the waste converter unit.  The char
produced is emptied into a mixer where it is combined with the pyrolysis
oil.  The gases produced in the converter pass through the cyclone and
into the condenser where the higher boiling point oils are removed and
mixed with the char.  The noncondensed gas then is used to operate the
engine generator system and also to supply heat to the drier.

Presented in Figure 26 and 27 are preliminary design drawings of the two
trailers which make-up the system.  The dominant feature in Figure 26 is
the drier.  The location and geometry of this unit largely governs the
design of the elements on this trailer and significantly influences the
overall system layout.  Likewise in Figure 27 the major component is the
waste converter, but interestingly the location of this unit has less
effect on the overall design than the drier.  The drawings show the
trailers in their stowed configurations to illustrate that adequate space
is available for all the required components.  Deployment of the system
would mainly involve moving the conveyors from their stowed to their
operational locations, connecting up the flexible pipe between the off-gas
system and the drier, and unloading the feed hopper by use of a collapsible
ramp stowed underneath.

In the operational mode, the trailers would be located adjacent to one
another as shown in Figure 28, which presents a plan view of the deployed
system.  Expanded metal platforms, not shown in Figures 26 and 27 would be
folded out from the trailer sides to provide a work space for the operating
crew.

                                   54

-------
Ln
                        Cold Water
                                                      Finished  Product—
                                                     Charcoal and Oil Mixed

                                                         Figure 25


                                             Mobile Pyrolysis  Unit Preliminary

                                                     Process Flow Diagram

-------
                                                                                Figure  26


                                                                   Plan and Elevation Views of Trailer I
                                                         CAS
                                                      FROM CONDENSER
Ul
                                               WET SAWDUST
                                                AM) BARK
                                          ttffi
                                                                 GAS TO MU.H-CYCUHC
                                                                        f---'.._. ^  r--x	


                                                                        !   f?;iY^   fe\^
                                                                        •   I  \  .' I  I.   •  '.  I < I
                                                   ~       ^        «     •<            -                ~        ">        'N

                                                  / »      / «.      / \     V^13-'!1 / '.V"-""-'^       /"       •' \      ' \
                                               ^ ^_Y__^__»__j. ,^_ _  x •'^'^'S^ Z-  -H-T" rf V -	*  _  _ /.  1 u	i _j


                                                          "          '    '                                  ^           ~"J
                                                       '   ,  Yv '      »  '!!!    \  v   ','**'   * >  \ '      \ /
                                                       I _ _=K- J-V_ -»_^vl.J	:J»*J.|_ i_' j^ _  _««_ w_ __ _^	 .
                                                       \      :      .     F       ','  -       \\
                                                               ' S S S / S /
                                                                                                            ///S/S/S////S

-------
                                                               Figure-  27


                                              Plan and Elevation Views of Trailer  II
                                                                        (36' \£)
                                                                           '
Ui
                                                              (G.SES

                                                               DRYER
-PROCESS AIR
 TO CONVERTOR

-------
00
                                                                                                                                LEGEND:
Front end loader
Bin conveyor
Receiving bin
Conveyor mill
Hammer mill
Drier
Feed conveyor
Converter
Cyclone
Condenser
Condenser cooling  fan
Draft fan
Combustion air fan
Off-gas burner
Drier fans
Burner exhaust
Drier exahust duct
Cyclone
Process air blotter
Generator
Engine
Cooling water radiator
Compressor
Conveyor
Char oil mixer
Char storage bin
Control room
Agitator
Front end loader storage
Cat walk
Engine blower
                                                                                               Figure  28

                                                                      Plan  View  of Deployed Mobile  Pyrolysis  System

-------
Figure 29 presents two elevation crossectional views of the pyrolysis
unit to be used.  Also shown are typical types of agitators that might
be employed to increase throughput.  In addition, a novel insulating
technique, involving the char and feed itself as a means of minimizing
heat loss, is shown.  The "char shelves" would simply trap a portion of
the downward moving waste and then this material because of its relatively
low conductivity would resist the passage of heat through the walls.  A
fibrous, non-ceramic insulator would act as a back-up system.  By use
of this method of providing an expendable insulator, most of the problems
of transporting the unit would be circumvented.  In fact this is a key
concept in making the entire system transportable.

Finally, Table 7 presents a complete list of components and their
characteristics used in the mobile system preliminary design.  To
illustrate the table, component number 19 (reference Figure 28) is the
process air blower, Dresser Model 3514-J, producing 542 cfm at one psig,
requiring 3.6 hp and weighing 640 pounds.  There are doubtless many other
commercially available components which could serve as well as those listed
in the table, and therefore the list is for illustrative purposes primarily.
However, the table shows that components either commercially available
now and/or readily fabricated could be assembled to provide a system with
the desired characteristics.  Moreover the system size, weight and load
distribution would be within the legal limits.


PRELIMINARY ECONOMIC ANALYSIS

The preliminary economic analysis of the portable waste converter was limited
to a study of only one system within an array of systems servicing wood yards
and was made on the basis of the current technological development of the
system.  Assumptions were made,  however, regarding the costs of sharing of
equipment among systems and the  supervision costs of a group of systems.   It has
been also assumed that by proper scheduling the systems can be kept continuously
operating except for down time between waste sites.

Listed below are more detailed assumptions used for the economic analysis
of an individual system:

        Interest rates are 9.5 percent

     .  System costs were computed by scaling-up the actual Cordele
        facility costs using a 1/2 power law and then multiplying the
        results by 2.5 to allow for manufacturer profit, inflation and
        increased complexity of the mobile system.  (For a 100 ton/day
        dry system the costs are about $405,000.)

     .  A total capital depreciation of ten years is taken

        The mobile unit is assumed to service each waste producer in
        its circuit once a year
                                   59

-------
        Figure 29
    Elevation-Crossection
Views of Mobile Pyrolytic Converter

-------
                                       TABLE  7
                                   LIST OF EQUIPMENT
                              FOR PORTABLE PYROLYSIS SYSTEM
Part
Number Part Name Function of the Part
1.


2.

3.



4.

5.

6.



7.


8.

9.

Front end loader To load wet feed from ground to
bin conveyor.

Bin conveyor. To transfer wet feed from front
loader to receiving bin.
Receiving bin Receives wet feet to feed hammer
mill.


Hanmer mill Transfers wet feed from receiving
conveyor bin to hammer mill.
Hammer mill Pulverizes feed.

Drier Drys the wet feed.



Feed conveyor Transfers dry feed from drier to
converter.

Converter Produces char and oil from the
dry feed.
Cyclone Separates the particles from the
converter output gases before
Description
Tractor-shovel with
hydrostatic-drive

Belt conveyor:
10' long, 12" wide
Fabricated container
including screw con-
veyor: 10' long,
12" diameter
Belt conveyor:
20' long, 12" wide
Hammer mill

Ducting system con-
tainer, 36" diam-
eter screw con-
veyor
Belt conveyor 30'
long, 12" wide.
10' long, 12" wide
See pp. 60 in
report
Dust collector
cyclone
Made By Model No,
International H-25B
and Hough

Stone

Fabricated
(Link-Belt)


Stone

Williams C-32

Link belt &
duct work
fabricated

Stone


Fabricated

Fabricated -

Capacity H.P.
1 yard of N/A
wet feed/
load
8 ton/hour 1/2
of wet feed
320 cubic 1/3
feet, 8 ton/
hour

8 ton/hour 3/4
of wet feed
3-5 ton/hour 75
of 2" bark
8 ton/hour 1
of wet feed


4 ton/hour 1-j-
of dry feed

4 ton/hour 3
of dry feed
_ N/A.

Carried On
Weight Trailer No.
6,200


850

850



1,700

6,000

4,700



3,400


22,100

1,128

i


ii

ii



i

i

i



i


ii

ii

entering the condenser.

-------
                                                                                    TABLE  7   (CONTINUED)
CT-
Part
Number Part Name
10. Condenser




11. Condenser cooling
fan



12. Draft fan




13. Combustion air
fan



14. Off-gas burner



15. Drier fans





Function of the Part
Condenses the oil in the off-
gas from the converter.



Provides cooling for the oil
condenser



Transfers off-gas from reactor to
the off-gas burner.



Supplies air to the off-gas burner
burner.



Bums non-condensible off-gas to
provide heat for drier.


Transfers hot. combustion gas from
off-gas burners through drier
and drier cyclone.



Description Made By
Single-Pass cross- Fabricated
flow



Industrial American
exhauster Air Filter



Industrial American
exhauster Air Filter



Industrial American
exhauster Air Filter



Horizontal Fabricated
cylindrical burner


2 Industrial American
exhausters Air Filter




Model No.
_




AAF Type
K, Adjusti-
ble Drive
2 hp motor
size 11
AAF Type
K, Size 11
Adjustible
drive, 5
hp motor
AAF Type
K, Size 19
Adjusclble
drive, 15
hp motor
N/A



AAF Type
K, Size 17
x 2 units,
Adlustible
drive, 20
hp motor
Carried on
Capacity H.P. Weight Trailer No.
N/A 1 x 10 5,940'
Btu/hr
from
500-F to
120°F
1800 c.f.a. 1-i- 195
at 3" of
water
pressure
drop
2100 c.f.m. 5.02 195
at 10" of
water
pressure
drop
lO.OOOc.f.m. 12.9 670
at 5" of
water
pressure
drop
8 ton/hour N/A 5,080
Gas M-26
from 150'F
to 700°F
8000 c.f.m. 37.4 for 1,300
at 10" of two
water units
pressure
drop

II




II




I




I




I



I





                16.      Burner exhaust
                                              Exhausts  excess  combustion  gas
                                              not  required  for drying.
Burner
stack
                                                                                                        PART  OF  THE  BURNER

-------
TABLE  7  (CONTINUED)
Part
Number Part Name Function of the Part
17.


18.


19.




20.


21.


22.

23.


24.


Drier exhaust duct Duct from drier to drier cyclone.


Drier cyclone Separates particles from drier
exhaust before venting to
atmosphere.
Process air blower Supplies process air to the
convertor.



Generator Supplies electrical power for
the unit.

Engine Drives the generator.


Cooling water Provides cooling water for
radiator process air tubes.
Compressor Supplies air to pneumatic
components.

Output Conveyor Transfers char and oil from
mixer to storage bin.

Description
Steel duct inlet
dimension 12" x
30"
Multi-clone


Roots Whispair Max,
rotary positive
blower


A-C generator
60 cycles

Derated gasoline
engine

Flat radiator

Automotive air
compressor

Belt conveyor,
12" wide,
10" long
Made By
Fabricated


Western-
Precipita-
tion
Dresser




Maraton


Haukesha


General
Radiators
Champion


Stone


Model No.
N/A


12 VMU
Size 8-2

3514-J,
Flange
mounted
drip-
proof



L1616G


_

VR 3-8


_


(Ib) Carried On
Capacity H.P. Weight Trailer No.
16,000 N/A 2,500
c. f .m.

16,000 N/A 2,300
c.f .m.

542 c.f.ra. 3.6 640
at 1 psig
pressure
drop

120 KW 160 "\

\ 9 000
Derated 338 at (
50 percent 1800
rpm )
35 G.P.M. 10 1,300

12.8 c.f.m. 3 500
at 140-170
psi
2 ton/hour 1/3 850
of char &
oil
I


I


II




II


II


II

II


II



-------
                                       TABLE 7 (CONTINUED)
Part
Number
25.



26.

27.

28.


30.


31.



32.


33.

Part Name
Char and oil mixer



Char and oil
storage trailer
Control room

Agitator


Cat Walk


Engine blower



Trailer I


Trailer II

Function of the Part
Mixes the char from the converter
and the oil from the condenser.


Stores the oil and char.

Contains operating controls for
the unit.
Prevents bridging in the reactor
and promotes uniform flow of
material.
Walking ramp to provide access
to system components.

Transfers and compresses off-
gas fuel to engine.


Carries components: 1, 4, 5, 6,
7, 12, 13, 14, 15, 16, 17, 18,
and 30.
Carries components: 2, 3, 8,
9, 10, 11, 19, 20, 21, 22, 23,
Description
Container, screw
conveyor 9" diam-
eter 5" long

Enclosed trailer

5" x 6" room

P A R V OF T H


Expanded metal


Roots whispair
Max rotary
positive blower

25-ton tandem axle
level deck load
runner, 445" long
25-ton tandem axle
level deck load
Made By
Fabricated
(Link-Belt)


Fruehauf

Fabricated

E C 0 N V E


Fabricated


Dresser



Fruehauf


Fruehauf

Model No.
_



JG9-F2-45
Top close
N/A

R TO R


N/A


1704-J
Direct
coupling
drive
C25L-J2
445" long

C25L-J2
445" long
Capacity H.P.
4000 Ib/hr 1/4
of material
with density
of 40 Ib/ft
58,280 Ib. N/A

N/A N/A




N/A N/A


115 c.f.m. 1.7
at 2 psig
and 7000
rpm
50,000 Ib N/A


50,000 Ib N/A

(Ib) Carried On
Weight Trailer No.
615 II



15,000

1,500 II




200 Ib I
for each II
trailer
142 II



44,435


55,000

24, 25, 27, 29, 30, and 31.
runner, 445" long

-------
        The time on site would average two to three weeks, assuming
        medium size sawmills

        The distance between sawmills is small enough so that the
        travel time is a minor part of the total down time between
        sites

        The total down time between sites is two days

        Wood wastes are typically 50 percent water

        If a disposal charge is made, it is $3/ton of raw wastes

        The crew operating the unit comprises a cadre, permanently
        assigned, and local filler personnel

        The crew has a crew boss who makes $15,000/year and one or
        more lead men at $12,000/year.  The filler personnel make
        $7,500/year

        It takes two men to operate the unit and there are two or
        three shifts

     .  Maintenance is conducted on the weekends

        The system operates 250 days/year

        Supervision overhead is $12,000/year

        Shared equipment expenses are $6,000/year or $9,000/year
        depending on the number of shifts

        The drier requires 1500 Btu of chemical energy from the
        non-condensible gas to evaporate each pound of water in the
        as received feed

        The derated engine operates at 15 percent thermal efficiency.
        Thus 360 Btu chemical heat energy are required to process
        one pound of dry feed

        One pound of dry feed produces .456 pounds of char oil mixture
        including a typical 10 percent moisture fraction

        The heating value of the char-oil mixture is 11,500 Btu/lb.
        This allows for the 10 percent water fraction

The dominant influence on the results of the analysis is the fuel price
which can be obtained for the char-oil mixture.  Because so many coal
prices are possible, depending upon whether "contract" or "spot market"
values are used it was not practical to select just one char-oil fuel
price.  Therefore three values, i.e., $20/ton, $35/ton, and $50/ton were

                                    65

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employed in the analysis.  It may be, because of the physical character
of the char-oil mixture and because the quantities produced initially
will likely not be large, that it is better suited for the spot market
which relies heavily on small to medium capacity stoker fixed systems.
Communications with stoker manufacturers indicate that the char-oil
mixture will burn readily on most stoker systems; in some cases, however,
minor modifications to the grate would be required.  Likewise there is
also the possibility that the mix could be used with packaged boilers,
modified with special burners.  The low sulfur character of the fuel
would be especially important to the small to medium size boiler operator,
since flue gas clean-up equipment is proportionately a much higher capital
cost item than for large utility boilers.  Regardless of the market,
the low sulfur character of the fuel should make it more valuable than
a high sulfur coal with a comparable heating value.
                                                     [ [
Thus with all these assumptions the economic analysis   was made and the
results are presented in Figures 30, 31 and 32, which,  for a given
fuel cost, show the net income, before taxes, of units as a function of
their operating capacity.  Parameters investigated are the number of
operating shifts and whether or not a disposal credit is charged.  These
figures together illustrate the dominant influence of the price of the
fuel on income and strongly suggest that three shift operation is highly
desirable.  Likewise it can be seen that the effects of collecting a
$3/ton of raw wastes disposal credit can have a significant impact on
the net profit.  Finally these figures demonstrate the great advantage
to be gained in uprating the system capacity.

Figure 33 represents a cross-plot of the data from Figures 30, 31, and 32
for a 100 (dry) ton/day unit, with net income plotted as a function of
fuel prices.  The figure reinforces the importance of three shift
operation to the system economics and again illustrates the influence
on profit of a disposal credit.  From the figure it appears that even
for 16 hr/day operation and without a disposal credit,  the break-even
point would be $20/ton.  And clearly as the fuel price increases, the
net income goes up very rapidly.

From this work, it appears that on strictly economic grounds, a strong
case can be made for the profitability of the portable waste conversion
unit.  And when the more intrinsic advantages to society, the environment
and our national economics are included, the argument for the development
of such a system is compelling.
-H-Presented in Appendix C is a sample calculation from this analysis.


                                  66

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   500
   400

£  300
£
OB
I
§
o
2
   200
   1OO
Including disposal charge and working 24 hours a day

Including disposal charge and
working 16 hours a day
          Not including disposal charge
          and working 24 hours a day
Not including disposal charge
and working 16 hours a day
       0      25     50     75     100     125    150
                 Dry Waste Feed Capacity (ton/day)
                                                175
200
                   Principal Assumptions:

                   1.   Fuel is worth $20/ton
                   2.   Interest—9.5 percent
                   3.   Depreciation—10 years
                   4.   Raw wastes are 50 percent moisture
                   5.   Disposal charge is  $3.00/ton of wet  sawdust
                   6.   The results apply to a medium size sawmill

                          Figure  30
                    Preliminary  Analysis

    Net Income of a Mobile Waste Converter with Varying
                Capacity--Fuel Price $20/ton($.87/106BTU)
                                 67

-------
  800
  700
  600

X-N
rt

^500

CO


2400
e 300
o
o
c
H
  200
  100
      0
          Including disposal charge and
          working 24 hours a day
          Not including disposal charge-
          and working 24 hours a day
                                                     Including
                                                     disposal
                                           charge and working
                                           16 hours a day
                                •Not including disposal charge
                                 and working 16 hours a day
            25     50
75
100
125
150   175
200
             Dry Waste Feed Capacity (ton/day)

              Principal Assumptions:

              1.  Fuel is worth $35/ton
              2.  Interest--9.5 percent
              3.  Depreciation--10 years
              4.  Raw wastes are 50 percent moisture
              5.  Disposal charge is $3.00/ton of wet sawdust
              6.  The results apply to a medium size sawmill

                       Figure 31

                   Preliminary Analysis

          Net Income of a Mobile Waste Converter

         With Varying Capacity—Fuel Price $35/ton ($1.52/106BTU)
                                68

-------
  900-
  800
  700
  600
"8 500
«J
CO
3
~400
§
o
o

w 300
  200
  100
                    Including disposal
                    charge and working
                    24 hours a day
Not including disposal
charge and working 24
hours a day
                         J_
                               ^Including disposal
                                 charge and working
                                 16 hours a day
                              -Not including disposal charge
                              and working 16 hours a day
            25     50      75     100    125    150    175    200

             Dry Waste Feed Capacity  (ton/day)

              Principal Assumptions:

              1.  Fuel is worth $50/ton
              2.  Interest--9.5 percent
              3.  Depreciation--10 years
              4.  Raw wastes are 50 percent moisture
              5.  Disposal charge is $3.00/ton of wet sawdust
              6.  The results apply to a medium size sawmill
                         Figure 32
                   Preliminary Analysis

         Net Income of a Mobile Waste Converter

        With Varying Capacity—Fuel Price $50/ton($2.17/106BTU)
                               69

-------
   800
   700
 M
 8  600
CO-

4) 500
e
w
CO
o
JC
•U
400
8 300
c

  200
  100
Including disposal charge and
working 24 hours a day
Not including disposal charge-
and working 24 hours a day


Including disposal charge-
and working 16 hours
per day
                                  Not including dis-
                                  posal charge work-
                                  ing 16 hours  per
                                  day
         5  10  15 20 25 30  35 40 45 50 55  60 65 70

               Price of Fuel  ($/ton)

      3      .50     1.0     1.5    2.0     2.5    3.0
                 Price of Fuel ($/10 Million Btu)

       Converter with Varying Prices

       Principal Assumptions:

       1.  Interest--9.5 percent
       2.  Depreciation--10 years
       3.  Raw wastes are 50 percent moisture
       4.  Disposal charge is $3.00/ton of wet sawdust

                      Figure  33

                 Preliminary Analysis
       Net  Income of  a 100 ton/day (Dry) Waste
                          70

-------
                          SECTION VII

                           REFERENCES
1.  Kemp, Clinton C., Testimony before the Subcommittee on Energy of
    the Committee on Science and Astronautics, U. S. House of
    Representatives, Ninety-Third Congress, June 13, 1974.

2.  Inman, Robert E. and Allich, John A., Testimony before the
    Subcommittee on Energy of the Committee on Science and
    Astronautics, U. S. House of Representatives, Ninety-Third
    Congress, June 13, 1974.
                                  71

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                          SECTION VIII

                           APPENDICES

                                                                   Page
A.  Laboratory Test Results                                         70

B.  Sample Calculation of Chemical,
      Mass and Energy Balances used
      to Reduce Test Data                                           92

C.  Economic Analysis - Sample Calculation for a 100 Ton/Day
      Unit Working 24 Hours a Day
      Including Disposal Charge                                    101

D.  Unit Conversion Tables                                         105
                                  72

-------
                           APPENDIX A

                    LABORATORY TEST RESULTS


This appendix contains the results of the laboratory tests described
in Section V.  The data is presented and is discussed in the following
order:

        Laboratory analyses for the 14 runs

        Trace element analyses for runs 7 and 15

        Stack emissions

        Viscosity data for pyrolytic oils

        Boiling point data for pyrolytic oil


Laboratory Analyses

Presented in Tables A1-A14 are the routine laboratory analyses of the
feed, char, oil, and off-gases used in the heat and mass balances.  In
most cases at least two values of each parameter were obtained.  Attention
is especially directed to the footnotes which clarify many of the numbers
tabulated.


Trace Element Analyses

Presented in Table A-15 are trace element analyses for runs 7 and 15.
In these tests, usually two values were obtained, however, only the
average of these is tabulated for the sake of brevity.


Stack Emissions

Stack emissions data for run 17 are presented below:

                     CO    -    10 ppm

                     S02   -     1 ppm
                                  73

-------
                     H S   -     0 ppm

                     NOx   -     1 ppm

The vortex burner was not operating properly during this test and some
variations in the CO level were observed.

Presented in Figure A-l is the viscosity of a typical pyrolytic oil as
a function of temperature.  As expected the viscosity reduces dramatically
with increasing temperature.

Presented in Figure A-2 is a plot of the percent of the oil sample
remaining as it is heated from 10°C to 300°C.  The smooth, continuous
shape of the curve and the lack of any discrete boiling points for the
mixture indicates the presence of numerous hydrocarbons.
                                   74

-------
Ul
                                                         Table A-l




                                                     LABORATORY ANALYSIS




                                                            Run 4


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen

Oxygen
t
Heating Value





Test
1
6.96
1.13
0.24


-

46.4

5.7

0.3

39.0

7674



Feed

Test
2
7.54
1.00
0.31


-

45.0

5.4

0.1

38.4

7749






Average
7.25
1.07
0.28


-

45.7

5.6

0.2

38.7

7712





Test
1
3.81
11.01
6.94


5.29

79.4

1.1

0.1

13.5

11,152



Char

Test
2
4.24
10.53
6.09


5.41

67.3

1.2

0.0

13.5

11,523



Oil

Test Test
Average 1 2 Average
4.03 30.7 - 30.7
10.77 -
6.52 - -


5.35 - -

73.3 47.2 46.5 46.9

1.2 5.9 6.0 6.0

0.1 0.4 0.3 0.4

13.5 53.8 41.9 47.9

11,337 - - 11,900*



Off
Non-
Condensible
Components
N2
CO
co2

H2

CH4

C2

s
J
C,
t
Heating
Value
**
Molecular
Weight
Gas


Percent
46.7
17.5
14.3

11.8

4.3

0.51

0.13

0.03

2,260*


26,6

     **
Heating value is in Btu/pound




These values of heating value were calculated from the elemental  composition.  They were used in the heat balance.




Molecular weight is in pounds/mole

-------
                                                   Table A-2




                                               LABORATORY ANALYSIS




                                                      Run 5


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen

Oxygen
f
Heating Value




Test
1
7.81
1.23
0.48


-

45.7

5.8

0.4

38.7

7549


Feed

Test
2
7.52
1.14
0.56


-

45.4

5.8

0.4

39.0

7536





Average
7.67
1.19
0.52


-

45.6

5.8

0.4

38.9

7542




Test
1
4.07
4.38
1.72


-

71.5

3.8

0.0

26.6

10,166


Char

Test
2
4.22
4.12
1.53


-

71.9

3.6

0.0

26.5

9,661


Oil

Test Test
Average 1 2 Average
4.15 66.3 - 66.3
4.25 -
1.63 -


_ _ _, _

71.7 36.7 37.8 37.3

3.7 7.9 8.0 8.0

0.0 0.2 0.4 0.3

26.6 58.2 51.7 55.0

9,914 15,900 18,900 15,800*


Off
Non-
Condensible
Components
N2
CO
co2

H2

CH,

C2

C3

C,
f
Heating
Value
**
Molecular
Weight
Gas


Percent
46.3
21.3
15.5

10.8

4.4

0.54

0.14

0.039

2,270*

27.3

 Heating value  is  in Btu/pound



 These values of heating value were  calculated  from the elemental composition.  They were used  in the heat balance.


*
 Molecular weight  is in pounds/mole

-------
                                                     Table A-3


                                                LABORATORY ANALYSIS


                                                       Run 6


Percent
Composition
Water
Ash '
Acid Insol-
uble Ash

Volatiles

Carbon
Hydrogen

Nitrogen
Oxygen
4.
Heating Value





Test
1
5.20
1.03
0.21


—

44.9
5.7

0.2
40.9

7683



Feed

Test
2
5.68
0.90
0.30


—

45.7
5.6

0.1
41.6

7728






Average
5.44
0.97
0.26


-

45.3
5.7

0.2
41.3

7705





Test
1
0.60
5.03
1.51


22.43

75.8
1.8

0.3
'19.5

13,138



Char

Test
2
0.45
4.92
1.77


19,44

83.4
1.9

1.1
13.1

13,062



Oil

Test Test
Average 1 2 Average
0.52 57.6 - 57.6
4.98 -
1.64 -


20.94 -

79.6 31.9 33.3 32.6
1.9 8.3 7.9 8.1

0.7 0.0 0.3 0.2
16.3 60.3 60.5 60.4

13,100 - - 13,600*



Off
Non-
Condensible
Components
N2
CO
CO
£,
H2
£.
CHA
A
C2
c3
J
C4
f
Heating
Value
**
Molecular
Weight
Gas


Percent
36.2
21.1
22.4

13.2

6.9

1.2
0.4

0.1
2,900*


27.6

  Heating value is in Btu/pound

 *
  These values of heating  value  were  calculated  from the elemental composition.  They were used  in  the  heat balance.
**
  Molecular weight is in pounds/mole

-------
CO
                                                              Table A-4


                                                          LABORATORY ANALYSIS


                                                                 Run  7


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen

Oxygen
+
Heating Value





Test
1
5.25
1.39
0.43


-

45.6

5.6

0.8

42.5

7726



Feed

Test
2
5.67
0.78
0.45


-

45.8

5.5

0.8

42.5

7675






Average
5.44
1.09
0.44


-

45.7

5.6

0.8

42.5

7700





Test
1
1.13
5.88
2.80


5.35

88.9

5.9

.0.3

4.9

13,287



Char

Test
2
1.09
5.90
2.46


5.92

84.8

5.5

0.9

8.8

13,208



Oil

Test Test
Average 1 2 Average
1.11 66.5 - 66.5
5.89 -
2.63


5.64 -

86.9 44.02 44.1 44.0

5.7 7.44 7.51 7.48

0.6 0.95 0.90 0.92

6.8 41.9 45.2 43.6

13,248 - - 16,300*



Off
Non-
Condensible
Components
N2
CO
co2

H2

CH4

C2

s

C4
f
Heating
Value
**
Molecular
Weight
Gas


Percent
38.6
25.6
14.8

13.2

4.82

0.81

0.13

0.02

2,820*


26.3

          **
'Heating value is  in Btu/pound

*
 These values of heating value were  calculated  from the elemental composition.  They were used in the heat balance.


 Molecular weight  is.in pounds/mole

-------
                                                     Table A-5


                                                LABORATORY ANALYSIS


                                                       Run 8


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen

Oxygen
4-
Heating Value





Test
1
6.51
2.26
1.24


_

46.7

5.7

0.1

41.0

7704



Feed

Test
2
6.19
2.11
1.13


-,

45.8

5.6

0.0

40.1

7708






Average
6.35
2.18
1.18


_

46.3

5.7

0.1

40.6

7706





Test
1
1.13
6.57
3.12


11.16

85.6

1.6

0.3

5.4

12,994



Char

Test
2
1.04
6.62
3.19


10.59

85.8

1.8

0.8

5.4

12,919



Oil

Test Test
Average 1 2 Average
1.08 57.2 - 57.2
6.59 - -
3.16 - -


10.87 -

85.7 52.7 45.8 49.3

1.7 7.6 8.0 7.8

0.5 0.4 0.7 0.6

5.4 40.1 45.8 43.0

12,956 - - 16,500*



Off
Non-
Condensible
Components
N2
CO
CO
2.
H0
2
CH.
4
C.
2
C0
3
C,
4
4-
Heating
Value
**
Molecular
Weight
Gas


Percent
48.6
14.9
18.7

9.8

4.48

1.69

0.11

—

2,180*


27.9

**
 Heating value  is  in Btu/pound

*
 These values of heating value were calculated from the  elemental  composition.   They were used in the heat balance.

*
 Molecular weight  is in pounds/mole

-------
                                                     Table A-6




                                                LABORATORY ANALYSIS




                                                       Run 9


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen
00
o
Nitrogen

Oxygen
j.
Heating Value





Test
1
6.21
1.02
0.82


-

45.3

5.9

0.8

46.5

7720



Feed

Test
2
5.88
1.05
0.86


-

45.8

5.0

0.2

46.8

7536






Average
6.05
1.04
0.84


-

45.6

5.5

0.5

46.7

7628





Test
1
1.81
9.52
5.04


7.36

80.6

1.4

0.5

9.0

12,536



Char

Test
2
1.69
9.44
5.00


7.51

80.8

1.4

o.i

7.2

12,542



Oil

Test Test
Average 1 2 Average
1.75 60.4 - 60.4
9.48 - -
5.02 -


7.44 -

80.7 44.1 43.1 43.6

1.4 7.6 7.6 7.6

0.3 0.5 0.2 0.4

8.1 47.0 48.2 47.6

12,539 - - 15,700*



Off
Non-
Condensible
Components
N2
CO
co2

HO
2
CH.
4
C.
2
C,
3
C,
4
4-
Heating
Value
**
Molecular
Weight
Gas


Percent
45.2
19.2
15.4

11.5

4.4

0.7

0.2

_

2,350*


26.8

**
Heating value is in Btu/pound




These values of heating value were calculated from the  elemental  composition.   They were used in the heat balance.




Molecular weight is in pounds/mole

-------
00
                                                           Table A-7




                                                      LABORATORY ANALYSIS




                                                             Run 10


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen

Oxygen
t
Heating Value





Test
1
5.97
1.26
0.50


-

47.3

6.0

0.3

43.3

7674



Feed

Test
2
6.09
1,29
0.51


-

46.8

5.9

0.2

44.6

7746






Average
6.03
1.28
0.51


-

47.1

6.0

0.3

44.0

7710





Test
1
2.25
9.31
4.50


10.60

83.9

1.7

0.6

6.0

12,290



Char

Test
2
2.33
9.13
4.47


11.20

85.6

1.7

0.7

5.4

12,293



Oil

Test Test
Average 1 2 Average
2.29 70.9 - 70.9
9.22
4.49 - -


10.90 -

84.8 47.7 51.3 49.5

1.7 8.0 7.0 7.5

0.7 0.5 1.3 0.9

5.7 46.7 36.6 41.7

12,292 - - 16,200*



Off
Non-
Condensible
Components
N2
CO
co2

HO
2
CH.
4
C2

C3

C4
t
Heating
Value
**
Molecular
Weight
Gas


Percent
47.4
19. j
12.3

9.7

3.8

0.47

0.09

-

2140*


27.0

      **
 Heating value  is  in Btu/pound




 These values of heating value were calculated  from  the elemental composition.  They were used in the heat balance.



*
 Molecular weight  is in pounds/mole

-------
                                                     Table A-8




                                                LABORATORY ANALYSIS




                                                       Run 12


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen
OO
bo Nitrogen

Oxygen
f
Heating Value





Test
1
6.17
1.12
0.23


-

46.6

5.9

0.2

43.5

7715



Feed

Test
2
6.18
1.05
0.24


-

46.4

5.7

0.4

39.3

7663






Average
6.18
1.09
0.24


-
~~~
46.5

5.8

0.3

41.4

7689





Test
1
2.37
7.41
2.41


21.99

81.6

2.4

0.3

17.7

12,429



Char

Test
2
2.37
7.34
2.92


21.22

80.6

2.4

0.4

18.0

12,356



Oil

Test Test
Average 1 2 Average
2.37 56.9 - 56.9
7.37 -
2.67 -


21.60 -

81.1 41.7 41.7 41.7

2.4 7.9 8.0 8.0

0.4 0.4 0.4 0.4

17.9 48.4 45.6 47.0

12.J93 20,000 19,400 16,600*



Off Gas
Non-
Condensible
Components
N2
CO
co2

H2

CH
t
C2
£.
C3

C,
4
•j-
Heating
Value
**
Molecular
Weight


Percent
39.5
16.2
21.7

10.2

4.76

0.29

0.06



2,010*


28.3

**
Heating value is in Btu/pound




These values of heating value were calculated from the elemental composition.   They were used in the heat balance.




Molecular weight is in pounds/mole

-------
00
IjO
                                                          Table A-9


                                                       LABORATORY  ANALYSIS


                                                              Run  13


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen
Oxygen
.
Heating Value





Test
1
6.80
1.15
0.38


-

46.3

5.8

0.3
44.4

7592



Feed

Test
2
6.74
1.14
0.36


-

46.3

5.8

0.2
46.9

7654






Average
6.77
1.15
0.37


-

46.3

5.8

0.3
45.6

7623





Test
1
1.67
5.81
2.93


34.30

75.5

3.2

, 0.4
21.6

11,408



Char

Test
2
1.58
6.07
3.16


35.32

78.0

3.1

0.3
20.1

11,456



Oil

Test Test
Average 1 2 Average
1.63 60.5 63.6 62.1
5.94 - - -
3.05 -


34.81 -

76.8 44.7 45.2 44.9

3.2 8.4 9.4 8.4

0.4 0.8 0.7 0.8
20.9 46.1 45.8 45.9

11,432 16,200 9880 16,800*



Off
Non-
Condensible
Components
N2
CO
co2

H2

CH,

C.

C3

C4
f
Heating
Value
**
Molecular
Weight
Gas


Percent
42.8
14.7
19.0

9.2

5.2

0.25

0.02

-
2,050*


28.1

      **
 Heating value is  in Btu/pound

*
 These values of heating  value were  calculated  from the elemental composition.  They were used in the heat balance.


 Molecular weight  is in pounds/mole

-------
00
-p-
                                                           Table A-.10


                                                        LABORATORY ANALYSIS


                                                               Run 15


Percent
Composition
Water
Ash
Acid Insol-
uble Ash


Volatiles

Carbon

Hydrogen

Nitrogen

Oxygen
f
Heating Value





Test
1
3.14
0.75
0.31



-

48.6

5.9

0.1

46.3

7932



Feed

Test
2
3.74
0.76
0.33



-

48.2

5.9

0.3

45.2

8003






Average
3.44
0.76
0.32



-

48.4

5.9

0.2

45.8

7968





Test
1
1.27
3.71
2.35



42.84

70.4

3.7

0.3

27.4

11,125



Char

Test
2
1.09
3.76
2.33



43.30

71.0

4.1

0.4

27.0

11,030



Oil

Test Test
Average 1 2 Average
1.18 61.7 - 61.7
3.74 -
2.34 -



43.07 -

70.7 45.9 45.8 45.9

3.9 7.6 7.5 7.6

0.4 0.1 0.1 0.1

27.2 46.3 47.8 47.1

11,078 16,700 16,900 16,300*



Off
Non-
Condensible
Components
Y
CO
co2

Ho
2

CH
H
c.
£,
S
J
C4
*f
+
Heating
Value
**
Molecular
Weight
Gas


Percent
36.8
21.7
15.1

10.5


5.5

1.43

a. 39

0.13

3,020*


27.1

       **
 Heating value is in Btu/pound

it
 These values of heating value were calculated from the elemental  composition.   They were used in the heat balance.


 Molecular weight is in pounds/mole

-------
00
                                                           Table A-ll





                                                        LABORATORY ANALYSIS




                                                               Run 16


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen

Oxygen
f
seating Value




Test
1
4.45
0.62
0.20


-

47.3

5.9

0.1

44.3

8117


Feed

Test
2
4.45
0.59
0.21


-

45.7

5.7

0.1

43.9

7986





Average
4.45
0.61
0.21


-

46.5

5.8

0.1

44.1

8052




Test
1
0.95
4.93
3.13


2.93

79.4

3.6

0.5

13.8

13,322


Char

Test
2
0.95
4.49
2.62


2.93

79.4

3.5

0.4

12.8

13,394


Oil

Test Test
Average 1 2 Average
0.95 49.7 - 49.7
4.71 -
2.88 -


2.93 -

79.4 42.1 40.0 41.1

3.6 7.9 6.3 7.1

0.5 0.1 0.8 0.5

13.3 47.2 46.8 47.0

13,358 - - 14,700*


Off
Non-
Condensible
Components
N2
CO
co2

H.
2
CH4
*t
c2
£.
C3

c.
4
f
Heating
Value
**
Molecular
Weight
Gas


Percent
44.1
21.2
14.1

12.7

4.11

1.02

0.13



2,530*

26.5

        **
Heating value is in Btu/pound




These values of heating value were calculated from the elemental composition.  They were used in the heat balance.




Molecular weight is in pounds/mole

-------
CO
                                                             Table A-12


                                                         LABORATORY ANALYSIS


                                                                Run 17


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen
Oxygen
f
Heating Value





Test
1
3.92
0.71
0.20


-

48.6

5.9

0.1
46.1

7999



Feed

Test
2
3.57
0.73
0.22


-

47.8

5.5

0.1
42.0

8017






Average
3.74
0.72
0.21


-

48.2

5.7

0.1
44.0

8008





Test
1
1.16
7.46
5.37


49.20

63.6

4.4

0.2
27.1

10,024



Char

Test
2
1.09
7.25
5.40


49.99

62.8

4.4

0.1
27.1

9964



Oil

Test Test
Average 1 2 Average
1.13 74.1 - 74.1
7.36 - - -
5.39 -


49.60 -

63.2 46.0 44.7 45.4

4.4 7.4 8.2 7.8

0.2 0.8 0.7 0.8
27.1 46.2 48.2 47.2

9994 - - 16,300*



Off
Non-
Condensible
Components
N2
CO
CO
f.
H2
Z.
CH
*T
C2

C,

C4
f
Heating
Value
**
Molecular
Weight
Gas


Percent
47.9
15.3
19.3

12.6

5.30

0.87

0.25

-
1,960*


27.3

        **
 Heating value is  in Btu/pound

*
 These values of heating value were  calculated  from the elemental composition.  They were used in the heat balance.

*
 Molecular weight  is in pounds/mole

-------
00
                                                           Table A-13




                                                       LABORATORY ANALYSIS




                                                              Run  18


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen
Oxygen
.
Heating Value





Test
1
5.63
0.49
0.12


-

47.6

5.8

0.4
45.1

7802



Feed

Test
2
5.90
0.41
0.09


-

47.4

5.9

0.6
46.3

7791






Average
5.76
0.45
0.11


-

47.5

5.9

0.5
45.7

7797





Test
1
2.24
6.51
3.85


5.33

88.2

0.9

0.8
14.0

12,735



Char

Test
2
2.22
6.20
3.68


5.55

87.9

0.9

0.7
15.2

12,823



Oil

Test Test
Average 1 2 Average
2.23 64.7 - 64.7
6.36 -
3.77 - - -


5.44 -

88.1 50.7 44.4 47.7

0.9 7.4 5.6 6.5

0.8 0.3 0.8 0.6
14.6 43.6 47.3 45.5

12,779 - - 15,200*



Off
Non-
Condensible
Components
N2
CO
co2

H2

CH,

C2

C3

C4
f
Heating
Value
**
Molecular
Weight
Gas


Percent
47.4
22.2
13.4

11.4

4.84

0.78

0.13

-
2,720*


26.6

         Heating value is  in Btu/pound
         These values  of  heating value were  calculated  froit the elemental composition.  They were used  in  the  heat  balance.
       **
         Molecular weight  is.in  pounds/mole

-------
00
00
                                                             Table A-14


                                                         LABORATORY ANALYSIS


                                                                Run 19


Percent
Composition
Water
Ash
Acid Insol-
uble Ash

Volatiles

Carbon

Hydrogen

Nitrogen

Oxygen
j.
Heating Value





Test
1
7.29
0.48
0.21


—

45.4

5.5

0.5

44.8

7718



Feed

Test
2
7.41
0.46
0.19


—

46.1

5.7

0.7

45.0

7712






Average
7.35
0.47
0.20


-

45.8

5.6

0.6

44.9

7715





Test
1
2.20
4.54
2.96


36.71

84.1

3.7

0.5

13.3

10,713



Char

Test
2
2.13
4.99
3.41


37.56

83.2

3.4

0.5

14.7

10,709



Oil

Test Test
Average 1 2 Average
2.17 69.8 - 69.8
4.77 -
3.19 -


37.14 - -

83.7 54.5 57.2 55.9

3.6 6.8 6.9 6.9

0.5 0.9 0.9 0.9

14.0 36.8 38.2 37.5

10,711 - - 16,000*



Off Gas
Non-
Condensible
Components
N2
CO
CO
£»
H
£.
CH
H
C2
f~
c.
J
C.
4
f
Heating
Value
**
Molecular
Weight


Percent
51.4
19.4
15.2

14.3

4 04
H1 • w*f
1.07

0 24
\J • ^*T


2,370*


26.4

        **
 Heating value is in Btu/pound

*
 These values of  heating value were  calculated from the elemental composition.  They were  used in the heat balance.


 Molecular weight is in pounds/mole

-------
CO
VO
                                                                 TABLE A-15

                                                           TRACE ELEMENT ANALYSES
               Run
Type
            Percent  Composition
               Number   Sample     Cr
                    Co
 Cu
Fe
Mn
Ni
                                                                Zn
                        Feed    .005
                        Char    .017
                        Oil     .0017
                15      Feed    .007
                15
                  .004     .010
                  .002     .005
Oil     .0017
          .39      .10
                 .008     .024
                          .29
                  .016     .028     3.12     .61
                           .022      .060     .90
          .26     .14
                15      Char    .022      .005      .017      1.98      .47
                 .008     .035     .09
                                                      .012     .042     .38
.0005    1.01     .0036    .0002    .003
                                   .010
                                                                                                                   Cl
                          .0096    .307
                                            .0061    .354
                           .0004     .57     .0022    .00008   .005     .008     .002     .0071
                                   .0054     .136
                                                      .0061    .108
                                    .0047     .0064

-------
 1000
  900
  800
  700
  600
  500

  400

  300
  200
0)
a
o
£ioo
«  90
8  80
•3  70
>
   60
   50

   40
   30
   20
  10
     10         20          40     60    80   100
                       Temperature (°C)

                           Figure A-l
          Viscosity of Pine Waste Pyrolysis Oil
200
                               90

-------
 100 I-
  75|-
CO
CO
60   '
•S3 so -

-------
                           APPENDIX B

           SAMPLE CALCULATIONS OF CHEMICAL, MASS AND
            ENERGY BALANCES USED TO REDUCE TEST DATA
This appendix presents a sample calculation of the chemical, mass and
energy balances used to reduce the test data for run 7.  The mass
balance follows the procedure presented in Figure 18.  The energy
balance is based on the results of the mass balance and, is relatively
straightforward.
MASS BALANCE

Input

Laboratory Analyses -

           Feed material (as run).

                Composition                   Percent (wt)

                     C                           45.7
                     H,                           5.6
                     C                           0.8
                     0^ (difference)             42.5
                     Moisture                     5.4

           Process Air

                Composition                   Percent (Vol)

                     N9                          79
                     °2                          21
Composition -

           Basis 100 pounds dry sawdust processed.
                                 92

-------
                Composition
             Weight (Ib)
                  Sawdust
                  Process Air
                  Moisture
                                 Total
                100
                 55.8
                  5.75
                162
Output

Laboratory Analysis -

              Char
                Composition

                     C

                     H
                     0_ (difference)
                     Moisture
              Oil
                Composition

                     C
                     H
                     0- (difference)
                     Moisture
              Gas
             Percent (wt)

                86.9
                 5.7
                 0.6
                 6.8
                 1.11
             Percent (wt)

                44
                 7.48
                 0.93
                47.6
                66.5
                Composition

                     N2
                     CO
                     co2

                     H2
                     CH,
Percent Volume

      38.6

      25.6
      14.8

      13.2

       4.82

        .81

        .13

        .02
Corrected to 100%
	Volume	

       39.4

       26.1

       15.1

       13.5

        4.93

         .81

         .13

         .02
                                93

-------
Composition -
           Basis 100 pounds dry sawdust processed.

              Char;  Using a moisture content of 1.11 percent; the
                     amount of water and dry char in the 16.3 pounds
                     of recovered char was calculated:
    Analyses
  16. 3 (mixture) x (1 -  .0111)
                                                clar
                                             ID mix
                                                    ) = 16.1 Ib  (char)
                                       Ib HO
  16. 3 (mixture) x .0111 (

                                               -  .2 Ib  (H20)
Oil;  The oil was collected and weighed.  The amount
      of dry oil was determined from the lower** of
      a laboratory determination using the Dean-Stark
      method or the calculated amount using CHNO analysis.
                                     Equivalent     Analysis
   % (wt)    Molecular Wt    mols    mols Water        %
c
H2
N2
°2
isture
44
7.48 2
.93
47.6 32

44.0-
3.74 3.74 1.52
.93
1.49 2.98 0
53.6
The amount of H.,0 from Dean-Stark method was 66.5 percent, therefore
the smaller amount was selected or 53.6 percent.

Using this value the amount of dry oil and the amount of water in the
recovered 21.8 pounds of oil-water mixture was calculated.
  21.8 Ib (mixture) x (1 - .536)
                                              Ib mix'
                                         Ib HO
                21.8 Ib (mixture) x .536  (•
                                         Ib
                                                      = 10.1 (Ib oil)
                                              H2°>
Off-Gas -

From the analysis, the molecular weight of the off-gas was calculated:
**The lower value is taken because the oil cannot have any more water
than that associated with the oxygen from the CHNO analysis.
                                94

-------
                        Analysis Corrected

     Composition          to 100 Percent              Molecular Weight
         N2

         CO


         co2



         H2

         CH4



         C2


         C3


         C4
39.4
26.1
15.1
13.5
4.93
.83
.13
.02
100 %
or mols
X
X
X
X
X
X
X
X


28
28
44
2
16
30
44
58


1100
731
664
27.0
79
25
6
1
2630 Ib

            Average Molecular weight =  •  >>   ..  =26.3 Ib/mol
                                        100 mols
To determine the total amount of off-gas produced (per 100 pounds of

sawdust) a nitrogen balance was made:



            Total nitrogen input (from process air):




                  1   M     •          Mols N?
  55.8 Ib(air) x —  (M°^ air) x .79 (Mn, n,J = 1.52 (mols





            Mols of off-gas



              1.52 (mols N )
                    mols N

              .394
                                    3.85 mols off-gas
                    mol off-gas



            Total weight of off-gas is:
            3.85 (mols) x 26.3 (-% = 102 Ib (off-gas)
                                mol
            Water:  The amount of water in the off-gas was determined

                    by a hydrogen balance.
                                  95

-------
            Input H


             Sawdust             5,9

             H20                  .64  (lbH2)

                                 6.54  (lbH2)

            Output H.
             Char:          16.3  (.057)  =   .93  Ib  H,
             Oil:           21.8  (.0748) =  1.63  Ib  H^
    off-gas

           mol

H,
z
CH4
C2
C3
C4
H

mol off-gas
.135

.0986
.0249
.0052
.001
.2647 Total mols Hn
/
                        mol off-gas

           mols H                                   .
    .2647 (—:	jrj	) x 3.85  (mol off-gas) x 2 —^7-  =  2.04  lb H0
           mols off-gas                           mols              2


    Total output =  4.60 lb H2


    Input - Output = lb H2 associated with water in off-gas

    6.54 lb H  - 4.60 lb H  = 1.94 lb H
                 1          1 mol HO    18 lb HO
    1.94 lb H. x 4 ?S „ 2 X -.	r-rr^   x	r-ir^r   = 17.5 lb  HO0
             2   2 lb H2    1 mol H2     1 mol H20               2

Total water is the sum of water  in off-gas, oil and char:

       17.5 + 11.1 + .2 = 28.8 lb H20

The total mass accounted for in  the output is the sum of the char,  oil,
off-gas, and water:


                                 96

-------
     16.1 + 10.1 + 102 + 28.8 = 157
Oxygen Balance;  An oxygen balance was made  as  a  check on the amount
of water in the off-gas.

     Input;

       Sawdust;
                                      lb 0
           100 (lb sawdust) x  .425  (lb sawdust) =42.5 (lb 02)

       Water in feed;

           5.75 lb H.O is equivalent  to 5.1  lb  0,
                    £•                           &*

       Process Air:
                          ,    ,    .         mol  0           lb  0,
           ee o it.   •     1  /mo is air.     on      .2      00
           55.8 lb air x ^  (   lb    ) x .21 —-     x 32
                                  = 12.9  lb 02

Total input;  42.5 + 5.1 + 12.9 = 60.5

Output;

     Char;  (including associated moisture)

            16'3 lb X '°68  () * 1'11 lb °
     Oil;   (including associated moisture)
                            lb 0
            21.8 lb x .476  (-rv—=7) =  10.4  lb  00
                            lb oil              2.
     Water;   (not in oil or char)

            14-8 lb x  -889  '          =  13-2  lb
     Off-Gas;  (dry)

         mols  00
       mols off-gas

     CO      .1305
     C0n     .151
                    ,total mols OQN
                    mols off-gas
                                  97

-------
            mols  02                                32  lh


     .2815 —	TJ	   x  3.85  (mols  off-gas)  x —-,—•:^-   = 34.7 Ib 0,,
           mols off-gas           v          6       mols  0               2



Total output 0  is the sum of  the amounts  from char,  oil, water and

off-gas.  The amount unaccounted for  is the difference  between input  and

output:



                     60.5 -  59.4 =  1.1  Ib  02




A carbon balance  was made to account  for oil  lost due to inefficiency

of the condenser  and some leakage in  the system.



     Input:



       Sawdust:   100 Ib x .482 Ib C = 48.2 Ib C



     Output;



       Char:  16.3 x .869 =  14.2 Ib C



       Oil:   21.8 x .440 =  9.59 Ib C



     Off-Gas;  From off-gas  analysis  the amount  of carbon in the gas

               is calculated:
                                                    mo 1 s 0

            Composition                             -ols of -£
                CO                                    .261


                C02                                   .151


                CH.                                   .0/49
                  4

                C2                                    .017


                C3                                    .004


                C4                                    ,001.

                                                       . „,,    ..total mols C-.
                                                      . 4o J    ( — •  ; -- jr? -- )
                                                              mol off-gas



        , _„    mols C      oor-i    ee        12  Ib  C    10 i  11- /••
       .483 — :; — rr -  x 3.85 mols off-gas x  --- r— — -  =  22.3  Ib C
            mol off-gas                         mol C




The total output of carbon is the sum  of  the carbon in the  char, oil,

and off-gas:



                 14.2 + 9.59 + 22.3 =  46.1 Ib



The difference between the input and output represents the  "lost carbon."


                   48.2 - 46.1 = 2.1 pounds





                                  98

-------
Total output, then is the sum of the char, oil, off-gas, water and  lost
carbon.

       16.1 Ib char + 10.1 Ib oil + 102 Ib off-gas + 28.8 Ib HO

               + 2.1 Ib "lost" carbon = 159 Ib

The amount of mass unaccounted for = 162 - 159 = 3 Ib.

The percentage mass balance error is

                 3
                162
                     x 100 = 1.9%
ENERGY BALANCE

Basis:  100 pounds dry sawdust, reference:  70°F, off-gas temperature:
        300°F, char temperature:  1101°F, ATcooling water - 10°F.

Input

From laboratory data the heating value of dry sawdust feed is 8139
Btu/lb.  Therefore the total heat was obtained by:

               100 Ib x 8139 Btu/lb = 914,000 Btu
Output

From the mass balance 16.1 Ib char, 10.7 Ib of oil, 102 Ib of off-gas,
and 28.8 Ib of water were produced.

The.heating value of the char was determined directly in the laboratory
to be 13,400 Btu/lb.  The heating value of the oil and the off-gas was
calculated from the constituent determinations to be 16,300 Btu/lb and
2820 Btu/lb respectively.  The heat content of the water was determined
from the steam tables.  Then the chemical energy was obtained by
multiplying the heating value of the product times the weight produced.

     16.1 Ib char x 13,400 Btu/lb = 216,000 Btu
     10.7 Ib oil x 16,300 Btu/lb = 172,000 Btu
     102 Ib off-gas x 2820 Btu/lb = 288,000 Btu
     2.1 Ib "lost" carbon x 14,500 Btu/lb = 30,500 Btu

Latent and sensible energy was calculated from the data as follows:

     28.8 Ib (water) x 1142 Btu/lb = 32,900 Btu
     102 Ib (off-gas) x  .2 Btu/lb °F x (300°F - 70°F) = 4690 Btu
     16.1 Ib (char) x 3 Btu/lb °F x (1101 °F - 70°F) = 4980 Btu
     10.7 Ib (oil) x 200 Btu/lb = 2140 Btu


                                  99

-------
Heat lost in cooling air tubes:

     2008 Ib x 1 Btu/lb °F x 10°F = 20,000 Btu.

The convective loss from the system was estimated to be:

     100 ft2 (1) Btu/ft2°F x 650°F = 6500 Btu

The total output energy is the sum of all these energies which is equal
to 778,000 Btu.  Therefore:

     Input Energy - Output Energy = 814,000 - 778,000 = 36,000 Btu

Percentage error in Energy Balance is

          36,000
         814,000
                                  100

-------
                            APPENDIX C


                       ECONOMIC ANALYSIS

            SAMPLE CALCULATION FOR A 100 TON/DAY UNIT
         WORKING 24 HOURS A DAY INCLUDING DISPOSAL CHARGE
Inputs;
     a.  The capacity of the unit is 100 ton/day dry sawdust
     b.  The unit is in operation 24 hr/day 250 days/year
     c.  Fuel is worth $35 per ton
     d.  Interest rate is 9.5 percent
     e.  Depreciation of the unit is 10 years
     f.  Raw wastes are 50 percent moisture
     g.  Disposal charge is $3.00/ton of wet sawdust
     h.  The results apply to a medium size sawmill
     i.  45.6 percent charcoal and oil can be obtained from the
         dry sawdust
Utilization Factor;

Utilization factor (n) is the ratio between the production time and
the total time.

Total Time includes:

     a.  Production time (PT), which is the average time in which the
         unit operates at each sawmill.  This is found by dividing the
         amount of sawdust that a medium size sawmill produces by the
         capacity of the unit.

     b.  Starting time (ST), which is the average time interval from
         arrival at the sawmill to the time the unit operates.

     c.  Turn-off time (TOT), which is the average time interval between
         the time the unit stops and the time that the unit is back on
         the road.

     d.  Traveling time (D/v), which is the average time that it takes
         to travel from one sawmill to another.  It is found by dividing
         the average distance between two sawmills (D) by the average
         speed that the unit travels (v).

                                  101

-------
so:

                       = 	FT
                     11   PT + ST + TOT + D/v

The total of starting time, turn-off time and traveling time is
approximately two days in Georgia.

so:

                   ST + TOT + D/v  =2


and:

                        PT
                 n =
                      PT + 2
Production time (PT) is the production rate of sawdust per year divided
by the capacity of the unit (CAP).
               n =
                          PR
                          CAP              PR
                       CAP
                           + 2         PR + 2 x CAP
or:

                     	Average production of a sawmill per year (TONS)
utilization factor = capacity of  x time interval     + Average production
                     the unit       between turning     of a sawmill per
                     (ton/day)      off the unit        year (ton)
                                    and starting it
                                    again at the
                                    next sawmill (day)
The production rate of sawdust by a medium size sawmill is approximately
3,000 ton/year.

So the utilization factor for a 200 ton/day unit is:


                               3000
                           200 x 2 + 3000
                                             . QQ
                                             °'89
                                   102

-------
Income;

The income per year, including disposal charge, is a function of:
capacity of the unit, number of shifts a day that the unit operates, the
amount of oil and charcoal that can be obtained from the dry sawdust,
utilization factor, number of days per year that the unit operates,
and the value of the fuel.
Income
 year
Income
 year
   Capacity of    Utilization    Number working    percent charcoal
   the unit    X  factor      X  days per year   X and oil obtained
           dry ton/day
        x  price of fuel
                                                   from the dry
                                                   sawdust

                     capacity of    number    disposal   utilization
                                          x
                     the unit wet   working    charge
                     ton/day        days
                                    per year
100 -^ x 0.89 x 250 (days) x  ^:°/0  x 35
                                ,JL.,
                                                     200
                                                                  ,.
                                                                  factor
ton
day
x 0.89 x 250 (days) x 3 (-*-) | = $488,610 per year.
Costs;

The different costs of the unit per year are:  labor, overhead,
depreciation, interest and maintenance.

First shift group:  includes one worker who earns $15,000 per year.  He
is the foreman of the whole crew.  There is also a helper who earns
$7,500 per year.

Second and third shift group:  includes one worker who earns $12,000
pear year.  He is the leadman of the shift.  There is also a helper
who earns $7,500 per year.

Driver:  one driver for each shift who earns $12,000 per year and serves
four units.

Overhead:  overhead for each unit is $12,000 per year.  It covers cost
at the headquarters for a manager, secretary and office space.   Such an
office headquarters serves ten units or more.

Depreciation:  depreciation cost assumes the life time of the unit to be
10 years with no value afterwards.  The interest rate is nine and one-half
percent payable over 10 years.  The cost of the unit as a function of
capacity is found by using the relation
                                             1/2
             Cost of Unit = 40,500 (capacity)
                                    103

-------
The cost of a 100 ton/day unit is then $405,000.

The annual payment for the unit is $64,504.

The maintenance cost is $11,000 per year.  It includes cost of parts
to be changed and covers the cost of a maintenance crew that services
four units.  The total operating cost for a 100 ton/day unit is
$158,004 per year.


Net Income;

The net income not including tax is the difference between the total
income and the total cost,

so:

          Net Income  = $488 610 _ $158,004 = $330,600 per year
          per year          '                          r
                                     104

-------
English
Unit


Btu


Cfm


ft


°F


hp


hr


inch


inch of


Ib


minute


psig


ton
        multiply by


        multiply by


        multiply by


        subtract 32


        multiply by


        multiply by


        multiply by


water   multiply by


        multiply by


        multiply by


        multiply by


        multiply by
      APPENDIX D


 UNIT CONVERSION TABLE



      Conversion


1.055 X 103 to obtain


4.72 X 10   to obtain

          _i
3.048 X 10   to obtain


and divide by 1.8 to obtain


7.457 X 102 to obtain


3600 to obtain


2.54 X 10~2 to obtain


2.458 X 10~3 to obtain


4.536 X 10"1 to obtain


60 to obtain


6.804 X 10~  to obtain


9.0718 X 102 to obtain
Metric
Unit


joules

       3
meters  /sec


meters


°C


watts


seconds


meters


atmospheres


kilogram


seconds


atmospheres


kilogram
                                      105

-------
                                 TECHNICAL REPORT DATA
                          (Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-76-090
                            2.
                                                       3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Clean Fuels from Agricultural and Forestry Wastes
                             5. REPORT DATE
                              April 1976
                                                       6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
          J.W. Tatom, A.R. Colcord, J. A. Knight,
and L.W. Elston
                                                       8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Engineering Experiment Station
Georgia Institute of Technology
Atlanta, Georgia  30332
                             10. PROGRAM ELEMENT NO.
                             1AB013: ROAP BJV-012
                             11. CONTRACT/GRANT NO.
                                                       68-02-1485
12. SPONSORING AGENCY NAME AND ADDRESS
 EPA, Office of Research and Development
 Industrial Environmental Research Laboratory
 Research Triangle Park, NC  27711
                             13. TYPE OF REPORT AND PERIOD COVERED
                             Final; 6/74-3/75	
                             14. SPONSORING AGENCY CODE
                              EPA-ORD
15. SUPPLEMENTARY NOTES Project officer for this report is J.D. Kilgroe, Mail Drop 61,
Ext 2851.
16. ABSTRACT
               r6port gives results of an experimental investigation of the operating-
parameters for a mobile waste conversion system based on the Georgia Tech
Engineering Experiment Station's partial oxidation pyrolysis process.  The object
of the testing was to determine the  combination of parameters producing the most
char and oil and the least gas from agricultural and forestry wastes. The tests
indicated both the dominant influence of air/feed on char and oil yields , and the
desirability of low values of this ratio.  In addition to  the testing, a preliminary
design of a 200  ton/day  mobile  pyrolysis system for conversion of agricultural and
forestry wastes into clean fuels was made and a simplified economic analysis con-
ducted.  The results of  this work indicate the technical feasibility and the economic
profitability of such a system.
17.
                              KEY WORDS AND DOCUMENT ANALYSIS
                 DESCRIPTORS
                                           b.lDENTIFIERS/OPEN ENDED TERMS
                                          c. COSATI Field/Group
Air Pollution
Agricultural Wastes
Forestry
Wastes
Waste Treatment
Oxidation
Pyrolysis
Oils
Economic An-
 alysis
Air Pollution Control
Clean Fuels
Forestry Wastes
Waste Conversion
Char
13B
02A
02F
07D
11H

05C
                                          07B,07C
13. DISTRIBUTION STATEMENT

 Unlimited
                 19. SECURITY CLASS (ThisReport)
                 Unclassified
                         21. NO. OF PAGES
                              105
                 20. SECURITY CLASS (Thispage)
                 Unclassified
                                          22. PRICE
EPA Form 2220-1 (9-73)

-------