EPA-460/3-74-012-a
July 1974
ALTERNATIVE FUELS
FOR AUTOMOTIVE
TRANSPORTATION -
A FEASIBILITY STUDY
VOLUME I - EXECUTIVE SUMMARY
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Mobile Source Air Pollution Control
Alternative Automotive Power Systems Division
Ann Arbor, Michigan 48105
-------
EPA-460/3-74-012-0
ALTERNATIVE FUELS
FOR AUTOMOTIVE TRANSPORTATION -
A FEASIBILITY STUDY
VOLUME I - EXECUTIVE SUMMARY
Prepared by
J. Pangborn, J. Gillis
Institute of Gas Technology
Chicago, Illinois 60616
Contract No. 68-01-2111
EPA Project Officer:
E. Beyma
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Mobile Source Air Pollution Control
Alternative Automotive Power Systems Division
Ann Arbor, Michigan 48105
July 1974
-------
This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federal employees, current contractors and
grantees, and nonprofit organizations - as supplies permit - from the Air
Pollution Technical Information Center, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711; or, for a fee, from the
National Technical Information Service, 5285 Port Royal Road, Springfield,
Virginia 22151.
This report was furnished to the Environmental Protection Agency by
The Institute of Gas Technology in fulfillment of Contract No. 68-01-2111
and has been reviewed and approved for publication by the Environmen-
tal Protection Agency. Approval does not signify that the contents
necessarily reflect the views and policies of the agency. The material
presented in this report may be based on an extrapolation of the "State-
of-the-art." Each assumption must be carefully analyzed and conclusions
should be viewed correspondingly. Mention of trade names or commer-
cial products does not constitute endorsement or recommendation for use.
Publication No. EPA-460/3~74-012-a
-------
PREFACE
This report is the result of a research team effort at the Institute of Gas
Technology. In addition to the authors, the major contributors to the study
were J. Fore, P. Ketels, W. Kephart, and K. Vyas.
This report consists of three volumes:
Volume I Executive Summary
Volume II Technical Section
Volume III Appendices.
ill
-------
TABLE OF CONTENTS
Page
STUDY OBJECTIVES 1
FUEL SELECTION METHODOLOGY 3
DOMESTIC RESOURCE BASE 6
ENERGY SUPPLY AND DEMAND MODELS 8
FUEL SYNTHESIS TECHNOLOGY 10
ALTERNATIVE FUEL PROPERTIES AND SYSTEM
COMPATIBILITY 15
FUEL SYSTEM ECONOMICS 17
SELECTED FUELS AND STUDY RESULTS 23
-------
LIST OF FIGURES
Figure No. Page
1 Alternative Fuel Evaluation Method 5
2 Production of Clean Fuels From Coal 12
3 Production of Clean Fuels From Oil Shale 14
4 Candidate Automotive Fuel Costs at Service
Stations for Current and Future Time Frames 24
VII
-------
LIST OF TABLES
Table No. Page
1 Initial-Consideration List 3
2 Transportation Energy Demands and Shortfalls
According to Model I 7
3 Adequacy of Domestic Resources 9
4 Model I Energy Supply and Demand by
Market Sectors jj
5 Tankage and Safety Properties of Potential Fuels 18
6 Bases for Fuel Cost Calculation by the DCF Method 20
7 Pattern Synthesis Processes and Fuel Production
Costs 21
8 System Base Costs for Candidate Fuels 22
9 Selected Alternative Fuels 23
10 Alternative Automotive Fuel Supply 25
IX
-------
STUDY OBJECTIVES
The United States is becoming increasingly dependent on imported petro-
leum as an energy source; this country now imports about one-third of its
crude oil and crude oil product supplies. Transportation is intensively depen-
dent on petroleum, and this sector of the economy now consumes about 25%
of the U.S. total annual energy supply and 55% of the U.S. crude oil
supply. The automotive portion (cars, trucks, and buses) amounts to 75%
of the transportation sector of the energy economy and, as such, consumes
more than 40% of the crude oil supply. Because of international and
domestic economic factors, political influences, and shortages due to
petroleum resource depletion, alternative (non-petroleum-based) fuels for
automotive transportation would be beneficial to bur society.
The objective of this study is to assess the technical and economic feasi-
bility of alternative fuels for automotive transportation, specifically
Identification and characterization of potentially feasible and practical
alternative fuels that can be derived from domestic, nonpetroleum
energy resources
Technical and economic assessments of the most promising alterna-
tive fuels for three specific time frames
Identification of pertinent fuels and research data gaps and recommen-
dations of alternative fuel(s) to best satisfy future U. S. automotive
transportation requirements.
Major emphasis in the selection of alternative fuels is placed on long-term
availability from domestic resources. Economics, competition with other
energy applications for limited energy resources, safety, handling, system
efficiency, environmental impacts, and engine and fuel distribution system
compatibility also are taken into account. This study provides background
information for the development of U. S. energy programs pertaining to
chemical fuels.
Working toward these objectives, we have generated a fuel selection
methodology that can be applied to a potential alternative fuel. We have
enlisted the factors of energy demand and supply, fuel availability, fuel
synthesis technology, and certain physical, chemical, and combustion pro-
perties of the fuel. Apparent technology and information gaps bearing on
a fuel's usefulness (for automotive purposes) are identified.
.1
-------
In this study, the petroleum resource base consists of crude oil, natural
gas, and natural gas liquids (including LPG). Conventional gasoline from
this petroleum resource base is the "reference" fuel. When possible, it is
the basis for quantitative and qualitative comparisons. "Automotive trans-
portation" refers to automobiles, trucks, and buses. The energy require-
ments for the remainder of the transportation sector are incidental to this
study. We are primarily considering vehicles propelled by heat engines
combusting chemical fuels. Electric vehicles those storing and delivering
energy electrochemically are excluded from this study. However, vehicles
that carry a chemical fuel and combust it in a fuel cell (to produce electricity
for a motor) are included.
This study is concerned with three time frames: near term, 1975-1985;
mid term, 1985-2000; and far term, beyond 2000. Because of the uncer-
tainties in future energy availability, technological advances, economics,
and public policy, forecasts or projections beyond the near term are very
difficult. Two energy demand and supply projections (models) are detailed
in the technical section (Volume II) of this report for two purposes: 1) to
present an illustration of the methodology of fuel selection and 2) to provide
an optimistic possibility of domestic energy self-sufficiency as well as a pes-
simistic possibility of continued dependence on energy imports. The projections
are not intended as models of energy allocation; rather, they are intended to
show quantitatively the deficits and excesses that could exist in future time
frames. The assumptions inherent in our energy demand and supply models
are specified, and the reader can change the projections by changing the
assumptions.
To apply the methodology of alternative fuel selection to a reasonable
number of fuels, we have studied 16 fuels in this program. As possible
energy sources for fuel synthesis, we have studied 12 potential domestic
sources of energy. Table 1 lists these energy sources, four abundant auxi-
liary material sources, and the potential alternative fuels. The conventional
crude oil and natural gas resource base has been excluded. Also, we have excluded
any fuel that would produce significant amounts of combustion products not
found in (unpolluted) air. In the potential automotive fuel list, "distillate
oils" refer to similar hydrocarbon mixtures kerosene, diesel oil, and
fuel oil (No. 1 or 2). Hydrazine is included a,s a fuel for fuel cells, and the
coal is a solvent-refined product (low in ash and sulfur content).
-------
Table 1. INITIAL-CONSIDERATION LIST
Energy Sources
Coal
Shale oil
Tar sands
Uranium and thorium
Nuclear fusion
Solar radiation
Solid wastes (garbage)
Animal wastes
Wind power
Tidal power
Hydropower
Geothermal heat
Auxiliary Material
Sources
Air (02, C02, N2)
Rock (limestone)
Water
Land
Potential Automotive
Fuels
Acetylene
Ammonia
Carbon monoxide
Coal
Distillate oils
Ethanol
Gasolines (C5-C10)
Heavy oils
Hydrazine
Hydrogen
LPG (synthetic)
Methanol
Methylamine
SNG
Naphthas
Vegetable oils
FUEL SELECTION METHODOLOGY
Candidate alternative fuels are selected from the initial-consideration
list by evaluations, whenever possible, of certain fundamental areas of con-
cern. The concerns that we have identified are as follows:
Adequacy of energy and material availability and competing demands
for fuels
The existence of known or developing fuel synthesis technologies
Safety (toxicity) and handling properties of fuels
Relative compatibility with contemporary fuel-transport facilities
and utilization equipment (tanks and engines)
Severity of environmental impacts and resource depletion
Fuel system economics (resource extraction, fuel synthesis and
delivery, automotive utilization).
For the initial choice of candidate fuels, preliminary economic assess-
ments have been made from various capital and operating costs published
in the technical literature. These preliminary co'st assessments have been
combined with quantitative rankings for each fuel in the other areas of
-------
concern. The quantitative rankings and particular criteria by which fuels are
evaluated have been derived during the course of the study, and they are dis-
cussed in Sections 2 through 9 and applied in Section 10 (Volume II) of this
report. After the candidate fuels had been chosen from the initial-consideration
list, the favored fuels for each time frame were selected by using more
detailed and accurate information, particularly data on fuel-system economics.
These economic data are derived in Appendix B (Volume III) and in Section 8
(Volume II) of this report. Again, a fuel ranking is constructed by numeri-
cally rating the above-listed concerns for each candidate fuel; in this case,
assessments are made for each time frame. Some of the concerns, for
instance, the safety and handling aspects (toxicity and physical and chemical
properties), do not change with time. Others, such as the availability of a
technology for fuel synthesis, can vary greatly during the three time frames
of this study, so some assessments must be repeated. The different judgments
for fuel selection must be as consistent as possible, and the criteria must be
quantified when possible.
In this study, fuel system economics have been restricted to exclude ve-
hicle utilization costs. The precision and accuracy of the data base on engine
efficiency, vehicle weight, and fuel consumption for alternative fuels in con-
ventional and unconventional power plants are inadequate to include this cost
factor in fuel selection procedures. Further, the data base on efficiency and
pollution aspects of resource extraction, fuel synthesis, and automotive utili-
zation is incomplete. Therefore, the severity of environmental impacts could
not be judged uniformly and could not be fairly applied to the selection of al-
ternative fuels.
The alternative fuel evaluation procedure is outlined in Figure 1. According
to this evaluation method, certain background information must be assembled
before the evaluation can proceed. This background information consists of
the following items:
a. Quantitative information on the U. S. domestic energy (and material)
resource base. This must include the conventional petroleum resource
base for reference. Assured, reasonably assured, and speculative
quantities are sought.
b. Energy demand and supply model(s). These models are divided into
market sectors to show deficits and excesses. The transportation
sector is of prime concern.
-------
U1
SYNTHESIS PROCESSES-
Commercial
Developmental
Conceptual
IDENTIFY
TECHNOLOGY/INFORMATION
GAPS
FUEL SELECTION (Surv
Candidates)-
Relative Ranking,
Subjective and
Qualitative; or
Normalization to
Gasoline and
Ranking
ring
SELECTED FUELS
Figure 1. ALTERNATIVE FUEL EVALUATION METHOD
-------
c. Information on fuel synthesis processes. Needed are the availability
of commercial processes, processes being developed, and conceptual
processes for fuel synthesis from unconventional energy sources.
d. A bank of data on fuel properties pertinent chemical, physical, com-
bustion, and toxicity data. Also, prospects for fuel transport (handling)
and fuel-engine compatibility and performance are needed. This also
establishes the data for conventional gasoline, the reference fuel for v
this study.
e. A resource depletion model. This should integrate resource depletion
due to automotive requirements with energy supply.
The evaluation procedure begins with a determination of whether a given
fuel can be synthesized by some process from an available energy (and
material) resource. If not, but if subsequent evaluations are satisfactory
relative to conventional gasoline (selection criteria met), a synthesis techno-
logy gap is identified. Other technology gaps that may be. identified concern
fuel transport or tankage, fuel-engine compatibility, and correctable environ-
mental effects. The energy demand and supply model determines for the
various time frames how much energy (fuel) is required and whether that
fuel will be available for automotive use, considering competing demands
from other (higher priority) sectors of the economy. These assessments
are followed by determinations of fuel safety and handling, and compatibility
and utilization. The overall resource depletion due to the synthesis and use
of a fuel is calculated, and the environmental effects due to potential material
pollutants are assessed (if quantitative determinations can be made). Finally,
the fuel is given a rating relative to conventional gasoline by normalization
of the quantitative data and the semiquantitative judgments. As a result, the
fuel has a certain ranking relative to the other potential alternative fuels.
DOMESTIC RESOURCE BASE
One prerequisite in the selection of an alternative automotive fuel is the
determination of whether or not its domestic resources are adequate to sup-
port a substantial portion of the transportation demand for a period that allows
major development and commercialization of a new industry. The term
"substantial portion of the transportation demand" is quantified by using
supply-demand projections for energy in the U. S. According to the Model I
projections used in this study, the transportation energy shortfalls vary
between 28 and 34% annually between 1975 and 2000, as shown in Table 2.
-------
Table 2. TRANSPORTATION ENERGY DEMANDS AND
SHORTFALLS ACCORDING TO MODEL I
1975 1980 1985 2000 2020
Demand, 1015 Btu 19.4 23.0 26.7 40.4 70.1
Shortfall, 1015 Btu (domestic) 6.4 7.4 7.4 13.8 41.7
Shortfall, % of demand 33 32 28 34 59
Integrating the Model I shortfall from 1975 to 2000 results in a total short-
fall of about 215 X 1015 Btu, or an average annual shortfall of 8. 6 X 1015 Btu.
In this study, we are interested in alternative fuel systems that could have
a major impact on the projected shortfalls. Therefore, as a benchmark,
we have chosen one-half of the shortfall, or an integrated value of 108 X 1015
Btu (1975-2000), as the level of energy supply that must be potentially achiev-
able by a viable and important alternative fuel system. This benchmark cor-
responds to about 15% of the total transportation energy demand. Hence, to
be adequate, a new (unconventional) energy source should have the potential
to supply 3-6 X 1015 Btu/yr of fuel between 1975 and 2000.
For renewable resources, the rate at which a resource becomes available
for conversion is a practical limiting factor. To be adequate, this energy
resource also must be able to meet about 15% of the transportation demand
for 25 years. Energy sources that are limited by a lack of required materials,
conversion efficiency (to a fuel), or other factors to a production rate of less
than 3-6 X 1015 Btu/yr are considered inadequate.
From a multitude of sources, but principally the NPC's U. S. Energy
Outlook, * we have assembled and categorized the domestic energy resource
base. Throughout this report, the following classifications are employed to
uniformly categorize the resource base: "assured" reserves are adjacent to
current producing areas and have been measured with a high degree of cer-
tainty. "Reasonably assured" reserves have a high probability of existing
i
National Petroleum Council, U. S. Energy Outlook: A Report of the
National Petroleum Council's Committee on U. S. Energy Outlook.
Washington, D.C., December 1972.
-------
based on geological and other information similar to that found in areas
currently being produced. "Speculative" reserves assume a high degree
of optimism and could possibly fall into one of the former classifications
by means of extensive exploration and development activity. We have chosen
this definition of resource base because, for various resources, the documen-
tation is adequate and categorization can be uniform. Use of other classi-
fications, such as "economically available" (minable), would result in less
consistency, because these quantities have been reported on different
economic bases.
We have summed the assured resource base, 75% of the reasonably
assured resource base, and 25% of the speculative resource base for the
finite domestic fossil and nuclear resources. These resources and sums
are presented in Table 3, in which the adequacy of the resource is rated
according to the requirement of 108 X 1015 Btu.
In the case of solar heat, we have taken one average state, or 2% of the
U. S. land area, as that potentially available for agricultural production of
a crop that could be converted to a fuel for automotive transportation. In
the cases of municipal andfeedlot wastes, we have taken the annual supply
projected for 1985.
ENERGY SUPPLY AND DEMAND MODELS
This study uses two energy models to bracket future supply and demand.
They show the fuel requirements resulting from different assumptions about
the effectiveness of conservation efforts, changing demand patterns, and the
drive toward domestic self-sufficiency. A third model, not fully developed,
shows the effects of high fuel costs, extreme conservation, and Federally
legislated vehicle efficiency (fuel economy) on automotive fuel demand. The
effect of these models on our selection procedure is to define the minimum
resource base requirements and fuel production rates that are required in
a particular time frame.
These models are not intended for the purpose of energy allocation in the
future, but merely as a quantitative indication of energy supply and demand
deficits and/or excesses. The models show how much energy is needed and
when it is needed for alternative fuels. They can be used as selection criteria
-------
Finite Resource
Coal
Oil Shale
Uranium (Fission)
Burner Reactors
Breeder Reactors
Tar Sands
Deuterium (Fusion)
Table 3. ADEQUACY OF DOMESTIC RESOURCES
Potential
Supply, 1015 Btu
67, 100
3,230
550
41, 250
127
Unassessed
Adequacy
Probable
Probable
Possible
Moderate technology gap
Not adequate
Serious technology gap
Renewable Resource
Hydropower
Total
Uncommitted
Geothermal Heat
Fuel Conversion
Solar Heat (Total Area)
2. 0% U.S. Area
Agricultural Production
Fuel Conversion
Tidal Power
Wind Power
Municipal Wastes
Animal Feedlot Wastes
Potential
Annual Supply
1.8
1.5 (as fuel)
7. 7 (as heat)
2.7 (as fuel)
49, 000 (as heat)
980 (as heat)
9. 8 (as crop)
4. 9 (as fuel)
Negl
4. 0 (as fuel)
2. 9 (as heat)
1.2 (as fuel)
6. 8 (as heat)
3.4 (as fuel)
1015 Btu-
25-Year
Fuel Supply
37.5
67.5
122.5
Negl
100
30
85
Adequacy
Not adequate
Not adequate
Not adequate
Speculative
Not adequate
Not adequate
Not adequate
Not adequate
Not adequate = >108x 1015 Btu.
-------
because they indicate for a given time frame that, after several "best
qualified" fuel systems are selected, other (additional) fuel systems are
not needed.
The primary model of energy supply and demand for this study, denoted
Model I, is based on a slightly modified (supply) Case I of the NPC report1
and on the low level of demand from the NPC report. The assumptions upon
which the Case I energy supply quantities are based closely approximate
an optimistic situation in which a maximum effort is undertaken to make
the United States self-sufficient in terms of energy supply at the earliest
possible date. These conditions best fit the ground rules of this study, i.e. ,
to assess the feasibility of alternative automotive fuels based on U. S. do-
mestic resources.
The projected quantities of energy supply and demand from Model I are
presented in Table 4. For each time frame, these quantities are categorized
by type of energy available to each sector of the economy based on historical
use patterns, assumed rates of future consumption, and priorities in allocation.
The transportation sector is assumed to have the lowest priority. Considering
practical energy conversion efficiencies in the synthesis of fuels and in the
generation of electricity, Table 2 is formulated to determine alternative
fuel needs.
FUEL SYNTHESIS TECHNOLOGY
The resource base assessment and energy demand and supply Model I
indicate that the domestic energy sources available for large-scale auto-
motive fuel production are coal, oil shale, nuclear energy (fission), and
maybe solar energy. However, the other energy sources (winds, tide,
waste materials, geothermal heat, etc.) deserve the development as con-
tributors to the overall U.S. energy supply, and local or limited use of
these unconventional energy sources may result indirectly in more (conven-
tional) fuel being available for transportation.
Considerable effort is being directed toward developing processes that
will convert coal to clean fuels gaseous, liquid, or solid. As shown in
Figure 2, coal can be gassified by means of two routes. The first route
produces clean gas of either medium (250-550 Btu/CF) heating value or high
(950-1000 Btu/CF) heating value. The latter is a supplement to pipe line -
quality natural gas (SNG). The second route to clean gas produces only low
10
-------
Table 4. MODEL I ENERGY SUPPLY AND DEMAND
BY MARKET SECTORS
1970 1975 1980 1985 2000* 2020*
1015 Btu
Demand
Residential/Commercial 15.8 18.2 21.1 23.9 36.2 62.8
Industrial 20.0 22.2 24.7 27.1 41.0 71.2
Transportation 16.3 19.4 23.0 26.7 40.4 70.2
Electricity Conversion 11.6 15.5 20.7 26.7 40.4 70.2
Nonenergy 4.1 5.0 6.2 8.1 12.3 21.3
Total 67.8 80.3 95.7 112.5 170.3 295.7
Supply
Oil
Conventional (Wellhead) 21.0 23.7 27.3
Oil Shale 0 0 0. 6
Coal Liquefaction Q Q Q. 2
Total 21.0 23.7 28.1 '34.7 47.9 50.7
Gas Production
Conventional (Well) 22.4 24.5 24.6 28.0 22.0 15.0
SNG From Coal 0 0 1. 0 2. 0 8. 0 10. 0
Total 22.4 24.5 25.6 30.0 30.0 25.0
Coal (Traditional Uses) 13.1 16.6 21.1 27.1 35.0 64.0
Hydro and Geothermal 2.7 3.1 4.0 4.7 5. 0 5. 0
Nuclear (Heat) 0.2 4.0 11.3 29.8 102.0 275.0
Total 59.4 71.9 90.3 126.3 219-9 419.7
The assumed rate of growth for 2000-2020 is 2. 8% /yr, which is the
same for the 1985-2000 period except for nuclear power supply figures.
(100-250 Btu/CF) heating value gas because the gas contains a considerable
amount of nitrogen. The nitrogen is introduced when air is used in the system
for combustion to furnish the heat for the gasification reactions.
Production of clean liquids or clean solids from coal is carried out by
three principal routes. In the first route, clean gas containing appropriate
proportions of carbon monoxide and hydrogen (synthesis gas) is converted by
the Fischer-Tropsch Process to hydrocarbon oil. The second route involves
heating the coal to drive out the naturally occurring oils in it (pyrolysis) and
11
-------
GASIFICATION
LOW-Btu
CO, H2, CH4,
N2, C02, H2S
CLEANUP
COAL
MEDIUM-Btu
CO, H2, CH4,
C02, H2S
CLEANUP
GAS
HYDROGEN
SULFIDE
METHANATION
CLEAN FUEL GAS
LOW-Bto (100-250)
CLEAN FUEL GAS
MEDIUM-Bto (250-5SO)
CLEAN FUEL GAS
HIGH-Btu (950-1000)
PYROLYSIS
CHAR '
HYDROTREATING
HYDROGEN ,
FILTRATION AND
SOLVENT REMOVAL
ASH
PYRITIC SULFUR
CLEAN LIQUID
FUEL
CLEAN LIQUID
FUEL
CLEAN LIQUID
FUEL
CLEAN SOLID
FUEL
A-74-1237
Figure 2. PRODUCTION OF CLEAN FUELS FROM COAL
then treating these oils with hydrogen for desulfurization and quality improve-
ment. Pyrolysis processes produce significant quantities of by-product gas
and char, which must be disposed of economically. The third route to clean
liquid fuel involves dissolving the coal in a solvent and filtering out ashes,
which include the pyritic sulfur. After the solvent has been removed, the
resulting heavy crude oil (syncrude) is treated with hydrogen to remove or-
ganic sulfur and to improve its quality. In one process, a solid fuel (solvent-
refined coal) is produced if the syncrude is allowed to cool before the hydro-
treating step.
12
-------
Many processes exist for making gaseous or liquid fuels from oil shale.
Some processes are on the pilot-plant scale (e. g. , TOSCO II Process, Gas
Combustion Retort Process, Union Oil Process) and some are in commercial
use (e.g., Petrosix Process, GCOS Process). As shown in Figure 3, oil
shale can be hydrogasified to gaseous fuel or it can be retorted to make liquid
fuel.
The processed (spent) shale is a fine, granular, dark residue dark
due to residual carbon that coats the particles because the Low temperature
in the processing retort does not produce any significant agglomeration
into clinkers. More than 75% (by weight) of the feed shale becomes spent
shale. Therefore, disposition of spent oil shale is a major problem, and
once this spent shale has been deposited, there remains the problem of re-
vegetating the deposit. Studies are being conducted to resolve this problem.
Appendix B (Volume III) contains detailed descriptions for four processes
that produce candidate alternative automotive fuels from coal and oil shale.
These "pattern" processes have been chosen because they consist of demon-
strated technology and because sufficient information is available for process
characterizations and detailed economic assessments. The economic assess-
ments are used to aid in the evaluation of alternative fuel systems by providing
fuel production costs. The pattern processes are as follows:
Gasoline and distillate hydrocarbons from coal via the Consol Synthetic
Fuel (CSF) Process plus product refining including catalytic cracking
Gasoline and distillate hydrocarbons from oil shale via the Gas
Combustion Process (Bureau of Mines) plus hydrotreating and re-
fining of the product
Methanol from coal via a Koppers-Totzek gasifier and Imperial
Chemical Industries (ICI) methanol synthesis
SNG (methane) from coal via a Lurgi gasifier with methanation.
In addition, Section 5 (Volume II) includes brief descriptions of many pro-
cesses based on coal and oil shale to produce synthesis gas (hydrogen and
carbon monoxide) and several alternative fuels. Required material and energy
inputs, operating conditions, product streams, and potential environmental
pollutants are listed. Also, Sections 5 and 8 (Volume II) include descriptions
of fuel synthesis technologies based on nuclear heat, solar energy (including
agricultural crops), and waste materials.
13
-------
LOW-Btu GAS
CLEAN FUEL GAS
LOW-Btu
HYDROGASIFICATION
OF OIL SHALE
T
MEDIUM-Btu
GAS
HYDROGEN OR
SYNTHESIS GAS
METHANATION
CLEAN FUEL GAS
MEDIUM-Btu
CLEAN FUEL GAS
HIGH-Btu
OIL
GASIFICATION
HYDROGEN
SULFIDE
RETORTING OF
OIL SHALE
OILS
HYDROTREATING
LOW =100-250 Btu
MEDIUM = 250-550 Btu
HIGH = 950+Btu
f
HYDROGEN
CLEAN LIQUID
FUEL
A-74-1238
Figure 3. PRODUCTION OF CLEAN FUELS FROM OIL SHALE
-------
Recently, attention has been given to the possibility of the use of process
heat directly from the core of high-temperature, gas-cooled nuclear reactors
to drive a chemical process. The production of hydrogen for use as an automo-
tive fuel by this means is a distinct possibility. With water as a raw material,
the products of thermal decomposition are hydrogen and oxygen. Because of
the temperature limitations of nuclear reactors and conventional process equip-
ment, direct single-step water decomposition cannot be achieved, but
sequential chemical reaction series have been devised in which hydrogen and
oxygen are produced, water is consumed, and all other chemical products are
recycled. This multistep thermochemical method offers the potential for
processes that can use high-temperature nuclear heat and be contained in
chemical process equipment.
ALTERNATIVE FUEL PROPERTIES AND SYSTEM COMPATIBILITY
This subject encompasses physical, chemical, and combustion properties,
safety (toxicity), transportability and storability, and compatibility with
engines. Appendix A (Volume III) contains a listing of the pertinent chemical,
physical, and combustion properties of potential alternative fuels. Section 6
(Volume II) deals with the details of transportability, storability, tankage,
and engine compatibility.
'Safety assessments might be made by considering combinations of the
combustion properties and toxicity of fuels. Combustion properties that
are indicative of the likelihood of accidental fire are flash point, ignition
energy, limits of flammability in air, and ignition temperature. Gasoline
and distillate oils are handled safely; however, these fuels have very low
lean flammability limits and low ignition temperatures. Gasoline also has
the lowest flash point of any of the liquid fuels. Thus, we find only minor
(insignificant) distinctions evident between fuels that are potentially safer
than gasoline in terms of combustion when gasoline is handled safely in the
reference system.
Toxicity is a different matter, and distinctions should be made. In our
investigation, we have sought the following fuel concentrations in air: least
amount for detectable odor, least amount causing eye irritation, least amount
causing throat irritation, and maximum concentration allowable for prolonged
(8-hour) exposure. Concentrations above this last value cause a variety of
15
-------
symptoms, differing with different fuels, but on the average, the effects
are deleterious and incapacitating. We have quantified alternative fuel
toxicity relative to gasoline by using the "toxicity ratio," which we define
as the ratio of the 8-hour exposure concentration (in air) of the fuel in question
to that of gasoline:
Toxicity ratio = ( ppm fuel y*
7 v ppm gasoline '
It would be inconvenient and expensive to introduce a fuel that has physical
and chemical properties unsuited for the equipment now used for energy supply.
The great economic incentive to retain existing facilities would have to be
overcome. Fuels that can be handled in existing petroleum-product-distribution
equipment have an enormous advantage.
At present, four separate transport systems handle four classes of fuels.
About 10 X 1015 Btu is delivered as gasoline by the liquid-fuels-distribution
system each year. The solid-fuel (coal) transmission system handles about
12 X 1015 Btu annually. Gaseous fuels, primarily natural gas, have their own
pipeline system, which accounts for about 20 X 1015 Btu yearly. The last
class of distribution system, which moves condensable gases like LPG, is
relatively small and would need a considerable (but possible) investment to
accommodate the huge quantities of fuel required to supplement gasoline
supplie s.
The compatibility of each fuel is judged against the changes and additions
to each of these four distribution systems that it would necessitate. The
best situation allows the continued use of the liquid-fuel pipelines, trucks,
and service stations system. A switch to one of the other three systems
requires, at the least, a substantial amount of new distribution equipment
and service-station facilities.
We have estimated automotive tankage weights and volumes after consul-
tation with manufacturers. Fuel energy content alone does not necessarily
indicate the true weight of ,a fuel system. Because fuel tankage weights in-
fluence total vehicle weight and hence fuel consumption, we have calculated
the tankage weights of alternative fuels at the energy equivalent of 20 gallons
of gasoline. Fuels requiring a fuel storage system weighing in excess of
500 pounds are poor alternatives to gasoline. Tankage weights in the range
of 200-500 pounds are considered good, and those in the range of 140-200
16
-------
pounds (comparable to that of gasoline) are excellent. Tankage volume does
not affect performance or fuel consumption, but can affect passenger and pay-
load space. For example, at 600 gallons, gaseous carbon monoxide is un-
acceptable, and at 110 gallons, acetylene is awkward. To quantify this
criterion, we have used the tankage index defined as:
Tankage _ / fuel tankage weight % / fuel tankage volume v
index gasoline tankage weight gasoline tankage volume
Just as it would be impractical to introduce a fuel that in the near term is
incompatible with the present distribution system, it would be impractical to
introduce a fuel that is incompatible with automotive power plants, present or
planned. The compatibility of fuels with engines is judged on an arbitrary nu-
merical scale. Details are presented in Sections 6 and 10 (Volume II). In the
near-term time frame, fuels are judged for compatibility with conventional
spark-ignited and diesel engines; for the mid term, stratified-charge
engines are included; and for the far term, Brayton, Rankine, and Stirling-
cycle engines and fuel cells are included along with conventional, stratified-
charge, and diesel engines.
Table 5 summarizes the tankage and safety properties of the potential
alternative fuels.
FUEL SYSTEM ECONOMICS
To further evaluate alternative fuels, we have applied a costing procedure
to the potential fuel systems. This method sums the calculated costs of re-
source extraction and synthesis, the costs of refining or liquefying, and the
costs of transmission and distribution. This procedure yields a delivered
fuel cost ($/Btu) to the service station.
The determination of fuel system costs has been done in two phases. An
initial "rough cut, " using published estimates of resource extraction and syn-
thesis costs, was done first. Transmission and distribution costs for similar
fuels or chemicals were used. For the several attractive candidate fuels
(those ranking most favorably with respect to gasoline), a second, detailed
determination of costs was made. Section 8 (Volume II) and Appendix B
(Volume III) contain pertinent details. The candidate fuels were found to be
gasoline and distillate hydrocarbons (coal and oil shale), methanol from
coal, SNG from coal, and nuclear-based hydrogen.
17
-------
Table 5. TANKAGE AND SAFETY PROPERTIES OF POTENTIAL FUELS
1X3
Fuel
Acetylene
Ammonia
Carbon Monoxide*
Coal
Diesel Oil or
No. 2 Fuel Oil
Ethanol
No. 6 Fuel Oil
Gasoline
Hydrazine
Hydrogen ( x)b
Kerosene
LPG (synthetic)
Methanol
Methylamine
Methane SNG (Qb
Naphthas (approx)
Vegetable Oil
(Cottonseed)
Chemical
Formula
C2H2
NH3
CO
C
Mix
C2H5OH
Mix
Mix
H2
Mix
C3H8
CHjOH
CH3NH2
CH«
Mix
Mix
Lower Heating
Value ,
Btu/lb
20,780
8,000
4,350
10,000
18,480
11.930
17,160
19,290
7,000
51,620
19,090
19,940
9,080
12,860
21,250
18,850
16, 110
Tankage Weight, C Tankage Volu
Ib gal
800
385
2000
200
150
235
165
145
710
200
145
180
280
260
165
150
165
390
45
600
18
22
30
22
22
65
105
22
27
41
35
45
22
22
c in Air
me.
Lean
2.8
15
12.5
d
-- '
4.0
--
1.4
4. 7
4. 1
0. 7
2.1
6. 7
4.9
5.0
/ 1.1
--
%
Rich
80
28
74
d
--
19
--
7.6
100
74
5
10
36
21
15
6
--
Ignition
Temperature,
°F
581
1ZOO
1128
d
494
793
765
430
518
1085
491
808
878
806
1170
430-530
530
B-
Dangerous for
Prolonged Exposure,
Ppm
Nontoxic
100
100
Nontoxic
500
1000
500
500
1
Nontoxic'
500
Nontoxic
20t)
10
Nontoxic
500
Nontoxic
54-753
Gaseous.
Cryogenic liquid.
0 Energy equivalent of 20 gallons of gasoline.
For coal dust, the flammability data vary with the type of coal. For dust of coal of medium volatility,
the ignition tempe rature is about 11 00°F. The minimum explosive concentration is about 50 oz/1000 cu ft.
e Asphyxiant.
-------
For these candidate fuels, the economics have been calculated by using
discounted cash flow (DCF) financing in accordance with the method contained
in The Supply-Technical Advisory Task Force Synthetic Gas-Coal report.2
The basis of this" financing process is outlined in Table 6.
For resource extraction and fuel synthesis, we have made careful determin-
ations of all components of capital and operating costs. Table 7 presents
the results for those candidate fuels and synthesis routes that could be
characterized in sufficient detail.
Similarly, the capital and operating costs have been derived for transmission
and distribution of the candidate alternative fuels to service stations. These
costs are combined with the fuel production costs to arrive at the fuel system
costs in Table 8. The corresponding reference (domestic crude) gasoline
costs are $1.60/106 Btu for crude production and refining, and $1.20/106 Btu
for product transmission and distribution, for a total of $2. 80/106 Btu
delivered.
The system costs of Table 8 are the base costs used for candidate fuel
evaluation in the future time frames. These costs are in terms of late-1973
dollars. They are the predicted fuel costs at the service station and vehicle
interface, but they do not include Federal and state sales and other taxes
normally imposed on gasoline and alcohol.
In the future, coal, oil shale, and fissile (nuclear) fuels will escalate in
real costs because of the necessity for deeper mining, the use of lower-assay-
material deposits, longer distance transport of materials including water,
and environmental and safety regulations. Synthesis costs also will escalate
because of the necessarily increased amounts of processing per unit of product.
Breeder processing of nuclear fuels also will be a necessary expense if the
nuclear energy supply is to be sizable (as predicted) after 1985. Economies
of scale cannot be expected to reduce costs because all plants and resource
extraction sites have already been considered in sizes above the range in
which economies of scale apply. Further, up-to-date technology and some
technological advances, particularly in resource extraction, were assumed
in deriving the base costs. Additional technological advances were assumed
Synthetic Gas-Coal Task Force, The Supply-Technical Advisory Task
Force Synthetic Gas-Coal. Prepared for the Supply-Technical
Advisory Committee, National Gas Survey, Federal Power Commis-
sion, April 1973.
19
-------
Table 6. BASES FOR FUEL COST CALCULATION BY THE DCF METHOD
Basis
25-year project life
16-year sum-of-the-years' -digits depreciation on total plant investment
100% equity capital
Essential Input Parameters
12% DCF return rate
48% Federal income tax rate
Handling of Principal Cost Items
Total plant investment and working capital are treated as capital costs at start-up completion.
"Return on investment during construction" ( equal to total plant investment X DCF return rate
X 1. 875 years) is treated as a capital cost at start-up completion.
Start-up costs are treated as an expense at start-up completion.
See Appendix B (Volume III) for detailed calculations.
-------
Table 7.
Raw
Material
Coal
Coal
Oil Shale
Coal
Coal
PATTERN SYNTHESIS PROCESSES AND FUEL PRODUCTION COSTS
(1973 Dollars)
Production Cost fl2% DCF)*
Volume Basis, Energy Basis,
Synthesized
Fuel
Gasoline
Gasoline and
distillate oils
Gasoline and
distillate oils
Methanol
SNG
Pattern Process
Consol Synthetic
Fuel ( CSF) plus
refining with
hydroc racking
Consol Synthetic
Fuel ( CSF) plus
refining with
catalytic cracking
Gas Combustion
Process (Bureau
of Mines) plus
hydrotreating and
refining
Koppers-Totzek
gasifier and ICI
synthesis
Lurgi gasifier
with methanation
$/gal
Btu
*
0. 33
0. 31
0.25
0. 23
1.84/103
SCFt
If 10% SCF financing is used, the resulting fuel synthesis costs
are 88% to 91% of the costs presented in this table.
Basis: the low heating value of the fuel.
2.81
2.51
2.05
3.88
2.14
-------
Table 8.
SYSTEM BASE COSTS FOR CANDIDATE FUELS
(1973 Dollars)a
Resource Base and
Resource Extraction
and Fuel Synthesis
Transmission
and Distribution
Total Cost Total Cost,
Synthetic Fuel
Coal
Gasoline (Primarily)
Gasoline and Distillate Oil
Methanol
SNG°
Oil Shale
-------
in the cost projections for future time frames. However, the cost of
domestic petroleum also will increase for many of the same reasons. The
expected real cost increases for each candidate fuel in each time frame
are detailed in Section 8 (Volume II). Figure 4 illustrates the projected
fuel costs throughout the time frames of this study.
SELECTED FUELS AND STUDY RESULTS
The selected alternative fuels for automotive use according to time
frame are presented in Table 9.
Table 9.
Near Term (1975-85)
Gasoline from oil
shale and water or coal
and water
Distillate (diesel) oils
from oil shale and water
or coal and water
SELECTED ALTERNATIVE FUELS
Mid Term (1985-2000) Far Term (Beyond 2000)
Gasoline from coal and
water or oil shale and
water
Distillate (diesel) oils
from coal and water or
oil shale and water
Methanol from coal
and water
Gasoline from coal and
water or oil shale and
water
Distillate (diesel) oils
from coal and water or
oil shale and water
Nuclear-based hydrogen
(from water)
Methanol from coal
and water
According to a scenario based on Model I energy demand and supply,
the production rates of synthetic fuels for automotive transportation and
the required fuel imports are presented in Table 10. The additional coal-
and nuclear-based energy included in this tab'le is that fuel (converted from
heat at 35% until 2000, at 42% in 2020) that is potentially available according
to Model I energy supply. By 2000, part of the nuclear portion of this could
be hydrogen. Methanol is not included. Because of water limitations in the
Western coal fields, full-scale gasolinje-plus-distillate-oil production and
full-scale methanol production are mutually exclusive. Of course, part-scale
production of both to some coal-industry product mix of gasoline, distillate
oils, and methanol is possible. According to the pattern process studies,
methanol synthesis requires 60% more water than gasoline and distillate
oil synthesis. Therefore, in terms of ultimate industry capacity, methanol
from coal is a less favored fuel. Nuclear plants for producing hydrogen
from water may be sited in areas where water is more abundant and not
a limitation to production rates.
23
-------
-,
s
10.00
9.00
^ 8.00
<£ 7.00
J 6.00
O
° 5.00
ro
& 4.00
3.00
2.00
1.00
HYPOTHETICAL COSTS, NO PRODUCTION PLANTS
PRODUCTION PLANTS COULD BE OPERATING
REFERENCE GASOLINE FROM DOMESTIC CRUDE
2. GASOLINE AND DISTILLATES FROM OIL SHALE
3. GASOLINE AND DISTILLATES FROM COAL
4. SNG FROM COAL
5. METHANOL FROM COAL
6. HYDROGEN FROM NUCLEAR HEAT AND WATER
1973 1975 I960 1985 1990
1995 2000
YEAR
2005 2010 2015 2020
A-I04-I803
Figure 4. CANDIDATE AUTOMOTIVE FUEL COSTS AT SERVICE STATIONS
FOR CURRENT AND FUTURE TIME-FRAMES
(1973 Dollars/Million Btu; Basis: Low Heating Value; 12% DCF Financing)
-------
Table 10. ALTERNATIVE AUTOMOTIVE FUEL SUPPLY
CORRESPONDING TO ENERGY DEMAND AND SUPPLY MODEL I
Conventional
Gasoline and
Diesel Oil*
Year
1975
1980
1985
1990
2000
2020
Potential Additional Required
Oil Shale Coal Coal- and Nuclear- Fuel
Fuelst Fuelst Based Fuels * Imports
-1015 Btu-
9.7
11.2
13.1
12.9
12.7
12. 7
Nil
0.2
0.7
2.0
2.8
2.8
Nil
0. 1
0.4
1.5
4,2
5.3
Nil
Nil
6.5
7.5
10. 1
30. 1
4.9
5.6
(0.9)
(1.4)
0.2
1. 1
Automotive portion (75%) of the transportation supply (55% of the
domestic crude fuel).
Gasoline and distillate hydrocarbons; automotive portion of the
transportation supply.
Hypothetical fuel production, automotive portion, in addition to the
energy industry growth of the scenario based on Model I.
The important conclusions that we have reached on the basis of this
study are as follows:
.It is feasible to produce alternative automotive fuels from domestic
resources within the foreseeable future and in quantities sufficient to
alleviate petroleum imports. The adequate energy resources are
coal, oil shale, and fissionable nuclear fuels. The preferred auto-
motive fuels are gasoline and distillate hydrocarbons, methanol,
and.hydrogen. If it were not for higher Apriority uses, SNG and
SLPG also would be favored fuels for automotive use.
The production of fissionable fuels (uranium and plutonium) from
fertile materials (thorium or depleted uranium) is a practical re-
quirement for nuclear energy to be assured as a major energy supply
beyond 1985. The breeding of U233 or Pu239 has been demonstrated,
and limited production of U233 from Th232 occurs in the newly com-
mercialized high-temperature, gas-cooled reactors. However, a
demonstration of a fast breeder reactor is needed to show commercial
potential for net production of fissionable fuel.
As a potential source of energy in the far-term time frame and beyond
and almost without raw material limits, fusion reactors promise an
eventual solution to the continuing energy crisis. Aside from capital
investment limitations, reactors creating the fusion of deuterium
nuclei and extracting some of the produced energy could be used for
electricity generation, hydrogen production from water, and process-
heat applications. However, demonstration of net energy production
25
-------
from a continuously operating fusion mechanism is not anticipated
in the near future. This required demonstration of concept con-
stitutes a serious technology gap. Therefore, it cannot be considered
as an energy source for automotive fuels before the year 2000.
With present agricultural technology, solar energy is converted to
plant material at an efficiency of about 1% . After conversion to
a chemical fuel, the overall efficiency is about 0.5%. Although
the energy is free, the land area and capital investment are not.
To be practical, solar plantations need higher energy efficiencies
and must not reduce necessary domestic food-crop capabilities.
A nonfossil and nonelectric process for producing a chemical fuel
from a renewable material resource is highly desirable. Such a
process might be coupled to solar energy, nuclear fusion process
heat, or nuclear fission process heat, to provide supplemental
amounts of a chemical fuel such as hydrogen or methanol. Methane
or alcohol from water and a renewable carbon resource (e. g. ,
carbon from vegetation) or an extensive resource (limestone) are
other possibilities.
At present, there is no satisfactory method to tank sufficient hydrogen
on-board a vehicle. Three options have been considered:
a. Liquid hydrogen is bulky, requires vacuum-jacketed tanks,
and suffers from the problems enumerated earlier.
b. Metal hydride storage is too heavy and, in most cases, re-
quires moderate- or high-temperature heat for decomposi-
tion to "generate" the hydrogen. The logistics of hydride
regeneration have not been defined sufficiently, and the most
practical and cost-effective scheme has not been delineated.
A systems study is in order.
c. Hydrogen can be carried by chemical bonding as another
material, preferably as a liquid, such as methanol, formal-
dehyde, acetic acid, methyl formate, or gasoline. These
chemicals can be decomposed (reformed) on-board the ve-
hicle to produce hydrogen. Feasibility studies and experi-
mental programs are in order.
Section 9 (in Volume II) contains a listing of technology and information
gaps related to alternative fuels for automotive use. Included are the aspects
of vehicle efficiency and fuel consumption, emissions and pollutants from
alternative fuels, and engine operating problems. Further, the need for
social and economic impact studies is expressed.
26
------- |