EPA-460/3-74-009-a
June 1974
FEASIBILITY STUDY
OF ALTERNATIVE FUELS
FOR AUTOMOTIVE
TRANSPORTATION
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
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EPA-460/3-74-009-a
FEASIBILITY STUDY
OF ALTERNATIVE FUELS
FOR AUTOMOTIVE TRANSPORTATION
VOLUME I - EXECUTIVE SUMMARY
Prepared by
F. H. Kant, R. P. Cahn, A. R. Cunningham,
M. H. Farmer, W. Herbst, andE. H. Manny
Exxon Research and Engineering Co .
P.O. Box 45
Linden, New Jersey 07036
Contract No. 68-01-2112
EPA Project Officer:
C. E. Pax
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
June 1974
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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, Environ-
mental Protection Agency, Research Triangle Park, North Carolina 27711; or may be
obtained, for a fee, from the National Technical Information Service, 5285 Port
Royal Road, Springfield, Virginia 22151.
This report was furnished to the U.S. Environmental Protection Agency by Exxon
Research and Engineering Co. in fulfillment of Contract No. 68-01-2112 and has
been reviewed and approved for publication by the Environmental 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 by the reader to assure that it is acceptable for his purpose. Results
and conclusions should be viewed correspondingly. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
Publication No. EPA-460/3--74-009-a
11
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FOREWORD.
For convenience, the material covered in this report is divided
into three volumes. Volume I is an executive summary comprising the re-
port summary, highlights of the various sections and a list of conclusions,
Volume II is the technical section, which is a complete description of the
work carried out under this contract. It includes the sections bound sep-
arately in Volume I. Volume III includes the appendices, which deal with
supplementary material for some of the topics discussed in Volume II.
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TABLE OF CONTENTS
SUMMARY
HIGHLIGHTS
iii
Page
CONCLUSIONS 20
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SUMMARY
This study identifies feasible and practical alternatives to
automotive fuels derived from petroleum for the 1975-2000 time period.
The alternative fuels are liquids derived from domestic coal and oil
shale — specifically, gasolines, distillates, and methanol. While many
uncertainties remain, initial production of the new fuels is likely within
the next five to seven years.
The United States has vast resources of coal and oil shale, suf-
ficient to permit large scale production of synthetic fuels. However,
other factors such as the availability of skilled manpower and water are
expected to constrain the rate at which the resources can be developed.
Complete replacement of petroleum with synthetic fuels is therefore im-
probable until after the turn of the century. Rather, it appears that
the alternative fuels will begin to be used in conjunction with petroleum,
that usage will expand as availability increases, and that the approach to
complete replacement will be evolutionary.
The study shows that there is an excellent chance of developing
alternative automotive fuels, or blending components, that can take ad-
vantage of the existing distribution and marketing system for automotive
fuels. Additionally, the new products may satisfy the fuel requirements
of conventional vehicles as well as the anticipated needs of several types
of automotive power plants now under development. Not surprisingly, fuels
similar to petroleum, derivable from both coal and oil shale, present the
least difficulty and uncertainty.
While differing in estimated cost, the individual fuels examined
in detail may all be producible at a cost level or range projected for petro-
leum fuels. Indeed, the shale fuels may be significantly lower in cost.
Nevertheless, the estimates of cost are sensitive to more than technological
uncertainties. For example, costs are sensitive to assumptions that concern
inherently unpredictable matters such as surface mining legislation, leasing
policy, and required level of investment return.
Early in 1974 consumption of automotive fuel was just over six
million barrels/day (MMB/D) or 12 x 1015 BTU/year, and this may be taken
as a lower bound of future consumption. Upper limits are estimated to be
about 9.5 MMB/D or 19 x 1015 BTU/year in 1985 and 12.5 MMB/D or 25 x lO*5
BTU/year in the year 2000. The total output of synthetic fuels, for all
purposes, including automotive fuels, could reach 25 x 1015 3TU/year by
the year 2000, but will only be about 4 x 1015 BTU/year in 1985, which is
about a third of the minimum projected automotive fuel demand.
Fuels were screened on the basis of economic, technical, and per-
formance criteria, with consideration given to the way in which each new
fuel could be brought into general use. Consideration was also given to
the environmental impact of producing and using the fuels. From a fairly
comprehensive list of initial candidates, feasible and practical alterna-
tive automotive fuels were identified:
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• gasoline-type and distillate-type fuels from
oil shale
• gasoline-type, distillate-type, and methanol
fuels from coal.
Each of these five fuels was then evaluated'in detail.
For the shale-derived fuels, the analysis began with mining,
crushing and retorting of the oil shale. The raw shale oil was upgraded,
and then transported by pipeline to a plant capable of converting the
shale syncrude into automotive fuels. The latter were then fed into a
distribution and marketing system, ending at a fuel pump in a service
station. Investment and operating costs were estimated for the entire
system for three points in time: 1982, 1990 and 2000.
The same procedure was applied to the petroleum-type fuels de-
rivable from coal, except that mining was followed by liquefaction rather
than retorting. Methanol from coal was made by gasification, followed by
methanol synthesis. In this case, the methanol product entered the dis-
tribution and marketing system without additional processing steps other
than keeping the fuel dry throughout the system.
Based on 1973 constant dollars, the costs per million BTU esti-
mated for the five fuels were*: (including a 10% discounted cash flow
return on investment)
1982
Shale:
Coal:
gasoline
distillate
gasoline
distillate
methanol
$/MMBTU
2.65
2.05
3.35
2.75
3.85
C/Gal.
31.5
26.5
39.5
36.5
22.
1990 2000
- $/MMBTU -
2.60
2.00
3.15
2.50
3.40
2.15
1.65
2.65
2.10
2.95
1973 $, ex tax at pump
Because internally consistent assumptions were used, the cost
estimates are more reliable on a relative rather than on an absolute basis.
However, the differential between the gasoline-type and distillate-type
fuels depends on a "prudent" refining scheme in which the ratio of gasoline
It must be stressed that these are 1973 costs. As of May 1974, costs
for capital projects have escalated substantially in excess of general
inflation.
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to distillate is not less than about 2:1. .The shale-derived fuels are
projected to be cheaper than coal-derived fuels over the entire time-
frame of the study. However, the quantitative development of shale oil
will probably be limited environmentally and by other resources, such as
manpower and water, rather than by economics and potential demand.
The ranking of fuels was not changed by consideration of user
economics, i.e., the total cost of vehicle operation as opposed to fuel
cost alone.
Potential product quality problems, related to the aromaticity
of coal-derived fuels on the one hand and the paraffinicity of shale-
derived fuels on the other, can most easily be dealt with by blending
with petroleum fractions, or with each other. Product quality consider-
ations with methanol depend on whether it will be used alone or in gas-
oline blends. In the former case, significant efficiency improvements in
a spark-ignition engine seem possible if the engine is modified. However,
such a modified engine would not be compatible with gasoline fuel.
Methanol appears to be an excellent gas turbine fuel. In partic-
ular, it could find growing application in stationary turbines where bulk
deliveries minimize the relatively high distribution costs of methanol vs.
hydrocarbon fuels. Methanol is also a leading candidate for fuel cells,
used either directly or via reforming to hydrogen.
The use of methanol/gasoline blends in spark-ignition engines
could lead to performance problems due to water sensitivity, vapor lock,
and excessive leaning out of the engine. On the other hand, use of these
blends would result in improved octane quality and could lead to signif-
icant fuel economy savings, in miles/BTU.
The uncertainties about the performance of methanol have to be
resolved before its merits relative to hydrocarbons can be established.
On balance, however, the compatibility of shale and coal hydrocarbons
with petroleum is a key point in favor of these fuels.
There is a critical need for product quality and performance
data on fuels from coal and shale, alone and in blends. This is one of
the research data gaps identified in a separate phase of the study. Other
data or technology gaps include:
New or improved technology for:
• in-situ recovery of shale oil
• hydrogen production for coal liquefaction
• selective removal of S, N, and 0 from coal and shale
• coal gasification plus methanol synthesis
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- Large-scale demonstration of environmentally acceptable disposal
of spent shale and reclamation of surface-mined coal areas.
General studies dealing with:
• alternative automotive fuels in the context of the entire
economy, based on utilizing all-resources including petroleum
• water availability in the Western states
The future availability of capital will have a strong influence
on investment priorities. This is an argument in favor of alternative
fuels, such as shale and coal gasolines and distillates, which are compat-
ible with the existing petroleum-based system. Major investments are be-
ginning to be made in these synthetic fuels. For example, about $450
million was bid on the first four shale tracts recently leased by the
government. Research and development programs on coal liquefaction by
industry and government, including construction of various demonstration
units, will probably total over one billion dollars in the next five years.
Some products of such shale and coal conversion plants will surely find
their way into the automotive fuel market. There is therefore beginning
to be a commercial underpinning of the technological and economic feasibil-
ity conclusions drawn in this study.
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HIGHLIGHTS
The highlights that follow reflect the contractor's judgment of
what are the most important points in each of the detailed sections of the
report.
Objectives (2.1)
Identify feasible and practical automotive fuels that are
producible from non-petroleum sources.
Define the alternative automotive fuels in terms of: when?
how much? at what cost?
Consider safety, toxicity, reliability, compatibility with
different engines, and convenience of use.
Identify R&D and other information gaps.
Approach (2.2)
Select alternative fuels with a reasonable chance of being
feasible and practical within the 1982-2000 time-frame which
is the most important with regard to potentially new fuels.
- Use preliminary screening to permit concentration of effort
on a small number of the most promising fuels to get maximum
information on cost, availability, and performance.
Relationship to Energy Supply/Demand in General (3.2)
- Automotive fuel questions should not be divorced from energy
matters in general.
Detailed analysis of "externalities" is beyond the scope of
the study, but identification and rough quantification of
the most important externalities is possible.
With some modification, the Department of Interior's energy
forecast of December 1972 may be used quantitatively as an
energy context for alternative automotive fuels.
Automotive Fuel Demand (3.3)
The goals of "Project Independence" probably set upper limits
on automotive fuel consumption of about 9.5 MM B/D in 1985 and
12.5 MM B/D in the year 2000. Consumption of just over 6 MM B/D,
early in 1974, may be taken as a lower limit.
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Domestic Resource Base (3.4)
The principal domestic fossil fuel resources are petroleum,
coal and oil shale. Nuclear energy tiiay facilitate the
utilization of these resources.
Other energy resources can lessen the industrial or stationary
demand for the principal fossil fuel resources, thereby in-
creasing their potential availability for automotive purposes.
U.S. Coal Resources (3.4.1)
- The domestic coal resource base is very large and, per se, will
not be the factor that limits the production of synthetic fuels
for several decades.
Western coal resources, recoverable by surface mining, appear
best suited economically to the production of alternative fuels.
The Federal government controls the mineral rights to much of
the Western coal. This important part of the resource base can-
not be utilized until the coal lands are leased.
U.S. Oil Shale Resources (3.4.2)
- The oil shale resource is very large and very important. How-
ever, environmental considerations and other factors such as
water availability are likely to limit the rate at which shale
oil can be produced.
- , Possible production levels during the next several decades are
more important than the ultimate "reserves" of shale oil.
Government leasing policy will be very important since the
government holds the mineral rights to about 80% of the richer
oil shale properties.
U.S. Petroleum Resources (3.4.3)
- Conventional petroleum supplies for the production of motor fuel
are likely to be available from domestic resources beyond the
year 2000.
- Production of domestic petroleum is likely to be higher in the
1980's than it is today. Even so, synthetic fuels from other
domestic resources will be needed.
U.S. Natural Gas Resources (3.4.4)
Production of domestic natural gas is also likely to increase,
thereby freeing liquid fuels, such as distillate, from stationary
uses .
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U.S. Nuclear Resources (3.4.5)
- Nuclear electricity capability is behind schedule, and available
capacity will be fully required for satisfaction of conventional
demands for electricity until about 1985.
- Eventually, nuclear energy may be applied to the production of
synthetic fuels and, possibly, in the long run to the production
of hydrogen fuel.
Capacity Build-Up (3.5)
- The rate at which resources can be brought into production must
be considered as well as the size of the resource base.
- Various constraints on the building of synthetic fuels plants
are expected to limit production in 1985 to products containing
the energy equivalent of about 3.7 x 1015 BTU/yr. This estimate
is for the total of all types of synthetic fuels including what
may be used as automotive fuels. By the year 2000, total output
could reach 25 x 10^5 BTU/yr. These estimates of synthetic fuel
supplied are equivalent to 4.2% and 18% respectively of the total
U.S. energy demand by final consuming sectors as forecast by the
Department of the Interior in 1972.
Criteria for Fuel Selection (3.6)
- Economic criteria include the ex. tax cost of fuel at the pump,
the operating cost of the vehicle that would use a particular
fuel, and the implied capital requirements of given fuel/vehicle
systems.
- Technical criteria include fuel availability, prudence in re-
source utilization and associated environmental impacts.
- Performance criteria include compatibility (i.e., the suitability
of a given fuel for use in a given vehicle), toxicity and safety,
efficiency of fuel use, environmental impact in use, and the con-
venience and acceptability of a given system as perceived by the
user (driver).
- Consideration must also be given to the way in which a new fuel
could be brought into general use, to interactions with the exist-
ing vehicle population and fuel delivery system, and the impact
on availability of resources.
Initial List of Fuels (4.1)
A list of fuels was prepared containing all candidates which
could conceivably become viable automotive fuels by 2000.
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- The list included (1) coal-derived fuels: gasoline, middle
distillate, methanol, higher oxygenated compounds, and hydrogen;
(2) shale-derived fuels: gasoline and middle distillate; (3)
ethanol by fermentation; (4) hydrogen from water; (5) ammonia
from coal or water-based hydrogen, and (6) hydrazine.
Physical and Chemical Properties (4.2)
- A detailed literature search yielded information on the proper-
ties of the above fuel candidates, but indicated that many data
gaps exist. These gaps reflect the fact that the fuels either
have not been available (coal and shale derived hydrocarbons)
or have not been completely evaluated in internal combustion
engines (methanol, hydrogen, ammonia).
The physical property data were analyzed in terms of their rela-
tion to combustion, storage and handling, automotive maintenance,
and "driveability".
Cost of Manufacture and Distribution (4.3)
The technology for fuel manufacture was reviewed in order to
choose a basis for estimating manufacturing economics.
Published information allowed such estimates to be made. Dis-
tribution costs were based on analyzing similarities to, and
differences from, the system presently used for petroleum prod-
ucts .
The following first generation costs (ex. tax, at the pump) were
estimated in terms of 1973 $/MMBTU (including a 10% DCF return):
Fuel Cost
Gasoline from Shale 2.65
Middle Distillate from Shale 2.05
Gasoline from Coal 3.35
Middle Distillate from Coal 2.75
Methanol from Coal 3.85
Methane from Coal 5.65
Oxygenated Compounds from Coal 4.60
Ethanol by Fermentation 7.10
Hydrogen from Coal 9.90
Hydrogen from Water 10.20
Ammonia 7.65
Hydrazine 20+
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Fuel-Vehicle Compatibility (4.4)
- A brief assessment was made of the compatibility of the above
fuels with various engine types including the conventional Otto
cycle, stratified charge, diesel, gas turbine, Stirling, Rankine,
and fuel cell.
- The compatibilities range from high (e.g., for coal and shale
hydrocarbons in all of the engines) to moderate (e.g., alcohols
and methane in Otto cycle engines) to low (e.g., hydrogen in all
engines or ammonia in Otto cycle engines).
Environmental Impact (4.5)
Coal and shale mining will have substantial environmental im-
pacts. In order to keep these to a manageable level, it will
be necessary to (1) permanently revegetate spent shale dispersal
areas with a minimum amount of water, (2) reclaim surface-mined
Western coal lands, (3) plan effectively for the influx of a
large number of people into sparsely populated areas.
- Information is very limited on exhaust emissions for the alter-
nate fuels. Coal and shale-derived hydrocarbons are expected
to result in emissions similar to petroleum fuels.
Toxicity and Safety (4.6)
- Hydrazine and ammonia are the most toxic of the fuels examined,
considering skin penetration, inhalation, and ingestion. Methane
and hydrogen are the least toxic. Shale and coal hydrocarbons
and alcohols are intermediate.
Consideration of safety in manufacture, handling, and use indi-
cate that hydrogen, methane, ammonia, and hydrazine present the
most serious problems. Shale and coal gasolines, as well as
methanol, are safer to handle. Shale and coal distillates and
ethanol are the safest of the fuels considered.
Ranking of Fuels (4.7)
- The fuels were ranked using the criteria described in Section 3.5.
- The following five fuels were judged most promising and were ex-
amined in detail:
(1) gasoline from shale
(2) distillate from shale (as coproduct with gasoline)
(3) gasoline from coal
(4) distillate from coal (as coproduct with gasoline)
(5) methanol from coal
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Cost of Automotive Fuels From Shale Oil (5.1)
- Economic estimates were prepared for manufacturing gasoline and
distillates from shale using the following sequence:
(1) mining and crushing.
(2) retorting, using the TOSCO design based on recycled
hot solids.
(3) upgrading of raw shale oil to high quality syncrude
by hydrogenation and coking at the mining site.
(4) pipelining of syncrude to a refinery.
(5) refining of syncrude to gasoline and distillates by
conventional processes, such as catalytic cracking
and reforming.
(6) distribution of products the same as for petroleum.
- The economics for steps (1), (2), and (3) were adapted from
those prepared by the National Petroleum Council (NPC) , adjusted
to the bases used in this study.
- The following costs in 1973 $, were estimated for the period
1982/1985 (including a 10% DCF return):
Shale Syncrude: ca. $5.50/Bbl (includes value of lease
bonus payment). The sensitivity of syncrude cost to in-
vestment level, rate of return, and oil content of shale
was calculated, e.g., with a 15% DCF return the syncrude
would cost $7.05/Bbl and would result in proportionate
increases in gasoline and distillate costs.
Shale Gasoline: $2.70/MMBTU ex. tax at pump.
Shale Distillate: $2.10/MMBTU ex. tax at pump.
- The distillate cost is applicable only to a case where distillate
and gasoline are co-products in the ratio of ca. 1:2.
- Cost projections were made for the 1982-2000 period allowing for
effects of new technology (see Section 5.4).
Cost of Hydrocarbon Fuels From Coal (5.2)
- The cost of gasoline and distillate from coal was based on the
following sequence:
(1) Surface-mining of Western coal.
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(2) Hydrogenation at the mine to syncrude using the HRI
"H-Coal" process; other processes were considered but
were rejected on the basis of insufficient available
information; hydrogen was supplied via gasification
(Lurgi process).
(3) Pipelining of syncrude to a refinery.
(4) Refining of syncrude to gasoline and distillate by
conventional processes, such as hydrocracking and
catalytic reforming.
(5) Distribution of products same as for petroleum.
- The following costs were estimated for the period 1982/1985 (1973 $)
Coal Syncrude: ca. $8.00/Bbl, based on $3/ton coal. The
sensitivity of this cost to changes in coal price, invest-
ment, and return level was calculated, e.g., with a 15% DCF
return and $5/ton coal the syncrude would cost $11.40/Bbl.
Coal Gasoline: $3.35/MMBTU ex. tax at pump.
Coal Distillate: $2.75/MMBTU ex. tax at pump.
- As with the shale fuel economics, the distillate/gasoline ratio
was ca. 1:2.
Cost projections for the 1982-2000 period reflected changes in
coal price as well as new technology (see Section 5.4).
Cost of Methanol From Coal (5.3)
The cost of methanol from coal was based on coal gasification
with the Lurgi process followed by methanol-synthesis from CO +
H£• This scheme produces methanol and methane (SNG) as co-
products. Other gasification processes seem to be less effi-
cient for this application, but information on these alternates
was very limited.
- Methanol distribution is significantly different from distrib-
uting petroleum products for two reasons:
(1) if used in a 10-15% gasoline blend, blended at the
pump, methanol must be distributed dry to avoid phase
instability.
(2) methanol has about 50% of the energy content of hydro-
carbon fuels, which results in higher distribution costs,
on a BTU basis.
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- The methanol cost at the pump, for the 1982-1985 period, was
estimated at $3.85/MMBTU.
- As with the other fuels, cost projections were made for the
1982-2000 period.
Comparison of Costs (5.4)
From the cost information developed in Sections 5.1-5.3, the
following projections were made:
1982
1990 2000
$/MMBTU c/Gal. - $/MMBTU -
Shale: gasoline
distillate
Coal:
gasoline
distillate
methanol
2.65
2.05
3.35
2.75
3.85
31.5
26.5
39.5
36.5
22.0
2.60
2;00
3.15
2.50
3.40
2.15
1.65
2.65
2.10
2.95
1973 $, ex tax at pump
Due to the many uncertainties in these estimates, +10% limits
on the costs seem reasonable. Nevertheless, relative costs
are felt to be fairly reliable.
Shale-derived fuels are projected to be cheaper than coal-
derived fuels over the entire time-frame of the study. The
development of shale fuels, however, will not be governed
solely by these economics. It will probably be controlled by
environmental, manpower, and resource limitations.
Methanol is slightly more expensive than coal liquids, reflect-
ing the greater contribution of distribution costs for methanol.
Methanol would therefore be more attractive in applications such
as transportation fleet accounts, or, more generally, in fuel
uses other than transportation.
Distillates are cheaper than gasolines, as long as a prudent
refining scheme is used, in which the two are co-products with
roughly 30-40% distillate.
A comparison among these fuels on the basis of capital intensity
gives the following:
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$/Barrel/Day
Production
of Syncrude Refining Total
Shale
Gasoline 6,700 • 2,000 8,700
Distillate** 6,500 400 6,900
Coal
Gasoline 11,600 2,600 14,200
Distillate** 12,200 1,300 12,500
Methanol 5,900 (11,800)* 5,900 (11,800)*
* On equivalent BTU basis.
** As co-product with gasoline.
The relative capital intensities parallel the relative costs at
the plant gate.
Another comparison was made of the relative efficiencies of
manufacturing these fuels:
Energy in Total Product/Total Input Energy
Auto. Fuel Product:
Shale
Coal Hydrocarbons
Methanol
* If Lurgi process by-products cannot be used as process fuel.
- Efficiencies for producing shale fuels are a little lower than
for coal fuels, reflecting losses in shale retorting. Methanol
production is less efficient than coal liquefaction unless the
gasification by-products can be used as a source of process
heat.
User Economics (5.5)
Gasoline
0.55
0.65
(0
Gasoline + Distillate
0.65
0.70
.55)*
An attempt was made to compare the cost of owning and operating
a vehicle over its life as a function of fuel type. This was
done by estimating the effect on vehicle weight and cost due to
fuel-connected factors related to compatibility, environmental
effects, toxLcity and safety.
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- Based on reference data for cost and weight of a 1973 model,
3500 Ib. vehicle, the following comparison was made for the
relative cost of fuel vs. other operating and fixed costs:
10 Year Life, 100,000 Miles
Relative Cost*
Engine
Otto Cycle
Diesel
Gas Turbine
Fuel
Shale Gasoline
Coal Gasoline
Methanol
Shale Distillate
Coal Distillate
Shale Distillate
Coal Distillate
Methanol
'uel
i.o|
1.3
1.5
1.3
iTo]
1.3
2.0
0,M,R,Tt
1.2
1.2
1.2
2.6
2.7
1.7
1.7
1.7
Fixed**
2.9
2.9
2.9
6.5
6.7
4.1
4.2
4.2
Total
5.1
5.4
5.6
10.0
10.7
6.8
7.2
7.9
* Reference point for each engine designated by |l.0|
engines not valid.
t Oil, mainenance, repairs, tires.
** Depreciation, insurance, license, and registration.
comparison among
- The data indicate that, for a given engine type, changes in
relative fuel cost are dampened by other costs unrelated to
fuel, so that total vehicle operating cost is not changed much.
- Another comparison of relative fuel cost per mile for the three
time periods and engine types indicates that these costs parallel
the relative ex. tax pump costs. This reflects the assumption
that, for the fuels examined, engine efficiency is not a signif-
icant function of fuel.
Performance of Gasolines and Distillates From Shale and Coal (6.1)
- High Research octane gasoline fractions based on catalytically
reformed coal and shale syncrude fractions will be quite aro-
matic but no more so than petroleum fractions reformed to the
same Research octane level. Comparable data on Motor octanes
are generally not available for these synthetic fuels.
- Due to the aromatic nature of coal vs. shale syncrude, naphtha
Ounreformed) and distillates based mainly on coal will have a
higher aromatics content. If, however, the coal-derived fuels
are blended either with shale or petroleum fractions, as is
likely to be the case, the aromaticities of the blends will be
similar to those in current use.
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- If gasolines rich in coal-based fractions are used, consideration
must be given to factors such as:'
(1) front-end volatility adjustment.
(2) maximum safe benzene concentration.
J
(3) materials of construction of the fuel system.
- It should be possible to make a good quality diesel fuel from
shale syncrude. However, more information is needed on cloud
point to determine if it should be reduced — e.g., by the use
of additives.
- There are almost no product quality data on distillates from
coal. Based on their composition, however, it is likely that
such fractions will be deficient in cetane number. If this is
confirmed, the options available for correcting the deficiency
are: (1) blending with shale or petroleum fractions (the best
alternative), (2) use of cetane improvers, or (3) more severe
hydrogenation.
- The suitability of coal distillates as a gas turbine fuel has
to be determined. High aromaticity could lead to excessive
flame luminosity and smoking.
Performance of Methanol and Methanol/Gasoline Blends (6.2)
- Pure methanol could be an attractive motor fuel for an Otto
cycle engine, based on its high octane number (106 Research and
92 Motor unleaded). It should be possible to operate at in-
creased compression ratio, leading to improvements in thermal
efficiency. However, the vehicle and engine have to be modified
to take account of the low volatility, high heat of vaporization,
and low heat of combustion of methanol. Methanol should be a
very good fuel for continuous combustion engines.
- The use of methanol/gasoline blends brings up a number of po-
tential problem areas :
(1) Water sensitivity: Methanol/gasoline blends are sus-
ceptible to phase separation in the presence of small
amounts of water. Unless a cost-effective solution is
demonstrated for this problem, it will be necessary to
insure that the customer receives a dry blend. The only
realistic chance for doing this depends on distributing
dry methanol and gasoline separately, and blending at
the pump.
(2) The non-ideality of methanol/hydrocarbon systems results
in excessive gasoline vapor pressure in the presence of
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5-10% methanol. Unless the automotive fuel system is
modified to handle a more volatile blend, methanol ad-
dition requires displacing butanes from gasoline, which
is economically undesirable.
(3) The use of methanol/gasoline blends results in operation
at a higher air equivalence ratio. It is important to
determine if such a change causes any driveability prob-
lems .
- The use of methanol/gasoline blends could also lead to some
practical benefits:
(1) Very limited data suggest some improvement in fuel econ-
omy, measured in miles/BTU, by blending 15% methanol into
gasoline. More information is required to define fully
the extent of such improvements.
(2) Exhaust emissions can be reduced. The emissions data
can be rationalized by considering changes in air/fuel
ratio. Whether CO, hydrocarbons, or NOX in the exhaust
increase or decrease depends on whether the initial
operation is leaner or richer than stoichiometric.
(3) Methanol is expected to have good octane blending char-
acteristics, but more data are needed on blending octanes
as a function of gasoline pool octane level.
Evolutionary Considerations (7)
- It is necessary to see an approach path from the present to a
new condition in the future.
- Although a given path may be technically possible, it is not
likely to be followed if easier or better paths are available.
New Engine/New Fuel Dilemma (7.1)
- Highway vehicles must be able to obtain suitable fuel wherever
they are driven. The general public will not purchase a vehicle
for which fuel is not readily available. This poses a special
: problem in the hypothetical case of introduction of new engine
and fuel products that are not compatible with existing engines
and fuels.
The Compatibility Scenario (7.2)
- Full compatibility of new fuels with existing fuels and engines
has numerous advantages. Nationwide distribution of new fuels
can evolve as availability increases, and the transition from
100% petroleum to 100% alternative fuels can be accomplished
without any discontinuity.
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Automotive Fuel Blends (7.3)
- The most likely way that automotive fuels from coal and oil
shale will be marketed will be as blends with petroleum fuels
and, perhaps, with each other, until the early part of the 21st
century.
Automotive Distillate Fuels (7.4)
- There may be both physical limitations and economic penalties
associated with increasing the ratio of distillate-type to
gasoline-type automotive fuels. This will be examined in an
amendment to the contract, and will be covered in a separate
report.
- There will be some difficulty in introducing automotive distil-
late fuels other than automotive diesel. Although an introduc-
tory strategy is available, the incentive for using it will
depend on the capacity of the new fuels to improve upon the
cost and performance of diesel fuel.
Fleet Account Stratagem (7.5)
- New fuels may be introduced to operators of fleets of commercial
vehicles. This builds operating experience and defers the prob-
lem of how to introduce a new fuel to the general public. The
maximum potential of the fleet market is about 5% of total auto-
motive fuel demand.
Automotive Hydrogen (7.6)
- It is very unlikely that the automotive transportation system
will evolve of its own accord in the direction of using hydrogen
as a fuel for private vehicles before the year 2000.
Labor Force Requirements and Implications (7.7)
- Through 1985, it seems likely that the manpower needed to design
and construct synthetic fuel plants will be a limiting factor.
- Longer range, beyond 1990, the balance of natural resources in
the Mountain states may be the limitation. Richness in mineral
resources may not be adequately matched by water availability
for all of the demands, direct and indirect, of a rapidly growing
synthetic fuels industry.
Capital Availability and Investment Implications (7.8)
Capital availability will set investment priorities; unnecessary
investments will be avoided. One implication is that the exist-
ing distribution and marketing system will not be duplicated to
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permit the introduction of fuels not compatible with the exist-
ing system — since new compatible, fuels can accomplish the
same objective at lower cost.
Research Data Gaps (8.1)
- Research data gaps were classified according to fuel type.
Fuels From Shale Oil (8.1.1)
- The disposal of spent shale in an environmentally acceptable way
has to be demonstrated for a commercial-scale operation.
- In situ retorting of shale is very important to large scale
growth of shale oil production beyond the 1985-1990 period. An
efficient, environmentally acceptable process has to be developed.
- Alternatives should be developed to severe mine-mouth upgrading
of raw shale oil to syncrude. One possibility involves mild
treatment with heat and/or hydrogen to make it pumpable to a
remote refining site.
- A complete spectrum of product quality and engine/vehicle per-
formance data is required, for shale oil gasoline and distillate
fractions alone and in blends with petroleum or coal-derived
materials.
Hydrocarbon Fuels From Coal (8.1.2)
- The permanent reclamation of surface-mined land has to be demon-
strated on a large scale.
- Long range, there is a need for an underground coal liquefaction
process, as an alternate to underground mining.
- More efficient methods are needed to generate hydrogen from coal
for use in hydrogenation processes.
- Liquefaccion processes must be improved to give more selective
molecular weight reduction with the minimum hydrogen consumption
— e.g., by developing better catalysts.
Coal syncrude refining has to be demonstrated with feedstocks
from a variety of different coals to give fuel products with
acceptable sulfur, nitrogen, and oxygen content.
- The Fischer/Tropsch process could be an interesting candidate
for coal liquids if the selectivity and thermal efficiency of
the process were substantially improved.
- Complete product quality and performance data are required for
coal gasoline and distillate fractions alone or in blends with
petroleum or shale-derived materials.
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Methanol From Coal (8.1.3)
Improved coal gasification technology is needed to produce the
CO + H2 for methanol synthesis.
The methanol synthesis reaction could be improved by a more
active catalyst (lower temperature and/or pressure) and by the
development of selective techniques for separating methanol
from unreacted CO 4- H2.
With regard to methanol/gasoline blends, complete information
is needed on water sensitivity, volatility, corrosion, exhaust
emissions, fuel economy and driveability.
With pure methanol fuel, data are needed on the maximum effi-
ciency improvement possible with various engines, making use
of the desirable combustion properties of methanol.
Methanol is potentially an important fuel cell fuel. Impurity
effects have to be defined both for direct fuel cell use and
as a feedstock to a reformer for fuel cell hydrogen.
Other Information Gaps (8.2)
Automotive fuel alternatives must be considered in the context
of the economy as a whole.
The future availability of water in the coal and shale regions
of the West requires a careful study. This study should be
part of a broader assessment of the the impact of coal and shale
mining and conversion industries in sparsely populated areas.
On-going studies should address the proper utilization of all
domestic resources including petroleum.
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9. CONCLUSIONS
The conclusions of this study can be classified into four
types:
(a) Virtual certainty; Where the evidence and logic are so persuasive
that it may be concluded that something will happen.
(b) Dependent on assumptions used; The conclusion is valid only if the
assumptions are valid, e.g., that surface mining will be permitted
or that the cost of automotive fuels may be adequately compared on
an ex-tax basis.
(c) Dependent on contractor's Judgment; Many factors affecting long
range projections are not forecastable in a rigorous way and must
be dealt with by judgment.
(d) information gaps; One objective of the study is to identify un-
certainties that can be resolved by additional work. In effect,
such conclusions are recommendations that the necessary work be
done.
The conclusions that follow are identified by (a), (b), (c),
or (d) to indicate the type of uncertainty associated with it. Unless
otherwise noted, the conclusions apply to the 1982-2000 time-frame.
(1) It is feasible and practical to make petroleum-type fuels from coal
and oil shale. They are the most attractive alternates to
petroleum over the time frame of the study. (a),(c)
(2) Initial production of these petroleum-type fuels is likely within
the next 5-7 years. (a)
(3) Automotive fuel components from coal and oil-shale will be blended
with petroleum fractions. (c)
(4) For practical purposes, if petroleum-type products from coal and
oil shale are blended with petroleum, no product quality problems
will be experienced by customers. However, at present, there are
many data gaps which will have to be filled. (c),(d)
(5) The potential for product quality problems is greater if unblended
coal or shale gasoline distillate is marketed: (c)
- early determination of product quality and other performance data
would be essential, but - (d)
- the scenario of unblended fuels is unrealistic (c)
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(6) Methanol from coal:
- is a feasible automotive fuel for spark-ignition engines, gas
turbines, and fuel cells. (a)
- in spark-ignition engines will require engine and vehicle modifi-
cation for optimum performance. (a)
- is an excellent gas turbine fuel, particularly suited for
stationary turbine applications. (c)
- if used widely as an automotive fuel, in the near and mid-term
future, would have to enter the market as a blend with gasoline
but, eventually, would be used unblended. (c)
- if used in a modified spark-ignition engine could lead to im-
proved efficiency relative to hydrocarbon fuels. (c)
- used in blends with gasoline could lead to driveability problems
unless the system is kept dry, the gasoline is debutanized and
the fuel system is modified. (c)
- is a sufficiently probable product that vehicle performance data
should be obtained using both methanoI/gasoline blends and neat
methanols. (d)
(7) Synthetic fuel production from coal and oil shale:
- will not be limited by the size of domestic coal and oil shale
resources. (a)
- will be limited initially by the availability of skilled man-
power and eventually by water availability and environmental/
ecological considerations. (c)
- will make only a minor contribution to automotive fuel supplies
in 1985, but has the potenti-al for becoming a major factor by
the year 2000. Realization of this potential is critically
dependent on a satisfactory resolution of the previous item, (c)
(8) Estimates of fuel costs;
- In the 1982/85 time-frame the cost of shale and coal syncrudes,
including a 10% DCF return, will be about $5.50/bbl and $8.00/
bbl respectively in 1973 constant dollars. (b)
- At the pump, on an ex-tax basis, the potential alternative auto-
motive fuels are estimated to cost:
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1982 1990 ' 2000
$MMBTU c/gal $MMBTU
Shale - gasoline 2.65 31.5 2.60 2.15
- distillate 2.05 26.5 2.00 1.65
Coal - gasoline 3.35 39.5 3.15 2.65
- distillate 2.75 36.5 2.50 2.10
- methanol 3.85 22.0 3.40 2.95
1973 $, ex tax at pump
- The absolute values projected are sensitive to the underlying
assumptions. (b)
- The lower cost projected for distillate than for gasoline depends
on a gasoline/distillate ratio of about 2:1. (c)
- The present average level of Federal plus state gasoline taxes
(about $0.90 per MM BTU) is comparable to the cost differences
projected above. Therefore, future taxation of automotive fuels,
particularly if different fuels are taxed differently, could have
a major impact on what the customer decides to purchase. (b),(c)
(9) The total cost of operating a vehicle of a given size and type
throughout its useful life depends on fuel cost. However, dif-
ferential taxation of vehicles and fuels could result in a dif-
ferent ranking than that obtained from cost calculations that
exclude this factor. (b),(c)
(10) Trends in fuel costs:
- after an initial period of high cost, synthetic fuels from coal
and shale are expected to decline in cost on a constant dollar
basis, reflecting new and improved technology. (c)
- eventually, the more economic synthetic fuel resources will be
depleted and costs will rise again. (c)
- the long-term trend in the cost of domestic petroleum is upward.
(c)
(11) Petroleum from domestic resources will be available at least
through the year 2000 and probably, although to a declining extent,
through the year 2025. (c)
(12) Other supplies and forms of energy, such as nuclear power, have the
potential for displacing liquid fuels from non-transportation
uses. (a)
(13) When such displacement occurs, particularly after 1985, liquid
fuels will be released for transportation use. (c)
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(14) Automotive fuel questions should not be divorced from energy
supply/demand in general, the future"demand for aviation fuels is
particularly pertinent. (c),(d)
(15) On-going studies should address the optimum utilization of all
domestic resources, including petroleum. It is impossible to
properly evaluate the impact of alternative fuels without con-
sidering petroleum as an integral part of domestic energy
supplies. (a)
(16) Many research data gaps were identified. The most important of
these point up the need for: (d)
- product quality and performance data on shale and coal-derived
fuels, alone or in blends with petroleum, in various types of
engines and vehicles.
- an improved process for producing hydrogen from coal.
- a more selective coal hydrogenation process.
- an improved coal gasification process, operating at elevated
pressure, which maximizes CO-HU.
- commercial demonstration of spent shale disposal.
- longer-range, an underground shale retorting process, which
minimizes environmental problems.
(17) The relative overall attractiveness of coal and shale-derived fuels
requires more than the technical feasibility analysis presented in
this study. However, this issue will be addressed in an EPA
sponsored alternate fuels impact study. , <.
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TECHNICAL REPORT DATA
(Please read Instructions on 'the reverse before completing) .
1.
4.
7.
9.
REPORT NO. 2. 3. RECIP
EPA-460/3-74-009-a
TITLE AND SUBTITLE 5. REPO
Feasibility Study of Alternative Fuels for Automotive June
Transportation - Volume I, Executive Summary 6. PERF<
AUTHOR(S) 8. PERF
F. H. Kant, R. P. Cahn, A. R. Cunningham, M. H. Farmer,
W. Herbst, E. H. Manny
PERFORMING ORG '\NIZATION NAME AND ADDRESS • 10. PRO
Exxon Research and Engineering Co. i^j
P.O. Box 45 11. CON
Linden, New Jersey 07036
68-
12. SPONSORING AGENCY NAME AND ADDRESS 13. TYP
Environmental Protection Agency FinaJ
Office of Mobile Source Air Pollution Control i4.spor
Alternative Automotive Power Systems Division
2929 Plymouth Road, Ann Arbor, Michigan 48105
lENT'S ACCESSION-NO.
RT DATE
i 1974
DRMING ORGANIZATION CODE
3RMING ORGANIZATION REPORT NO.
GRAM ELEMENT NO.
!017
TRACT/GRANT NO.
-01-2112
E OF REPORT AND PERIOD COVERED
June 1973- June 1974
MSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This study identifies feasible and practical alternatives to
automotive fuels derived from petroleum for the 1975-2000 time period. The
alternative fuels are liquids derived from domestic coal and oil shale —
specifically, gasolines, distillates, and methanol. While many uncertainties
remain, initial production of the new fuels is likely within the next five
to seven years.
17
a.
18
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS b. IDENTIFIERS/OPEN ENDE
Automotive fuels Automotive fuels
Substitutes Non-petroleum fue
Feasibility Synthetic gasolir
Forecasting Coal liquids
Oil-shale
Methyl alcohol
Gasoline
. DISTRIBUTION STATEMENT 19. SECURITY CLASS (This 1
Unclassified
Release unlimited 20. SECURITY CLASS ^«,
Unclassified
D TERMS c. COSATI Field/Group
13 B
.Is
les
leportf 21. NO. OF PAGES
30
lage) 22. PRICE
EPA Form 2220-1 (9-73)
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