EQrT
Because large quantities of products are expected to enter the market, process developers, regulators. and users are concerned with environmental
Effects of synfuel use Major products of these technologies and their anticipated general uses are indicated in Table 1.
Masood Ghassemi Rajan lyer Robert Scofield TR W Energy Systems Group Redondo Beach, Calif: 90278 Joe McSnrley
U.S.Environmental Protection Agency Research Triangle Park, N.C. 27711
Most synfuel-related environmental assessment studies have focused on technologies for synfuel production and on emissions from production facilities. On the other hand, little attention has been directed toward an examination of environmental concerns associated with the projected widespread utilization of synfuel products. For that reason, EPA sponsored a study to project synfuel production and use during the next 20 years and to rank products from the standpoint of environmental concerns. The objective is to provide input to the EPA efforts of assessing environmental implications of a mature synfuel industry and of large-scale utilization of synfuel products, and planning and prioritizing regulatory and research and development (R&D) programs. The data base used consists of information obtained from major process developers, potential product users, and published literature. Synfuel technologies likely to be used in commercial plants over the next 20 years are oil shale, coal gasification (low-/medium-Btu and substitute natural gas [SNG]), and coal liquefaction (direct and indirect).
’
€ 1
r end-use appllcatl el products
P
Industrial, utllny. and
marine fuel: F(wIurt. arric1c.i in ES&T haw by-liner. repii’(enl rhr ricwr ojrhe ourhors, and art edifed hy rhc Worhingron sra// //you are inrwerrrd it, wnrrihulingan arrkle. ronra~rrhe manoginp Cdil,V
888
Environmental Science a Technology
Buildup scenarios The development of a US. synfuel industry will be influenced by factors such as the availability of capital to finance the huge construction costs and the willingness of process developers, the private investment sector, and government to accept the technological risks involved in the construction of “first-of-a-kind” facilities. Other important considerations will include U S . energy policies and prices of domestic and imported natural gas and oil; the availability of skilled manpower, raw material, and equipment for plant construction and operation; and the timely development of the supporting infrastructure necessary for energy product manufacture, distribution, and use. In addition, environmental regulatory requirements, the time and effort required to acquire technical data to support permit applications and obtain a proval, and the time and effort requi ed to attain full commercial status for technologies/ processes currently under development will have to be taken into account. Based on different assumed levels of impacts exerted by these factors, several scenarios for the synfuel industry’s buildup to the year 2000 were developed and discussed with major synfuel suppliers and users, and industry and government planners. On the basis of these discussions, the scenario illustrated in Figure 1 was selected as the most realistic and was used for environmental analysis. This scenario is consistent with the general consensus among technical experts and potential major suppliers that shale oil is more nearlycost-competitive and closer to commercialization than are high-Btu gasification or coal liquefaction, and that commercial coal-liquefaction fa-
metalluglcaloils:
0013-93SX/81/0915-0888501.25/0 @ 1981 American Chemical Society
cilities will not probably come on-line and to Regions 3, 4, and 5 for direct before the early 1990s. liquefaction products. Synfuel industry buildup and product utilization patterns are ana- Data base lyzed for three time frames: 1980The environmental data currently 1987, 1988-1992, and 1993-2000. available on synfuel products are very Table 2 presents the product-bylimited and pertain mainly to certain product estimates of synfuel utilization primary products (for example, crude in the US. For comparison, the esti- shale oil or coal liquefaction synmates are also expressed as percent- crudes). Very little data are available ages of the total product consumption. on many of the secondary synfuel It should be noted that, even though on products (for example, methanol and a national scale, the projected synfuel gasoline derived from coal) or on utilization would account for small emissions associated with combustion fractions of the total product usage, in of synfuel products. The combustion some regions a very high fraction of tests conducted with certain synfuel currently used products are expected products have been aimed primarily at to be replaced by synfuel products. As evaluating handling and performance noted in Table 3, by the year 2000 it is characteristics. expected that about 36% of all refinery In general, the product/emissions feed and 48% of all middle distillate characterization has been in terms of used in EPA Region 8 would originate gross properties (for example, ultimate analysis, composition by chemical from shale oil. class, and emissions of smoke and Regions of maximum impact particles during combustion), which by Table 4 shows EPA regions in which themselves do not provide an adequate synfuel products would most likely be basis for assessing environmental sigused, as well as projections for the nificance. The current product charproducts’ utilization patterns. As noted acterization data base is a collection of in the table, except for oil shale in the results reported by different investi1988-1992 and 1993-2000 time gators who used samples/batches of frames and for direct coal liquefaction products obtained from pilot plants in the 1993-2000 time period, the operated under varying conditions. Accordingly, significant inconsistransportation, distribution, and use of products are expected to be confined to tencies exist in the reported results. the regions where each synfuel is pro- Environmental analysis is further duced. Consequently, environmental complicated by a lack of data on impacts would also be confined pri- analogous petroleum and natural gas marily to the production regions, ex- products that the synfuel products will cept for those caused by the natural replace and that, because of their transportation of pollutants across large-scale and widespread use, have regional boundaries. The projections generally come to be viewed by the indicate that, up to the year 2000, en- public as environmentally acceptable. vironmental impacts will be largely limited to EPA Regions 5 and 8 for oil Comparison with petroleum Table 5 identifies the differences in shale; to Regions 4, 6 , and 8 for medium-Btu gas; to Regions 3, 4, and 8 chemical, combustion, and health effor indirect coal liquefaction products; fects characteristics of synfuel prod-
ucts and their petroleum analogues, based on the reported characterization data. As noted in the table, for the majority of products for which data are reported, these differences primarily relate to the higher content of aromatics and fuel-bound nitrogen (FBN) and the greater emissions of NO, during combustion. Although no test data for synfuel products are available, high concentration of aromatics in fuels have been shown to enhance production of polynuclear aromatic hydrocarbons (PAHs) during combustion. However, specific substances that make up the aromatic or FBN fractions in various synfuel products (or their petroleum counterparts) are not known. In the case of fuels, high aromaticity has been implicated in an increase in smoke production; nonetheless, the limited combustion data which are currently available do not indicate that all aromatic synfuels have higher smoke levels. High FBN content can raise the level of NO, emissions; the excess NO, emissions of synfuels are believed to be correctable by combustion modifications. The nitrogen content of synfuels (and the high arsenic content of the crude shale oil) can also be lowered to meet appropriate fuel specifications by employing certain refining processes (for instance, hydrotreating to reduce FBN). Another example of controlling undesirable product characteristics through process control, or in-plant treatment, is the elimination of traces of carbon monoxide and nickel carbonyl in SNG by proper operation of the methanator. The data in Table 5 identify crude shale oil and liquefaction fuel oils as more hazardous than their petroleum analogues because of greater muta-
FIGURE 1
Forecast for synfuel Industry buildup
1982
1984
1986
1988
1990
1992
1994
1996
1998
2ooo
Volume 15, Number 8. August 1981 867
genic, tumorigenic, and cytotoxic properties. These properties, which are characteristic of high boiling, tarry coal, and petroleum materials, are caused by the presence of substances or classes of substances such as PAHs, hetero- and carbonyl-polycyclic compounds, aromatic amines, and certain inorganics, such as arsenic in crude shale oil. Environmental concerns relate to occupational exposure, public exposure, and general environmental pollution. The occupational hazards affect workers manufacturing and using the products, as well as personnel involved in facility maintenance and product distribution. Public exposure primarily relates to air pollution resulting from product uses, such as gasoline being burned in automobiles, and hazardous fugitive emissions from ,
,
storage tanks, product transfer points, leaks, and spills. In the general category of environmental pollution, major contributors include accidental spills, sludges from product storage tanks and spill cleanups, and solid, liquid, and gaseous wastes associated with combustion and combustion-related air pollution control.
Priority ranking A system was developed to rank synfuel products from the standpoint of environmental concerns, so that those products and areas requiring more immediate, greater regulatory or R&D attention can be identified. The ranking is based on the data presented previously and is subject to the limitations of the existing data base and to the assumptions used in developing the productions and use scenarios. These
--
.,,,
TABLE 2
Eslimacea quantity of synfuel produc'
C i 4 e shale oil (fuel) Shale 011 refinery feed Shalejet fuel
0.0008
Shale diesel fuel Shale residuals Shale gasoline
0.042
0.07 0.015
0.007 0.13
MediumBtu gas (Coal)
SNG (coal) Gasifier tars. oils
Oaslller phenol F-T LFG F-T mediumBlu gas F-T SNG F-T heavy fuel oil F-1 mine MilM gasollne F-T diesel fuel Fuel mtthanol
SRCll fuel dl
1SRGll LFG
-EDS fuel Oil
WnSpMha EDS Lw
Kcoal fuel011
"
0 Kcoal LFG 0 sOuc.: TRW torecaa in amrwtto EPA.
888 Envlronmntal Science (L Techrmlogy
I
rankings will most likely change as more data become available, especially for those products for which little or no data are currently available. It should also be noted that this specific approach represents only one of many approaches to rank synfuel products on the basis of environmental concerns. Two approaches were originally examined for ranking synfuel products: using the limited product characterization data currently available (Table S), supplemented by engineering judgment where appropriate, and assuming that in the absence of detailed characterization data, and unless the available data indicate otherwise, it would be reasonable to say that a synfuel product would be more hazardous than its petroleum analogue. Under the first approach, chosen to develop product rankings, a synfuel
product would not necessarily be considered more hazardous because of the mere lack of detailed characterization data. Instead, assignment of a more positive ranking is supported by actual data or is based on strong indications of greater potential hazards. Prioritization of regulatory and R&D activities does not have to await collection of additional data, which should proceed concurrently as a separate effort. The second approach operates on the premise that if there is any room
for error, it is more advisable to err on the safe side. This scenario asserts that, in the absence of detailed characterization data and strong evidence to the contrary, synfuel products-new chemicals from a more “exotic” source-should be considered more hazardous. Nearly all synfuel products would be given a positive ranking, thereby reducing a ranking system’s usefulness as a guide in prioritizing regulatory and R&D activities. Acquiring detailed characterization data would be emphasized, while products that are known to present greater environmental concern may not be concentrated on. Attribute rating procedure Table 6 presents the assessment of the environmental concerns for various synfuel products relative to their petroleum analogues on a “barrel-perbarrel” basis. As indicated by the headings in the table, the relative ranking considers potential for exposure, emission, toxic hazard, cost of control, and adequacy of existing regulations. A (+) ranking is assigned to a product if it presents greater concern than the petroleum analogue; a rank-
ing of (0) indicates similar or lower levels of concern. Table 7 presents the results of synfuel products ranking. The products are ranked into three groups: 1, those eliciting the most concern; 2, those indicating modest concern; and 3, those generating a low level of concern at the present time. As noted in the table, from 1980 to 1987, the synfuel products of concern will primarily be shale oil products, medium-Btu gas, and SNG. Shale oil refinery feed will elicit the most regulatory attention; other shale oil products and mediumBtu gas will elicit modest concern; SNG will require a low level of attention. In the 1988-1992 period, when products from the SRC-I1 (solventrefined coal) and Fischer-Tropsch (F-T) processes will also be marketed, the products eliciting the mast concern will be shale oil refinery feed, SRC-I1 fuel oil, and gasifier tars and oils. F-T products and LPG from SRC-I1 are ranked as low-priority products during 1988-1992. During the 1993-2000 time frame, shale oil refinery feed, medium-Btu gas, gasifier tars and oil, and liquefaction fuel oils are given ‘‘I”
Estimated utilization patterns for synfuel products in EPA regions affected ** Th.ham
1980-1987 1988-1992
ROdunHln
8 8(410)
R*Ww
*
Utmr.iwpmdlct.
8
8: Gas (30). tars10118 (0.98-1.9), phenols (0.154.30). naphtha (0.25-0.72)
1993-2000
8 (200)
8 (200)
1993-2000
3 (50)
3 (50)
(15.41, mlddistillate (18.7). residuals (10).
4(100) 5 (200)
4(100) 5 (200)
llate (37.4). naphtha (30.8).residuals (20.0). (61.6). mlMistillate (74.8). residuals (40.0),
.
.
m~*IWlonsmm!ssUetoIlowcnastates:1 = ~.N.H.,M.Mase.,R.I..Cam.;2-NJ.,N.Y..P.R..V.I..:3=D.C..Del..Md..RL.V~.. 4 =Ala.. Fk.. Oa. Ky.,MISS.,N.C.. S.C., Tem.; 5 = UI., W., MW.. Minn., OMa. W r : 0 =Ark.. La.. N.M.. Okia.. Tsx.: 7 =
W.Va
B~Cola..Mont..N.D..S.D..Utah,Wyo.:S=ArB..~wall.Nav.,Cellf.:10-~~.Idaho.Ore..Wash. (YB pmdun qu8ntlIleS h 105 bbilday 0 11 eq”l”alent(l.
s mt aenerats tars, dk and phsno$. 1s antlclpated.
Volume 15, Number 8. August 1981
860
IAMU 3
870
Environmental Science a Technology
rankings. The rankings generally indicate that the greatest level of environmental concern and regulatory requirements are for shale oil refinery feed and coal liquids. These liquids have been demonstrated to be more hazardous than petroleum crude and fuel oils (a major factor in assigning a “I” ranking). This and the fact that shale oil products are expected to be the first synfuels to enter the market on a large scale are the major factors that “flag” nearterm environmental concerns for shale oil products in general, and shale oil fuel and refinery feed in particular.
Data limitations leum products that they will partially As noted previously, there are a or totally replace. The first category of number of major gaps in the existing .data limitations has an impact on the data base that preclude accurate regional environmental implications analysis of the environmental concerns and synfuel production scenarios and associated with future large-scale market analyses that were developed, utilization of synfuel products in the whereas the second category of limiU S . These gaps are: present uncer- tations introduces uncertainties in the tainties regarding the size of the in- estimated characteristics of synfuel dustry, specific synfuel technologies products and the analysis of environthat will be used and product slates mental concerns. Both types of data that will be produced, locations of limitations affect the regional enviproduction facilities and product dis- ronmental implications and the ranktribution systems, and the specific ing of the synfuel products. At present, the first category of data areas of synfuel use; and lack of adequate characterization data on synfuel gaps can only be partially filled, perproducts and on the analogous petro- h m s through engineering and eco-
TABLE 6
-T SNG
Volume 15, Number 8. August 1981
871
nomic analyses to determine optimum product slates. Many of the gaps in the second catecorv. - ~ , . however. ~~. can and should be filled through testing and evaluation of synfuel products obtained from U S . pilot plants and from commercial facilities abroad. A number of chemical and biological/ecological testing programs that are expected to improve substantially the quality of the existing data base on synfuel products are currently under way. These programs are conducted and sponsored largely by DOE and EPA. In addition, a number of product performance testing efforts that may provide excellent opportunities for cost-effective collection of end-use environmental . _.data, are under .way . or . ~~~~~~~
~~~~
~
Reported or estimated envirc.. mentally significant characteristics of synfuel products relative to those of their petroleum analogues, based on exposure potential, combustive and evaporative emissions, toxic hazards, cost of control. and the extent of regulatory protections under key existing environmental legislations. Products for which the environmental risks and control needs are greater, end for which less regulatory protections are anticipated, are given a higher ranking. * The~matedquantayofpcoducts
used, both in absolute terms and as percentages of the total (synfuel and
petroleum) used nationwide (Table 3) and regionally. The geater the amount of the product used and the percentage of usage, the greater the potential for presenting environmental hazards, and hence a higher positive ranking. Considerable scientific and engineering judgment. Because of the lack of a solid data base, heavy reliance was placed on the professional judgment of experts most familiar with the domestic energy supply and demand picture, synfuel production/refining technologies, expected environmental characteristics of synfuel products, applicable controls, and regulatory needs. f
(US.Air Force, Wright-Patterson AFH: U S . Navy). standing diesel engine tests with SRC-II and shale oil diesel fuels DOE Bartlesville Enerev Research Center), testing a spectru; of synfuel gasoline and jet fuels in ground and air transportation vehicles ( U S Department of Transportation), and evaluating the use of synthetic fuels in utility boilers (Electric Power Research Institute). ~~~~~~~~~
~~~
~
Priority ranking of synfuel products from the standpoint of environmental concernsa Rodu*
1980-iS87
1988-1e92
1098-2000
-
-
1
1
“ 1 2
3 I poduct not produced a
072 Environmental Science &Technology
Recommendations Several recommendations grew out of the study: A more systematic approach to product characterization and testing. Much of the currently available synfuel product characterization and testing data are fragmentary and cannot be correlated. The results generally do not cover all parameters of environmental interest; rather, they have been obtained in “isolated” studies which used samples from different batches of products. Better coordination among various ongoing and planned studies (perhaps through establishing a “test tracking” system that would promote exchanges of information developed by various studies) is recommended to avoid duplication of effort and to ensure generation of appropriate environmental data in a most cost-effective manner. Collection of environmental data in conjunction with planned performance testing programs. Several synfuel product performance testing efforts are being planned by various government agencies. It is most appropriate and timely to review these programs and to take full advantage of opportunities for simultaneous collection of environmental data. These data, which can be correlated with product performance, in conjunction with a sys-
tematic product characterization effort, can provide valuable, timely inputs to the evolution of the synfuel industry and would ensure that: environmental considerations are included in the selection of processes, equipment, and product slates for commercial facilities the drafting of specifications for synfuel products. new-source performance standards for synfuel plants, and emissions standards for facilities using synfuel products are based on the best available technical data. Consideration of end-use environmental implications in the selection of the product slates and in the develop ment of the synfuel industry. Some synfuel processes and subsequent refining operations can be altered or added to include products that could be used in end-use applications with potentially fewer and more controllable environmental impacts. Studies should be undertaken to define the engineering and economics of such alterations and additions. In this connection, better coordination and exchange of technical data should be promoted among process developers, regulatory agencies, and potential users and planners to ensure that environmental considerations are incorporated in the development and marketing of synfuel products. Compilation of characterization/ performance data on analogous petroleum products. Very little data are available (or if available, have not been published) on potential pollutants or on toxicological and ecological properties of many of the petroleum products to provide a baseline for assessing the safety of synfuel products. It is recommended that the potential sources of data on petroleum products be contacted in an effort to compile all available data and identify data gaps. It is also recommended that the synfuel product testing and characterization efforts include parallel testing of petroleum-derived analogues. Acknowledgments This feature is excerpted from a report (EPA-600/7-81-025) entitled “Environmental Aspects of Synfuel Utilization,” December 1980, prepared by TRW Environmental Engineering Division for US. EPA Industrial Environmental Research Laboratory, Research Triangle Park, N.C., under Contract No. 68-02-3174. Work Assignment No. 18. Gratitude is expressed to the process developers who provided data for use in synfuel utilization projections and the major potential suppliers and users of synfuel products who expressed their views on synfuel commercialization, product utilization. and related environmental issues. Additional key project staff at TRW included E. Bohn. J. Cotter, J.
Cowles, J. Dadiani, D. Dickehuth. L. Fargo. K. Lewis. R. Maddalone, M. Oyster. W. Parker. and S. Quinlivan. This article was read and commented on before publication by Charles C. Coutant. Oak Ridge National Laboratory: J. K. Ferrell, North Carolina State University of (Raleigh):and Noel D. Uri of the Office Energy Use Analysis, U.S. Department of Energy.
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\la\ood Ghasserni (left) i.s .st,,jiw p r o j ~ t eri,giwer “ I T K W Enuironnrmtal Enyinrrring Dicision and directs major progm,m i n enrironmenral assessment of ,yynfiiel technologies, hazardous waste management, and toxic substances control. He has an undergraduate degree i n ciuil engineering and M.S. and Ph.D. degrees i n entiranmental engineering, a l l from the University of Washington.
Rajan lyer (right) is a managerfor special projects in the Energy Utilization Office ofthe T R W Energy Engineering Division. He holds a Ph.D. i n power engineering from Illinois Institute of Technology and an M.B.A. infinance and operations research from George Washington University.
Robert Scofield (left) ir (imember ojtlre professioiirrl stuff in the Industrial W o r e Manqenienr Section of T R W Emironmental Enginewing Division. He pecializes i n the assessment of health effects of industrial products and wastes. Scofield has a B.S. i n biology and an M.P.H. i n environmental health management from UCLA. He is a candidate for a doctoral degree i n environmental science and engineering at UCLA.
Joe MeSorley (right) is a project officer in the EPA’s Industrial Environmental Research Laboratory, Research Triangle Park, N.C. He is currently responsiblefor coordinating EPA’s synfuel utilization R& D program. This EPA program w i l l determine. through sampling and analysis, physical, chemical, and biological characteristics of emissions. effluents, and waste materials that are generated during transportation, handling, storage, and end uses of the synfuel products and byproducts. McSorley is a research chemist and has been with EPA since 1971.
P O h n 1308 Janesville
M isconsin 53547
A Division 01 Snmm Rc1at.d Matenah, Inc.
CIRCLE 3 ON READER SERVICE CARD
Volume 15. Number 8. August 1981
873
