Functional Area Problems. Opportunities, and Constraints 55 



market incentives, could lead to commercially viable 

 processes toward the end of the decade. Production of 

 usable fuels through coal liquefaction involves combining 

 dissolved coal with hydrogen to yield a crude liquid, then 

 refining the crude liquid to remove unwanted compounds 

 (such as those containing nitrogen and sulfur) and to 

 produce usable fuels. These fuels can include methane, 

 light hydrocarbons, gasoline, jet fuel, diesel fuel, and fuel 

 oils. Commercial feasibility depends in large measure on 

 producing a crude liquid with a high concentration of 

 usable components. In several processes this depends in 

 turn on using catalysts to induce a high rate of selectivity 

 among the chemical reaction processes (NRC-15; 

 ENERGY). 



A good deal of scientific research will be needed to 

 improve the efficiency and reliability of future commer- 

 cial synthetic fuel production and to minimize associated 

 environmental problems. Priority research areas include 

 those focused on mechanical and elastic properties of 

 various coals, and on their chemical structures and com- 

 positions; on the ways in which noncarbon components of 

 coal affect catalytic conversion processes; and on cataly- 

 sis itself (NRC-14; ENERGY). First-generation commer- 

 cial synthetic fuel products will probably mirror closely 

 the natural gas and petroleum-derivative products that 

 they will replace. However, particularly in the case of 

 liquids, these products are not the most efficient ones to 

 produce from coal. Methanol produced from synthesis 

 gas (a mixture of carbon monoxide and hydrogen) is. for 

 example, potentially a very good fuel. Likewise, hydro- 

 carbon fuels with lower hydrogen-to-carbon ratios could 

 be less expensive than presently used liquid fuels. In the 

 future, as synthetic fuels from coal become more impor- 

 tant, there will be increasing incentives to adapt engines 

 and other combustion equipment to bum these alternative 

 fuels (NRC-15). 



LIMITATIONS ON THE USE OF COAL 



Available domestic coal reserves could satisfy all U.S. 

 energy needs and the needs of much of the industrial world 

 for several decades into the next century. But there are 

 limitations on its use. Water is needed in all coal mining 

 processes both to repair environmental damage in strip 

 mining and for producing synthetic fuels from coal. A 

 good deal of the U.S. coal reserves are located in the semi- 

 arid West, where water-intensive agriculture is already 

 limited by available water supplies. Mining and produc- 

 Uon processes that reduce water consumption, make use 

 of available brackish water, and keep the discharge of 

 pollutants into surface streams and rivers below accept- 

 able limits will clearly be needed if the Nation is to 

 substantially increase its use of coal (NRC-15). More 

 efficient use of water for agriculture could also be an 

 alternative, cost-effective option. 



The production of carbon dioxide will very likely set 

 the ultimate limit on burning all fossil fuels. Coal is, 

 however, of special concern, since its low hydrogen-to- 

 carbon ratio leads to the release of larger amounts of 

 carbon dioxide for given amount of heat than most other 

 hydrocarbon fuels. By the same token, the higher the ratio 

 of carbon to hydrogen in a given fuel, the greater the 

 amount of carbon dioxide that will be produced for a given 

 amount of energy output. This circumstance argues in 

 favor of using synthetic fuels with low carbon-to-hydro- 

 gen ratios. There is a great deal of uncertainty about how 

 rates of increase in the atmospheric concentrations of 

 carbon dioxide are related to rates of fossil fuel combus- 

 tion, and also about the rates at which carbon dioxide can 

 be reabsorbed by vegetation and the oceans. However, 

 climatic effects might be measurable as early as the first 

 decade of the 2 1st century, and few analysts are prepared 

 to dispute the argument that if fossil fuels — primarily 

 coal — were to remain as the principal source of energy in 

 the industrial countries, serious problems would ensue by 

 the middle of the century (NRC-15; ENERGY; NR). 

 Thus, while coal, and fuels made from coal and shale, 

 will be an essential component of the energy source mix 

 that this country will rely upon until well into the next 

 century, and while synthetic fuels may well be used indefi- 

 nitely for some limited purposes, coal cannot provide the 

 sole basis for future U.S. — or world — energy needs. 



NUCLEAR FISSION 



Most analysts agree that nuclear power will have to 

 provide some fraction of U.S. energy needs for the re- 

 mainder of the century, though the pace and direction of 

 the development of nuclear energy remains highly uncer- 

 tain. At present, a total of 72 nuclear power plants, all of 

 which are based on light water fission reactors, provide 

 about 13 percent of the Nation's electricity. By 1995 there 

 could be as many as 190 light water reactor plants in 

 operation supplying approximately 30 percent of the elec- 

 tricity used in the country. However, since forecasts of 

 electricity demand growth during the next 10 years have 

 recently been revised downward, this projection is subject 

 to considerable uncertainty. Decreasing growth rates and 

 future uncertainties have created serious problems for 

 electric utilities which must design, capitalize, and begin 

 constructing new plants years in advance of their antici- 

 pated use. Additionally, a burdensome regulatory climate 

 derived in part from a lack of public confidence about the 

 safety of nuclear power has led several utilities to cancel 

 orders for nuclear power reactors. Indeed, no new reactors 

 have been ordered by the utilities industry since 1978 

 (ENERGY). This slowdown in the development of nu- 

 clear power for generating electricity has been taken as 

 evidence by some critics that no additional nuclear fission 

 plants will be needed in the future. 



