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By JAMES KROHE JR. Biomass: growing Btus  The search for fuels to run the world may lead us back to the woodpile, food, along with grains, weeds, crop residues, industrial and livestock wastes, sewage and garbage, are all types of biomass. Derived directly or indirectly from living plants, biomass can be fermented into ethanol, digested by bacteria to produce methane, squeezed to get oil and burned or gasified for heat. Biomass is renewable; it does not cause smog, til spills or acid rain. And although biomass can be tricky to deal with (requiring carefully designed systems), Hoes offer a limited — but important — fuel alternative FOR CENTURIES it was the perfect fuel, and its virtues have not diminished over time. It is infinitely renewable, plentiful, relatively nonpolluting, available in myriad forms. "It" is biomass, a modern term for the oldest of energy sources. Biomass is any fuel derived, directly or indirectly, from living plants — algae, firewood, peat, ethanol fermented from grains, even manure. Biomass used to run the world, and in many poorer countries, where the most pressing energy crisis is not shortages of oil but of firewood, it still does. In Illinois, as in most of the U.S. and the industrialized West, biomass is essential only to the running of human machines, in the form of food. But the rediscovery of the biological fact that food is fuel has opened up new possibilities to energy thinkers in the post-OPEC era. Ultimately biomass is a form of solar energy, captured by plants. Plants are nature's solar collectors, converting the energy of the sun via photosynthesis into a variety of substances: carbohydrates (ranging from the simplest sugars to starches), cellulose (a glucose compound which is the single most abundant organic compound on Earth) and lignins (tough fibers which bind cellulose cells together). These substances are secreted in a plant's seeds, stems, leaves and fruit, in proportions that vary with the species, and constitute an energy storehouse. There are many keys to this storehouse, some ancient, some very new. Direct combustion — burning — is the simplest, and usually the least efficient. Pyrolysis is a method of breaking down plant molecules under heat and rearranging them in the absence of oxygen; such "destructive distillation" can transform woody plant matter into methyl alcohol, or methanol or convert corn husks into a flammable gas consisting of hydrogen, carbon monoxide and carbon dioxide. Biomass also may be fermented into alcohol by the action of bacteria acting on sugars derived from starches or cellulose, or digested by bacteria which obligingly emit combustible methane as a by-product. The processes are as bewildering in their variety as the plants they are designed to exploit. Many are unproven economically, if not technically; most have some potential application in Illinois. Wood The form of biomass energy — "bioenergy" in the jargon of energy planners — with which most people are familiar is firewood. Hardwoods like oak or hickory are remarkable energy reservoirs. A hundred pounds of hardwood releases as much heat energy as 1,000 cubic feet of natural gas or seven gallons of heating oil. Once a ubiquitous heat source, wood has been rediscovered in the post-OPEC age; the Worldwatch Institute has estimated that in the U.S. in 1979 wood stoves furnished more energy than all the nation's nuclear power plants. Because firewood is not sold at pumps but is gleaned from state forests, public parks and backyard wood lots, it is impossible to tell how much wood is consumed in Illinois stoves and fireplaces each year. A 1972 study commissioned by the Illinois Department of Conservation's (DOC) forestry division projected fuelwood consumption statewide in 1980 at 50 million cubic feet, or 9 trillion Btu — less than one quarter of 1 percent of the state's overall energy usage in recent years. Even so, that is a lot of wood. Fuel-wood use might be more popular were wood not such a difficult resource to exploit. Most of Illinois' wooded land is in its deep southern counties, where its people aren't. For those who can get it, wood is a bargain. However, the Illinois Department of Energy and Natural Resources (DENR) reports that wood is being removed from Illinois woodlands faster than it is growing back. As happened in the 19th century, the price for firewood has gone up as convenient local supplies have been exhausted. Rural landowners can still get firewood for the cost of their own labor, but a cord of wood in the winter of 1981-82 sold for up to $120 in the Springfield area and as much as $180 in Chicago. The firewood supply pinch is likely to get more painful rather than less. Partial support for the energy series has been provided through a grant from the Office of Consumer Affairs of the U.S. Department of Energy. Opinions and conclusions expressed in the article are solely the responsibility of the author. May 1982/Illinois Issues/27 Home stoves aren't the only places to burn wood, however, nor are logs the only form in which to burn it. The 1972 IDOC forestry study estimated that "rough" trees, rotten trees and deadwood amounted to more than the entire projected 1980 demand. Wood waste, including sawdust, from lumber yards and mills can be burned in plant boilers; at least one Illinois mill dries lumber with heat from its own waste. And although it is seldom considered, urban forests generate resources of their own; a 1975 study by the City of Chicago revealed that its annual tree-trimming operations left 40,000 tons of waste. But waste wood in any form in Illinois is not plentiful enough to be more than a short-term supply. A few years ago, two University of Illinois researchers began looking for ways to provide fuelwood in quantities that are both sizable and sustainable. Using a U.S. Department of Energy (DOE) grant, foresters Gary Rolfe and Tim White began a five- to six-year test in 1978 intended (quoting the authors) "to measure the energy potential of juvenile, fast-growing hardwoods raised under intensive silviculture systems." The pair planted seedlings of several species such as poplars, cottonwoods, black locust and sycamores on marginal farmland at the university's Dixon Springs Agricultural Center in Pope County. There are an estimated 750,000 such marginal acres in Illinois, and turning them into short-rotation woody biomass plantations offers obvious economic attractions; farmers could grow trees on ground unfit for row crops and get cash and erosion protection in return for very little work. The system requires the use of whole trees, not just logs. Rolfe explains, "Autumn olive is the best producer so far. It yields about four to five tons per acre on a dry weight basis. All the species yield about 8,000 Btu per pound." The heat value of trees is modest compared to Illinois coal. In tests, it took 1.6 pounds of ground-up sycamores to match the heat yield of 1 pound of coal. But the ash content of whole trees was only about 1 percent compared to 13 percent for coal, and while the coal contained an average of 2.2 percent of polluting sulfur, there is virtually no sulfur in wood. "Even using these yields, which we consider fairly low, we get a very positive energy balance," Rolfe says. "About 10 to 1 in fact. What's really encouraging, though, is the yield from coppice," the new growth which sprouts from the stump of a cut tree. The regrowth from harvested trees has been roughly twice that from the initial seedlings. "Our ultimate hope is for a mixed species planting which will yield from 6 to 10 tons per acre per year," he says. In round figures, that's the energy equivalent of 6 tons of coal per acre per year. Every year. Crop residues Illinois already is one of the planet's more prodigious producers of energy crops. Its corn and soybeans alone constitute a Btu reservoir of staggering size. At present virtually all of this stored energy is being fed to animals, which is perhaps the least efficient conversion system yet devised. But there are even more basic inefficiencies in the present grain production system. We now use only a fraction of the corn or bean plant — its seeds. The corn farmer especially leaves behind in his field a veritable cellulose mine consisting of field stubble, shredded husks and stalks and corn cobs. Scientists call this extraneous plant matter crop residue; farmers typically call it trash. By any name, there is a lot of it in Illinois. In 1978, crop residues from the state's seven principal crops added up to 39 million tons, of which about 33 million would have been collectible. Cellulosic residues of this sort have a crude heat value of roughly 8,400 Btu per pound. (A ton of corn cobs can generate the heat of 134 gallons of propane.) Illinois farms thus harbor the energy equivalent of 31 million barrels of crude oil. Exact rates of energy recovery vary, of course, with the recovery technology. Direct combustion is simplest, and crudest. Gasification in one of the biomass gasifiers now entering the market is a more sophisticated method. There is no lack of applications for such systems on the farm. Drying corn, for example, takes roughly twice the energy it takes to plant, cultivate and harvest it. DENR has estimated that the proprietor of a 300-acre grain farm could save as much as $3,500 a year in energy bills by using residues instead of natural gas or propane to dry grain, and that is enough to pay for the gasifier in as little as three years. 
Even left on the fields, crop residues play an important role on the farm, where they control erosion and replace needed nutrients in the soil. Any computation of the economics of residue recovery must include the cost of extra fertilizers to replace nutrients lost up the smokestacks of furnaces. But most farms have too much of a good thing; DENR estimates that farmers could leave half their residues in place and still harvest the equivalent of 1.5 tons of coal per acre without risking damage to the land. Unfortunately, residues are not a very concentrated form of energy. Collection and handling is cumbersome and expensive (up to $52 a ton by one estimate). The availability of residues fluctuates with the seasons, and with plantings. For these reasons most planners argue that crop residues arc suited for small-scale local applications, especially on the farm. The total energy replacement thus will be small; farmers use only about 3 percent of the energy used in Illinois, and residues would replace only a fraction of that fraction. But residues could easily replace, say, 25 percent of the energy used on individual farms. For the farmer, teetering on ever-thinner profit margins, a corn cob may be as good as a coal mine. 28/May 1982/Illinois Issues Cheese whey? "Waste" is a word that the new generation of energy thinkers seldom use. They argue that there is no such thing as waste, only underutilized resources. Growing food produces a lot of such "waste," and so does processing it. According to a study commissioned by the DENR (then known as the Illinois Institute of Natural Resources or 1INR) the Illinois food processing industries generated more than 500,000 tons of spoiled sweet corn, cheese whey and similar leftovers in 1978. (This figure includes waste from Illinois-grown products only; it does not include food imported to Illinois for processing.) Much of the vegetable wastes are simply fed to livestock, and one firm burns tea dust in its own boilers. Most of the rest, especially watery wastes like cheese whey, are simply flushed away. But even whey contains enough recoverable sugars to make it a suitable fermentation feedstock. The IINR study estimated that food processing wastes could be fermented into 3 million gallons of ethanol a year, which could leave Illinois motorists with the novel task of computing their fuel efficiency in terms of miles per asparagus. Ethanol The same virtues which make corn so palatable to the hog — high concenirations of energy in the form of sugars which are themselves contained in eas ly digestible starches — make it a natural fermentation feedstock. Illinois teds the nation in the production of elhanol from corn. Roughly 150 million gallons a year were pumped from 10 commercial plants and about 40 smaller, on-farm stills in 1981. Nearly all this output comes from the plants of the Archer Daniels Midland Co., which pioneered in the manufacture of "power" alcohol in 1978. For all its success, the renewable ethanol business is still in its infancy. Research proceeds into more efficient fermentation and distillation processes, especially in smaller-scale systems, new uses for the stillage leftovers, new types of engines designed to burn ethanol alone or in combination with other fuels. Most critical of all is the search for new feedstocks; new "energy crops" such as sweet sorghum (which has not only starchy kernels but sugary stalks) and the Jerusalem artichoke have been grown experimentally in Illinois. Meanwhile work proceeds across the state on ways to make alcohol economically for on-farm use. A DOE grant is funding tests on a 10,000-gallon-a-year still at Illinois State University, Normal. At Northern Illinois University, DeKalb, reflecting solar concentrators are being tested to learn if the sun can be used to distill ethanol. At Southern Illinois University's Carbondale campus, researchers are looking for ways to break down cellulosic residues for fermentation. At a research farm run by the Farmers Service Co-op in McLean County, wet stillage is being test-fed to livestock. At the U.S. Department of Agriculture's Northern Regional Research Center (NRRC) at Peoria several labs are hunting for yeasts and enzymes which might someday convert cellulose directly to alcohol. It would be rash to predict the results of these investigations. Still, it seems safe to say that the ethanol business probably hasn't been invented yet. _________________________ Plant oils Burning, gasifying and fermenting aren't the only tricks by which energy may be extracted from plants. A small group of agronomic explorers in Peoria is saying that all one needs to dig for oil is a plow. The prospect of using plants to get motor fuels — usable directly in diesel engines or blended with diesel fuel — is exotic but hardly unthinkable. Among the planet's catalog of 300,000 plant species are several which directly manufacture complex hydrocarbons of the sort which comprise fossil fuels. Researchers in the western states are testing a desert shrub so rich in these hydrocarbons that its nickname is "gasoline tree." At NRRC's Peoria labs some 7,000 species of plants have been screened for oil and protein content, fatty acid composition, and so on. The list includes many species common in Illinois such as sumac, Indian hemp, milkweeds, ragweeds, goldenrod, spurges, pokeweed, and dandelion as well as more exotic species like the Madagascar rubber vine. Yields of these so-called "whole-plant oils" are potentially much larger than those of "seed-oil" plants like the soybean because the stems and leaves as well as the seed are used. In addition to conducting these preliminary inquiries, the Peorians have investigated methods to breed, cultivate and process such energy crops economically. As is the case with short-rotation hardwoods, such weedy wonders could be grown on land unsuited to row crops. As is the case with corn-based ethanol, the process extracts energy while leaving protein-rich residues which can be further processed into livestock feed and even fermented into ethanol. Such multi-use crops, some Peoria researchers have concluded, would actually improve overall agricultural productivity. They envision networks of "botanochemical" factories equipped to process plants harvested from a radius of roughly 15 miles (to minimize transport costs). Drawing on a crop area of roughly 60,000 acres, each such factory would handle up to 500,000 tons per year of whole-plant produce. But would Illinois farmers turn into husbanders of energy? Perhaps. NRRC staff calculate that the gross annual return to farmers (in 1978 dollars) would be about $200 per acre for an herbaceous perennial oil crop such as milkweed. This compares well with corn (which earned the average U.S. farmer $214 per acre in 1978) and soybeans (which earned $194). As W.M. Doane, the head of the NRRC's Bio-materials Conversion Lab wrote recently, with understatement typical of a scientist, "The 5 billion tons of total plant biomass produced annually in the United States is taking on a different perspective." May 1982/Illinois lssues/29 Animal wastes Haste, it is said, makes waste. So does almost everything else. Vast sums are spent in Illinois on systems to dispose of animal wastes, including those of human animals. They range in scale and technology from feedlot manure settling ponds to backyard septic tanks to the mammoth sewage factories of the Chicago Metropolitan Sanitary District, but all waste treatment facilities have as their aim rendering innocuous that which is not. However, what is waste to one organism often is food to another. Animal waste, be it manure or municipal sewage, is fodder for bacteria. Certain bacteria which feed in the absence of oxygen — anaerobic bacteria — can digest wastes and obligingly emit combustible gas as a by-product. The process requires little more than duplicating in a mechanical digester the conditions which existed in ancient swamp bottoms — warmth, nutrients, moisture — from which rose our reserves of natural gas. In the process pathogens in the waste are killed, odors virtually eliminated and fertilizing minerals such as nitrogen are left intact in a stable sludge which can be spread on farm fields. Left behind by these microbial alchemists is a crude form of "natural gas," consisting of roughly 60 percent methane and 40 percent carbon dioxide — low in energy and not concentrated enough to ship through a pipeline but sufficient to use on-site. The anaerobic digestion of animal wastes is old news among the larger feedlot operators, whose sewage disposal problems rival those of many suburbs. Indeed, methane is merely a happy by-product of systems installed chiefly to reduce raw wastes to some more handleable form. "Biogas" is used on several farms to heat confinement barns or, more commonly, to run the digesters themselves. People are the most populous single species of "livestock" in Illinois, and sanitary engineers face the same problems faced by farmers and long ago hit on the same solution. As is the case on the farm, methane is a usable byproduct of what is essentially a waste stabilization process. Most Illinois cities use anaerobically produced gas to run sewage treatment plants. This gas, like that generated on the farm, is not pure methane; it contains corrosive hydrogen sulfide and water which would have to be removed before it could be used generally; in any event the energy yields are low. (One estimate from the late 1970s put the potential replacement of natural gas by biogas from sewage solids at 0.13 percent.) Solid wastes _______________________ City dwellers produce residues of a sort too, in the form of garbage. Its precise ingredients vary from town to town, even from month to month, but on the average roughly three-fourths of ordinary household garbage is combustible paper, wood or plastic. Burned in specially equipped boilers, garbage can produce steam, which in turn can run factories or generate electricity. How much steam is not clear. DENR estimates that there are about 6 million tons of trash produced in Illinois each year, trash which has a gross heating value equal to 8 million barrels of oil. Most of this treasure is buried in landfills. But in congested urban areas, landfill sites are becoming scarce. Burning trash reduces its bulk enormously (by 80 to 90 percent), thus reducing disposal problems. Many cities use municipal incinerators for just that reason. Incinerating in a boiler, however, results in the same kind of useful recycling which anaerobic digestion performs on animal wastes: It makes a nasty waste disposal problem more tractable and yields energy in the bargain. But burning garbage isn't as simple as it sounds. Garbage can be as much as 25 percent water by weight. Separating metals and glass from the garbage boosts the combustion efficiency of the resulting fuel as does shredding it into "Refuse Derived Fuel" or RDF, but neither can be done without costly equipment. (The recovery of recyclable metals in the sorting process often is a key to the economic success of such facilities.) Garbage has less consistent heat value than coal or gas, complieating management. Early generations of plants emitted too much ash, or odors, or suffered equipment breakdowns. Experimental projects to generate process steam in one of Chicago's municipal incinerators and sell it to nearby industrial customers foundered on such shoals. A similar plan in 1977 to burn garbage at Springfield's municipal electric generating station was shelved when tests revealed that the trash generated by the city's bureaucracies has a high proportion of paper; apparently memos made a lowgrade boiler fuel. Still, the logic of combusting municipal wastes is so compelling that several cities are reluctant to abandon the idea. Chicago's Northwest Incinerator, for example, processes approxi-mately one-fifth of the city's trash into steam which is sold to a nearby candy factory. In St. Louis, the Bi-State Development Authority is negotiating with Union Electric Co. for the sale of electricity and heating steam from a new plant which would transform 2,500 tons per day of household and commercial garbage from downtown St. Louis and the Metro-East area of Illinois into electricity and heating steam — trash which presently is either landfilled or burned in what one Bi-State official characterizes as "environmentally unacceptable" incinerators. At the twin cities of Champaign-Urbana, which annually use five to six acres of land to dispose of their trash, plans are nearing completion for a resource recovery facility which will convert 100,000 tons of trash a year into low-pressure process steam. The steam will be sold to a local soybean processing plant, enabling that firm to reduce its consumption of natural gas by 70-80 percent. Environmental aspects 30/May 1982/lllinois Issues In the past several decades, the industrialized West has consistently underestimated the social cost of its dependence on fossil fuels by not including in its calculations the damage done to air, water and human tissues by acid rain, oil spills, coal wastes and smog. Just as factoring in such costs makes fossil fuels seem less a bargain, factoring in the environmental results of biomass use tends to make biomass a better bargain than its energy return alone would suggest. Virtually every variety of biomass system, from manure digesters to corn cob gasifiers to ethanol-from-cheese-whey factories, makes something out of what had heretofore been considered nothing. It matters little whether one regards a cogenerator run on garbage as an energy system with environmental benefits or an environmental system with energy benefits. Biomass systems do not offer solutions to local pollution problems alone. One of the most pernicious environmental perils presently nagging scientists is the increase in a atmospheric levels of carbon dioxide resulting from the burning of coal, oil and natural gas in the last 100 years, the so-called greenhouse effect. Biomass fuels do release CO2 when burned (or fermented; roughly 15 pounds of a 56-pound bushel of corn fermented into ethanol is converted inlothegas). The difference is that burning fossil fuel releases into the atmosphere in a matter of a few dozen years the carbon locked up in the original plant matter over a period of millions of years. Biomass has no such ecological deficits. Burning biomass releases basically the same amount of CO2 that was taken up during the life span of the plants for photosynthesis. 
Since so many biofuels are pulled from the soil, there have been worries that widespread use of biomass would spur erosion, with the result that one irreplaceable resource would be traded away to save another. Prudence and planning could ease such pressures; for example, DENR staff estimate that as much as half the crop residues now left in Illinois fields could be removed without increasing erosion. Many of the new energy crops (such as milkweeds) require less soil-disturbing cultivation than corn or beans, and mixed crops of hardwoods which include nitrogen-fixing species would actually improve the soil as they grow. At the very minimum, squeezing oils or fermentable sugars out of present major crops such as soybeans means that, although we may not save any soil, we would get more for it. In sum, none of the environmental problems associated with biofuels seem intractable. The bar to wider use of biofuels is economic rather than environmental, except in certain small-scale applications. The diffuse nature of biomass, coupled with its fairly low per-unit energy content, makes the economics of large-scale applications tricky. It is technically feasible to run a power plant on corn residues, for example, but the cost of gathering and moving residues from a wide enough area would cost more for transportation than could be saved in coal. New crops raised especially for their energy content would reduce this disadvantage, but biofuels by their natures tend not to pack as many Btus per bushel as their fossil cousins. As was the case with synthetic fuels made from coal, much of the initial promise of biofuels lay in their ability to replace imported oil used in gasoline. With global supplies plentiful at the moment and prices expected to remain stable through the 1980s, that market has largely evaporated. The lifting of the post-OPEC gloom may have revealed new and potentially important careers for biomass as a petroleum substitute. Selling initially to the short-lived gasohol market, ADM has since found a market for ethanol as an octane booster in unleaded gasoline. Since boosting the octane in the refinery stages requires considerable energy, this new role does not diminish ethanol's utility as a petroleum replacement; the only difference is that instead of replacing petroleum in the gas tank it replaces it at the refinery. May 1982/Illinois Issues/31 The same opportunities may await future marketers of vegetable oils. More than $10 billion are spent in the U.S. each year to buy petroleum feedstocks used to manufacture synthetic polymers for plastics, rubber, adhesives and coatings. Such uses account for roughly 10 percent of the oil and natural gas consumed in the U.S. each year. Only 5 billion pounds of agriculturally derived fats and oils (mostly animal fats) are used for non-food manufacturing, which is a scant 2 percent of the production from petrochemicals. But as oil prices climb, substitutes from plants may begin to look much more attractive. ____________________ Biomass is never likely to be another coal or oil. Instead, says DENR, the quality and quantity of a given biomass resource, the technology used for its conversion, even its location are "all integral to the economic viability" of biomass. The key is "matching this resource base to a potential end-user and appropriate conversion technology." In short, a place for every energy source, and every source in its place. Even assuming such intelligent application, how much coal, oil or natural gas can biomass replace in Illinois? The answers vary wildly according to the assumptions one makes about fuel sources, conversion efficiencies, land use and so on. DENR, for example, estimates that all the crops grown in Illinois in 1979, from corn to peaches, could have yielded 3.8 billion gallons of ethanol — a respectable portion of the roughly 5 billion gallons of gasoline used in Illinois that year, but plainly impossible to do. Such simplified analyses underestimate the impact that new energy sources have in small but vital segments of the economy. Crop residues may never run color TVs in Chicago, but by providing low-cost energy for crop drying they might keep some farmers in business. A job need not be big to be worth doing. Policy Until fairly recently, government has not shown much interest in small jobs, at least in the energy field. Federal money for research, for loan guarantees and price supports for alternative fuels has been budgeted for mammoth plants to make synthetic oil and gas from coal or shale. Biomass has been very much the runt of the litter of alternatives which were born after 1974. This may be because of its inherently modest potential for commercial-scale applications; it may also be that biomass resources, being so diffuse as to make concentrated ownership impossible, have no vested economic interests to lobby the case for biomass funding in Congress and in state legislatures. An apparent exception to this rule would seem to be ethanol. Ethanol enjoyed the enthusiastic support of the Carter administration, which proposed a package of grants and loan guarantees for both commercial and on-farm stills amounting to approximately $3 billion. But critics insisted that the ethanol program revealed less about Carter's commitment to biofuels than it did about his commitment to winning the farm vote. Corn prices were — and remain — depressed, and ethanol was embraced in farm states as a new market for corn. The free-marketeers of the Reagan administration have largely rescinded Carter's promises of biomass funding. The price of corn is still low, but so (at present) is the price of oil, with the result that the expected ethanol explosion, lacking a commercial spark, has yet to go off. Even in Illinois where only coal is a more plentiful energy resource than corn, policymakers have been only slightly more receptive to biomass' possibilities. While the state's coal reserves are being mapped in great detail, no reliable catalog of its biomass resource has been commissioned. No comprehensive survey of state forests has been made since the 1960s, nor are there anything but estimates of the nature and amounts of animal wastes generated each year. Still, biomass had enough friends id the General Assembly for that body to expand the $65 million 1974 Coal Development Bond Act into the Coal and Energy Development Bond Act in 1977. At that time, the legislature authorized an additional $5 million in bond funds to be spent in support of red search into various renewable alternative energies, including biomass. What is the future likely to hold for biomass in Illinois? Experts in state government are uncomfortable about making predictions. But given the limiting factors inherent in all biomass resources — especially their bulk and their relatively low Btu harvest — it seems likely that most bioenergy facilities in Illinois in 1990 will be small-scale operations using local resources for local needs. Farms will run integrated on-farm units designed to produce methane, ethanol and fertilizer and feed by-products. Here and there, food processors may use waste to generate energy for process steam or electricity. Ethanol production is likely to continue at the commercial scale, but probably will continue to thrive only as an adjunct to existing corn processing plants. People who like their energy solutions simple find little to praise in biomass. But one of the lessons of the post-OPEC era is that energy systems need to be judged not merely according to their Btu output. To many, the appeal of biomass is moral as well as mundane. Bioenergy systems show much of the symmetry of natural ecological systems, and so offer ways to generate usable energy without adding materially to the weight of pollutants on the globe. Biomass is not likely to supply all the U.S. energy needs, or even a largish part of them. This is true even in the states like Illinois where farming provides both the raw material and the market for bioenergy. This diminishes biomass' market, but not necessarily its importance. A job need not be big to be worth doing. □ 32/May 1982/Illinois Issues |