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Biomass Resources for Energy and Industry Lynn and Judy Osburn The point where the cost of producing energy from fossil fuels exceeds the cost of biomass fuels has been reached. With a few exceptions, energy from fossil fuels will cost more money than the same amount of energy supplied through biomass conversion. Biomass is the term used to describe all biologically produced matter. World production of biomass is estimated at 146 billion metric tons a year, mostly wild plant growth. Some farm crops and trees can produce up to 20 metric tons per acre of biomass a year. Types of algae and grasses may produce 50 metric tons per year.[1] Dried biomass has a heating value of 5000-8000 Btu/lb. with virtually no ash or sulfur produced during combustion. About 6% of contiguous United States land area put into cultivation for biomass could supply all current demands for oil and gas. And this production would not add any net carbon dioxide to the atmosphere.[2] For its Mission Analysis study conducted for the U.S. Department of Energy in 1979, Stanford Research Institute (SRI) chose five types of biomass materials to investigate for energy conversion: woody plants, herbaceous plants (those that do not produce persistent woody material), aquatic plants, and manure. Herbaceous plants were divided into two categories: those with low moisture content and those with high moisture content. Biomass conversion may be conducted on two broad pathways: chemical decomposition and biological digestion. Thermochemical decomposition can be utilized for energy conversion of all five categories of biomass materials, but low moisture herbaceous (small grain field residues) and woody (wood industry wastes, and standing vegetation not suitable for lumber) are the most suitable. Biological processes are essentially microbic digestion and fermentation. High moisture herbaceous plants (vegetables, sugar cane, sugar beet, corn, sorghum, cotton) marine crops and manure are most suitable for biological digestion. Anaerobic digestion produces high and intermediate Btu gasses. High Btu gas is methane. Intermediate-Btu gas is methane mixed with carbon monoxide and carbon dioxide. Methane can be efficiently converted into methanol. Fermentation produces ethyl and other alcohol’s, but this process is too costly in terms of cultivated land use and too inefficient in terms of alcohol production to feasibly supply enough fuel alcohol to power industrial society. Pyrolysis is the thermochemical process that converts organic materials into usable fuels. Pyrolysis produces energy fuels with high fuel-to-feed ratios, making it the most efficient process for biomass conversion, and the method most capable of competing and eventually replacing non-renewable fossil fuel resources. Pyrolysis is the technique of applying high heat to organic matter (lignocellulosic materials) in the absence of air or in reduced air. The process can produce charcoal, condensable organic liquids (pyrolytic fuel oil), non-condensable gasses, acetic acid, acetone, and methanol. The process can be adjusted to favor charcoal, pyrolytic oil, gas, or methanol production with a 95.5% fuel-to-feed efficiency.
Chemical decomposition through pyrolysis is the same technology used to refine crude fossil fuel oil and coal. Biomass conversion by pyrolysis has many environmental and economic advantages over fossil fuels, but coal and oil production dominates because costs are kept lower by various means including government protection. Pyrolysis has been used since the dawn of civilization. If some means is applied to collect the off-gasses (smoke), the process is called wood distillation. The ancient Egyptians practiced wood distillation by collecting tars and pyroligneous acid for use in their embalming industry. Pyrolysis of wood to produce charcoal was a major industry in the 1800s, supplying the fuel for the industrial revolution, until it was replaced by coal. In the late 19th Century and early 20th Century wood distillation was still profitable for producing soluble tar, pitch, creosote oil, chemicals, and non-condensable gasses often used to heat boilers at the facility. The wood distillation industry declined in the 1930s due to the advent of the petrochemical industry and its lower priced products. However, pyrolysis of wood to produce charcoal for the charcoal briquette market and activated carbon for purification systems is still practiced in the U.S. The wood distillation industry used pyrolytic reactors in a process called destructive distillation. The operation was carried out in a fractionating column (a tall still) under high heat (from 1000-1700°F). Charcoal was the main fuel product and methanol production was about 1% to 2% of volume or 6 gallons per ton. This traditional method was replaced by the synthetic process developed in 1927. The synthetic process utilizes a pyrolytic reactor operating as a gasifier by injecting air or pure oxygen into the reactor core to completely burn the biomass to ash. The energy contained in the biomass is released in the gasses formed. After purification the syngas, hydrogen and carbon monoxide in a 2 to 1 ratio, is altered by catalysts under high pressure and heat, to form methanol. This method will produce 100 gallons of methanol per ton of feed material.[4] At congressional hearings on alternative fuels held in 1978, Dr. George T. Tsao, Professor of Chemical Engineering and Food and Agricultural Engineering, Director of Laboratory of Renewable Resources, Purdue University, said $30 per ton for biomass delivered to the fuel conversion plant is an adequate base price for the energy farmer. The price of $30/ton has also been suggested by other researchers.[5] Energy Farming According to a 1984 report by the Hawaii Natural Energy Institute, of the clean renewable energy alternatives, “only biomass energy holds promise to provide liquid fuels for transportation in the near future.”[6] The Hawaii Natural Energy Institute worked with the University’s Department of Agricultural Engineering to determine the most suitable plants and sites for “growing methanol.” Researchers began work in 1978 to demonstrate the commercial viability of biomass energy plantations and methanol from biomass fuel production, under a Department of Energy subcontract titled “Hawaii Integrated Biofuels Research Program.” Several types of eucalyptus trees and indigenous nitrogen fixing trees were studied, as well as sugar cane and other napier grasses. Tree farming (sylvaculture) presented several problems and produced disappointing yields. Production costs are high. Trees must be transplanted as clones or selected vigorous seedlings. Eucalyptus is a heavy nitrogen feeder, which is one of the reasons nitrogen fixing acacias and other trees were also experimented with. (Run off from the nitrogen fertilized pineapple fields is already killing coral reef ecosystems by fostering algae growth that smothers the coral.) Weed control is essential and adds to the cost of production. The tree crop takes four to seven years to be ready for harvest. In addition to cultivating expenses, “harvesting accounts for almost two-thirds of Eucalyptus feedstock cost,” according to the Hawaii Natural Energy Institute.[7] Not only is chipping wood expensive, the noise pollution chipping creates presents problems, especially on a small island. Compare this to hemp. Hemp is planted inexpensively from seed sown directly in the field; hemp actually improves the soil in which it is grown, without chemical fertilizers; hemp chokes out weeds by virtue of its fast dense growth; hemp biomass harvesters (modified hay cubers) are cheaper to operate and are much quieter than wood chippers. And according to the U.S. Department of Agriculture, over a twenty year period one acre planted in hemp produces as much pulp as 4.1 acres of trees.[8] One species of nitrogen fixing tree (Leucaena leucephala) yielded 15 dry tons per acre the first year and nearly 40 tons from regrowth the second year. However, this was on low, fertile “prime” agricultural land. The average yield of this species was similar to that of eucalyptus -- between 10-20 dry tons per acre per year. Due to concern over the intense competition for land usage on the islands, Leucaena was experimentally grown on marginal agricultural land “up country” on the slopes of Haleakala, Maui. The yields in these colder micro-climates were dismal. The grasses studied yielded better than did sylvaculture. The Integrated Biofuels contract also supports bio-fuels research by the Hawaiian Sugar Planters’ Association. They are breeding low sugar “energy” cane that produces higher dry matter production. Yields average between 20-30 dry tons per acre per year. The Hawaiian Natural Energy Institute estimated that “an energy-only sugarcane agricultural operation in an unirrigated site would have to yield . . . 26 tons per acre per year of fiber to equal the cost of production,” given the 1987 cost of oil, the year the estimate was made.[9] The Institute’s 1990 report concluded that thermochemical (pyrolytic) production of methanol from biomass is the most economical alternative for transportation fuel. They also confirmed Stanford Research Institute’s conclusion from the late seventies that woody or low moisture herbaceous plants are the most efficient biomass source for thermochemical conversion into liquid fuels such as methanol. Sugarcane is a high moisture herbaceous plant. It is most suitable for biochemical (fermentation) conversion into ethanol for use as a renewable source of feedstocks for the chemical industry. (Ethanol cannot compete economically with methanol as a source for commercially available transportation fuel.) High moisture plants can be fermented to produce methane, also used for generating electricity. In fact, sugar factories supplied most of the electrical power on all the major islands neighboring Ohau during the first half of the century, by burning the hydrocarbon rich sugar cane waste, baggase, in steam co-generators. Today every sugar company operating in Hawaii has an electricity production contract with one of the four Hawaiian public utility generating companies. The sugar companies supply ten percent of all electricity generated in Hawaii. In some counties up to 60% of the electricity originates from sugar plantations. However, because the goal of their energy production is limited to steam for electricity, sugar factories waste much of the potential biomass energy releasing unconverted particles that pollute the atmosphere. On the other hand, biomass-to-methanol production is clean and efficient: most of the gasses released during biomass combustion are collected for fuel. The added cost of the extra drying needed for grasses such as sugar cane, corn and napier makes these high moisture plants an inefficient source for “growing methanol.” It is the cellulose in low moisture herbaceous and woody plants that provides the hydrocarbons necessary for fuel production. Hemp is 80% cellulose and is both a low moisture herbaceous and a woody plant. Hawaii Natural Energy Institute projected a cost of $280 million to build a facility capable of processing 7000 tons of biomass per day into 760 million liters per year (MLPY) of methanol. With a total investment of $335 million, the facility could more than double methanol production to 1700 MLPY from the same amount of biomass.[10] Approximately 3300 MLPY of methanol can replace the 1200 MLPY of gasoline and the 640 MLPY of diesel fuel consumed in Hawaii today. And bio-methanol can be produced at a price competitive with regular low lead gasoline on a cost per mile basis.[11]
Biomass for Chemical Feedstocks The U.S. chemical industry consumes more than 7% of America’s petroleum and natural gas liquids to manufacture over 54 million metric tons of primary chemicals. The chemical industry plays a major role in the maintenance of our standard of living. Thousands of ordinary products used every day in every American household are made from a handful of primary chemical feedstocks. Biomass will compete favorably with fossil mass for niches in the chemical feedstock industry. Biomass has several advantages over fossil mass as a raw resource for this industry. Biomass is a renewable, flexible and adaptable resource. Crops can be grown to satisfy changing end-use needs. The success of the biomass derived chemicals industry will depend on the supply and demand for feedstocks, primary chemicals and key intermediates the petrochemical industry cannot make such as cellulose, lactic acid and levulinic acid. The first thermoplastics and synthetic fibers were made from cellulose derivatives. Acetaldehyde, a major petrochemical key intermediate, can be made from lactic acid. And levulinic acid salts have been proposed to replace ethylene glycol as an engine coolant.[14] Cellulose suitable for polymer manufacture is expensive. Petrochemical polymer substitutes were cheaper to produce and rapidly won over markets opened by cellulosic plastics and fibers. Whether cellulosics can win back those markets depends on finding an economical crop to grow as a cellulose resource and the ability of cellulosic polymer scientists to develop new properties that can be used to create new products. Pulpwood is the chief resource for cellulose production. Demand for wood by the paper industry has caused prices to increase. Some chemical manufacturers are looking at alternative crops. Government agencies are promoting kenaf as a cellulose crop superior to pulpwood. Hemp produces greater biomass tonnage per acre per year in more regions of America than either pulpwood or kenaf. Hemp farming is the key to providing large enough amounts of raw biomass at costs low enough to enable cellulose to recapture those lost markets. Hemp can do this because the natural fiber it produces, when sold to textile manufacturers, pays for the cost to grow the crop. The waste material or hurds that are left when the hemp fiber is removed from the biomass is 77% cellulose. The hemp plant makes five times as much hurds as it does fiber.
More research needs to be done to develop new product potential for the low molecular weight lignin. Unlike lignins currently on the market it is soluble in common organic solvents like ethanol and acetone making structural transformation easier. Key intermediates made from LMW lignins should be low priced because much of the cost of generating them will be covered by the value of the pure cellulose and hemicellulose produced during the steam explosion process. Phenol and benzene can be made from LMW lignin in direct substitution for petrochemical processes. Or indirect substitutes may be made in the form of phenolics or epoxies. Cellulose can be converted into glucose by acid digestion. The glucose will oxidize to produce lactic acid. Once the biomass chemical industry can supply the raw materials, low cost lactic acid will compete as a direct substitute for petrochemicals and take advantage of its own unique properties. Lactic acid forms lactide, and lactide can form polymers. These lactide polymers make transparent films and strong fibers and are biodegradable. Research and development for lactide polymers will tailor new products to meet requirements for specific end uses in direct competition to petrochemical polymers.[15] Levulinic acid is a highly versatile chemical intermediate that can be made from many biomass feedstocks. It has attractive applications now as a source of lactone solvents. It used to be manufactured commercially from wood, but now a low cost alternate resource must be found to produce it. Hemp is the most likely candidate. Tree Free Farm-Grown Paper In 1916 two dedicated USDA scientists projected that at the rate the U.S. was using paper we would deplete the forests in our lifetimes. So USDA scientists Dewey and Merrill looked for an alternate agricultural resource for paper products to prevent the disaster we now face. They found the ideal candidate to be the waste material left in the fields after the hemp harvest. The left over pulp, called hemp hurds, was traditionally burned in the fields when the hemp fiber had been removed after the time consuming retting (partially rotting the hemp stalk to separate the fiber from the hurds) process was completed. Hemp hurds are richer in cellulose and contain less lignin than wood pulp. Dewey and Merrill found after much experimentation that harsh sulfur acids used to break down the lignin in wood pulp were not necessary when making paper from hemp hurds. Sulfur acid wastes from paper mills are known to be a major source of waterway pollution. The coarse paper they made from hemp hurds was stronger and had greater folding durability than course wood pulp paper. Hemp hurd paper would make better cardboard and paper bag products than wood paper. They found the fine print quality hemp hurd paper to be equal to writing quality wood pulp paper.[16] The only problem to implementing the paper industry resource change from wood to hemp hurds was that machinery to separate hemp fiber from the hurds needed to be developed. Separation was still done by hand after the machine breaks had softened the hemp stalks. One year later G.W. Schlichten, inventor of the decorticating machine, finished the first production run using his decorticator to separate hemp fiber and hurds from a crop raised on the Timken Ranch in Imperial Valley, California. Upon seeing Schlichten’s machine in operation, businessman E.F. Chase proposed to E.W. Scripps, founder of the second largest newspaper chain in the U.S., that all of his paper pulp needscould be met by hemp grown and processed utilizing Schlichten’s decorticating machine; and at a lower cost than required for making paper from wood.[16a] Chase wrote, “I believe [the decorticator] will revolutionize many of the processes of feeding, clothing and supplying other wants of mankind...” “Mr. Schlichten raised five tons of hemp stalks to the acre on a one hundred acre patch on the Timken Ranch. He will pay the growers $15.00 per ton for dry hemp stalks delivered to his machine. They have only to be shocked to dry properly in a few days. Thus the farmer gets $75.00 an acre for this crop which matures in 100 days. The stubble and that part of the leaves and tops which remain on the field (containing in excess of 50% of nitrogen), are wonderful fertilizer. Moreover, the hemp kills all weeds. The farmer’s land is left in fine condition for immediate planting of other crops. A second crop could be raised...” “From each ton of dry hemp stalks, costing him $15.00, Mr. Schlichten gets the following:”
G.W. Schlichten’s produced about 125 tons of hemp fiber and 312.5 tons of hemp hurds from his 100 acre hemp field. Hemp Seed Industries Nutrition: Cannabis hemp seeds contain all the essential amino acids and essential fatty acids necessary to maintain healthy human life. No other single plant source provides complete protein in such an easily digestible form, nor has the oils essential to life in as perfect a ratio for human health and vitality. The complete protein in hempseed gives the body all the essential amino acids required to maintain health, and provides the necessary kinds and amounts of amino acids the body needs to make serum albumin and serum globulins like the immune enhancing gamma globulin antibodies. The body’s ability to resist and recover from illness depends upon how rapidly it can produce massive amounts of antibodies to fend off the initial attack. If the globulin protein starting material is in short supply the army of antibodies may be too small to prevent the symptoms of sickness from setting in. The best way to insure your body has enough amino acid material to make the globulins is to eat foods high in globulin proteins. Hempseed protein is 65% globulin edestin plus quantities of albumin. Its easily digestible protein is readily available in a form quite similar to that found in blood plasma. Though hempseed protein is an important dietary component to building a strong immune system, hempseed oil is even more critical to human health and vitality. Hempseed is the richest source in the plant kingdom of essential fatty acids. Hempseed oil comprises 35% of the total seed weight and is among the lowest in saturated fatty acids at 8% of total oil volume. The oil pressed from hempseed contains 55% linoleic acid (LA, also known as Omega-6), 25% alphalinolenic acid (LNA, also known as Omega-3) and 1.7% gamma linoleic acid (GLA, also known as Super Omega 6). Only flax seed oil (linseed oil) has more linolenic acid at 58%, but hempseed oil is the highest in total essential fatty acids at 80% of total oil volume.[17] “These essential fatty acids are responsible for our immune response. In the old country the peasants ate hemp butter. They were more resistant to disease than the nobility.” The higher classes wouldn’t eat hemp because the poor ate it. --R. Hamilton, ED.D., Ph.D. Medical Researcher-Biochemist U.C.L.A. Emeritus. LA and LNA are involved in producing life energy from food and the movement of that energy throughout the body. Essential fatty acids govern growth, vitality and state of mind. LA and LNA are involved in transferring oxygen from the air in the lungs to every cell in the body. They play a part in holding oxygen in the cell membrane where it acts as a barrier to invading viruses and bacteria, neither of which thrive in the presence of oxygen. The bent shape of the essential fatty acids keeps them from dissolving into each other. They are slippery and will not clog arteries like the sticky straight shaped saturated fats and the transfatty acids in cooking oils and shortenings that are made by subjecting polyunsaturated oils like LA and LNA to high temperatures during the refining process. LA and LNA possess a slightly negative charge and have a tendency to form very thin surface layers. This property is called surface activity, and it provides the power to carry substances like toxins to the surface of the skin, intestinal tract, kidneys and lungs where they can be removed. Their very sensitivity causes them to break down rapidly into toxic compounds when refined with high heat or improper storage exposes them to light or air. Nature provides seeds with an outer shell that safely protects the vital oils and vitamins within from spoilage. It’s a perfect as well as perfectly edible container. Hempseed can be ground into a paste similar to peanut butter only more delicate in flavor. Udo Erasmus, Ph.D. nutritionist says: “hemp butter puts our peanut butter to shame for nutritional value.” The ground seeds can be baked into breads, cakes and casseroles. Hempseed makes a hearty addition to granola bars. The energy of life is in the whole seed. Hempseed foods taste great and will insure we get enough essential amino acids and essential fatty acids, to build strong bodies and immune systems, and to maintain health and vitality. Drying Oils for Industry: “Linseed [and hempseed -ed. note] oil is used for mixing paints, because it is a very lively, flexible, penetrating, lustrous oil thanks to its very high content (40%) of alpha-linolenic acid.[17a] Essential fatty acids attract oxygen. This property has made them useful in the paint and varnish industry in drying oils which dry and harden into thin elastic films when exposed to air. Hemp seed oil, like linseed oil, was a major ingredient in paints, varnishes, soaps and perfumes.[18] The Marijuana Tax Act of1937 effectively strangled the hemp seed oil industry,[19] allowing its chief competitor, petroleum oils, to substitute for hemp seed oil as the primary feedstock in the paint and varnish industries. Hemp grown for seed produces from 12 to 25 bushels of seed per acre or 900 to 1200 pounds of seed per acre.[20] There are eight gallons in a bushel, and hemp seed consists of 30% to 35% oil by volume.[21] Hemp: Humanity’s Oldest Textile Plant: The hemp plant belongs to the mulberry family, Moraccae, which includes the mulberry, the Osage orange, the paper mulberry, and hop plant. Hemp is closely related to the nettle family, which includes ramie, an important fiber-producing plant of Asia. Hemp was probably the earliest plant cultivated for the production of a textile fiber. The “Lu Shi,” a Chinese work of the Sung dynasty, about 500 A.D., contains a statement that the Emperor Shen Nung, in the 28th Century B.C., first taught the people of China to cultivate hemp for making hempen cloth. Later the seeds of this plant were used for food. The original home of the hemp plant was Asia, and the evidence points to central Asia. Historical evidence must be accepted rather than the collection of wild specimens, for hemp readily becomes naturalized, and it is now found growing without cultivation in all parts of the world where it has been introduced. Hemp cultivated for the production of fiber, cut before the seeds are formed and retted on the land where it has been grown, tends to improve rather than injure the soil. It improves its physical condition, destroys weeds, and does not exhaust its fertility. Hemp will grow well in a fertile soil after any crop, and it leaves the land in good condition for any succeeding crop.[22] Very few of the common weeds troublesome on the farm can survive the dense shade of a good crop of hemp -- a good dense crop 6 feet or more in height will leave the ground practically free from weeds at harvest time. And hemp is remarkably free from diseases caused by fungi.[23] Hemp prefers plenty of moisture but will tolerate drought after its first six weeks of growth. Hemp “will endure heavy rains or even a flood of short duration.”[24] Hemp requires an abundant supply of plant food, attaining in four months a height of 6 to 12 feet and producing a larger amount of dry vegetable matter than any other crop in temperate climates. The single best fertilizer for hemp is undoubtedly manure. It supplies the three important plant foods, nitrogen, potash and phosphoric acid, and it also adds to the store of humus, which appears to be more necessary for hemp than for most other farm crops. A commercial fertilizer containing about 6% of available phosphoric acid, 12% of actual potash, and 4% nitrogen would be a good fertilizer for hemp.[25] Dempsey has described the various components of the total hemp plant biomass yield. He estimates that a good yield of green hemp plants would be about 18 tons per acre.[26] Footnotes:
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