RURAL REFINERIES REQUIRED TO REPLACE OIL-BASED CHEMICALS

Although constructing a largely self-reliant local economy will certainly not mean a return to the materials and technologies of the Middle Ages, it will involve picking up some strands of technological development where they were dropped earlier this century as a result of the increasing availability of oil and, to a lesser extent, coal. As David Morris, a co-founder of the Institute for Local Self-Reliance in the United States, puts it, sustainability and self-reliance necessitiate moving from a hydrocarbon-based economy to a carbohydrate-based one - that is, from a system based on the consumption of the densely-compacted remains of prehistoric plant matter to one based on fresh plant material - and he stresses the prospects that this would open up for rural communities.

"One cannot know the future unless one knows the past" Morris says . "Little more than a hundred years ago, plant matter was a basic industrial raw material. The first commercially successful plastic was not made from oil but from cotton. What happened is that a billiard ball manufacturing company, Phelan and Collender, concluded from surveys that the rate of slaughter of Afican elephants was proceeding at such a pace that it would soon exhaust the supply of ivory for their product. They offered a $10,000 prize to anyone who could create a material as hard as ivory that was also abundant and widely accessible"⁴³.

Chemists had already learned that if cotton was treated with nitric acid, an insoluble explosive, guncotton, was produced, but that if less nitric acid was used, the product, though flammable, was not explosive and was soluble in a mixture of alcohol and ether. If the solvents were then allowed to evaporate, a hard horny transparent substance was left which could be made workable by adding turpentine or camphor oil. In 1862, a prolific inventor, Alexander Parkes, showed a sample of the plastic, which he called Parkesine, at the International Exhibition in London but he although he realised its potential he was unable to commercialise it and his company collapsed in 1868. However, two American printers, John and Isaiah Hyatt, were inspired by the ivory-substitute competition to carry out their own experiments and produced a plastic which they brand-named Celluloid which was used to make buttons, dominoes, false teeth and eventually cinematic film as well as billiard balls.

Other plastics and synthetic fibres based on natural materials soon followed. Count Hilaire de Chardonnet extruded dissolved cellulose through a fine nozzle to make rayon, and the first commercial rayon factory opened in France in 1889. This led to a cellulose acetate yarn, Celanese, which was introduced in the 1920s and had a third of the synthetic fibre market by 1940. In the 1930s, cellulose acetate was moulded into steering wheels, instrument panels and knobs for cars, uses which brought it into competition with Bakelite, the first hard, durable plastic which was invented in 1909 and was made from phenols and formaldehyde both of which were, or could have been, derived from wood. Cellulose is also, of course, the basis of Cellophane which is made from wood pulp.

However, the further development of a chemical industry based on natural feedstocks was halted by the growth in oil refining to produce petrol for motor vehicles. Refining left the oil companies with a lot of embarrassing waste gases such as methane, ethylene, propylene and butylene and they undertook extensive research to find uses and hence a market for them. Gradually, their laboratories developed products which, as they were cheaper and in many cases technically superior, replaced almost everything being made from plant material. For example, paint manufacturers found that petroleum-based resins gave them shorter, more predictable drying times than plant resins and that naptha (white spirit) was a much cheaper thinner than turpentine distilled from pine trees. US petrochemical output soared from only 10,500 tons in 1921 to 1.5 million tons in 1939. Being waste-based, these chemicals were remarkably cheap - their average price on the outbreak of World War II was only 13 cents per pound.

By 1945, petroleum-based synthetic fibres such as nylon had only 0.5% of the US clothing market, whereas plant-based synthetics like rayon and Celanese had over 10%. By 1980, however, as a result of the introduction of acrylic and polyester fibres, clothing made from oil had a 64% market share. Plastics production also soared, rising from 6m. tones a year in the US in 1965 to 30m. in 1990, but plant matter-derived plastics virtually disappeared. Even Cellophane suffered. Displaced by polymerised ethylene, polythene, its production dropped to less than a quarter of the postwar peak. Of all non-food products made from plant material, only paper and cardboard output continued to expand in the US, although even this growth was less than it might have been because of competition from oil-based products, particularly polythene. For example, polythene envelopes replaced paper ones for posting many periodicals and polythene bottles reduced sales of cardboard milk cartons by 60%.

Petrochemical consumption in the US is now 109m. tons a year, 75 times greater than its 1939 figure and almost 16 times greater than the consumption of biochemicals. Morris, however, thinks that the trend might be about to begin running in the other direction for two reasons. One is that the cost of producing chemicals from plant matter is falling. The second is that environmental regulations have raised the cost of producing and disposing of oil-based products and also of disposing of plant wastes, encouraging farmers and processors to find uses for them, just as oil refineries had to do with their waste seventy years ago.

"Consider sawdust" he says. "About 50m. tons of sawdust are produced each year creating a disposal problem. It can be burned inside the sawmill, but the dust particles are a fire and explosion hazard. It can be tipped in landfills, but sawdust is easily blown about and hard to handle. It can sit in piles in the sawmill yard but rain will eventually cause tannic acid to leach into the water table." These problems, he says, stimulated a Missouri company to open a plant to convert sawdust into fuel oil and activated carbon, which is used in waste-water treatment plants and as a toner in copying machines. The same company claims that a second plant in upstate New York makes speciality chemicals from plant waste 30% more cheaply than from oil.

"A 50% recovery rate for agricultural wastes would generate 175 million tons of feedstock, theoretically sufficient to displace virtually all petrochemicals" he comments, pointing out that the wastes have a much higher value as chemicals than as fuel. "Lignin, which on average comprises about one-third of woody crops, has an energy value of $6 a ton and a chemical value of $120. Besides cellulose, a ton of wood can produce 350 pounds of lignin and 80 gallons of ethyl alcohol."

He adds that, in contrast to the techniques used to manufacture petrochemicals, the biological processes used to convert plant matter are inherently environmentally benign. "Breaking down organic minerals like coal and oil requires high pressures and temperatures - breaking the carbon-hydrogen bond requires over 600 deg C. Most chemical processes also employ large quantities of strong inorganic acids or alkalis such as sulphuric acid and sodium hydroxide. These can result in effluents which harm the environment. The hydrogen-oxygen and oxygen-carbon bonds of cellulose are weaker and almost all bio-processes occur at 30-40 deg. C, at near-atmospheric pressure and at near-neutral pH levels".

A table in a major 1992 study The carbohydrate economy: Making chemicals and industrial materials from plant matter which Morris wrote with Irshad Ahmed, shows that vegetable-based chemicals are still much more expensive than petrochemicals in a lot of product categories: the difference varies from about 20% for inks and 50% for detergents to 100% for paints and 200% for plastics⁴⁴. Nevertheless plant-matter based products have gained market share because of a combination of green consumerism and direct regulation. Plant matter-based detergents, for example, have benefitted equally from the 75% drop in enzyme costs over the past few years and from the growing bans on phosphates. Printers have two incentives to purchase printing inks based on vegetable oils: first, regulations may soon be promulgated limiting the evaporative emissions of hydrocarbons from inks; and, second, vegetable oil-based inks reduce the need for clean-up chemicals which may themselves create environmental problems.... Paint manufacturers already face regulations on hydrocarbon compound emissions, which are an important ingredient in the formation of ground-level ozone.

"Biorefineries can become the backbone of a new rural economy" Morris says. "Because plant matter, unlike petroleum, is costly to transport, processing facilities will tend to be modestly-sized and located near their raw material suppliers. 200m. tons of waste and virgin plant matter would be sufficient to supply 700-2,000 new biorefineries. The higher estimate would allow one such facility in every rural county in the country."

He sees the biorefineries being run by farmers' co-operatives and says that several co-operative biorefineries are already operating. "Minnesota Corn Processors is the largest corn-to-ethanol producer in the state. The Dairyman's Co-operative in California converts whey into ethanol and whey protein concentrate. And a fledgling kenaf co-op is operating in Mississipi" he says.