Biochemicals sweep US free of petrochemicals
US ENVIRONMENTAL regulation to check industrial pollution and technological advances are causing a shift from petrochemicals to eco-friendly compounds, called biochemicals, which are obtained from plant matter such as wood and cellulose.
Manufacturers can now separate different components of plant matter as easily as those of crude oil and convert these into products with properties similar to those derived from fossil fuels, say David Morris and Irshad Ahmed of the Institute for Local Self-Reliance (ILSR), a US-based non-profit research and educational organisation that provides technical assistance and information on environmentally sound economic development strategies.
Converting plant matter into biochemicals using the pyrolysis process -- burning with low or zero levels of oxygen -- does not generate harmful wastes and is less of a burden on the environment, say the scientists, than the processing of fossil fuels, which requires strong and difficult-to-dispose chemicals such as sulphuric acid and sodium hydroxide. In some cases, where the biological processing is based on the enzymatic action of microbes as in some detergents, the waste serves as food for other organisms.
Growing market According to Morris and Ahmed, apart from a few chemicals and adhesives, there were virtually no plant-derived industrial products in the US market a decade ago. But today such products compete with those derived from petroleum in just about every major category: bio-paints have captured about 3 per cent of the paint market; vegetable oil-based inks account for 6 per cent of the printing ink market; more than 10 per cent of detergents are plant-based; some plastic bottles now are made from a plastic manufactured by a bacteria; most US newspapers use vegetable oils instead of mineral oils for their colour sections and vegetable oils and flower fragrances are being used in shampoos.
The spurt in plant-derived products in USA is largely a result of environmental regulations that have raised the cost of making and using petroleum-based products. About a quarter of the total number of US states ban phosphates in detergents, which has paved the way for a dramatic expansion in the use of microbial enzymes. Several states have enacted legislation that encourages the use of degradable plastics, which has opened up the market for bio-plastics.
Many cities are seeking to curb the amount of evaporative emissions from petroleum products; this has led to substitution of vegetable oils for mineral oils in a wide variety of products such as paints and inks. Even when the prices of plant-derived products are higher than petroleum-derived products, many consumers are willing to pay a "green" premium for them.
As plant matter is bulky and expensive to transport, the shift to biochemicals will encourage the setting up of small biochemical refineries close to the source of raw material, which will ensure economic well-being in rural areas.
Technological advance Meanwhile, technological advances are lowering the cost of plant-derived products. Over the past seven years, the cost of pigments from plant matter has declined by 20 per cent and the cost of inks has dropped by more than 30 per cent. Morris and Ahmed say advanced pyrolysis techniques may be able to extract from sawdust a type of carbon used in inks for about half the price of that derived from natural gas.
The scientists say there are sufficient agricultural wastes in the US to provide sufficient raw material to displace almost all the petrochemicals in the country. Substituting biochemicals for petrochemicals thus not only substitutes renewable materials for non-renewables, but also finds use for waste.