Biotechnology and industrial sustainability in producing clean industrial products:

Biotechnology and industrial sustainability in producing clean industrial products:

A. Introduction: Various points have been given below regarding role of biotechnology and industrial sustainability in producing clean industrial products:

a. Industrial sustainability demands a global vision and co-ordinated policy approaches.
b. In an industrial context, sustainability is equated with clean industrial products and processes.
c. Biotechnology is competitive with and in many cases complements chemical methods for achieving clean technologies.
d. It is essential to determine what is clean or cleaner, using Life Cycle Assessment and related methods.
e. Biotechnology is a versatile enabling technology that provides powerful routes to clean industrial products and processes and is expected to play a growing role.

B. Biotechnology and CO2 emissions: Fossil carbon represents the single most important raw material for energy generation and for chemicals manufacture, but its oxidation product, CO2, is an important greenhouse gas. Any means of reducing fossil carbon consumption, either by improving energy efficiency or by substituting alternative resources will directly result in lowered CO2 production and thus reduce global warming.

C. Industrial processes: Use of biotechnology has already resulted in energy reduction in industrial processes. In only a few instances can the reductions be quantified, and these are presented in this report. Others are only available as anecdotal evidence. As yet, there are insufficient data to allow scaling up these figures to cover whole industrial sectors.

Examples: a. Ammonium acrylate, a key intermediate in the manufacture of acrylic polymers, is made by hydrolyzing acrylonitrile to acrylic acid and reacting this with ammonia. The reaction is energy-intensive and gives rise to by-products which are difficult to remove. A process, based on a bacterial enzyme which directly synthesises ammonium acrylate of the same quality under less energy-demanding conditions, has been operating for several years at full scale.

b. In paper making, treating cellulose fibres in the pulp using cellulase and hemicellulase enzymes allows water to drain more quickly from the wet pulp, thereby reducing processing time and energy used for drying. Trials have shown that machine speeds can be increased by up to 7 per cent and energy input reduced by as much as 7.5 per cent. Replacing thermomechanical pulping by biopulping has resulted in up to 30 per cent reduction in electrical energy consumption.

D. Materials: Biomass, as it grows, consumes CO2. Substances made from such renewable raw materials are therefore a zero net contributor to atmospheric greenhouse gases, unless fossil fuel is used in their manufacture. A wide range of chemicals and structural materials can be based on biological raw materials including biodegradable plastics, biopolymers and biopesticides, novel fibres and timbers. Plant-derived amides, esters and acetates are currently being used as plasticisers, blocking/slip agents and mould-release agents for synthetic polymers. Uses of biohydrocarbons linked to amines, alcohols, phosphates and sulphur ligands include fabric softeners, corrosion inhibitors, ink carriers, solvents, hair conditioners, and perfumes.

E. Chemicals from biological feedstocks: It is no longer necessary to start with a barrel of oil to produce chemicals. Corn, beets, rice – even potatoes – make excellent feedstocks. The fact that micro-organisms transform sugars into alcohol has been known for a very long time. But only since the advent of genetic engineering is it feasible to think about harnessing the sophistication of biological systems to create molecules that are difficult to synthesise by traditional chemical methods.

For example, the polymer polytrimethylene terephthalate (3GT) has enhanced properties compared to traditional polyester (2GT). Yet commercialization has been slow to come because of the high cost of making trimethylene glycol (3G), one of 3GT’s monomers. The secret to producing 3G can be found in the cellular machinery of certain unrelated microorganisms. Some naturally occurring yeasts convert sugar to glycerol, while a few bacteria can change glycerol to 3G. The problem is that no single natural organism has been able to do both. Through recombinant DNA technology, an alliance of scientists from DuPont and Genencor International has created a single micro-organism with all the enzymes required to turn sugar into 3G. This breakthrough is opening the door to low-cost, environmentally sound, large-scale production of 3G. The eventual cost of 3G by this process is expected to approach that of ethylene glycol (2G). The 3G fermentation process requires no heavy metals, petroleum or toxic chemicals. In fact, the primary material comes from agriculture – glucose from cornstarch. Rather than releasing carbon dioxide to the atmosphere, the process actually captures it because corn absorbs CO2 as it grows. All liquid effluent is easily and harmlessly biodegradable. Moreover, 3GT can readily undergo methanolysis, a process that reduces polyesters to their original monomers. Post-consumer polyesters can thus be repolymerised and recycled indefinitely.

F. Clean fuels: While biomass can be consumed (incinerated) directly to produce energy, it can also be converted into a wide range of chemicals and liquid fuels. Although, in energy terms, annual land production of biomass is some five times global energy consumption, biomass presently provides only 1 per cent of commercial energy. Biomass energy cannot compete at present-day prices with fossil fuels and has so far penetrated the market only where governments have effectively subsidised its use. Bioethanol is a CO2-neutral alternative liquid transportation fuel. As new technologies – including continuous fermentation, production from lignocellulosic (wood and agricultural crop) waste – and more efficient separation techniques are developed, the cost of bioethanol will compete with that of gasoline. Over a 20-year period, US ethanol production, based solely on lignocellulosic waste, could rise to 470 million tonnes a year, equal to present gasoline consumption in energy terms.