What is the role of biorefineries

Geoff Covey and Stephen Grist

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In recent years there has been considerable interest in the concept of biorefineries – factories that will use biomass as a feedstock to produce a range of chemicals similar to those currently produced from crude oil in an oil refinery. One point of debate is whether the development of biorefineries will be an opportunity or a threat to the pulp and paper industry.

It is the view of the present authors that much of the cur rent discussion is based on an incorrect understanding of the issues and of the scale of the industry. This paper will address the markets which the first few generations of bio refineries are likely to serve. Over a longer period of time the situation is likely to change.

Currently products are made from oil because this is the cheapest route. The pulp industry produces about as much by product lignin as it does chemical pulp. This is avail able as a very low cost raw material (fuel replacement value at most) and yet the quantity of lignin that is con verted into profitable products is minute. The difficulty is that lignin is not an ideal feedstock, and is unlikely to be come one until crude oil prices are much higher than at present.

Over half of the oil produced is used to make transport fuels. In the near future, these are likely to be partly re placed with ethanol or other liquid chemicals produced from sugars and poly saccharides. The technology used here is much more familiar to the pulp and alcoholic bever age industries than to the oil industry, and there is scope for the pulp industry to grow by serving this market.

The next largest use for oil is probably as a fuel for station ary units. At the present state of development of synthetic fuels, it is much more economic to fire such units with solid biomass (or in some cases to use gasified biomass) than to go to the expense and complexity of producing synthetic liquid fuels.

Only about 15% of oil ends up as ‘other products’ – includ ing bitumen, petrochemicals, polymers, fibres and solvents. As oil becomes scarce and more expensive, we can expect bio mass to replace it for some of the ‘easier’ applications (such as ethanol). The remaining oil produced will be used to produce these other chemicals – but in competition with organics derived from bio mass. We can expect there to be a gradual shift with the products which can be most easily (and cheaply) be made from biomass moving to this route first.

Thus any shift to bio refining could represent an opportunity rather than a threat to the pulp and paper industry – possibly through alliances with oil companies and perhaps agricultural processing companies. The challenge will be to take this opportunity.