ABSTRACT
Most organic chemicals in use today are derived from nonrenewable petroleum and natural gas, with some still being made from coal. After use, the bulk of these ultimately end up as carbon dioxide, the main greenhouse gas that is causing global warming. For a sustainable future,1 these must be based on renewable resources2 from elds and forests. Before the advent of cheap petroleum and natural gas, many of them were. It is instructive to look back at these older methods to see if they might be economical today if the cost of global warming were included in the prices of the organic chemicals that we use. Further optimization of the processes with the knowledge that has accumulated since they were in use should increase yields and lower costs. Biocatalysis (see Chapter 9) is an example. Formerly it was used more for the production of commodity chemicals than it is today. Some of these earlier fermentation methods have not been studied much lately. Because energy is often a large factor in producing chemicals, renewable sources (see Chapter 15) will have to replace the fossil fuels used today. Biocatalysis with renewable raw materials has become more popular with the recent escalation of prices for oil and gas. The adoption of such sources of energy and raw materials will cut the amount of acid rain substantially, for there is not much sulfur in either the raw materials or the fuels.
