Chap. 12. Feedstocks 307reactions produce byproduct materials from the feedstock and from spent reagent. Their
impacts can be reduced by reclaiming byproducts, if a use can be found for them, and by
regenerating reagent, when that is possible. In some cases, elimination reactions can be
carried out without use of a reagent, reducing the impact of this kind of reaction.
+
Feedstock AFeedstock BAddition
Product containing
all the material
originally in
feedstocksFeedstockSubstitutionReagentProductByproductsFeedstockEliminationReagentProductByproductsreactionreactionreactionFigure 12.1. Illustration of three major categories of reaction processes by which feedstocks are acted
upon by reagents to produce desired products.
12.3. Biological Feedstocks
Organisms have provided a huge share of the materials used by humans throughout
their existence. Trees have served as sources of wood for construction and firewood.
Animals provided hides and fur to protect primitive humans from Ice Age cold. The
American bison was the source of food, shelter, clothing, and a wide variety of other
useful items to plains-dwelling Native Americans. Protein silk is obtained from the
cocoons of insects, and protein wool from sheep and related animals.
Biomass, the plant material generated from photosynthesis is the leading candidate
to replace petroleum as a feedstock for the organic chemicals industry. There are several
major categories of biomass that can be used for feedstock: