Agricultural Residues
ALVIN   C.   DALE
Associate in Agricultural Engineering
Purdue University
Lafayette, Indiana
Attempts to utilize agricultural residues and wastes are not new.
As early as 170 B. C. Romans were separating starch from a type of
corn. In 1800 a British act prohibited the manufacture of starch from
wheat due to a dangerous food shortage of that era. Most of these
early uses for residues were probably the result of chance discoveries
on the part of very observing individuals.
In the eighteenth and nineteenth centuries scientists began investigating the composition of plants. With their new knowledge came new
uses for plant residues. The majority of these uses were based on
chemical pulping of the residues to reduce them to a cellulose fiber
suitable for manufacture of paper. In 1828 wheat and rye straw were
being pulped for paper. By 1930 the interest of several outstanding
leaders in the fields of agriculture, science, and industry had become
aware of the potential value of concerted research into the industrial
utilization of agricultural products. In May, 1935, the National
Farm Chemurgic Council was formed to further research of this type.
POTENTIAL   OF   AGRICULTURAL   RESIDUES
Agricultural residues include cornstalks, corn cobs, straws, stems,
stalks, bagasse, hulls, etc. The United States Department of Agriculture estimates that 200 million tons of these residues are produced annually in this country. Of this total less than 1% is used industrially
for the production of such materials as strawboard, insulating board,
straw paper furfural, and many other materials. Hence, an enormous
amount of raw materials is being wasted each year.
An important fact regarding agricultural residues is that when the
chemist and engineer succeed in solving the problems involved in converting these materials into products which are suitable for processing
there will be sources of supply which would be replaced annually.
The quantity of residues readily available is dependent upon concentration of production, farm practices, and uses made of them on the farm.
The cost of these residues to industry is made up chiefly of collection
and transportation costs which in many instances in the past have
been higher than industry could bear.
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