c / 7 . 5 — The Chemical Industry • 91 
OtlK’r plant carbohydi'atos include corn- 
starch, molasses, and lignin. I'he last, a polymer 
tbiind in wood, could he used as a |)i'ecursor I'oi' 
the hiosynthesis of aromatic (benzene-like) 
chemicals, making their production simpler and 
moi’e economical. ,\e\ ertheless, the increase in 
the |)i'i('e of peti'oleum is not a sufficient reason 
for switching raw matei'ials, sinc'e the cost of 
carholn cirates and other biological materials 
has been inci'easing at a relati\ e rate. 
PHVSICALI.V MILDER CONDITIO, \S 
In general, there are two main ways to speed 
chemical I'eactions: by increasing the reaction 
tempei'ature and by adding a catalyst. ,\ catalyst 
(usualK a metal oi' metal com[)le.\l causes one 
specific reaction to occur at a faster rate than 
others in a chemical mi.xtui’e by [)io\ iding a sur- 
face on which that reaction can he pi'omoted. 
E\en using the most effecti\ e catalyst, the con- 
ditions needed to accelerate industrial organic 
reactions often require e.xtremely high tem- 
peratures and pressures— sexeral hundred de- 
grees Celsius and se\eral hundred pounds per 
square inch. 
Biological catalysts, or enzymes, on the other 
hand can speed-up reactions without the need 
for such e.xtreme conditions. Reactions occur in 
dilute, aqueous solutions at the moderate condi- 
tions of temperature, pressure, and pH (a meas- 
ure of the acidity or alkalinitx’ of a solution) that 
are compatible w ith life. 
ONE-STEP PRODUCTION METHODS 
In the chemical synthesis of compounds, each 
reaction must take place separately. Because 
most chemical reactions do not yield pure prod- 
ucts, the product of each indi\ idual reaction 
must be purified before it can be used in the 
next step. This approach is time-consuming and 
expensixe. If, for example, a synthetic scheme 
that starts with ethylene (a petroleum-based 
product) requires 10 steps, with each step yield- 
ing 90 percent product (very optimistic yields in 
chemical syntheses), only about one-third of the 
ethylene is conx erted into the final end product. 
Purification may be costly; often, the chemicals 
inx’olx ed (such as organic solx ents for extrac- 
tions) and the byproducts of the reaction are 
toxic and require special disposal. 
In biological systems, micro-organisms often 
complete entire synthetic schemes. The conver- 
sion takes place essentially in a single step, 
although sexeral might occur within the orga- 
nisms, XX hose enzymes can transform the pre- 
cursor through the intermediates to the desired 
end product. Purification is not necessary. 
REDUCED POLLliTION 
.Metal catalysts are often nonspecific in their 
action: xxhile they may promote certain reac- 
tions, their actions are not ordinarily limited to 
making only the desired products. Consec|uent- 
ly, they haxe sexei'al undesirable features: the 
formation of side-products or byproducts; the 
incomplete conxersion of the starting materi- 
al(s); and the mechanical and accidental loss of 
the product. 
The last pi'ohlem occurs xvith all types of syn- 
thesis. rhe first txxo represent inefficiencies in 
the use of the raxv materials, lliese necessitate 
the separation and recycling of the side-prod- 
ucts formed, xvhich can he difficult and costly 
because they are often chemically and physi- 
cally similar to the desired end products. (Most 
separation techniques are based on differences 
in physical properties— e.g., density, volatility, 
and size.) 
W hen byproducts and side-products have no 
x alue, or xvhen unconx erted raxv material can- 
not be recycled economically, problems of 
xxaste disposal and pollution arise. Their solu- 
tion requires ingenuity, xlgilance, energy, and 
dollars. Many present chemical processes create 
useless xxastes that require elaborate degrada- 
tion procedures to make them environmentally 
acceptable. In 1980, the chemical industry is ex- 
pected to spend S883 million on capital outlays 
for pollution control, and xvell over $200 million 
on R&D for new' control techniques and re- 
placement products. These figures do not in- 
clude the millions of dollars that have been 
spent in recent years to clean up toxic chemical 
dumps and to compensate those harmed by 
poorly disposed xvastes, nor do they include the 
cost of energy and labor required to operate 
pollution-control systems. 
A genetically engineered organism, on the 
other hand, is designed to be precursor- and 
