Environmental Engineering Reference
In-Depth Information
Chapter III
B
IOMATERIALS
A.
P
ROBLEM AND
S
IGNIFICANCE
1. Overview of Importance
The worldwide production of plastics reached 260 billion pounds per year at the end of
the 20th century, with a value of over $310 billion to U.S. economy in 2002 [1]. Large
quantities of petroleum are used to produce present-generation plastics, but oil is of finite
supply, and as world economies continue to develop oil it will become more and more
expensive [2]. Additionally, pollution results from the manufacture, use, and disposal of
plastic materials. As the world's finite supplies of petroleum are used up, and as the growing
industrial economies of China and other regions continue to rapidly boost demand, oil prices
are skyrocketing, along with the prices for all products that rely on oil supplies.
Moreover, the increased demand is driving us to drill in sensitive areas and to use lower-
grade crude oils that are less economical and that contain contaminants that threaten the
environment. However, plastics offer profound societal benefits, including increased
agricultural production, reduced food spoilage, reduced fuel consumption in lighter-weight
vehicles, better health care, and low-cost, net-shape manufacturing. We need plastics, but the
financial hardship consumers are feeling at the gas pump from increasing prices is also
sharply impacting the plastics industries where production costs are rising and being passed
on to the consumer. What will happen to our environment, to human and animal health, and
to the plastics industries-the fourth largest manufacturing sector of the U.S. economy
employing more than 1.2 million citizens (1)-if sustainable technologies are not developed
and deployed? While energy recovery through combustion, recycling, and minimizing use of
plastics all aid pollution prevention, a new paradigm is emerging that holds great promise—
namely the production of plastic materials using renewable resources as feedstocks. This
approach is becoming increasingly viable due to advances in industrial biotechnology.
It can be argued that using bioengineering techniques to make plastic materials is more
economically favorable than using these same techniques to make fuels. The reason for this
economic advantage is simply that plastics have a greater value than fuels. Consider gasoline
at a retail price of $3 per gallon; the price before taxes would be approximately $2.25-$2.65
per gallon. This means that for approximately $2.50, about 7 pounds of gasoline can be
purchased; that is, the price per pound is about $0.35. For comparable crude oil prices,
commodity plastic resins would cost anywhere from $0.50 per pound to upwards of $3.00 per
