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Americans. Some of the existing removal processes, although very simple in theories
and principles, are considered to be economically unfeasible by industry and govern-
ment leaders. For example, carbon dioxide could be easily removed by a wet scrubbing
process, but the technology is not considered cost-effective, because the only reuse is
the solution in the process. In response, President Bush decided not to regulate carbon
dioxide emission at industrial plants. He also rejected the Kyoto international global
warming treaty, but US EPA Administrator Christine Todd Whitman stated: “We can
develop technologies, market-based incentives and other innovative approaches to
global climate changes.”
9.4.3. Carbon Dioxide Reuse
An industrial ecology approach to carbon dioxide has been extensively studied
(decarbonization) by Wang and his associates (25,26,33) at the Lenox Institute of
Water Technology in Massachusetts. Their studies showed that decarbonization is
technically and economically feasible when the carbon dioxide gases from industrial
stacks are collected for in-plant reuse as chemicals for tanneries, dairies, water-treat-
ment plants, and municipal wastewater plants. It is estimated that tannery wastewater
contains about 20% of organic pollutants. Using the tannery’s own stack gas (contain-
ing mainly carbon dioxide), dissolved proteins can be recovered from the tannery
wastewater. Recovery of protein can also be accomplished at a dairy factory. By bub-
bling dairy factory stack gas containing mainly carbon dioxide through dairy factory
wastewater stream, about 78% of the protein in the stream can be recovered. Stack gas
containing mainly carbon dioxide can be used at a water-treatment softening plant as
a precipitation agent for hardness removal. Neutralization and warming agent can be
accomplished at a municipal wastewater-treatment plant by using stack gas containing
carbon dioxides. At plants that produce carbon dioxide gas, a large volume of carbon
dioxide gases can be immediately reused as chemicals in various in-plant applications,
which may save chemical costs, produce valuable byproducts, and reduce the global
warming problem.
9.4.4. Vehicle Emission Reduction
A second industrial ecology approach is to develop a new generation of vehicles
capable of traveling up to 80 mpg while reducing nitrogen oxides, carbon dioxide, and
hydrocarbon levels. Specifically, a “supercar” is to be developed to meet the US EPA’s
Tier 2 emission limits (33). There are growing health concerns about persistent bioac-
cumulative toxics that are produced from the combustion of coal, wood, oil, and current
vehicle fuels (46).
The issues of energy versus environment have been continuously discussed by many
scientists and policy-makers (44–46). In the United States, automakers are racing to
build hybrid vehicles and fuel-cell vehicles (53). On January 29, 2003, President
George W. Bush announced a $1.2 billion Freedom Fuel Program to speed the develop-
ment of hydrogen-powered vehicles in 17 yr using fuel-cell technology (58,61,65). Fuel
cells create energy out of hydrogen and oxygen, leaving only harmless water vapor as
a byproduct of the chemical process. For automobiles, this would end their damaging
air pollution and eliminate American dependence on foreign oil. Menkedick discusses
the energy and the emerging technology focus (46).