Chemistry Reference
In-Depth Information
Chapter 14: Green Chemistry in Practice
JOSEPH J. BOZELL
1 Introduction
is hyperbole, but the perception is real in society and
the media.
Realisation of the goals of green chemistry will not
occur without their widespread, concerted adoption
by the chemical industry. The industry is the logical
interface between promising laboratory-scale tech-
nologies described in earlier chapters and benefit to
society at large because of its pre-existing infrastruc-
ture for manufacture, isolation and distribution of
products. However, this will not be an easy task.
Many of these new approaches are foreign to the
chemical industry, and will be met with considerable
reluctance and scepticism. The challenge, of course,
is to demonstrate to the industry that these tech-
nologies will simultaneously address their economic
needs as well as the environmental needs of the
world.
The chemical industry has played a key role in the
development of the international economy and is
still a vital part of the world's industrialised nations.
In the USA the impact of the chemical industry can
be seen from its statistics: in 1994, the industry sup-
ported almost a million jobs and shipped 70 000
products at a value of $341.3 billion, which is equiv-
alent to about 1.9% of the gross domestic product.
Moreover, the industry possesses one of the few
trade surpluses in the US economy, which was about
$20.5 billion in 1997 [1].
However, the public's perception of huge smoke-
stacks and sprawling industrial complexes as being a
source of pride in a nation's strength have given way
to those images being representative of ecological
despoilment and environmental havoc, with every
use of the term 'chemical' being preceded by the
adjective 'toxic'. The terms 'black chemistry' and 'red
chemistry' were coined to describe how the public
now views and fears much of the conventional
manufacturing carried out by the chemical industry.
Black chemistry refers to waste as pollution. Red
chemistry refers to the toxic aspects of production,
and disasters such as those experienced by Union
Carbide at Bhopal [2]. Certainly a lot of this imagery
2 What is the Impact of Green Process
Technology on the Chemical Industry?
Implementing new, environmentally friendly tech-
nology in practice will go a long way towards chang-
ing the black and red imagery to green. But
evaluation of the impact of process change, and thus
determination of whether the technology will be
adopted, is an exceedingly complicated issue!
A starting point for qualitative industrial assess-
ment of new technology could be the 12 principles
of green chemistry suggested by Anastas [3]. Devel-
oping a manufacturing route that embodies many of
these elements likely would be perceived as envi-
ronmentally benign. Yet the context of these princi-
ples may not align well with that of the industry.
Pereira has defined 10 qualitative environmental
process objectives that would be important from an
industrial viewpoint [1].
Regardless of qualitative principles, the primary
quantitative issue from an industrial perspective is
that of economics. The chemical industry exists to
make profits and products, in that order. If a process
is no longer profitable, it is jettisoned, either by elim-
ination from the product line or by improvement
through modifications designed to return it to pro-
fitability. This is a reality that must be understood
whenever any new green approach is proposed. The
chemical industry has been very successful in devel-
oping high-yield economical routes for the manu-
facture of a wide range of chemical building blocks
and intermediates. It understands and can manipu-
late existing technologies and primary feedstocks
with amazing control, even at incredibly high annual
production levels [4]. Some of these processes have
been in place for decades. Any new methodology
designed to displace them will be subjected first to a
stringent economic screen and will (in the absence
of legislation
forcing
replacement) be discarded if
338
