Page 34 - Sustainability in the process industry

CHAPTER 2

Process Integration

2.1 Introduction: The Need for Process Integration

Energy and water saving, global warming, and greenhouse gas
emissions have become major technological, societal, and political
issues. These issues are of strategic importance because they are all
closely related to energy supply. Numerous studies have been
performed on the subject of improving energy efficiency while
reducing emissions of greenhouse gases, volatile organic compounds,
and other pollutants.
In response to these industrial and societal requirements, several
novel methodologies emerged since 1970. They included process system
engineering (Sargent, 1979; Sargent, 1983) and “Process Integration”
(Linnhoff et al., 1982; Linnhoff et al., 1994) followed by a number of
works from the UMIST Group. Both disciplines were involved in dedicated
conferences such as ESCAPE (European Symposium on Computer
Aided Process Engineering), which was facilitated by the European
Federation of Chemical Engineering Working Party on Computer
Aided Process Engineering (CAPE, 2009), and PRES (Conference on
Process Integration, Modelling and Optimisation for Energy Saving
and Pollution Reduction; PRES, 2009), which is supported on an annual
basis by chemical and chemical engineering societies (e.g., Hungarian
Chemical Society, Czech Society of Chemical Engineering, Italian
Association of Chemical Engineering, Canadian Society for Chemical
Engineering). It has gradually become evident that resource inputs and
effluents of industrial processes are often connected to each other.
Examples of this connection include the following:
1. Reducing external heating utility is usually accompanied by
an equivalent reduction in the cooling utility demand
(Linnhoff and Flower, 1978; Linnhoff et al., 1982; Linnhoff
et al., 1994); obviously, this also tends to reduce the CO
2
emissions from the corresponding sites.
2. Reducing wastewater effluents usually leads to reduced
freshwater intake (Wang and Smith, 1994; Bagajewicz, 2000;
Thevendiraraj et al., 2003).

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