Green Engineering: Environmentally Conscious Design of Chemical Processes

Chapter 14Industrial Ecology

byDavid T. Allen

14.1 Introduction

The environmental performance of chemical processes is governed not only by the design of the process, but also by how the process integrates with other processes and material flows. Consider a classic example—the manufacture of vinyl chloride.

Billions of pounds of vinyl chloride are produced annually. Approximately half of this production occurs through the direct chlorination of ethylene. Ethylene reacts with molecular chlorine to produce ethylene dichloride (EDC). The EDC is then pyrolyzed, producing vinyl chloride and hydrochloric acid.

Cl₂ + H₂C=CH₂→Cl H₂C-CH₂Cl

Cl H₂C-CH₂Cl → H₂C=CH Cl + HCl

In this synthesis route, one mole of hydrochloric acid is produced for every mole ...