Systematic Framework for Environmentally Conscious Chemical Process Design: Early and Detailed Design Stages

This paper presents a systematic and hierarchical approach for incorporating environmental considerations into all stages of chemical process design. The complexity of the environmental and economic assessments increases as the design proceeds. The design method integrates computer-aided process simulation with a suite of environmental impact, economic, and decision analysis software tools. At the earliest design stage, the environmental assessment includes emission estimates from major process equipment, considers pollution control efficiency, and generates nine risk-based environmental impact indices. The economic assessment is based on the cost of raw materials and reaction stoichiometry. This assessment method was applied to the selection of alternative feedstocks for a reaction step:  benzene versus n-butane for maleic anhydride (MA) production. Using known yields and selectivities, the n-butane route was shown to be superior to the benzene route in both the raw material cost and environmental impact...