Using Sustainability Footprint in Optimization Framework for Prospective Design of Chemical Processes

Using sustainability footprint in optimization framework for prospective design of chemical processes

AIChE Annual Meeting, Salt Lake City, UT, November 8-13, 2015

Debalina Sengupta¹, Rajib Mukherje2¹, Subhas K. Sikdar³, Mahmoud M. El-Halwagi¹

1.       Texas A &M University, College Station, TX

2.       Vishwamitra Research Institute, Crystal Lake, IL

3.       NRMRL, US EPA, Cincinnati, OH,

Abstract

            A chemical product can be obtained by different process pathways involving varying amounts and types of resources, utilities, product, and byproduct formation. Evidently, the sustainability in terms of economic, environmental and social impacts of these processes will vary relatively. When such competing process options are presented, and compared to an existing process pathway, it is necessary to evaluate the most sustainable process among these competing options. Traditional process design stands on process synthesis and process analysis as the two pillars determining the technical and economic viability of the process options. Process integration techniques make use of these syntheses and analyses methods to arrive at the selection of the best process.

Sustainability of a chemical process is generally evaluated with indicators that need process and chemical properties data. These indicators individually reflect the impacts of the process on the respective areas of sustainability. For example, traditional economic indicators represent the economic dimension, environmental indicators the environmental dimension, and human health indicators represent the societal dimension. Process flow and economic data were used to compute the indicators in these categories. In order to choose among several alternative processes an overall comparative analysis is essential. To make a decision on the most sustainable process, the indicators need to be rationally aggregated into a single index. We use the sustainability footprint method (D_e) to evaluate the relative sustainability of each of the competing processes.

             

In this paper, we will present the results of this ongoing research on using the sustainability footprint method as a measure of overall sustainability of a process. We will also report on the research challenges faced during the use of the sustainability footprint method in mixed integer optimization framework for prospective sustainability analyses.