Sustainable Process Intensification Using Building Blocks

In an immensely competitive market, many chemical plants need to increase their productivity for meeting the growing demands of chemical products, but at the same time, reduce the use of fresh raw materials and utilities to stay profitable. As the environmental regulations become stricter than before, they also need to reduce emissions and become environmentally sustainable. When resources are scarce, intensification and sustainability are the only choices for survival. However, there exists inherent trade-offs between the economics and the environmental sustainability of chemical process systems. In this work, we ask whether systematic process intensification can break through the current barriers posed by these trade-offs and lead to novel designs which are not only more economic, but at the same time, are also environmentally more sustainable compared to their non-intensified counterparts. Our recently proposed building block-based representation provides a systematic approach to analyze this, and we pose the sustainable intensification problem as a multi-objective MINLP optimization problem, which is solved using ε-constraint method. Here, we demonstrate the methodology with a case study on ethylene glycol production and show that intensification could make chemical processes significantly more sustainable compared to the base case.