An integrated framework for sustainable process design by hybrid and intensified equipment

With the increasing concern of the competitive market and carbon emissions, a sustainable, efficient process design becomes more and more important. The task of sustainable process design is to find efficient configurations and operating parameters to produce products or utilize materials. Currently, the scientific community's major focus is on separation synthesis, which aims to identify the best downstream separation configurations through different methods such as optimization, heuristic, and hybrid methods. Besides, innovative separation techniques with lower capital/operating costs and carbon emissions were proposed and identified to further improve the downstream process performance. However, most of the separations synthesis methods were based on conventional unit operations and usually applied for generating sustainable processes with a given reaction pathway without considering the possibilities of different raw materials. Generally, to produce a given target product, multiple reaction pathways are available, and each reaction pathway leads to different downstream processes. Also, applying intensification in the early stages of process design, e.g., separation synthesis, can generate sustainable process flowsheets with higher energy efficiency and lower environmental impact. This work aims to develop an integrated process synthesis framework, which includes reaction synthesis for the reaction pathways selection and separation synthesis involving intensified/hybrid units. So, for the new process design, given the product one needs to produce, this framework could identify the optimal reaction pathway with its best separation route. The developed framework was used to solve three case studies, including the new process design of dimethyl carbonate (DMC) production and retrofitting design of cumene and styrene production. For all the case studies, the framework was able to generate multiple innovative solutions that are sustainable and energy-efficient.