Integration of Methanol Aromatization with Light Hydrocarbon Aromatization toward Increasing Aromatic Yields: Conceptual Process Designs and Comparative Analysis

Methanol aromatization occurs with considerable byproducts of light hydrocarbons, resulting in a low yield of benzene, toluene, and xylene (BTX). This work proposes two novel process designs by integrating methanol aromatization with light hydrocarbon aromatization to increase the BTX yield so as to increase profitability and sustainability. For a comprehensive analysis, detailed process simulation models are developed in Aspen HYSYS for the two integrated processes with C3–C5 hydrocarbon single-pass conversions of 35, 55, 75, and 95%. On this basis, technoeconomic analysis and life cycle assessment are conducted for eight cases to systematically compare their profitability and sustainability measured by the net present value and greenhouse gas emissions, respectively. Advantages of the two integrated designs over the nonintegrated methanol to aromatics design are also explored. The results show that integrating light hydrocarbon aromatization with methanol aromatization can significantly increase the BTX yield and net present value by over 49 and 204%, respectively. Besides, producing BTX from the two integrated designs can lower greenhouse gas emissions by 9.87–15.20%. This study also finds that preseparation of the light hydrocarbon aromatization product shows better profitable and sustainable performances than direct coprocessing of the two aromatization products.