Methanol Aromatization for the Co-Production of Para-Xylene and Light Olefins: Process Simulation and Evaluation

Methanol conversion contributes to the development of Methanol Economics and serves as a route to solve the problem of methanol overcapacity, as well as a means to alleviate the dependence of chemicals on petroleum resources. This work designs the process of methanol aromatization for the coproduction of para-xylene and light olefins. Dividing-wall column and crystallization technology are adopted during aromatics separation and para-xylene recovery from mixed xylenes, while heat pump distillation is used for the para-xylene enrichment of the uncrystallized xylenes. The light olefins in the product are refined with the widely used Lummus technology in industries. Based on this process, energy consumption, economic, and environmental analyses are systematically conducted. The use of dividing-wall columns and heat pump distillation can effectively reduce energy consumption by approximately 14.27%. Techno-economic evaluation finds that the introduction of energy-saving technology exhibits favorable economic attractiveness, and the project remains profitable as long as the methanol price is less than 383.41 $/ton and the product price of para-xylene is not less than 898.70 $/ton. Furthermore, the use of dividing-wall columns and heat pump distillation can lower the global warming potential by 0.1225 × 103 kg CO2-eq/ton. Overall, this work provides a foundation for the research and process design of methanol aromatization.