Process analysis for the simultaneous production of aromatics and syngas from shale gas and CO2

Abstract

The production of benzene, toluene, and xylene (BTX) from shale-derived CH4, C2H6, and C3H8 is considered a promising alternative to their fossil-based counterparts. Herein, we evaluate a production technology for aromatics and hydrogen with non-oxidative and CO2 co-feeding reactions to predict the economics and environmental impact of each process. The optimal process for producing aromatics and hydrogen varies depending on the presence or absence of CO2, and we experimentally confirm the difference in the reaction systems. The operating conditions of both processes are optimized using an experiment-based surrogate model in terms of thermal energy demand and profit of products, which account for the highest portion of BTX production cost. Particularly, the CO2 emissions and economic feasibility of the proposed BTX production processes are compared with those of an ethane cracking center using shale gas and the naphtha reforming/Cyclar process to produce BTX. In the CO2 co-feeding case, the CO2 reduction effect is proven compared to other processes, and the economics was improved by the sale of H2 and CO compared to the non-oxidative BTX production. Furthermore, the BTX production cost reflecting the carbon price is comparable to that of commercial processes; as the carbon price increases, the economics has the potential to outperform existing processes. These findings present a platform for economic evaluation based on CO2 emissions as well as the economic benefits of processes that reduce CO2 emissions for energy-efficient conversion of shale gas into high value-added products.