Abstract:
The conversion of methanol to aromatics faces challenges in terms of complex product composition and low product yield. Integrating interaromatics conversion techniques can improve the overall conversion efficiency of methanol to aromatics, but they still suffer from the complicated multi-component matching mechanisms and coupling nonlinearity. Herein, the corresponsive, competitive, symbiotic and cooperative relations between 5 types of reaction products lumped (benzene, toluene, xylene, C
9 and C
10) and 6 kinds of conversion techniques (alkyl transfer of benzene with heavy aromatic hydrocarbons, toluene selective disproportionation, toluene methanol methylation, toluene disproportionation and alkyl transfer, xylene isomerization and heavy aromatics lightening processes) were studied. A superstructure model of the reaction products and conversion techniques was constructed to uncover all plausible paths, which involve component species and distribution, technique types and size, and connecting forms. The superstructure model is further converted into nonlinear programming equations in order to identify the optimal solution through computation. Based on the optimal path identified, an efficient coupling method for the conversion of methanol to aromatics was proposed and the multi-component coupling mechanism of reaction products and conversion techniques revealed. This resulted in the direct conversion of hydrocarbon elements sourced from reaction products to
p-xylene and improvement of the product yield. Finally, it was shown that the yield of
p-xylene could be increased from 12.73% to 44.47% with the aid of the proposed method.