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Producing aromatics from coal via methanol is a novel technology, which could mitigate the energy shortage in a petroleum-poor area. However, the selectivity of methanol to aromatics is merely 40−70 wt % due to the byproducts of light hydrocarbons. In this paper, three novel designs are proposed to improve the aromatics yield by directly or indirectly converting light hydrocarbons into aromatics. In addition, cofeeding of coal and natural gas is applied in two of the three designs. On the basis of detailed process modeling and simulation, the process designs are assessed by mass balance, technoeconomic, and life cycle analyses. The results show that the aromatics yield is significantly improved by integrating light hydrocarbon conversion units. The CO 2 emissions and water consumption are notably decreased in the two cofeeding designs. In addition, the net present value of the design integrated with steam reforming of C 2− hydrocarbons and aromatization of C 3+ hydrocarbons is the highest, about 1.9 times as much as that of the nonintegrated design. The cofeeding design integrated with steam reforming of C 2− hydrocarbons and aromatization of C 3+ hydrocarbons leads to the lowest global warming potential and abiotic depletion potential, only 46.1 and 71.1% of the nonintegrated design, respectively. It implies that a more complex design shows better environmental performances.

This work develops a novel superstructure considering a reaction−separation system for aromatics production from methanol, which consists of methanol aromatization, water removal, product separation, and light hydrocarbon aromatization units. On the basis of rigorous simulation of these units in Aspen HYSYS, a multiobjective simulation−optimization model is established for synthesis of methanol to aromatics process to simultaneously optimize the net present value and unit ReCiPe score. A matrix-based method is proposed to determine the Pareto-optimal curve and identify the optimal production routes through data interaction between MATLAB and Aspen HYSYS. The most profitable production route generates a net present value 39.0% higher than the lowest one, and the most environmentally sustainable production route shows a unit ReCiPe score 66.42% lower than the worst one. Monte Carlo simulation is used to investigate the effects of uncertain economic parameters on the three obtained Pareto-optimal production routes, which present robustness in the face of fluctuations of raw material and product prices as well as capital investment. Besides, the optimal production routes for variant reaction effluents are also analyzed to show the insight in production route selection.