Emergy evaluation of aromatics production from methanol and naphtha

Aromatics are traditionally produced by the catalytic reforming of naphtha.However,with the demand of aromatics increasing and the reserves of petroleum resources declining,measures should be made to reduce the dependence of aromatics production on petroleum resources.Methanol-to-aromatics is proved to be an effective way to replace traditional naphtha-to-aromatics path.In order to compare the economic and environmental performance of aromatics production from naphtha and methanol,this paper carries out an emergy evaluation for each system by sorting out the simulation and literature data.Based on the emergy data collected,the emergy indices of each system are calculated.The results show that the sustainabilities of methanol-to-aromatics systems are higher than that of the naphtha-toaromatics system,indicating the advantages of aromatics production from methanol.Among the methanol-to-aromatics systems,the aromatics from biomass-methanol system has the highest sustainability,indicating that the biomass based methanol-to-aromatics system is worth promoting.The sustainability indexes of methanol-to-aromatics systems based on coal and coke oven gas are less than 1,which means unsustainable.Meanwhile,the sustainability of natural gas based system is slightly higher than 1.The economic and environmental benefits of these systems can be optimized by improving resource utilization and reducing investment costs.Furthermore,the combination of different raw materials for methanol production should be considered.