Life cycle water footprint and carbon footprint analysis of coal gasification to clean fuel dimethyl ether

Abstract

Dimethyl ether is an ideal clean fuel that can replace diesel and liquefied petroleum gas, and has broad application prospects. The work analyzed the life cycle water footprint and carbon footprint of dimethyl ether production from coal gasification. The research results reveal that the water footprint of coal-to-dimethyl ether under the basic scenario is 11.2667 L H2O/MJ, and the carbon footprint is 0.2716 kgCO2-eq/MJ. In the whole production process, the synthesis of dimethyl ether is the main water consumption unit, occupying 99.70% of the whole water footprint. At the same time, this unit is also the major carbon emission unit, occupying 95.26% of the total carbon footprint. By studying and analyzing the distribution of water consumption and carbon emissions in the production process of dimethyl ether, it is found that power utilization is the major contributor to water footprint, accounting for 68.44% of the total water footprint. Although direct carbon emissions are the main impact on the carbon footprint, with electricity usage accounting for 6.33% of the total carbon footprint, they cannot be ignored. Based on this, the water footprint and carbon footprint of 31 provinces under the influence of power structures are studied. In addition, sensitivity analysis was conducted to study water consumption and carbon emissions under 24 different scenarios. This study introduced the relevant water consumption and carbon emissions in the process of producing dimethyl ether from coal gasification within a certain range, and emphasized the impact of regional differences in power structure on the results. The research results provide important references for reducing resource consumption in the production process of dimethyl ether and formulating environmental investment plans.