Environmental sustainability improvement in chloromethanes production based on life cycle assessment

Abstract

Chloromethanes (CMS), as major chlorine-consuming products and upstream raw material for emerging industries, play an irreplaceable role in the chemical industry and impose non-negligible environmental pressure during production. This study adopted the cradle-to-gate life cycle assessment approach to quantify the environmental performance of CMS production in China by using integrated data from five CMS enterprises, which underpin approximately 21 % of China's total CMS production capacity. An integrated and regionalized life cycle impact assessment method was employed to suit Chinese conditions and avoid spatial differences. The results indicate that fossil depletion is the dominant impact category, which was ascribed mainly to methanol production (37.0 %), electricity generation (27.3 %), and steam production (23.4 %). The coke oven gas-to-methanol process shows superiority in mitigating fossil consumption and CO 2 emission compared with the traditional coal-to-methanol process, with reduction ratios of 80.3 % and 83.2 %, respectively. Renewable energy power generation and pollution transfer in inter-regional power transmission also deserve attention. Green methanol, waste heat reuse, and advanced heat recovery technologies are recommended for further alleviation of the environmental burden. In addition, CMS-related industrial chains can improve industrial concentration and promote integrated development to achieve high-efficiency utilization of raw materials and energy.