Technological approaches and policy analysis of integrated water pollution prevention and control for the coal-to-methanol industry based on Best Available Technology

Abstract

Coal-to-Methanol (CTM) production is an energy- and water-intensive industry that creates considerable industrial pollutants and wastewater. We developed a bottom-up model to analyze reduction potential of industrial pollutants, based on Best Available Technologies (BATs), and to analyze and estimate targets for total pollution control. This paper explores the total pollution control and emission standard approaches of environmental management based on the analysis of water pollution in China's CTM industry. A set of pollution prevention and control systems are built and incorporated into the bottom-up model. In order to project future water pollution emission trends, we designed three scenarios: Baseline scenario (S1), process planning scenario (S2), and technology promotion scenario (S3). Results show that the emission reductions of water pollution via structural adjustments during processing are better than those from upgrading existing technology in China. So best available gasification processes like advanced cleaner production of entrained flow pressurized continuous gasification, and coke-oven gas for methanol should be promoted and systematically installed in new enterprises. A technological upgrade is needed of existing CTM enterprises that use old processes. According to the ranking of water pollution emission reduction potentials, wastewater zero discharge in the ammonia and methanol integrated production and emission reduction of water pollutants in coal-water slurry gasification both have significant and comprehensive mitigation effects on wastewater, chemical oxygen demand (COD) and Ammonia-N. Recommended BATs for reducing industrial pollutants and wastewater can be determined based on emission reduction cost per unit of pollutant required to achieve the emission target for water pollution.