Water-CCUS nexus: challenges and opportunities of China’s coal chemical industry

Abstract

Carbon Capture and Storage (CCS) technology has begun to transform into the boom of CO2 utilization technology, which is of great significance to China considering its coal-based primary energy mix. CO2 utilization technology can be divided into three categories, i.e., CO2 geological utilization (CGU), CO2 chemical utilization, and CO2 biological utilization. In this paper, first, the development status of the different utilization technologies in China is introduced, and then, the situation, distribution, and water characteristics of China’s Coal Chemical Industry (CCI, i.e., an industry to convert coal to synthetic fuel and/or chemical products) are analyzed in detail. Subsequently, utilization technologies suitable for China’s CCI are proposed combining water consumption of CCS technology. The results of this research led to the following conclusions: (1) CO2 utilization technology is undoubtedly the best choice for the CCI; (2) CGU technologies are viewed as the best choices for the coal chemical industry, with supplementary, small-scale chemical utilization of three wastes, i.e., waste gas, wastewater, and industrial residue; (3) The CO2-Enhanced Oil Recovery (EOR), CO2-Enhanced Uranium Leaching (EUL), CO2-Enhanced Coal Bed Methane recovery (ECBM), and CO2-Enhanced (Saline) Water Recovery (EWR) technologies show great promise, and CCI preferentially uses the option with low water consumption, such as CO2-EWR. However, as the carbon market matures, CO2-EOR will become the first priority.