Design and analysis for chemical process electrification based on renewable electricity: Coal-to-methanol process as a case study.

• Indirect and direct electrification of coal-to-methanol process are investigated. • Energy efficiency of the semi-electrification scenario reaches to 64.31 %. • Semi-electrification scenario achieves the minimum CO 2 emissions. • Total production cost of semi-electrification scenario is 301.0 $/t and a payback time of 4.13 years. • Fully-electrification scenario is not an ideal choice from comprehensive performances comparison. Electrification of traditional large-scale chemical industry based on renewable electricity can greatly reduce process CO 2 emission, and store intermittent renewable electricity into chemical products locally to decrease power grid frequency regulation caused by fluctuating renewable electricity. This study presents a framework for electrification of chemical industry from indirect and direct aspects using the state-of-art coal-to-methanol process as a case study. Traditional coal-to-methanol (Process 1) suffers from high CO 2 emission due to mismatch of H/C ratio between coal and methanol. A pulverized coal gasification-integrated SOEC process (Process 2) has been investigated, the water–gas-shift unit is avoided and a simplified acid gas removal process is implemented to replace traditional acid gas removal unit in Process 2. Electric heaters and heat pump system are applied in Process 2 as direct electrification methods to form semi-electrified scenario (Process 3). To discuss the effect of electrification levels on process performances, a fully electrified process (Process 4) is also designed. The results show that: CO 2 emissions of the four processes are 2.19, 0.71, 0.52 and 0.63 t/t MeOH, and energy efficiency are 57.40 %, 62.32 %, 64.31 % and 57.63 %, respectively. Production costs are 159.1, 294.3, 301.0 and 358.3 $/t MeOH, IRRs are 14, 31, 29 and 14.5 %, respectively. Through this research and analysis, we hope to explore integration potential of renewable electricity and traditional chemical industry, and design a greener methanol production route based on renewable electricity. [ABSTRACT FROM AUTHOR]