Reviews of clean coal conversion technology in China: Situations & challenges

Technological progress and coupling renewables enable substantial environmental and economic benefits from coal-to-olefins

China's growing demand for bulk chemicals and concerns regarding energy security are scaling up coal-to-olefins (CTO) production. Three generations of independent dimethyl ether/methanol-to-olefins technologies have been successively launched with greatly improved production efficiencies. However, to date, widespread concerns regarding the intensive environmental impacts and potential economic risks have not been addressed in the context of this industrialization. Here we show that, through the technological progress from the first to the third generation, life cycle energy consumption, water consumption, and carbon emissions can be reduced to 119.5 GJ/t, 27.6 t/t, and 9.1 t CO2-eq/t, respectively, and human health damage, ecosystem quality damage, and resource scarcity impacts can be decreased by 40.5 %, 50.1 %, and 16.4 %, respectively. This is accompanied by an excellent performance in terms of production cost, net present value, and internal return rate at 792.5 USD/t, 173.4 USD/t, and 19.4 %, respectively. Substantial environmental and economic benefits can be gained by coupling renewables in the form of using green hydrogen from solar and wind power to synthesize methanol. Particularly, life cycle carbon emissions and resource scarcity impacts are reduced by 23.4 % and 22.4 %, respectively, exceeding the reduction in technological progress. However, coupling renewables increases the life cycle energy consumption to 154.5 GJ/t, counteracting the benefits of technological progress. Our results highlight the importance of technological progress and coupled renewables for enhancing the sustainability of the CTO industry.

The impact of China's emission trading scheme policy on enterprise green technological innovation quality: evidence from eight high-carbon emission industries

Emission trading scheme (ETS) is one of the most important ways to mitigate carbon emissions. As the largest carbon emitter in the world, China implemented ETS policy in 2013. Whether ETS policy can boost enterprise green technological innovation (GTI) quality in China remains to be discussed after reviewing the previous studies. All 318 A-share listed enterprises of China's eight high-carbon emission industries from 2008 to 2021 are chosen to investigate the influence of the ETS policy on enterprise GTI quality by the difference-in-difference (DID) method. Furthermore, heterogeneous effects of ETS policy on the quality of enterprise GTI are analyzed from three aspects: enterprise life cycle, corporate environmental management, and industry classification. The findings indicate that China's ETS policy has a positive influence on the quality of GTI in eight high-carbon emission industries. Further heterogeneity analysis demonstrates (1) China's ETS policy has varying effects on the eight high-carbon emission industries; (2) China's ETS policy can improve GTI quality of enterprises in the maturity stage of their life cycle, but not for those in their growth stage. (3) Comparing the effect of China's ETS policy, GTI quality of enterprises with higher environmental management score is stimulated, while GTI quality of those with lower score is not.