绿氢在石化和化工行业的减碳经济性分析

Carbon reduction and techno-economic analysis of using green hydrogen in chemical and petrochemical industry

通过使用可再生能源电力电解水所制取的氢气(即绿氢)来替代使用煤炭、天然气等化石燃料所制取的氢气(即灰氢)作为石化和化工原料,可以促进石化和化工行业低碳转型。虽然当前绿氢成本较高,但在电价不断下降、化石能源价格持续上涨以及碳税、碳交易的综合影响下,绿氢的经济性将具有与灰氢相竞争的优势。本文以石化和化工行业中氢气消费量和碳排放量最高的三个子行业为研究对象,即合成氨、合成甲醇、原油加工,首先介绍了氢气参与到石化和化工过程中的工艺特征和发展趋势,包括传统工艺和新兴工艺,如电化学合成氨、二氧化碳加氢制甲醇、生物油加氢脱氧;接着,对石化和化工行业碳排放进行总结,重点分析了氨、甲醇、精制柴油的碳排放强度;最后,对绿氢替代当前化石燃料制氢、工业副产氢的减碳经济性进行分析,结果表明在碳交易价格为100CNY/t时,绿氢具有替代煤制氢的经济可行性成本为14CNY/kg。

The low-carbon transformation of the petrochemical and chemical industries can be promoted by replacing hydrogen(i.e.,gray hydrogen)made from fossil fuels such as coal and natural gas by hydrogen(i.e.,green hydrogen)made from electrolysis of water using renewable energy power as petrochemical and chemical raw materials.Although the current cost of green hydrogen is higher,under the combined influence of decreasing electricity price,continuous increase of fossil energy price and carbon tax and carbon trading,the economy of green hydrogen will have the advantage of competing with gray hydrogen.Taking the three sub-sectors with the highest hydrogen consumption and carbon emission in the petrochemical and chemical industries as representatives,namely ammonia,synthetic methanol,and crude oil processing,this paper firstly introduces the process characteristics and development trends of hydrogen participation in petrochemical and chemical processes,including traditional and emerging processes,such as electrochemical ammonia synthesis,carbon dioxide hydrogenation to methanol,and bio-oil hydrodeoxygenation;then,the carbon emission of the petrochemical and chemical industries is summarized,focusing on the carbon emission intensity of ammonia,methanol,and refined diesel;finally,the carbon reduction economics of green hydrogen replacing current fossil fuel hydrogen production and industrial by-product hydrogen is analyzed.The results show that green hydrogen has an economically feasible cost of 14CNY/kg H_(2) to replace coal hydrogen when the carbon trading price is 100CNY/t.