气煤联供实现资源高效利用和碳减排技术进展

Review on coal and gas co-feed processes for better resource use and lower carbon emission

为解决煤化工过程资源利用率低和碳排放高的问题,有研究者提出以天然气、焦炉气、页岩气等富氢资源和煤炭资源联供方案,旨在实现源头碳减排。文章指出依据联供过程技术的差异,较有代表性的方案可分为集成甲烷部分氧化和集成甲烷干/水蒸气重整的气煤联供过程。文章以生产甲醇为例,从资源利用和经济效益等方面对集成甲烷部分氧化和集成甲烷干/水蒸气重整的气煤联供过程进行分析和比较。集成甲烷部分氧化的工艺碳元素利用率达到57.9%,每吨甲醇排放CO_2为1.50t,较传统煤制甲醇工艺排放减少37.5%。甲醇产品成本稍低于传统工艺。集成甲烷干/水蒸气重整工艺的碳元素利用率最高,达到83.7%。减排效果最明显,每吨甲醇排放CO_2为0.90t,较传统工艺排放减少62.5%,但是由于CO_2转化增加能耗,甲醇产品成本有所提升。由于气煤联供过程有利于CO_2减排,当碳税高于65CNY/tCO_2时,两个气煤联供工艺的生产成本低于传统的煤制甲醇工艺。

The low resource efficiency and high carbon emission are severe in coal chemical industries.A great number of co-feed processes of coal and hydrogen-rich gas were proposed to achieve carbon reduction at source.The integrated hydrogen-rich gas includes natural gas,coke-oven gas and shale gas.The representative co-feed processes can be divided into the co-feed process integrated with methane partial oxidation(MPO)and the co-feed process integrated withdry/steammethane reforming(DMR/SMR)according to the differences in process.Tech-economic analysis was conducted for these two processes by means of resource utilization and economic performance,compared with the conventional coal to methanol(CTM)process.The co-feed process with MPO has higher carbon elemental utilization ratios up to 57.9%.It emits 1.50t CO2 per ton methanol,giving 37.5% reduction.It has a slightly lower production cost.The process integrated with DMR/SMR has the highest carbon utilization ratios of 83.7%.The carbon emission reduction effect is the most obvious.This process emits 0.90t CO2 per ton methanol,which is 62.5% lower than the traditional process.It has a slightly higher production cost brought by the energy consumption of CO2 conversion.With the carbon tax higher than 65CNY/t,the advantage of these co-feed processes is emerging on economy due to its carbon reduction.