新型煤化工的生命周期碳排放趋势分析

Anylysis on Carbon Emission Based on the Life Cycle of New Coal Chemical Industry

近年来新型煤化工的发展势头强劲,不仅使煤转化过程的碳排放有大幅增长的趋势,更会带动整个产业链碳排放的增长。为了全面认识新型煤化工发展给气候变化带来的潜在影响,本文采用生命周期评价的方法,以煤制烯烃、煤间接液化、煤直接液化、煤制天然气作为新型煤化工的代表,分析了从煤炭生产到产品消费的整个产业链的碳排放现状和趋势。结果显示,从生命周期的角度认识煤化工发展带来的碳排放潜力,中期新型煤化工生命周期CO2eq（CO2当量）排放量是现状的10倍,远期甚至达到现状的21倍,新型煤化工发展呈现过热势头,这给我国的碳减排目标带来不容忽视的压力,其中尤以煤制天然气、煤经甲醇制烯烃和间接液化发展潜力较大;分析表明,整个产业链的碳排放主要来自于煤转化过程,约占54%63%,然而该环节排放的CO2纯度较高,适于碳捕集、利用和封存（CCUS）,可以显著降低新型煤化工快速发展给气候变化带来的影响;其次,新型煤化工上下游产业链碳排放约占37%~46%,其中用电导致的间接排放占7%15%,可通过推广超临界和超超临界发电技术以及高压和超高压输电技术减排。

New Coal Chemical Industry is developing vigorously recently, which not only leads to a significant carbon emission growth from coal conversion, but also from the upstream and downstream industrial chain. In order to comprehensively figure out the potential influence of New Coal Chemical Industry to climate change, Life Cycle Assessment method is used to calculate the current and potential CO2 emission of coal to olefins（CTO）, direct coal to liquid（CTL）, indirect CTL, and coal to synthetic natural gas（SNG）. The result shows that, the CO2 eq emission in the middle term will be 10 times as much as the present value, and the emission in the long term emission will be 21 times as much as the present value. The New Coal Chemical Industry is overheating and it will bring significant pressure to carbon emission reduction goal of China. Coal to SNG contributes the most to carbon emissions growth, followed by CTO and indirect CTL. 54 %–63 % of CO2 comes from the conversion process which has high purity and could be significantly decreased by CCUS. The CO2 emission from upstream and downstream industrial chain accounts for about 37 %–46 %, in which the indirection emission due to electricity usage accounts for 7 %–15 %, which could be reduced through the promotion of the supercritical and ultra-supercritical power generation technology, and the high and ultrahigh pressure transmission technology.