关键词: 煤制天然气；碳排放；生命周期；环境影响 

Abstract: China has long been using the coal as the major energy, leading to a severe environmental pollution. China is speeding up to reform the natural gas marketization so that coal-made gas as a supplement to the routine natural gas gains a fast growth, but remains its economy and environmental impacts questionable because a carbon emission accounting model of coal-made gas has not been systematically established in China, which is fundamental to study its carbon emission. This paper uses mass balance to emission factor to set up a carbon emission accounting model of coal-made gas in its entire life cirle that is employed to estimate the carbon dioxide emission based on a case study on KQ coal-made gas in its entire life circle, and compares it with the traditional coal path, and presents suggestions for China's coal-made gas industry on low-carbon emission reduction, offering references and decision-making basis in promoting coal-made gas industrial development. 

Key words: coal-made gas, carbon emission, life circle, environmental impact