中国中长期碳减排战略目标初探(Ⅳ)——天然气能源在中国的应用前景和碳减排分析

A Preliminary Study on China′s Long and Medium-Term Strategic Goals for Reducing Carbon Emissions(Ⅳ)——Prospect for NG Use in China and Analysis of Carbon Emission Reduction

中国目前天然气在能源消费结构中的比例不到4%。与欧美发达国家相比,中国在商业和居住方面的年人均天然气消费量要低30多倍;按照EIA的中长期预测,中国天然气仅占家庭用能的21%～28%、商业用能的14%～20%,与发达国家大约相差1倍。中国用于发电的天然气使用量不到2%,由于风电比例的提高,非常有必要争取2050年将天然气调峰发电的比率提高到5%以上。如果2030年中国天然气产量达到3000×108m3并加大从国外的进口量,使消费量达到5000×108m3,天然气在能源消费结构中的比率有可能提高到14%。制约中国天然气消费量提高的因素包括国内天然气产量、国外进口量、基础设施建设和天然气价格等。提出2050年中国实现天然气消费量达到6000×108m3和8000×108m3的两个情景,其基础是确保常规天然气产量为2500×108m3,页岩气产量达到1000×108~1500×108m3,煤层气和煤制替代天然气产量达到1000×108~1500×108m3,进口量为1500×108~2500×108m3,这是一个非常艰巨但却有可能实现的目标。如果2050年中国天然气消费量达到8000×108m3的高消费量情景,按照发改委能源研究所设定的节能情景的能源消费总量测算,天然气在一次能源消费结构中的比例可上升到14%;按低碳情景测算,天然气的比例可上升到18%;按强化低碳情景测算,天然气的比例可上升到20%,达到目前世界的平均水平。两个天然气消费情景的二氧化碳排放量分别为7.4×108t和9.6×108t。从各方面而言,增加天然气消费量都是正效应而非负效应。

Natural gas currently represents less than 4% of China′s energy mix.Compared with developed countries in Europe and America,China′s per capita natural gas consumption is more than 30 times lower.According to EIA′s long and medium-term forecast,natural gas represents only 21% to 28% of all energy use in a Chinese household and 14%-20% in a commercial energy consumer,about 100% lower than the shares in developed countries.China uses less than 2% of its natural gas in power production.As the share of wind power in total power production is on the rise,it is very necessary for China to raise the share of power from NG-fired generators serving as power shaving capacity to over 5% by 2050.Is China raises its natural gas production to 3000×108m3 and meanwhile increases natural gas imports to boost its natural gas consumption to 5000×108m3,the share of natural gas in the country′s energy mix is expected to rise to 14%.Factors restraining China′s natural gas consumption from growing further include domestic natural gas production,natural gas import,infrastructure construction and natural gas price.This article presents two scenarios in which China raises its natural gas consumption to 6000×108m3 and 8000×108m3 respectively by 2050.The preconditions for achieving these goals are China′s conventional natural gas production must reach 2500×108m3,shale gas production must reach 1000×108~1500×108m3,production of coalbed methane and coal-derived fuel gas must reach 1000×108~1500×108m3 and natural gas imports must reach 1500×108~2500×108m3.These objectives are tough but still possible to achieve.If China′s natural gas consumption reaches 8000×108m3,the objective in the high-consumption scenario,based on calculations of energy consumption under the energy saving scenario established by the Energy Research Institute of the National Development and Reform Commission′s（ERI）,the share of natural gas in China′s primary energy mix can rise to 14%.If calculations are made under a low-carbon scenario,the share of natural gas in the energy mix can rise to 18%.If calculations are made under an intensified low-carbon scenario,the share of natural gas can rise to 20%,the world′s current average level.The carbon dioxide emissions under the two natural gas consumption scenarios would be 7.4×108t and 9.6×108t respectively.Anyway,the effect of raising natural gas consumption will be positive.