燃气电厂与超低排放燃煤电厂环境及生态效应对比

较之于超低排放燃煤发电,燃气发电是否仍然具有环保与生态方面的比较优势,是我国未来电源结构优化决策时的重要考量因素。为此,基于我国火电行业现有的环保标准,从污染物排放水平、污染物治理产生的问题、碳排放及资源消耗等方面对比了二者的环境和生态效应。研究结果表明:①在实施低氮燃烧改造和加装SCR后,燃气电厂的常规污染物排放量明显低于超低排放燃煤发电;②燃气发电单位度电CO_2排放量较超低排放燃煤发电减少约50%,并可显著节约水资源与土地资源;③由于超低排放燃煤发电存在着SO_3等可凝结颗粒物和重金属排放等问题,因而燃气发电的环保、生态效应优势更为显著。进而提出以下发展建议:①继续加大环保政策力度,鼓励燃气电厂建设;②参照北京、深圳地区对燃气轮机的NO_x排放标准,修订《火电厂大气污染物排放标准:GB 13223—2011》,将全国范围内燃气轮机NO_x的排放限值设定为15 mg/m~3,同时取消对燃气轮机烟尘、SO_2的排放限值;③加快构建和完善全国碳市场并设定"地板价",通过碳价机制形成气候友好的公平竞争市场环境,引导电力企业加快向低碳电力结构转型的步伐。

Comparison of environmental and ecological effects between gas-fired and ultra-low emission coal-fired power generation plants

Whether gas-fired power generation still has the comparative advantages in environmental protection and ecology compared with ultra-low emission (ULE) coal-fired power generation is an important factor to be considered in domestic power structure optimization decision in the future. Based on existing environmental protection standard of domestic fossil-fuel industry, this paper compared the environmental and ecological effects of gas-fired power generation with that of ULE coal-fired power generation from the aspects of pollutant emission level, issues caused by pollutants control, carbon emission and resource consumption. And the following research results were obtained. First, after low-nitrogen combustion modification and SCR installation are implemented in gas-fired power generation, its emission of conventional pollutants is much lower than that of ULE coal-fired power generation. Second, CO2 emission per kilowatt hour of gas-fired power generation is about 50% lower than that of ULE coal-fired power generation. By means of gas-fired power generation, water and land resources can be saved greatly. Third, ULE coal-fired power generation suffers the emission problems of condensable particles (SO3) and heavy metals, so gas-fired power generation is much more advantageous in terms of environmental protection and ecological effect. Finally, several development suggestions were proposed. First, intensify environmental policies continuously and encourage the construction of gas-fired power generation plants. Second, by referring to NOx emission standard of gas turbines in Beijing and Shenzhen, revise the "Air Pollutant Emission Standard of Fossil-Fuel Power Plants (GB 13223-2011)" and set domestic NOx emission limit of gas turbines at 15 mg/m3 and cancel dust and SO2 emission limits of gas turbine. Third, accelerate the construction and improvement of national carbon market and set the "floor price", establish a climate-friendly market environment of fair competition by virtue of carbon price mechanism, and speed up the transformation of electric power enterprises to the low-carbon power structure.