2×200 MW级某天然气热电联产项目的生命周期环境影响评价

江苏省近年来大力发展燃气热电联产项目。2012年江苏省天然气利用量居全国首位。对江苏省2×200 MW某天然气热电联产项目进行了生命周期环境影响评价。生命周期评价（LCA）结果表明,对于该燃气热电联产项目,非生物资源消耗（CADP）、全球暖化（GWP）和酸化（AP）是相对重要的环境影响类型,可吸入无机物（RI）相对较为次要。生产运行阶段对各类环境影响类型,尤其是CADP和GWP均有重要贡献;天然气生产和管道输运则对AP和RI有显著贡献;建设拆除阶段对各类环境影响类型的贡献均较小。与燃煤发电相比,天然气热电联产在环境影响方面具有较大优势,其GWP、AP和RI分别约为煤电的20%、15%和5%;但天然气的稀缺性造成了天然气发电在非生物资源消耗方面存在巨大劣势,其CADP是煤电的3~3.5倍。

Life-Cycle Environmental Impact Assessment of a Typical 2×200 MW Natural Gas Combined Cycle-Combined Heat and Power Plant

Jiangsu Province has witnessed vigorous development of natural gas combined cycle(NGCC)-combined heat and power (CHP) plant in recent years. In 2012, the utilization of natural gas in Jiangsu Province ranked first in China. The life cycle assessment of a typical 2×200 MW natural gas combined cycle-combined heat and power plant is proposed in this paper. The life cycle assessment(LCA) results indicate that the indicators, such as Chinese abiotic depletion potential (CADP), global warning potential (GWP) and acidification potential (AP), are important environmental impact categories in this type of co-generation plant. In contrast, the indicator of respiratory inorganics (RI) is minor. Plant operation contributes to all environmental impact categories, especially CADP and GWP. Natural gas exploitation and pipeline transportation only markedly contribute to AP and RI. Finally, construction & decommissioning contributes less to all the indicators. Compared with coal-fired power, natural gas has greater advantages in terms of environmental impacts. Compared with coal-fired power, the GWP, AP and RI of natural gas-fired power account for 20%, 15% and 5% of those of coal-fired power, respectively. However, due to the scarcity of natural gas resources, the CADP of natural gas-fired power is 3~3.5 times of that of coal-based power.