我国民用天然气灶NO_(x)排放因子实测研究

In-situ Study on the Emission Factors of NO_(x) from Residential Natural Gas Stoves in China

氮氧化物(NO_(x))作为大气中细颗粒物(PM2.5)和臭氧(O3)协同防控的关键前体物,准确识别其污染源排放特征是理解和管控区域大气污染的关键基础性研究。天然气作为清洁能源在我国家用燃气中广泛使用,但其NO_(x)排放特征鲜有报道。通过采集民用天然气灶烟道废气样品,采用“碳平衡法”计算出其NO_(x)的平均排放因子为(0.44±0.06)g/kg-fuel;通过家用天然气灶火力控制试验,得到天然气灶在小火、中火及大火燃烧过程中NO_(x)的排放因子分别为0.38 g/kg-fuel、0.56 g/kg-fuel和0.19 g/kg-fuel。本研究测得的民用天然气灶NO_(x)的排放因子低于燃煤的排放因子,说明在推进“煤改气”过程中,民用天然气灶的推广将有利于NO_(x)的减排,但也需要注重壁挂式天然气炉等高NO_(x)排放终端消费设备的技术革新及其带来的潜在环境效应。

Nitrogen oxides(NO_(x))is a crucial precursor for the co-control of particulate matter(PM2.5)and ozone(O3).Improving the NO_(x)emission factors of different sources is essential to work for understanding and managing regional atmospheric pollution.Natural gas is widely used in domestic gas as clean energy,but its NO_(x)emission characteristics are rarely reported.This study performed the in-situ measurement of NO_(x)emission factors of stack gas samples from residential flues of domestic natural gas stoves.Using the carbon mass balance method,the average NO_(x)emission factor of natural gas burning during cooking is(0.44±0.06)g/kg-fuel.Through the fire control experiment of household natural gas stoves,the NO_(x)emission factors of natural gas stoves in the combustion process of the small,medium,and large fire are 0.38 g/kg-fuel,0.56 g/kg-fuel and 0.19 g/kg-fuel,respectively.The NO_(x)emission factors of natural gas stoves measured in the study are lower than that of coal combustion.In promoting“coal-to-gas”,the promotion of residential natural gas stoves is conducive to NO_(x)emission reduction.However,it is also necessary to pay attention to the technological innovation of high NO_(x)emission terminal consumer equipment such as wall-mounted natural gas stoves.