广西秸秆露天焚烧碳排放量特征分析

Analysis of Carbon Emission Characteristics of Open-air Straw Burning in Guangxi

采用排放因子法估算因秸秆焚烧产生的温室气体CO、CO_(2)和CH_4的排放量及碳排放量,并基于火点数据将碳排量进行网格化分配。结果表明,2022年广西秸秆露天焚烧总量为550.45万t,生物质燃烧源CO、CO_(2)和CH_4的排放量分别为31.46万t、722.70万t和1.44万t,其中,甘蔗秸秆焚烧对排放影响最大,贡献占比55.8%;秸秆露天焚烧释放的总碳量为211.87万t。生物质燃烧源排放的大气污染物分布不均衡,CO、CO_(2)和CH_(4)三项污染物排放量和碳排放总量高值区主要集中在桂中的来宾和南宁以及桂西南的崇左。崇左市秸秆露天焚烧碳排放量占广西19.5%,来宾占17.2%,南宁占15.9%,其他城市碳排放量占比均在10%以下。受农作物耕作和收割季节性影响,广西秸秆露天焚烧呈季节性变化,主要集中在1—4月和11—12月,甘蔗榨季是秸秆露天焚烧高发期。

This paper used the emission factor method to estimate the emissions of greenhouse gases CO,CO2 and CH4 and carbon emissions caused by straw burning,and allocated carbon emissions in a grid based on fire point data.The results showed that the total amount of open-air straw burning in Guangxi in 2022 was 5.5045 million tons,and the emissions of CO,CO2,and CH4 were 0.3146 million tons,7.227 million tons,and 0.0144 million tons respectively.The total carbon emission was 2.1187 million tons.Among them,the most impact came from sugarcane straw with a contribution of 55.8%.The distribution of air pollutants emitted by biomass combustion sources was uneven.The high value areas of CO,CO2 and CH4 pollutant emissions and total carbon emissions were mainly concentrated in Laibin and Nanning,as well as Chongzuo in southwest Guangxi.The carbon emissions from open-air straw burning in Chongzuo City accounted for 19.5%of Guangxi's,17.2%for Laibin,and 15.9%for Nanning.The carbon emissions of other cities were all below 10%.Affected by the seasonality of crop farming and harvesting,the open-air straw burning in Guangxi changed seasonally,mainly from January to April and November to December.The sugarcane crushing season was a period of high incidence of open-air straw burning.