The Mitigation Potential Of Greenhouse Gas Emissions From Central Heating Based On Direct Combustion Of Bundled Crop Straws

China has abundant crop straw resources holding huge utilization potential.At the same time,facing the prohibition of straw burning,the comprehensive utilization task is very difficult.In recent years,in order to solve the problem of straw consumption and vigorously develop renewable energy,straw baling direct combustion technology has developed rapidly in straw-rich areas such as Northeast China and North China,and has gradually become one of the straw comprehensive utilization technologies promoted by agricultural and rural departments.In this context,this study focuses on the straw baling direct-fired central heating project,aiming at the reality that the current domestic research on straw baling direct-fired central heating mode and its comprehensive benefits,especially the ecological benefits,is relatively weak.By using literature review,policy review,case analysis and other research methods,the operation mode and characteristics of the current domestic straw baling direct-fired central heating project are summarized.By constructing the estimation model of greenhouse gas emission reduction of straw baling direct-fired central heating based on LCA carbon footprint method and voluntary emission reduction methodology of greenhouse gas,three straw baling direct-fired central heating projects,namely Keliang Farm,Jingxian County,Hengshui City,Hebei Province,Sanjiang Village,Changtu County,Liaoning Province,and Dong’an Village,Wuzhan Town,Zhaodong City,Heilongjiang Province,are taken as cases to calculate the feasibility of straw baling direct-fired central heating technology in China.The research content of this paper includes five parts.The first part,straw baling direct-fired central heating technology overview.This part mainly summarizes the conventional technology of biomass clean heating,the application and equipment of straw baling direct-fired central heating technology,and the related technical and economic parameters of straw baling direct-fired boiler.The second part,straw baled direct-fired central heating mode analysis.In this section,according to the different heating subjects,the existing domestic straw bundled direct-fired central heating projects are summarized into four operating modes,and the characteristics of straw bundled direct-fired central heating mode are summarized.The third part constructs the estimation model of greenhouse gas emission reduction for straw baling direct-fired central heating.Based on LCA carbon footprint method and greenhouse gas voluntary emission reduction methodology,the calculation formula of‘net emission reduction of straw baling direct-fired central heating project=project baseline emission–project activity emission–leakage emission’is compiled.The baseline emission of projects such as burning fossil fuel heating and straw natural maturity,and the emission and leakage emission of projects such as on-site fossil fuel and power consumption,off-site transportation of biomass waste,burning biomass waste heating and biomass stacking are estimated.Finally,the net emission reduction of greenhouse gas in straw baling direct-fired central heating project can be calculated.The fourth part,straw baled direct-fired central heating greenhouse gas emission reduction estimation case analysis.Through the analysis of typical cases,the emission reduction of greenhouse of straw baling direct-fired central heating is quantitatively estimated,and the economic and ecological benefits of straw baling direct-fired central heating projects are calculated.The fifth part puts forward suggestions for promoting the development of straw baling direct combustion technology.Through research,the paper obtains the following four research results.（1）Straw bundled direct combustion central heating technology needs to be further promoted.Compared with developed countries,the theoretical and application research of straw baling direct combustion technology in China is still in its infancy,and there are still many technical problems in heating boiler equipment,and the development path of heating industry needs to be further studied.（2）Straw baling direct-fired central heating operation mode is diverse,outstanding advantages.At present,the common straw baling direct-fired central heating mode in China can be summarized as’enterprise+user’contract energy management mode,’cooperative+user’operation mode,’village collective+user’central heating mode and’farm+user’mode according to the different heating subjects.The above models have a lot of straw can be consumed in the season,simple process,easy to promote,clean and environmental advantages.（3）Straw bundled direct-fired central heating project can effectively replace fossil energy and achieve greenhouse gas emission reduction.The net emission reduction of straw baled direct-fired heating project on Keliang Farm is 3 329.95 t CO₂.Then,for each 1 t straw consumption in Keliang Farm heating project,1.51 t CO₂ emission will be reduced.The emission reduction of straw baling direct-fired central heating project in Sanjiang Village is 11 053.15 t CO₂.So,in the project baseline scenario,Sanjiang village heating project consumption of 1t straw,will reduce 1.58t CO₂emissions.The emission reduction of straw baling direct-fired heating project in Dongan Village,Wuzhan Town,Zhaodong City,Heilongjiang Province is 5 500.5 t CO₂.Then,in the project baseline scenario,Dong’an village heating project consumes 1t straw,will reduce 1.67t CO₂ emissions.（4）China vigorously promotes straw baling direct-fired central heating technology.In view of the outstanding problems existing in the development process of this technology,efforts should be made to break the bottleneck of key technologies,optimize the development mode,and improve the awareness of local and farmers.