Agricultural Waste Utilization Status And Biogas Production Potential Assessment In Hubei Province

With the rapid development of agricultural modernization and the increasing demand for agricultural products,agricultural waste has also increased.For the increasing agricultural waste,biogas projects with anaerobic fermentation technology as the core have played an important role in reducing environmental pollution risks and waste resource utilization.In this paper,the total amount of agricultural waste resources in Hubei Province was estimated and the utilization status of agricultural waste resources was comprehensively analyzed.At the same time,based on the estimated data,the spatial distribution of agricultural waste biogas potential was evaluated,and the suitability of biogas project site selection was explored.（1）In order to fully understand the utilization status of agricultural waste resources in Hubei Province,this study analyzed the total amount of agricultural waste and its utilization status in Hubei Province by consulting data and conducting field surveys,and using the resource calculation model.The results showed that the total amount of agricultural waste in Hubei Province in 2020 was 4.92×10⁷ t,and the resources of straw and livestock manure were equivalent,which were 2.58×10⁷ t and 2.34×10⁷ t,respectively.Among them,the comprehensive utilization rate of straw in Hubei Province in 2020 is 93%,and the comprehensive utilization level is high.There are two main storage modes:decentralized and centralized.The decentralized mode is suitable for small-scale professional cooperatives,while the centralized mode is suitable for storage centers with large throughput.For the utilization of straw resources,it was found that straw in most areas was still mainly returned to the field.After leaving the field,the straw is mainly used for feed utilization,and the key counties with feed utilization account for 80%.In addition,in 2020,the comprehensive utilization rate of livestock and poultry manure in Hubei Province will be 92%,and livestock and poultry manure resource utilization farms will account for about 53%of large-scale farms.The resource utilization method is mainly anaerobic fermentation to produce biogas.（2）In this study,the biogas potential calculation model was used to evaluate the biogas potential of various regions in Hubei Province in combination with Arc GIS software.The evaluation results show that the biogas potential of agricultural waste in Hubei Province in 2020 is 2.02×10¹⁰ m³.The biogas potential of straw was 1.11×10¹⁰ m³,and the contribution rate of rice was the highest,reaching 33.37%.The biogas potential of livestock and poultry manure was 0.92×10¹⁰ m³,and the contribution rate of pigs was the highest,reaching 38.59%.From the distribution of different regions,Xiangyang has the highest biogas potential,accounting for 19.06%of the province’s biogas potential.In order to better evaluate the actual production of biogas,this paper calculates that the potential value of available biogas of agricultural waste in Hubei Province in 2020 can reach 4.41×10⁹ m³,which is equivalent to reducing carbon emissions by 2.20×10⁶ t,with significant environmental benefits and economic benefits of 2.20×10⁷ USD.However,there is a significant difference between the calculated available potential and the actual production.The average gas production difference rate in the province can reach 96.64%,which indicates that there is still much room for progress in the development of biogas industry in Hubei Province.（3）In order to promote the sustainable development of biogas industry,this study uses the analytic hierarchy process（AHP）,combined with geographic information system（GIS）,to evaluate the suitability of biogas project construction site selection in Hubei Province.The results show that the site selection of biogas project should comprehensively consider three aspects of society,economy and environment,including residential area,road,railway,scenic area,water body and other constraint indexes.The weights of biogas potential,residential area,natural scenic area,water body and traffic road are 0.505,0.245,0.102,0.102 and 0.046 respectively.Based on the evaluation of biogas potential grade,it is found that the areas with high suitability evaluation of biogas project construction in Hubei Province are mostly distributed in the central region（Xiangyang,Jingmen,etc.）and the eastern part（Huanggang,Xiaogan）,while Shennongjia and Ezhou are not suitable for biogas project construction.This study provides a more objective reference value for the site selection of subsequent biogas project construction in Hubei Province.