Research On The Optimization And Improving Path Of Regional Straw Utilization Mode

The straw utilization is not only of great significance for solving the pollution problems caused by straw burning,but also has a positive role in alleviating the energy crisis,promoting the development of low-carbon economy,and increasing employment opportunities.Since China began to explore the straw utilization in 1997,the level of straw utilization has been continuously improved in the past 20 years.But the current academic research on the straw resource utilization is still insufficient.On the one hand,with the continuous enrichment of straw utilization methods,which straw utilization methods are more sustainable,there is currently a lack of systematic evaluation of the main straw utilization methods.On the other hand,with the dynamic evolution of the straw utilization industry,it will be an inevitable trend for multi-industry consume local resource of straw.In this trend,how to adjust the structure of the local straw utilization industries can make the local economic and environmental benefits of the industry get the best results.Such research is also extremely scarce.In addition,the improvement of the level of straw utilizat:ion not only means the improvement of the comprehensive utilization rate of straw,it also means the improvement of utilization efficiency and environmental benefits.Therefore,it is necessary to consider from the macro level,how to further plan the improvement path of straw utilization level.This thesis starts from five directions of straw utilization:fertilizer,energy,raw material,feed and base material,selects nine typical straw utilization methods in Shandong Province as the research object,and uses the emergy analysis method to analyze them.Furthermore,by comparing the evaluation results of the nine utilization modes,the characteristics of the nine utilization modes are obtained.The results of emergy analysis show that there are big differences in the economic and environmental characteristics of the nine methods.Except for the edible fungi cultivation with straw,the emergy yield rates of the other eight methods are all greater than 1,which indicates that most of the existing straw utilization methods have value-added role to straw.Except for straw-bioethanol production and straw-based particleboard production,the Environmental load rate of the other seven straw utilization methods are all lower than 3,showing low environmental impact.Based on the results of sustainable development indicators,straw biogas production and straw feed production have the best sustainability.The thesis believes that it should be used as the main encouraging industries.The sustainability index of straw-bioethanol production and straw-based particleboard production is less than 1,indicating that these two methods still need further technological innovation,and are still not suitable for scale promotion.On the basis of emergy analysis and combined with multi-objective linear programming,the thesis constructs an optimization model for regional comprehensive utilization of straw.The Pareto solution set is obtained through the non-dominated sorting genetic algorithm.The boxplot is used to analyze the solution set,and the optimization schemes under three different priority objectives are obtained.The following optimization plan found that if the main goal is to improve regional economic benefits,it is recommended to reduce the proportion of straw returning to the field in the current layout of straw utilization in Shandong Province,and mainly increase the proportion of straw biogas production.If priority is given to the regional environment,it is recommended to still use straw returning to the field as the main straw utilization method,and the proportion of other methods can be adjusted in a proper amount.At the same time,no matter what policy considerations are inclined,under the current technical level,straw-based particleboard production and straw-bioethanol production are not suitable for large-scale development.In addition,the layout of straw comprehensive utilization should pay attention to suit proper measures to local conditions,and should avoid blindly expanding the scale of straw utilization,which will increase the risk of a decline in regional environmental benefits and sustainability.Finally,the thesis designs a research model for the advancement path of "Fiscal Expenditure-Middle Path-Straw Utilization Level" to explore the intensity of different paths that fiscal expenditure affects the level of straw utilization from a macro perspective.The results show that fiscal expenditure has the most significant impact through the two intermediate paths of comprehensive utilization industry of waste resources and infrastructure.It is recommended to increase fiscal investment on these two intermediate paths to improve the level of straw utilization.The intensity of the impact of fiscal expenditure on the level of straw utilization through education level,agricultural development foundation,energy conservation and environmental protection investment,and innovative research and development investment is positive,that is,fiscal expenditure through these paths has a positive significance in improving the level of straw utilization.Among them,the path with the lowest impact intensity is innovative research and development investment.The reason is that the impact of innovative research and development investment on the level of straw utilization is relatively weak.It is recommended that innovative research and development investment should be inclined to the direction of straw utilization.