Effect Of Ammonia Swelling + Hydrogen Peroxide On Different Agroforestry Waste Resource Recovery Pathways

In recent years,with the rapid growth of the global economy,a continuous energy supply is needed.In many developing countries,the storage of fossil fuels is rapidly decreasing due to the substantial expansion of productivity.In addition,excessive dependence on fossil fuels has also brought a series of ecological problems,such as air pollution and ozone layer destruction.Therefore,it is urgent to explore clean and renewable energy to solve the energy crisis and environmental degradation.At present,the production of sustainable biomass energy from lignocellulosic raw materials has been widely used as a reliable fuel choice.As a large agricultural country,in recent years,China’s agricultural development will produce a large number of rich agricultural and forestry wastes.Agricultural and forestry waste is a kind of potential energy that is not fully utilized.It is widely available,easy to collect and transport,and does not damage the stability of the ecosystem.Therefore,the feasibility of using agricultural and forestry wastes to produce renewable biomass should be discussed.In this thesis,different kinds of cellulose（straw,poplar and pine）such as vegetation,hardwood and cork are used as raw materials to develop a new pretreatment method,which can reduce pretreatment time,improve pretreatment efficiency,control process cost and make better use of agricultural and forestry wastes.Pretreatment of biochar prepared by adding H₂O₂and AFEX.Among them,the pretreatment method of AFEX+H₂O₂mainly analyzes its influence on lignin degradation and enzymatic reaction of various agricultural and forestry wastes and its pretreatment mechanism.So as to realize efficient utilization and transformation of lignocellulose and provide a new way for resource utilization of agricultural and forestry wastes.The main research work of this topic is summarized as follows:（1）Study on enzymatic saccharification of lignocellulose from different agricultural and forestry wastes by ammonia fiber expansion（AFEX）combined with hydrogen peroxide（H₂O₂）pretreatment.The existence of alkaline H₂O₂can open the ester and ether bonds of wood-carbon composites and reduce the biological play resistance.The results showed that the combined pretreatment process of AFEX AFEX+H₂O₂could significantly improve the degradation rate and saccharification efficiency of lignin compared with physical and chemical pretreatment alone.It has the best effect on rice straw,the best degradation rate of lignin is 67.83%,and its saccharification efficiency can be improved by 58.7%.When poplar is treated,the best degradation rate of lignin is 24.36%,and its saccharification efficiency can be improved by 39.5%.When pine is treated,the degradation rate of lignin is 18%,and its saccharification efficiency can be improved by 20.6%.The pretreatment method has better treatment effect on herbaceous agricultural and forestry wastes than hardwood,cork and other agricultural and forestry wastes.（2）Study on the performance of ammonia fiber expansion（AFEX）combined with hydrogen peroxide（H₂O₂）pretreatment of agricultural and forestry wastes for hydrogen production by dark fermentation.Compared with untreated agricultural and forestry wastes,AFEX+H₂O₂pretreatment has better hydrogen production performance.The gas production from straw,poplar and pine can reach 145.49 m L/g,80.75 ml/g and57.52 ml/g respectively.Moreover,AFEX+H₂O₂can affect the community structure of microorganisms,improve the abundance of Clostridium butyricum,which is beneficial to butyric acid fermentation to produce more hydrogen and increase the utilization rate of agricultural and forestry wastes.（3）Study on the effect of AFEX pretreatment of agricultural and forestry wastes to prepare biochar on the cultivation of edible fungi.The biochar prepared after pretreatment has high surface porosity and specific surface area,which can provide more adsorption sites for nutrients.The results showed that biochar pretreated by AFEX could improve the growth rate and yield of edible fungi.When P.ostreatus was cultured,the growth rate of mycelium could reach 7.047 mm d^-1,and the yield could be increased by 45.25%.The growth rate of mycelium can reach 5.857 mm d^-1when P.eryngii is cultivated,and the yield can be increased by 51.73%.The growth rate of mycelium can reach 7.571 mm d^-1when P.geesteranu is cultivated,and the yield can be increased by45.95%.In this thesis,the combined pretreatment method of AFEX and H₂O₂is used to realize the resource utilization of agricultural and forestry wastes in two ways.It has certain economic benefits while reducing environmental pollution.