Optimization Design Of Biomass Supply Chain Network Under Feedstock Seasonality And Disruption Risks

With the development of social economic,mineral energy is gradually depleting.Biomass energy,which is produced form crop straw,is characterized with clean and renewable energy.In recent years,lots of countries in the world have attached great importance and invested heavily to the development of the biomass energy industry for the sake of strengthening energy security and reducing greenhouse gas emissions.However,the growth of biomass feedstock is characterized by strong seasonality,and collection facilities also randomly fail due to natural or man-made disasters.Therefore,how to sustainably guarantee the supply of biomass feedstock is a major challenge for the development of biomass energy.In view of this,on the basis of field investigation and summarizing of representative literature,the study focuses on the optimization design of biomass supply chain network considering feedstock seasonality and disruption risks.Specifically,the main work and innovation include the following three aspects:(1)In the context of the biomass supply chain,both feedstock seasonality and the disruption risks are considered.This dissertation proposed a multi-level assignment mechanism for the collection facilities,and designate a primary facility and several backup facilities to each farmer and biomass plant.If the primary collection facility fails,then the feedstock acquisitions are made by the backup facilities to prevent disruption of the entire supply chain system.The dissertation analyzes the effect of feedstock seasonality and disruption risks on the supply chain network,and optimizes the locations and assignments of collection facilities.Through the numerical experiments,it is found that the disruption risk significantly affects both the optimal facility locations and the supply chain cost,and the feedstock seasonality does not affect locations of the collection facilities.(2)A three-stage multi-period model for the design of biomass supply chain under feedstock seasonality and time-varying failure probability is proposed.The amount of feedstock collected in each period and inventories are optimized,the impact of feedstock seasonality on the inventories is analyzed.It is found that when the quantity of feedstock fluctuates with seasons,the collection facility needs to maintain more feedstock inventory to ensure the stable production of the biomass energy plant,thus the amount of collected feedstock,inventory cost and total supply chain cost will significantly increase.Unlike the existing literature,this paper proves that the traditional “nearest assignments” strategy is not the optimal strategy when the inventory cost is considered.(3)The dissertation proposes the strategy of facility reinforcement and allows the biomass energy enterprises to avoid the disruption risks by increasing the construction cost of the collection facility.By relaxing the assumption that the failure probability of each facility is the same in previous studies and considering the different failure probability of facilities,a multi-period biomass supply chain optimization model under strategy of facility reinforcement is proposed.The location and reinforcement plan is optimized.Furthermore,the dissertation analyzes the impact of failure probability and reinforcement cost on the location and reinforcement plan.It is found that reinforced collection facility should be placed in the transport convenient location which has a huge amount of feedstock.When the failure probability is substantial of the reinforcement cost is minimal,all collection facilities in the supply chain network should be reinforced,while only one collection facilities in the network should be reinforced if the failure probability is minimal or the reinforcement cost is substantial.