Multi-objective Modeling And Optimization Of Sustainable Biofuel Supply Chain Under Disturbance

Bioenergy has attracted more and more attention all over the world due to its environmental and economic benefits.As an important source of emission reduction in future transportation industry,biofuels have received strong support from the Chinese government.However,the development of biofuels industry is still difficult.The high uncertainty of raw material yield,market price,production cost and many other parameters makes the development of biofuels industry face enormous challenges.Designing a viable biofuel supply chain network can effectively improve the production and utilization ratio of biofuels and promote the development of biofuels industry.As a biomass raw material,kitchen waste with large yield and easy recovery has good prospects for development and can solve public health and safety problems in China.Therefore,in this paper,from the perspective of improving the operational efficiency of the biofuel supply chain,kitchen waste is used which can produce the biodiesel as the object to design and optimize the biofuel supply chain.The research on the optimization of sustainable biofuel supply chain network in this paper has important theoretical significance for enriching the theory of supply chain network planning,and has important guiding significance and reference value for the practice of biofuel logistics network planning.The general framework of this paper is from deterministic model to uncertain model,from single-factor disturbance to multi-factor disturbance.Firstly,a biofuel supply chain system and its modeling framework under deterministic environment are proposed,and the facility location,transportation and distribution structure under the multi-objective optimization model are obtained.System uncertainties usually occur at all stages of the supply chain.Then,uncertainties is incorporated into the process of supply chain modeling can make decisions more robust.Therefore,in the third,fourth and fifth chapters of this paper,the disturbance factors in the collection,production,transportation and sales stages of the biofuel supply chain are analyzed respectively.Thirdly,the stochastic programming model and robust optimization model under the disturbance are constructed.The results and the correlated sensitivety.of the disturbance model and the deterministic model is compared and analized.External macro-environmental changes will cause significant changes in the whole stage of the biofuel supply chain.Therefore,in the last part of this paper,the impact of the current government’s laws and policies to promote biofuels on the whole stage of the supply chain of biofuels is also discussed.The main contents of this paper include:(1)From the perspective of sustainable development of biofuels,the content and characteristics of supply chain decision-making are analyzed to design the biofuels supply chain under certain conditions.Strategic and tactical decisions related to location,production,inventory and distribution are also solved in a multi-planning cycle.In order to effectively solve the large-scale supply chain problems in the model of this section,a heuristic algorithm based on Pareto optimal NSGAII is proposed and is applied to a case study in Jiangsu Province.Experiments show that this method can improve the efficiency of calculation and obtain satisfactory Pareto optimal solution.(2)From the view of contract signing,a two-stage stochastic programming model under single-factor supply disturbance is proposed to optimize the supply chain in the kitchen garbage collection stage.The three main directions of kitchen waste are analyzed to determine the reasonable price for the purchase of biofuel operators.By signing contracts between restaurants and biofuel operators,restaurants are encouraged to provide a certain proportion of kitchen waste to meet the demand of biodiesel production.The first stage supply chain network structure and the second stage transportation decision-making problem are obtained by solving the problem.The actual case of Yangtze River Delta shows that the the total system cost of stochastic programming model under disturbance is lower and the anti-disturbance ability of the tochastic programming mode is stronger than the determining model.The impact of different parameters on acquisition price,supply chain network design and expected total system cost is deeply explored,and the decision-making results,sustainability and various aspects are analyzed in different situations.(3)Based on the contract strategy,a mixed integer programming model is proposed to optimize the supply chain of biodiesel under certain conditions.Ben-Tal’s interval transformation method is used to linearize the supply chain under the price disturbance of biodiesel,and the robust optimization model under the disturbance is obtained.The agreement price,supply chain network structure and tactical decision are determined by solving the Yangtze River Delta case.The sensitivity of different biofuel prices to deterministic model and robust model is studied.The changes of expected system profit and agreement price are analyzed,and the profit point of biofuel operators is determined.(4)From the perspective of multi-modal transportation,the supply chain optimization model of biodiesel transportation stage under certain conditions is constructed considering the characteristics of truck,train and barge.Through Mulvey scenario transformation method,the above deterministic model is linear transformated a roubust model under disturbances of demand level,storage cost and processing cost of biodiesel.The practical case in Yangtze River Delta is used to obtain the feasible solution,and the optimal transportation mode of biofuel supply chain is obtained.By comparing the results of robust optimization under disturbance and deterministic model,the market environment applicable to robust optimization model is determined.Then the sensitivity analysis of the change of truck transportation distance limit and carbon emission price is further carried out,and the comparison of unilateral and multimodal transportation systems is made.(5)Summarize China’s policies which support and encourage the production and consumption of biofuels in the past 20 years,refine these policies and use mathematical symbols to formulate a two-stage stochastic programming model of biofuels.Study the policy impact of the whole stage of the supply chain of biofuels under multi-factor disturbances.The conditional risk value of profit is proposed to control risk while optimizing economic indicators.Based on the analysis of the results of biofuels cases in the Yangtze River Delta,the policies and regulations that have a significant impact on the supply chain network of biofuels are determined to encourage biofuels operators to produce biofuels and manage risks simultaneously.In conclusion,the numerical results based on specific examples reveal the tradeoff between sustainability objectives,the impact of major factors on supply chain objectives and the structural changes of biofuel logistics network.The comparison of different models can more clearly show the influence of various factors on the optimization results of biofuel supply chain network.Through the staged and overall optimization of the biofuel supply chain,the efficiency of the biofuel supply chain can be effectively improved,the system cost can be reduced,the profit of biofuel operators can be improved,and the sustainable development of the biofuel industry can be promoted.