Optimization Of Production Planning In Biofuel Plant Under Uncertainty Environment

As the global consumption of fossil energy continues to increase,people’s awareness of environmental protection has gradually increased.The use of biofuels is considered to be an important strategy to reduce greenhouse gas emissions in the transportation sector,which is dominated by petroleum fuels,to promote the rural economy and to improve energy security.Government agencies around the world have developed plans and policies to encourage the production and use of biofuels,which may help achieve sustainable development goals.Bioethanol is considered to be a good alternative to transportation fuels,which can bring good economic and environmental benefits.Bioethanol plants will make detailed production plans to get more profit.However,in the process of making the production plan of bioethanol plant,there are some uncertain problems,such as the selection of raw materials,the transportation of raw materials,the pretreatment of raw materials,the saccharification and fermentation technology and the government’s policy on biofuel.For bioethanol production and demand of uncertain problems,adopt the method of multistage stochastic programming and random,the robust optimization method to study the multi-source under uncertainty environment bioethanol production planning problem of the factory,finally achieved in empirical bioethanol production plan,and to make bioethanol plants reduce overall operating costs.The production plan of a bioethanol plant can obtain the transportation and purchase of raw materials as production and demand change,the production of intermediate products obtained through the pretreatment process,the inventory after pretreatment,and the quantity of bioethanol transported to different markets.This paper mainly studies the modeling and optimization of the production plan of bioethanol plant with various raw materials and production methods under uncertain environment.The yield fluctuation of bioethanol production due to different pretreatment methods,fermentation temperature and enzyme activity was studied.The effect of policy factors on bioethanol demand was also considered.The main research work of this paper is as follows:（1）Aiming at the production planning problem of bioethanol plant with multiple raw materials and production modes,a production planning model considering different pretreatment methods and fermentation methods was established,and the carbon emissions in the pretreatment,saccharification,fermentation and transportation processes were restricted.The economic objective function and carbon emission objective function of production planning are introduced,and a dual objective optimization method is adopted to solve the problem.The results show that the model can balance economic and environmental benefits well.（2）The uncertain factors in the production of bioethanol were analyzed,and the causes of the uncertain factors,the composition of the uncertain factors and the solutions were studied.A multi-stage stochastic programming method was proposed to solve the production planning problem of bioethanol production in uncertain environment.Considering the uncertainty factors of bioethanol yield and demand,as well as the influence of backorder,a scenario tree model was established,which combined the uncertainty of demand and production with probability to form a hybrid scenario tree model.The simulation results show that the model is effective for each stage of production planning.（3）In view of the uncertainty of the yield and demand of bioethanol affected by policy,a single probabilistic model cannot accurately describe the relationship between the uncertainties.Combined with the historical data of demand and yield under different policies,a data-driven method is used to model the uncertainty set under different policies.A stochastic robust optimization model was constructed by combining stochastic programming with robust optimization,and a column generation decomposition algorithm was used to solve the model.