Studies On The Process For 1,3-propanediol From Raw Glycerol By Clostridium Butyricum And The Influence Of The Renewable Materials On The Fermentation Process

1,3-Propanediol(1,3-PDO)is an important chemical compound with wide range of applications.It is mainly used as a monomer for the synthesis of PTT.The decrease of the world oil supplies and the unsteadiness of world oil market caused the increase of the price for both fossil fuel and its derivatives.Despite that,it is necessary to make great efforts to reduce CO2 emissions from the fossil fuel combustion as this greenhouse gas is the fundamental source of global warming.For these ecological and economic reasons that much interest has been taken in converting biomass resources into biofuels.One of biofuels that used worldwide is biodiesel.The bioglycerol is commonly generated through the transesterification of rapeseed,soybean,sunflower or palm oils during the manufacturing of biodiesel for modern fuels and fuels components.In this paper,industrial raw glycerol was used as the substrate to produce 1,3-PDO by Clostridium butyricum.The content of this paper include culture progress optimization,the impact of activated carbon,diatomite and chitosan on fernmentation.1.Repeated batch cultures were carried out to achieve the goal of shorten the total fermentation time and improve productivity.In the present study,we tried to devise a repeated batch fermentation strategy coupled with adsorption of C.butyricum to achieve continuous fermentation and enhance the productivity.The concentration and productivity of was 42.89 g/L,45.78 g/L,44.48 g/L,42.39 g/L,2.14 g/(L · h),1.91 g/(L · h),1.85 g/(L · h),2.12 g/(L · h)respectively for esch cycle.Furthermore,it revealed the effect of repeated batch fermentation on metabolic profiles.2.1n this study,an green and easily operated process without genetic modification was established to achieve the purpose of 1,3-PDO and lactic acid co-production.At the same time,a novel strategy which used the NaOH consumption rate(slope)to guide feeding rate was established to solve trouble of rapid determination of glycerol concentration.This is the first report about efficient 1,3-PDO and lactic acid co-production enhanced by activated carbon adsorption during the fed-batch fermentation process.The concentration of 1,3-PDO and lactic acid was 62.45 g/L,30.74 g/L respectively.The mechanism of this green process was further analysed and this newly designed technology could be applied in some other similar processes conveniently.3.The effects of chitosan and diatomite on the fermentation of C.butyricum were studied.The experimental results show that chitosan can also reduce the toxicity of the environment to the bacteria,and the investigation of its mechanism also were carried out.The concentration and yield of 1,3PDO was 53.56 g/L,0.56 g/g respectively.The addition of diatomite has no effect on fermentation.