Studies On Vinegar Clarification Use Ceramic Membrane

Development of vinegar clarification use ceramic membranes was necessary in the paper:applying ceramic membranes in clarification of vinegar which have bacterium, suspendimentand sedimentation have some advantages such as resist acid, alkali and detergent etc. that hasbeen studied in recent years.But it industralize restrictly because of concentration polarizationand membrane fouling on the membrane process that leading to the decline of productivityand rise up of invest.To reduce membrane fouling, promote permeation flux and reduce invest duringapplicating ceramic membranes in clarification of vinegar, this process were studiedsystematically in this thesis to provide foundational studies for this progress industralization.Through comparision to many clarification methods of vinegar, the quartz sand filtrationand ceramic membrane separation united to clarify vinegar.It is that vinegar waspretreatmented by quartz sand firstly, separation by ceramic membrane secondly.The studyshows that this united clarification methods,compared with by the only ceramic membranefiltration, the membrane flux attenuation became slower and the membrane regenerationbecame easier at retain effective composition of vinegar and guarantee clarification effect.The optimal operation conditions and cleaning quartz sand ways on the pretreatmentprocess were studied and fixed on.The ceramic membrane with pore size around 80nm which owed high permeation fluxand slow retention rate at guarantee clarification effct was selected to clarificate vinegar. Theoptimal operation conditions on the ceramic membrane clarification process were discussedand fixed on. The vineger abtained from this way could meet the quality standard for vinegarissued by nation.According to the reasons and process of vinegar turbid, the ingredients leading to themembrane fouling can be confirmed by analyzing with SEM and EDXA etc., including mostof microorganism,organism and a few inorganism. Jam model on the membrane process waschoosed to analysis the membrane fouling mechanism and calculate the distribution ofmembrane resistances, gel layer is the main resistance, 50~53%. Because gel layer wascovered by concentration polarization layer gradually , concentration polarization layer andgel layer should control by some ways to reliese membrane fouling. The study shows that gasand liquid back-flush technology were no good to reliese membrane fouling,but vinegarpretreated before ceramic membrane filtration was a better way.To get good cleaning effect ,pure water should be used on the cleaning contaminativemembrane process. With 0.1%NaOH, 0.2%H2O2 and 0.1% H2SO4 united to clean fouledmembrane can owned best cleaning effect, pure water permeate flux could return to 97% ofthe originality. Cleaning effect will be bad if the cleaning sequence of alkali and acid reversed.Cleaning effect can be confirmed by analyzing with SEM. The appropriate cleaningconditions were fit on at the same.By the cost anelyze according to 6000 ton per year, the membrane cost of the quartz sandfiltration and ceramic membrane separation united to clarificate vinegar was 49000 yuan, totalinvest was 48380 yuan, average cost per year was 4692 yuan less than the cost of the onlyceramic membrane filtration. This process cost was about 39.7 yuan/ton.The profie was75357600 yuan per year.This clarification process of vinegar is proved to be economic andstable in nearly two years operation.