Research On Molecular Distillatiotn Separation Technology Of Heavy Alkyl Benzene

The annul production capacity of dodecyl benzene has reached 800 thousand tons.Meanwhile,the utilization of the HAB(heavy alkylbenzene),by-product when producing dodecyl benzene,has become the important key point to improve profit for dodecyl benzene manufacturing enterprises and rational use of HAB is benefit to properly utilizing resources.In this dissertation,the content of HAB without clay refining was analyzed through extraction and column chromatograph.The experimental results showed that the main components of HAB were alkylbenzene,dialkylbenzene.Besides,GC-MS was utilized to analyze the structures of HAB.The structure of several alkylbenzenes and 1-Methy-4-heptyll-1,2,3,4-tetrahydronaphthalene was determined.In the meatime,Fourier transform ion cyclotron resonance mass spectrometry was introduced to characterize the molecular weight distribution of HAB.The HAB was treated by centrifuge and subsidence to improve the physicochemical property and molecular distillation experiment device was adopted to separate HAB.It was showed that the effect of heating temperature,system pressure and feed rate on the yield of HAB was evident.The interaction influence of process parameters was investigated by Box-Behnken design method.Through numerical analysis the optimum parameters of molecular distillation device was: heating temperature 209.5?,pressure 31 Pa,feed rate 5.48kg/h and wiper speed 141 rpm.On this condition,yield of HAB reached 80.5%,and the loss of material was significantly lower than that of vacuum distillation without using of clay.HAB fractions separated by molecular distillation were synthesized to HABS and their capacity to reduce interfacial tensions were compared.Besides,the components difficult to sulfonate was investigated and the results showed that HABS exhibited good interfacial activities to improve oil recovery rate.