Studies On The Selective Dehydration Of Glycerol To Acrolein

Acrolein is one of the important organic chemical materials and products with wide usage. At present, acrolein is produced by oxygennation of propene process mostly.Propene is belong to petrochemical resources. We all know that petrochemical resources are becoming more and more inadequate. Crude natural glycerol is one of the main products of sugar degradation and biomaterial conversion. Moreover, it is the primary byproduct of biodiesel and bioethanol with about10%content as a cheap, large-volume market product. This paper discussed a new process which acrolein is produced through selective dehydration of biosustainable resources:bio-glycerol. The process can improve the added value of biodiesel glycerol, reduce the cost of biodiesel, and promote biodiesel industry.The process of the glycerol selective dehydration was studied using a fixed-bed reactor. The reaction was performed at atmospheric pressure and280-340℃. The glycerol solution was transported to the reactor through an isobarical pump and was reacted with the catalyst in the reactor and then the products were flowed down to the collector after condensation. The products were analysed qualitatively and quantitatively by GC-MS and GC.In this work, the process of glycerol selective dehydration to acrolein was studied in detail. We aimed to screen several kinds of solid acidic catalysts in order to pick out the efficient catalyst for the selective dehydration of glycerol into acrolein. We found that the catalyst Fe-ZSM-5(75) showed much activity for glycerol dehydration to acrolein. Then, we obtained the optimum reaction conditions using mono-factor experimental method with the Fe-ZSM-5(75) catalyst. Under the optimum reaction conditions such as air flow(10ml· min-1), reaction temperature (320℃), LHSV(0.24h-1), glycerol concentration (25wt%), the experimental results indicated that the glycerol conversion was100mol%, the yield of acrolein was over70mol%with the yield of acetaldehyde (about10mol%) as the primary by-product during120h of reaction time.Finally, the life-time and the regeneration of the catalyst were checked in the glycerol dehydration reaction. The possible mechanism of glycerol dehydration and catalyst deactivaity was brought forward.