Study On The Process Of Preparing Methyl Vinyl Ether

Methyl vinyl ether (MVE) is a useful intermediate and monomer. Its homopolymers and copolymers are widely used in fields of coating, adhesive, cosmetic, oral care materials etc. There are no domestic factories to produce vinyl ethers by now. So the study of the process of producing MVE has important value.We prepared MVE by splitting dimethylacetal (CH3CH(OCH3)2) in the gaseous phase. The reaction proceeded in a continuous tubular reactor packed the catalysts containing calcium phosphate.The catalyst consisted of main catalyst (calcium phosphate powder), cocatalyst(C), adhesive(bentonite and A) and extrusion assistants(glycerine). The catalyst can be shaped by extruding. The conditions of shapping, such as the ratio of water/powder, calcine temperature etc. can affect the properties of catalyst greatly. According to the results obtained by experiments, when (water/powder)=0.45, the catalyst's strength is highest; and when calcine temperature is 650 , the activity and selectivity of catalyst reached highest level.The two main variables which can affect the reaction greatly is reaction temperature and space velocity. We optimized the process conditions. The results showed that the optimal conditions is: reaction temperature =320 , space velocity = 270h-1. Under these conditions, the conversion is 95% and the selectivity is over 98%. The residence time is 13.3s and the process capacity of the catalyst is 0.98kg/h kgcat..The results showed that the catalyst, with calcium phosphate as the main part, is active and selective in the splitting of acetal. The activity of the catalyst will decline after being used continuously for more than 100 hours. But the activity can be regenerated by calcining in air. This indicates that the activity of the catalyst is stable. After being used for 140 hours, no catalyst was cracked. This indicated that themechanical intension of the catalyst is excellent.In a word, the process of producing MVE from acetal on the catlium phosphate catalyst is simple, safety, high conversion and selectivity. And the catalyst is cheap. So it is an appropriate process for the industrialized preparation of MVE.