Application of a WO3/SiO2 catalyst in an industrial environment: part I Original Research Article

An 8% WO3/SiO2 catalyst was used in the metathesis reaction of 1-octene and an industrial cut, 1-heptene. The industrial 1-heptene feed stream consists of 75% 1-heptene, 10% n-alkane and the balance are branched hydrocarbons. The reaction conditions for the metathesis reaction were optimized using a reactor, equipped with a recycle loop. Temperature, liquid hour space velocity (LHSV) and recycle ratio were used to optimize the reaction conditions. It was found that 460 °C, LHSV=16 h−1 and feed to recycle ratio of 1:5.6 gives a conversion of about 88%, C10–C13 selectivity of 60%, C12 selectivity of 41% and an online lifetime of about 700 h when using the 1-heptene feed stream. The lifetime of the catalyst increased to 1200 h after regeneration in a flow of air at 550 °C. The conversion drops slightly, but the selectivity to the primary metathesis product increases to 46%. Both the spent catalyst and the regenerated catalyst have about 46% coke formation after deactivation.