Method for preparing styrene by gas-phase dehydration of phenethyl alcohol

The invention relates to a method for preparing styrene by gas-phase dehydration of phenethyl alcohol, which comprises the following steps: a, raw material pretreatment, namely pretreating a phenethylalcohol material without epoxypropane to obtain a phenethyl alcohol raw material with the mass concentration of more than or equal to 90%; b, raw material proportioning, namely proportioning water and phenethyl alcohol according to a mass ratio; c, dehydration reaction of phenylethyl alcohol: vaporizing the proportioned water and phenylethyl alcohol, heating and then carrying out dehydration reaction; and d, preparation of crude styrene, namely cooling and condensing gas formed after dehydration reaction, and removing a water phase to obtain crude styrene. According to the method, styrene polymerization can be effectively reduced, the yield of reaction byproduct tar is reduced, and the reaction operation period is prolonged. 本发明涉及一种苯乙醇气相脱水制苯乙烯的方法，包括以下步骤：a.原料预处理：对脱除环氧丙烷的苯乙醇物料进行预处理，得到质量浓度大于等于90%的苯乙醇原料；b.原料配比：按照质量比配