A method for the purification of naphthalene by selective hydrogenation and subsequent separation

摘要

The invention relates to a process for the purification of naphthalene. This process comprises a selective hydrotreatment corresponding to a hydrodesulphurization and / or hydrodenitrogenation and / or hydrodéhydroxylation and / or hydrogenation of olefins, while limiting the hydrogenation of the naphthalene. The catalyst used comprises a matrix, at least one metal of group viii, at least one metal from group vi and optionally phosphorous. It has a specific surface area of at most of 220 m * * 2 / g, a pore volume of 0,35 - 0,7 ml / g and an average pore diameter of more than 10 nm. The process carried out at 150 - 325 deg.c, under 0,1 - 0,9 mpa, with an hsv of 0,05 - 10h * * - 1, a ratio h2 / naphthalene of 0,1 - 1,3 mol / mol. The effluent from h2 s, nh3 and the water is subjected to a method of separation of the naphthalene by distillation or preferably by crystallization. In addition, a recycling of tetralin separated to the hydrotreatment makes it possible to significantly increase the yield of naphthalene. In this case, the weight ratio of tetralin / naphthalene to the input of the reactor is between 0,005 and 0,08.par.