用工业萘制备高纯萘产品的研究

Preparation of Extremely Pure Naphthalene From Industrial Naphthalene Fraction

高纯萘产品是许多高科技化学品的起始原料,可以通过工业萘脱硫精制得到。现有工业萘产品的主要杂质为硫化物苯并噻吩,用普通分离方法难以脱除干净。以过氧化氢为氧化剂,甲酸为催化剂,用氧化法对工业萘进行了脱硫研究,考察了过氧化氢配比、甲酸配比、反应温度、反应时间等因素对脱硫率的影响。结果表明,甲酸配比增加,脱硫率提高;随过氧化氢配比增加,脱硫率先上升后下降,存在一个最佳值范围;适当提高反应温度,可降低油相的粘度,有利于油水两相充分混合和提高反应效率,最佳反应温度为89～92℃;以纯度97.06%以上的工业萘为原料,在n(H)/n(F)=3.65,n(H)/n(S)=8.49、反应温度89℃、反应时间60min的条件下,脱硫率可达到97.90%,再经过精馏精制之后,所得产品中含萘质量分数超过99.90%,显著高于现有精萘产品质量。

Extremely pure naphthalene is the raw materials of some high level industrial products, and it can be attained from the industrial naphthalene fraction by desulphurization and purification. The primary impurity in industrial naphthalene fraction is the sulfide thionaphthene, which is very difficult to be removed off by ordinary separation methods. Oxidative desulphurization with oxidant hydrogen peroxide and catalyst formic acid was studied, and the effects of formic acid amount, hydrogen peroxide amount, reaction temperature and reaction time on desulphurization ratio were investigated experimentally. The result indicates that the desulphurization rate simply increases with the increasing of formic acid amount, but it increases at first and then goes down with the increasing of hydrogen peroxide amount, and there is an optical amount range. The viscosity decreases with the increasing of temperature, which is help to the mixing of oil and water phase, and thus to improve the reaction and the desulphurization rate, and the optical temperature is 89-92℃C. Under the optimized condition of n（H）/n（F） =3.65, n（H）/n（S）=8.49, 89 ℃ and 60 min, the desulphurization rate can reach to 97.90%, and after purified the oil phase by distillation to remove the resultant and the non-sulfide impurity, the content of naphthalene in the product is more than 99.90%, and is clearly higher than the industrial product （97.06 % ）.