α-蒎烯催化加氢反应的研究

Study on catalytic hydrogenation of α-pinene

以FYX - 2G型高压搅拌釜为加氢反应器 ,测定了在不同搅拌器型式和搅拌转速下高压釜的持气量和反应效果 ,认识到α 蒎烯催化加氢是外扩散控制的反应 ,当搅拌转速为 6 0 0r/min时 ,基本上能消除外扩散的影响。考察了Raney镍和Pd/C催化剂、反应温度在 35 3～ 499K ,压力在 4 0～ 10MPa的条件下对α 蒎烯加氢转化率和选择性的影响 ,结果表明Raney镍更适宜于α 蒎烯催化加氢 ,其转化率随温度、压力增加而提高 ,但选择性下降。采用温度 35 3～ 433K、压力 4 0～ 7 0MPa的操作序列 ,克服了α 蒎烯加氢转化率与选择性互为逆向的缺点 ,缩短了反应时间 ,制得了顺反比高达 18 2∶1的蒎烷 ,并且发现加氢反应从温度 433K开始有副产物对烷生成 ,当温度超过 45 6K时 ,加氢过程还出现飞温现象。

Gas hold-up and reaction e ffect of high-pressure kettle in different types of stirrers and rotational speed were determined by using a high-pressure agitated autoclave (type FYX-2G) as reactor.The result shows that the catalytic hydrogenation of α-pinene is a reaction of external diffusion control.The effect of external diffusion cloud be eliminated when rotational speed was up to 600 r/min.The effects of Raney nickel and Pd/C catalyst,reaction temperature (353～499K),and pressure (4.0～10.0MPa) on conversion and selectivity of hydrogenation were also investigated.It was found that Raney nickel was suitable for hydrogenation of α-pinene,and its conversion increased with temperature and pressure,but the selectivity was opposite.The shortcoming that conversion opposited to selectivity was eliminated,and the reaction time was shorten by using operation series of temperature (353～433K) and pressure (4.0～7.0 MPa).The ratio of cis-pinane to trans-pinane in product prepared by author could be up to 18.2∶1,and by-product p-menthane appeared at temperature 433K.When temperature was more than 456K,runaway phenomenon happened in high-pressure kettle.