工业双戊烯连续催化脱氢反应制备对伞花烃的20t/a放大实验

Preparation of p-Cymene by Continuous Catalytic Dehydrogenation of Industrial Dipentene in 20 t/a Scale

工业双戊烯主要是由苧烯、异松油烯、α-松油烯、γ-松油烯和对伞花烃等单环萜烯组成的混合物,总有效成分的质量分数为91.66%。在20 t/a连续反应放大装置上,工业双戊烯经Pd/C催化连续脱氢反应所得主产物为对伞花烃,反应副产物包括反式-对[艹孟]烷、顺式-对[艹孟]烷、对[艹孟]烯和2,6-二甲基辛烷等。结果表明,当工业双戊烯进料速度为4 L/h和氮气流速为2 L/m in时,在260－310℃,随着反应温度的提高,产物中对伞花烃的质量分数和产率也同步提高;反应温度由260℃升至280℃,产物中对伞花烃的质量分数由86.26%提高到90.40%,产率由92.65%提高到97.09%,20℃的温度差使产物中对伞花烃的质量分数和产率分别提高4.14%和4.44%;反应温度280－10℃,产物中对伞花烃的质量分数在90.40%－91.95%,产率在97.09%－98.76%,30℃的温度差仅使产物中对伞花烃的质量分数和对伞花烃的产率分别提高1.55%和1.67%。280℃是可选择和长期运行的反应温度,此时对伞花烃的产率为97.09%。

Industrial dipentene is a mixture of monocylie terpenes mainly containing limonene, terpinolene,α-terpinene,γ-terpinene, and p-cymene in the total mass fraction of 91.66%. The main product of the continuous catalytic dehydrogenation of the industrial dipentene by Pd/C catalyst was p- cymene in 20 t/a equipment. The by-products included trans-p-menthane, cis-p-menthane ,p-menthene, and 2,6-dimethyloctane. The results showed that the mass fraction of p-cymene in the product and the yield of p-cymene increased simultaneously with increasing temperature at the conditions of the industrial dipentene feed rate 4 L/h, nitrogen flow rate 2 L/min, and reaction temperature range 260 - 310 ℃. The mass fraction of p-cymene in the product was from 86. 26% up to 90. 40% ,and the yield of p-cymene was from 92.65% up to 97.09% at 260 - 280 ℃. The increasing rate of the mass fraction ofp-cymene in the product and the yield of p-cymene were respectively 4. 14% and 4. 44% in the temperature difference of 20 ℃. The mass fraction of p-cymene in the product was between 90.40% and 91.95% ,and the yield of p-cymene was between 97.09% and 98.76% at 280 - 310 ℃. The increasing rate of the mass fraction of p-cymene in the product and the yield of p-cymene was only 1.55% and 1.67% respectively in the temperature difference of 30 ℃. The selected temperature for long-time running was 280℃, and the yield of p-cymene was 97.09% at this condition.