4-甲基-2-戊醇催化脱氢制甲基异丁基酮反应工艺

在铜系催化剂作用下,4-甲基-2-戊醇(MIBC)进行催化脱氢反应制备了甲基异丁基酮(MIBK),考察了原料组成、反应温度、LHVS、N2与原料的配比对脱氢反应的影响,分析了催化剂的耐热性能,并对使用前后的催化剂进行了表征。实验结果表明,MIBC脱氢反应的较佳条件为:反应压力0.1 MPa、反应温度190～230℃、LHVS在1.00 h-1以下、原料中MIBK和MIBC的总含量大于99%(w),在此条件下,MIBC转化率可控制在60%以上,MIBK选择性可达到98%以上。以脱氢产物直接作为脱氢原料进行循环脱氢实验时发现,经过4次脱氢反应后,产物中MIBK含量达到98%(w)以上。催化剂经耐热处理后,MIBC转化率下降了11.5%,MIBK选择性基本不变。表征结果显示,与使用前的催化剂相比,使用后及耐热后的催化剂的比表面积和孔体积均减小,活性组分铜晶粒的粒径增大。

Dehydrogenation of Methyl Isobutyl Carbinol to Methyl Isobutyl Ketone

Methyl isobutyl ketone(MIBK) was prepared by the dehydrogenation of methyl isobutyl carbinol(MIBC) over a Cu-based catalyst.The effects of raw material composition,reaction temperature,LHSV and gas/liquid mole ratio on the dehydrogenation were investigated.The thermal stability of the catalyst was studied.The catalysts before and after the dehydrogenation were characterized by means of XRD and pore structure analyzer.The results show that under the optimum conditions of pressure 0.1 MPa,reaction temperature 190-230 ℃,LHSV 1.00 h-1 and the total content of MIBK and MIBC more than 99%(w),the conversion of MIBC and selectivity to MIBK can reach more than 60% and more than 98%,respectively.When the dehydrogenation products were directly used as raw materials and after 4 cyclic dehydrogenation runs were conducted,the content of MIBK in the products could reach more than 98%(w).After the thermal treatment of the catalyst,the conversion of MIBC decreased by 11.5%,but the selectivity to MIBK was almost unchanged.The characterization results demonstrate that both the specific surface area and the pore volume of the catalysts drop but the crystalline size of the active content Cu0 grow up after the dehydrogenation or overheat.