间硝基甲苯催化加氢合成间甲苯胺的工艺研究

【作者】 程雪清；

【导师】 叶志文；

【作者基本信息】 南京理工大学 ， 应用化学， 2008， 硕士

【摘要】 本论文对间硝基甲苯催化加氢制备间甲苯胺工艺进行了研究，其中包括液相催化加氢和气相催化加氢。在液相催化加氢研究中，分别采用了Raney Ni、Ni-B非晶态合金和漆原镍三种催化剂。研究发现，采用Raney Ni为催化剂，NaOH与Al-Ni合金的质量比为1．7时制得的催化剂活性较高，在催化剂与原料质量比为6：100，甲醇作溶剂，反应时间为1h，反应压力1MPa，反应温度为80℃条件下间硝基甲苯转化率达100％；采用Ni-B催化剂，当BH₄^-／Ni²⁺=2左右制得的催化剂活性较高，在催化剂与原料质量比为3：10，无水乙醇作溶剂，反应时间为1h，反应压力1MPa，反应温度为100℃条件下间硝基甲苯转化率达100％，同时通过TEM对Ni-B非晶态合金进行表征；采用漆原镍为催化剂，展开剂为醋酸，锌粉与NiCl₂·6H₂O质量比为3：2时制得的催化剂活性较高，在催化剂与原料质量比为5：3，甲醇作溶剂，反应时间为1．5h，氢气流速15mL/min条件下间硝基甲苯转化率达100％，新鲜催化剂放置一周后活性才开始下降，催化剂可以循环使用10次，活性基本不变。在气相催化加氢中，使用固定床反应器作为反应装置。制备了铜硅胶催化剂，并考察了不同铜含量以及分别加入Ni、Co、Cr、Mn四种助剂对催化剂性能的影响，研究表明加入Cr助剂的含铜量为20％的硅胶铜催化剂是最好的。接着考察了各项工艺操作参数，包括催化剂的活化温度、反应温度、气液比、液时空速对问硝基甲苯的转化率的影响。研究结果表明：催化剂的活化温度在240℃以上，反应温度在270℃，气液比在9：1～11：1之间时，间硝基甲苯的转化率可以达到100％，催化剂的最大负荷为1．1mL／h·mL-cat。更多还原

【Abstract】 This dissertation studied the appliance of catalytic hydrogenation technology to the preparation of m-toluidine from m-nitrotoluene, including liquid catalytic hydrogenation and gas phase catalytic hydrogenation.Three different catalysts were used in the process of liquid catalytic hydrogenation. It has been found that the Raney Ni catalyst which was prepared on the condition that m（NaOH）:m（Al-Ni）=1.7 has the best performance. Under the condition that m（catalyst）: m（m-nitrotoluene） =6:100, methanol as solvent, reaction time was 1h, reaction pressure was 1MPa, reaction temperature was 80##, the conversion of m-nitrolotuene reached 100%. Ni-B amorphous alloy catalyst which was prepared on the condition that BH₄^-/Ni²⁺=2 has the best performance. Under the condition that m（catalyst）: m（m-nitrotoluene）= 3:10, anhydrous ethanol as solvent, reaction time was lh, reaction pressure was 1MPa, reaction temperature was 100℃, the conversion of m-nitrolotuene reached 100%. And the Ni-B amorphous alloy was characterized by TEM. The urushibara nickel catalyst which was prepared on the condition that m（Zn）:m（NiCl₂·6H₂O）=3:2 and acetic acid as the developing agent has the best performance. Under the condition that m（catalyst）: m（m-nitrotoluene）=5:3 ,methanol as solvent, reaction time was 1.5h and hydrogen velocity was about 15 mL/min ,the conversion of m-nitrolotuene reached 100%. Fresh catalyst’s performance just declined after a week’s time and the catalyst was not obviously deactivated after being used for 10 cycles.The fixed-bed reactor was used as the device where m-toluidine was prepared from m-nitrotoluene by gas phase catalytic hydrogenation. The effect of different contents of copper and supports, such as Ni, Co and Cr in Cu/SiO₂ catalyst was examined.It has been found the optimum catalyst was composed of 20% of copper and 0.8% Cr. And then we study the technological conditions of gas phase catalytic hydrogenation.The optimum technology was as follows, activation temperature 240℃,reaction temperature 270℃,oil-hydrogen ratio 9:1～11:1,LHSV 1.1 mL/h·mL-cat, conversion of m-nitrotoluene was 100%.更多还原