羰基合成醋酐联产醋酸工艺研究

Process of carbonylation for synthesizing acetic anhydride and acetic acid

在确定选用均相铑系催化剂后,为了进一步研究中试放大,需对羰基合成小试工艺进行研究。实验采用贵金属铑为主催化剂,碘甲烷为助催化剂,以醋酸甲酯、甲醇和一氧化碳为原料,选用锆材高压釜,均相羰基化合成醋酐并联产醋酸。在温度180—200℃下,压力3.0—6.0MPa,催化剂质量分数700×10-6—1000×10-6,碘甲烷质量分数10%—15%和停留时间70—90min的工艺条件下,按一氧化碳计醋酐选择性为95.4%,CO转化率为97.4%,羰基产物醋酐收率为92.9%;催化剂的时空收率(按醋酐计)为38671.28g/(mol.h)。此工艺参数的提出可以初步指导中试放大并为工业化生产提供基础数据。

After determining to use the homogeneous rhodium catalyst,it is necessary to do research on the small test device for further study on the pilot plant. By selecting precious metals rhodium as the main catalyst and methyl iodide as promoter,using methyl acetate,methanol and CO as feedstock,and choosing zirconium autoclave,the acetic anhydride and co-product acetic acid were synthesized through homogeneous carbonylation. Under the reaction conditions of 180-200 ℃,pressure 3.0-6.0 MPa,catalyst mass fraction 700×10-6-1 000×10-6,methyl iodide 10%-15% and residence time 70-90 min,the selectivity of acetic anhydride is 95.4%（as CO）,the conversion rate of CO is 97.4% and the acetic anhydride product yield is 92.9%; the space-time yield of catalyst is 38 671.28 g/（mol·h） （as acetic anhydride）. The parameters of such process can preliminary guide the pilot and provide the basic data for industrialization.