摘要
采用涂覆法制备了高硅铝比HZSM-5／堇青石规整催化剂，采用N2吸附一脱附、XRD和SEM等技术对催化剂进行了表征，研究了涂覆条件对HZSM-5涂覆量的影响，并对比考察了规整和散堆粒状催化剂在甲醇制丙烯反应中的催化活性。实验结果表明，涂覆量与涂覆次数和ZSM-5含量成正比；载体的吸水率越高，涂覆量越大；添加硅溶胶可以显著降低浆料的黏度，同时提高涂层强度。在浆料中ZSM-5含量为20％（W）、硅溶胶含量为2％（w）、载体吸水率为31％时，经3～4次涂覆，催化剂的涂覆量（W）可以达到25％～35％，负载厚度为0．05～0．25mm。在480℃且进口甲醇和丁烯分压为10kPa的条件下，规整催化剂的甲醇转化速率是传统粒状催化剂的12倍左右，在相同甲醇转化率下副产物的选择性仅为粒状催化剂的1／4。
A monolithic HZSM-5/cordierite catalyst with high silica-alumina ratio was prepared by immersion-coating method and was characterized by means of N2 adsorption-desorption, XRD and SEM. The effects of the immersion-coating conditions on ZSM-5 loading were investigated, and the prepared monolithic catalyst was compared with cylindrical HZSM-5 catalyst in methanol to olefin process. The results showed that, the ZSM-5 loading was proportional to both the ZSM-5 content in slurry and the immersion times, the cordierite support with high water adsorption capacity was more easily to be coated, and adding ludox could decrease the slurry viscosity significantly and increase the coating strength. Under the conditions of ZSM-5 content 20%（w） and ludox content 2%（w） in slurry, and water adsorption capacity of the support 31%, the ZSM-5 loading reached 25%-35%（w） and its thickness ranged from 0.05 mm to 0.25 mm after the immersion 3-4 times. It was indicated that, over the monolithic catalyst, the methanol conversion was about 12 times higher and the byproduct selectivity was three quarters less than those over the cylindrical catalyst under the conditions of 480 ℃, methanol partial pressure 10 kPa and butene partial pressure 10 kPa.
出处
《石油化工》
CAS
CSCD
北大核心
2016年第2期156-162,共7页
Petrochemical Technology
