水热法制备镁铝尖晶石载体

Preparation of a magnesia-alumina spinel catalyst support with hydrothermal method

MgAl2O4是一种优良的催化剂载体。与γ Al2O3相比,MgAl2O4不仅能提高催化剂的强度,同时由于载体具有碱性,可提高催化剂的变换活性,且载体比较稳定,抗水合性远优于氧化铝系载体。采用水热合成法,在一定的温度下,选用适当的矿化剂及助剂,合成出适合于镁铝尖晶石载体制备用前驱物粉体。该粉体经成型、焙烧后可制备出镁铝尖晶石结构的载体。试验结果表明,载体强度超过160N/cm,经水热试验后强度仍大于150N/cm,可满足高压、高汽气比条件下应用的要求。

Magnesiaalumina spinel, when used as catalyst support, is superior to alumina in that it enhances strength of the catalyst while endowing the catalyst with alkalinity, which favors its shift activity. The spinel is also superior to alumina in its property and phase stability and much higher tolerance to hydration. Hydrothermal synthesis of magnesiaalumina spinel was studied. Magnesiaalumina precursor powder was prepared using appropriate mineralizer and promoters. The precursor was then dried and calcined to form support with the structure of magnesiaalumina spinel. Test results showed that the support, with initial strength of 160 N/cm, exhibited strength of 150 N/cm after hydrothermal treatment, which meets the requirement of high pressure and high steam/gas operation.