A Method To Prepare A Catalyst For The Synthesis Of Gasoline From Carbon Monoxide And Hydrogen
The catalyst is prepared by mixing a zinc-chromium-aluminum compound (a contact) produced by reacting a precipitant and nitrates of respective metals, followed by drying and high-temperature calcination, with a high silica zeolite prepared by hydrothermal crystallization of a silicon compound in the presence of aluminium-containing compound in a alkaline medium, followed by decationization and calcination. The contact to zeolite weight ratio ranges within (1-9):1.
To improve the catalyst activity and selectivity, the zinc-chromium-aluminium contact is prepared with the use of sodium carbonate as the precipitant. The calcination at 380-400°C is carried out for 3-4 hr. To prepare the high silica zeolite, diatomite containing 3-8 wt.% of alumina and exposed to mechanochemical treatment is used as the aluminium-containing compound. In order to prepare catalyst having improved stability, iron sulphate or gallium sulphate is added to diatomite in the amount of 0.68-2.05 wt.% before the mechanochemical treatment.