Name | secondary hydrocarbon steam reforming catalysts |
Synonyms | secondary hydrocarbon steam reforming catalysts |
Uses
Mainly used for two-stage steam conversion in ammonia synthesis or hydrogen production plants. After a period of conversion of natural gas, refinery gas, light oil and other hydrocarbons, due to the limitation of reaction equilibrium at a period of outlet temperature, there is still about 10% CH4 in a period of outlet gas. In order to further convert it into hydrogen, it is necessary to increase the reaction temperature to facilitate the right shift of the equilibrium of the reversible endothermic conversion reaction. The two-stage conversion catalyst can withstand higher temperatures than the one-stage catalyst, and the residual methane content in the gas after the two-stage conversion can be reduced to below 0.5%. Z204 can also be used for the first stage conversion of natural gas in medium and small ammonia plants. Z205 is used for the upper heat-resistant layer of the second stage; CZ-5 is used for the upper heat protection layer of the second stage.
Production method
The reaction temperature of the two-stage conversion is 950~1300 ℃, which requires the catalyst to have stable activity and good mechanical strength at high temperature. There are two main preparation methods.
prepare commercially available nickel nitrate or nickel nitrate prepared by dissolving nickel blocks with nitric acid to the required concentration, add α-Al2O3 powder, and neutralize with potassium carbonate solution under stirring to generate precipitation. Share the precipitate with the mother liquor, wash the precipitate many times, filter, dry, calcine, and then mix with pure calcium aluminate cement and graphite evenly, press molding, water or steam curing, and prepare a bonded catalyst.
Mix alumina powder with other additives for rolling, and send the granulation net to roll into fine particles. The carrier is obtained by pressing and forming with a molding machine and sintering at high temperature in a calciner. The carrier is impregnated with a solution of nickel nitrate and an auxiliary agent (accelerator), and then drained, dried and roasted to obtain a sintered catalyst.