Light Hydrocarbon Synthesis From Syngas On Fe-based Catalyst

Syngas catalytic conversion technology is one of ways to active alternative fuel and bulk chemicals instead of petroleum during the post-petroleum era. The main active metal components of syngas catalytic conversion contain Fe. Co. Ru and Ni element.Iron base catalyst has the characteristics of cheap and good catalytic performance. So it is widely used to Fischer-Tropsch synthesis and industrial production. Al2O3 has the characteristics of high spicific surface, high mechanical strength, good thermal stability, and good open-framework, so it can play an important role on the active component dispersion and increases strength of the catalysts and so on. As a result.Al2O3 is be use as a a common carrier for iron base catalyst.In the paper,Al2O3 support was prepared by sol-gel process then Fe/Al2O3 catalyst and iron base catalysts adding Mn, K were synthesized via isometric impregnation method. The compsite and structure property of support and catalyst were characterized by XRD, SEM, BET,TPR and so on. Al2O3 best preparation conditions were investigated during the sol-gel process.The support and Fe/Al2O3 catalyst structural characteristic and additives influence on the structural and reduction performance of iron base catalyst were investigated, Then Fe/Al2O3 catalytic CO hydrogenation performance be evaluated on the fixed-bed reactor; Study the temperature, airspeed, carrier and additives factors influence on the iron base catalyst for CO hydrogenation performance.Experimental results revealed thatγ-Al2O3 BET surface area is up to 341.5 m2/g under the conditions of the molar ratio of aluminium isopropoxide to water 1:3 and calcining in 800℃; the best active metal iron loading amount is 20% for Fe/Al2O3 catalysts;The sol-gel Al2O3 supported Fe/Al2O3 catalysts exhibited higher activity and selectivity for light alkenes than industrial Al2O3 and SiO2 supported catalyst; Under the conditions of space velocity of 1000 h-1, reaction temperature of 300℃, reaction pressure of nomorl pressure, and the molar ratio of hydrogen to carbon monoxide of 2.0, the conversion of CO on Fe/Al2O3 catalyst reached 42.7%;Under this circumstance, with the increase of the airspeed, CO conversion rate reduces, perhaps the reactant and product cost shorter time over the surface of the catalyst,As a result, CO conversion rate and product chain growth ability reduce and methane selective increases along with the airspeed increasing. Mn, K additives can improve CO conversion rate and reduce iron base catalyst reduction temperature. K additive can restrain the generation of CH4, promote Mn and active metal scattered, and improve the selectivity of unsaturated hydrocarbons.