Catalytic Performance Of Amorphous Aluminosilicate Supported Cobalt Catalyst In Fischer-tropsch Synthesis

With the consumption of energy,oil resources are exhausted,but all kinds of vehicles in daily life are difficult to leave fuel.Fischer-Tropsch synthesis is a mature technology to convert small molecule gas(CO+H₂)into clean liquid fuel and chemicals,and this technology has received more and more attention.But in the traditional Fischer-Tropsch synthesis process,the product distribution of Fischer-Tropsch synthesis follows the ASF distribution,and the selectivity of fuel(C₅-C₂₀)is low.Aluminosilicate is commonly used in Fischer-Tropsch synthesis.Although the ASF distribution can be braken by crystalline ZSM-5-supported Fischer-Tropsch catalyst and the selectivity of products of C₅-C₂₀0 improved,the effect of acidity on product distribution is not detailed.Herein,the main research direction of this paper is to explore the effect of aluminosilicate hydrochloric acid on the distribution of Fischer-Tropsch synthesis products.The research contents of this paper include:preparing nano-scale flaky amorphous aluminosilicate by gel-hydrothermal method,investigating the influence of synthesis conditions on the hydrochloric acid property of aluminosilicate,then loading Co₃O₄ particles,and selecting the appropriate calcination temperature;The effect of SiO2₂ content on the catalytic performance of the catalyst for Fischer-Tropsch synthesis was investigated.The effect of the ratio of amorphous aluminosilicate to crystalline aluminosilicate(ZSM-5)on the catalytic performance of Fischer-Tropsch synthesis was compared.The results show that:(1)The influence of calcination temperature on the catalytic performance of aluminosilicate supported cobalt catalyst for Fischer-Tropsch synthesis was compared by changing the calcination temperature of support.The results show that the acidity of the support decreases with the increase of calcination temperature.The series of supports have little influence on the activity and stability of the catalysts.The biggest difference is that the aluminosilicate calcined at low temperature has appropriate acidity,which can crack long-chain hydrocarbon products without increasing the selectivity of small molecular byproducts such as CH₄,thus making the selectivity of products in the fuel section higher.(2)The catalytic performance of cobalt catalyst for Fischer-Tropsch synthesis can be improved by changing the content of SiO₂.In the process of Fischer-Tropsch synthesis catalysis,with the increase of SiO₂ content,the B acid content of aluminosilicate increases,which inhibits the formation of Fischer-Tropsch synthesis wax and increases the product selectivity of fuel oil.When SiO₂ content increases to a certain extent,the stability of the catalyst is going to poor.(3)The catalytic performance of the catalyst is improved while the stable amorphous aluminosilicate is mixed with crystalline ZSM-5,the amorphous aluminosilicate is excessive,the stability and CO conversion of the catalyst are better,the crystalline ZSM-5 is excessive,the initial activity of the catalyst is higher,but its stability is poor,and the selectivity of products in the fuel section is basically the same as that of the amorphous aluminosilicate supported Fischer-Tropsch synthesis catalyst.When amorphous aluminosilicate and crystalline ZSM-5 are mixed according to the mass ratio of 1:1,compared with the crystalline ZSM-5 supported Fischer-Tropsch synthesis catalyst,although the initial activity of the catalyst is slightly reduced,its stability and product selectivity of the fuel oil are also improved.