Abstract:
In order to investigate the effect of binder addition parameter on the structure and performance of iron based Fischer Tropsch synthesis catalysts,a series of Fe Cu K SiO2 catalysts were prepared by varying the parameters including temperature,pH value and aging time during binder precursor addition.The effect of binder addition parameters on both physical chemical properties and FT synthesis performance of those catalysts were investigated using low temperature N2 physical adsorption,XRD,Air jet cup attrition test,H2 TPR and activity test on fixed bed reactor.The XRD results indicate that all of the samples exhibit same bulk structure of ferrihydrite,while the different binder addition parameters have no effect on the crystalline structure of those catalysts.Based on the N2 physical adsorption results,the pore volume of the catalysts becomes larger in narrow range as the result of increasing temperature,aging time and decreasing pH value of binder induction procedure.The attrition index decreases first and then increases as the temperature and aging time of binder induction increase,indicating that there are optimized conditions for these two parameters to improve the overall catalyst’s attrition performance.As the result of activity tests,the sample binder induced under 55 ℃ exhibits the lowest deactivation rate as well as the best selectivity.The CO conversion of the catalyst decreases when the aging time of binder induction is prolonged until 210 min.Attrition index of the catalyst decreases obviously when the binder is induced under lower pH value.The results of H2 TPR indicate that the increased Fe O Si SMSI should be responsible for the increased attrition properties of the catalysts.