Two alpha functions(BM,SRW) and three different mixing rules(MHV2,WS,HG) for the PR and RKS-EOS were investigated in the vapor-liquid equilibrium calculation of related binary systems for Fischer-Tropsch synthesis oil system.Furthermore,two different equations of states(EOS) of SR-POLAR and PC-SAFT,together with two activity coefficient equations of UNIF-DMD and UNIF-HOC were investigated.The results showed that various prediction methods had similar deviations for weakly polar systems.However,these method had different prediction abilities for other systems.UNIF-DMD,RKS-HG and RKS-MHV2 models gave more accurate prediction for non-associating strongly polar system,RKS-MHV2 and UNIF-HOC models showed the smallest deviation for associating strongly polar system containing water,UNIF-HOC and SR-POLAR models showed the smallest deviation for associating strongly polar system containing acids,and UNIF-HOC,SR-POLAR models showed the smallest deviation for other associating strongly polar systems,while RKS-MHV2 and RKS-HG took the second place.PC-SAFT model would bring big deviation for unsymmetrical system when binary parameters were lacking,but would give small deviation for all systems when binary parameters were available.
A series of iron-based Fischer-Tropsch synthesis （FTS） catalysts incorporated with Al2O3 binder were prepared by the combination of co-precipitation and spray drying technology. The catalyst samples were characterized by using N2 physical adsorption, temperature-programmed reduction/desorption （TPR/TPD） and MSssbauer effect spectroscopy （MES） methods. The characterization results indicated that the BET surface area increases with increasing Al2O3 content and passes through a maximum at the Al2O3/Fe ratio of 10/100 （weight basis）. After the point, it decreases with further increase in Al2O3 content. The incorporation of Al2O3 binder was found to weaken the surface basicity and suppress the reduction and carburization of iron-based catalysts probably due to the strong K-Al2O3 and Fe-Al2O3 interactions. Furthermore, the H2 adsorption ability of the catalysts is enhanced with increasing Al2O3 content. The FTS performances of the catalysts were tested in a slurry-phase continuously stirred tank reactor （CSTR） under the reaction conditions of 260 ℃, 1.5 MPa, 1000 h^-1 and molar ratio of H2/CO 0.67 for 200 h. The results showed that the addition of small amounts of Al2O3 affects the activity of iron-based catalysts to a little extent. However, with further increase of Al2O3 content, the FTS activity and water gas shift reaction （WGS） activity are decreased severely. The addition of appropriate Al2O3 do not affect the product selectivity, but the catalysts incorporated with large amounts of Al2O3 have higher selectivity for light hydrocarbons and lower selectivity for heavy hydrocarbons.
Hai-Jun WanBao-Shan WuXia AnTing-Zhen LiZhi-Chao TaoHong-Wei XiangYong-Wang Li
