tailieunhanh - Combined steam and CO2 reforming of CH4 over nickel catalysts based on Al2O3–MO (m= Mg, Ca, Ba)

The results showed that MgO was the most suitable promoter comparing with CaO and BaO in CSCRM. The presence of MgO in Ni/Al2O3 changed catalysts’ characteristics leading to an increase in the catalytic activity and stability with time on stream (TOS). It was found that the suitable catalyst was Ni–based on Al2O3–MgO of mass ratio 2:1 which showed a high metal dispersion as well as dominated spinel structure. | Journal of Science and Technology 55 (1B) (2017) 49–56 COMBINED STEAM AND CO2 REFORMING OF CH4 OVER NICKEL CATALYSTS BASED ON Al2O3–MO (M= Mg, Ca, Ba) Phuong P. H. 1, Loc . 1, 2, *, Sang P. T. 1, Tri N. 2 1 Oil & Gas Processing Department, Faculty of Chemical Engineering, HCMUT–VNUHCM 268 Ly Thuong Kiet Street, Ward 14, District 10, Ho Chi Minh City, Vietnam 2 Institute of Chemical Technology, Vietnam 1 Mac Dinh Chi Street, Ben Nghe Ward, District 1, Ho Chi Minh City, Vietnam * Email: Received: 30 December 2016; Accepted for publication: 2 March 2017 ABSTRACT A series of 10 wt% Ni/Al2O3–MO (M = Mg, Ca, Ba) catalyst was prepared by impregnation method for applying in the combined steam and carbon dioxide reforming of methane (CSCRM). In this study, five supported nickel catalysts were impregnated on different supports. All of the supports have been obtained by co–precipitation method and also have been investigated. Several techniques, including N2 physisorption measurements, X–ray powder diffraction (XRD), temperature–programmed reduction using H2 (H2–TPR), and transmission electron microscopy (TEM) were used to investigate catalysts’ physicochemical properties. The results showed that MgO was the most suitable promoter comparing with CaO and BaO in CSCRM. The presence of MgO in Ni/Al2O3 changed catalysts’ characteristics leading to an increase in the catalytic activity and stability with time on stream (TOS). It was found that the suitable catalyst was Ni–based on Al2O3–MgO of mass ratio 2:1 which showed a high metal dispersion as well as dominated spinel structure. The CH4 and CO2 conversion at 800 °C reached % and %, respectively. Catalytic stability of this catalyst with TOS at 800 °C could reach to more than 20 hours until it started decreasing. Keywords: CH4 bi–reforming, combined steam and CO2, Ni–based catalysts, Al2O3–MgO supports. 1. INTRODUCTION The conversion of hydrocarbons to hydrogen and syngas plays an .