Un Ho Jung

The promotional effect of K on the catalytic activity of Ni/MgAl2O4 for the combined H2O and CO2 reforming of coke oven gas for syngas production

A K-promoted 10Ni-(x)K/MgAl2O4 catalyst was investigated for the combined H2O and CO2 reforming (CSCR) of coke oven gas (COG) for syngas production. The 10Ni-(x)K/MgAl2O4 catalyst was prepared by co-impregnation, and the K content was varied from 0 to 5 wt%. The BET, XRD, H2-chemisorption, H2-TPR, and CO2-TPD were performed for determining the physicochemical properties of prepared catalysts. Except under the condition of a K/Ni=0.1 (wt%/wt%), the Ni crystal size and dispersion decreased with increasing K/Ni. The coke resistance of the catalyst was investigated under conditions of CH4: CO2: H2: CO:N2=1 : 1 : 2 : 0.3 : 0.3, 800 °C, 5 atm. The coke formation on the used catalyst was examined by SEM and TG analysis. As compared to the 10Ni/MgAl2O4 catalyst, the Kpromoted catalyst exhibited superior activity and coke resistance, attributed to its strong interaction with Ni and support, and the improved CO2 adsorption characteristic. The 10Ni-1K/MgAl2O4 catalyst exhibited optimum activity and coke resistance with only 1wt% of K.

Preferential CO Oxidation Over Ru/Al2O3-Coated Metal Monolith Catalyst for Small-Scale Fuel Processor

Ru/Al2O3-coated FeCralloy monolith catalyst was applied for the preferential CO oxidation (PrOx) to reduce CO concentration less than 10 ppm in reforming process. FeCralloy monolith was pre-calcined at 900 °C after electrochemical surface treatment which results in the formation of uniform Al2O3 layer on the metal substrate. Pre-calcined monolith was coated with 10 wt% Al2O3 sol and followed by 1.2 wt% Ru/Al2O3 catalyst washcoating. The highly dispersed 1.2 wt% Ru/Al2O3 catalyst was prepared by the deposition-precipitation method using 5 wt% NaOH solution as a precipitant. The characterization as to surface area, metal dispersion, and reduction temperature of catalysts were analyzed by BET, CO-chemisorption and H2-TPR. PrOx test was performed with GHSV of 5,000–30,000 h−1 at 100–200 °C. The λ(2[O2]/[CO]) was adjusted between 1 and 2 and the effect of H2O and CO2 was examined at λ = 2. As a result, the metal dispersion of Ru coated on the FeCralloy monolith is higher than that of commercial pellet catalyst with the shape of sphere. The monolith catalyst shows higher CO conversion and CO2 selectivity than the commercial catalyst due to the enhancement of thermal conductivity and the maximization of available Ru active site on the metal substrate. In addition, monolith catalyst has a superior tolerance to H2O and CO2. From this study, it is found that the Ru/Al2O3-coated monolith catalyst shows robust catalytic activity with 100 % CO conversion and 50 % CO2 selectivity under 0.61 % CO, 0.61 % O2, 59 % H2, 19 % H2O, 16 % CO2, N2 balance at GHSV = 5,000 h−1 from 100 to 160 °C in PrOx.