Synthesis of Alcohols and Alkanes from CO and H₂ over MoS₂/γ-Al₂O₃ Catalyst in a Packed Bed with Continuous Flow

Effects of reaction conditions on the production of alcohols (AOH_s) and alkanes (Alk) from CO and H₂, which can be obtained from the gasification of biomass, using a molybdenum sulfide (MoS₂)-based catalyst of MoS₂/γ-Al₂O₃were studied. A high-pressure fixed packed bed (HPFPB) was employed to carry out the reaction. The results indicate that the conversion of CO (X_CO) and specific production rates of alcohol (SPR_AOH) and alkane (SPR_Alk) are highly depended on temperature (T). In T = 423–573 K, maximum yield of alcohols (Y_AOH) and SPR_AOH occur at T = 523 K. In the meantime, well performance gives the selectivity of ethanol (S_EtOH) of 52.0 C%. For the studies on varying H₂/CO mole ratio (M_H/C) from 1 to 4 at 523 K, the appropriate M_H/C to produce EtOH is 2, giving higher ratios of SPR_AOH/SPR_Alkand Y_AOH/Y_Alkthan those with other M_H/C. As for varying the total gas flow rates (Q_G) of 300, 450, 600 to 900 cm³ min⁻¹ tested at T = 523 K and M_H/C = 2, the lower QG provides longer reaction time (or gaseous retention time, t_R) thus offering higher X_CO, however lower productivity. For setting pressure (P_ST) = 225–540 psi, a supply of higher pressure is equivalent to providing a larger amount of reactants into the reaction system, this thus suggests the use of higher P_ST should give both higher X_COand productivity. The assessment of the above results indicates that the MoS₂/γ-Al₂O₃ catalyst favors the production of alcohols over alkanes, especially for ethanol. The information obtained is useful for the proper utilization of biomass derived gases of CO and H2.