Thermodynamic analysis of syngas conversion chemistry

The liquid phase catalytic conversion of syngas to methanol (LPMeOH{trademark}), and syngas to methanol and dimethyl ether (LPDME process) was investigated in a three-phase mini-pilot plant version of a mechanically agitated slurry reactor system. In this reactor system, the catalyst particles in powder form are slurried in the oil phase and this slurry is agitated by a mechanically driven impeller. Syngas reacts in the presence of the methanol synthesis catalyst (Cu/ZnO/Al{sub 2}O{sub 3})-oil slurry to form the product methanol in the LPMeOH process. The productivity of methanol in this process, is adversely affected by the chemical equilibrium limitation. Hence the dual catalytic approach (LPDME process), where the productivity of methanol is enhanced by the co-production of dimethyl ether with methanol, was developed to alleviate the chemical equilibrium limitation. In this LPDME process, syngas reacts in the presence of the methanol synthesis catalyst and the methanol dehydration catalyst ({gamma}-alumina), which are both slurried in the oil phase. The thermodynamics of the liquid phase methanol synthesis process and the liquid phase dimethyl ether process were investigated. The equilibrium conversions of H{sub 2}, CO, and syngas in both the processes are compared for nominally identical operating conditions. The effect of water and CO{submore » 2} addition to the feed syngas, and the effect of temperature and pressure on the LPMeOH process and the LPDME process were also compared.« less