Synthesis and Characterization of Nanosize Catalyst for the RWGS Process and Performance Examination using a Pilot-Scale High-Pressure Reactor

Catalyst reduces the activation energy of molecules and is generally composed of an active part distributed on a large surfaced stable support or ligand. Since the catalytic reactions occur at the surface of the catalyst, this necessitates the method of catalysts preparation after suitable pretreatment to have an active, moderately high and accessible surface area. Also, the pretreated catalysts should have sufficient mechanical strength and stability so that the particles will remain relatively unchanged during their use as catalysts. Nanosize metal oxide catalysts deposited on alpha-alumina are prepared using combustion synthesis in the present work. Alumina acts as support, a promoter as well as a catalyst in this process. Aluminum nitrate, cobaltous chloride, nickel chloride, ammonium molybdate, and urea are used as raw materials to synthesize cobalt-nickel-molybdenum on alumina by combustion method. The solution at 500oC in a muffle furnace produced voluminous solid within 5 minutes. Particle size, morphology, chemical characterization of the sample were analyzed by scanning electron microscopy (500 nm), X-ray diffraction, and energy disperses X-ray analysis techniques. The results showed that the concentration of nickel among all three promoters was the least. Increasing levels of carbon dioxide in the atmosphere have detrimental effects such as an increase in temperatures, melting of glaciers, the rise in the levels of seas and oceans, submergence of low-lying land areas and disruptions in the ecological cycles. In order to combat this, the present work was extended to convert carbon dioxide to carbon monoxide by reverse water gas shift reaction. Carbon monoxide can be later used to produce methanol and dimethyl ether which has a higher calorific value. Present process was carried out in a pilot-scale high-pressure reactor at 400 ℃ and 7 bar using nanoparticles of nickel-cobalt-molybdenum on alumina. Product stream was analyzed by gas chromatography with a thermal conductivity detector.