Surface Area and Porosity Measurements of Steam Reforming and Methanation Catalysts

Supported nickel catalysts are used for steam reforming of natural gas and methanation of carbon oxides in hydrogen-rich streams in the production of ammonia, methanol and hydrogen. These catalysts are loaded into reactors in the oxide form and are then activated into metallic nickel state by in-citu reduction. The activity of the catalyst depends on the properties of the reduced catalysts. Of particular importance is the nickel (active) surface area of the catalyst, since the catalytic reactions takes place on the available nickel surface. This paper reports the experimental results on the BET, nickel surface areas, pore volume, and pore size distribution of commercial steam reforming and methanation catalysts used in Saudi Arabia. Variables studied in the catalyst reduction were temperature, heating rate, reducing gas composition, duration and space velocity. Experiments were carried out in a modified Pulse Chemisorb 2700 unit, which is capable of in-situ reduction and chemisorption. BET area was obtained by nitrogen adsorption while porosity was determined by mercury penetration method. The results of this study are discussed in the light of physical and chemical changes taking place during the in-situ reduction of steam reforming and methanation catalysts.