Comparative study of prepared and industrial low temperature shift catalysts

Abstract

Experimental studies have been carried out to investigate the effect of preparation methods, preparation variables and operating conditions on the activity and, especially, on the life of the laboratory scale Low Temperature Shift (LTS) catalysts. In every case, the results observed on industrial catalyst are compared with the results obtained using the prepared catalysts. Copper based catalysts have been prepared following co-precipitation, solution and incipient wet impregnation technique. The activity test results, presented graphically, show that preparation methods have considerable influence on LTS catalyst. To find out the optimum catalyst composition, reduction and reaction conditions, the effect of CuO concentrations (15-41%), ZnO/AhO) ratio (0.73-4.27), reduction temperature (150- 350°C), reduction time (1-6 hr), and reaction temperature (ISO-400°C) on the activity of the prepared catalysts has been studied. The conversion of carbon monoxide is observed to change about 90% when concentration of CuO in catalyst is increased from IS to 41%. Significant increase of the rate of reaction has been noticed with increasing ZnO/AhO) ratio. Industrial catalyst and the catalysts prepared by impregnation method have been used for short-term and long-term stability tests to establish the deactivation trends. The physical properties of the catalysts, which are used to correlate with the results of activity testing, viz. total pore volume, active metal surface area and Temperature Programmed Reduction (TPR) profile have been determined using conventional characterization methods. Considerable influence of preparation method and catalyst composition on BET area, pore volume and TPR profile of the catalysts has been observed.