Catalytic pyrolysis of n-heptane on unpromoted and potassium promoted calcium aluminates

Steam pyrolysis of n-heptane has been studied over different calcium aluminates and potassium impregnated calcium aluminate in a fixed bed reactor at atmospheric pressure. Various calcium aluminate catalysts were prepared by changing the precursor salt for obtaining CaO, which was subsequently used with Al2O3 for catalyst preparation. Depending on the source of CaO, the catalytic properties such as X-ray diffraction patterns, surface area, weight loss during reduction and the amount of CO2 chemisorbed (basicity) were different. Compared to the unpromoted catalysts, K2CO3 impregnated catalyst significantly reduced the coke deposited on the catalyst, but only had marginal effect on the products selectivities. The activation energy for the coke gasification reaction was 140kJ/mol. (C) 2002 Elsevier Science B.V. All rights reserved.