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

Abstract

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 Al 2O 3 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 CO 2 chemisorbed (basicity) were different. Compared to the unpromoted catalysts, K 2CO 3 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 140 kJ/mol.