Steam Reforming of Hydrocarbons on Calcium Oxide

Abstract

The reactions of hydrocarbons in the presence of steam on basic catalysts such as calcium oxide were studied in a tubular flow reactor with a fixed catalyst bed at mainly 900°C.Steam reforming to produce CO, CO2 and H2 catalytically proceeded in parallel with thermal cracking over the catalysts. The catalytic activity did not correspond to the rate of the reaction between steam and carbon deposited in the steam reforming, but it corresponded to that of reaction between steam and carbon deposited in the absence of steam.Aliphatic hydrocarbons were somewhat less reactive than aromatics in the steam reforming on calcium oxide. While the rate of reaction between steam and carbon deposited from aliphatic and aromatic hydrocarbons was almost same with each other.The difference in the reactivity of aliphatic and aromatic hydrocarbons seems to be caused by the decrease of partial pressure of steam in the steam reforming of aliphatic hydrocarbons due to cracking, resulting in the decrease of the rate of reaction between steam and intermediate deposited carbon.