COCRACKING AND SEPARATE CRACKING OF ETHANE AND NAPHTHA

This paper presents experimental data on the thermal cracking of a naphtha-ethane mixture in a pilot plant, under conditions representative of industrial operation. The effects of the interaction between ethane and naphtha on the ethane conversion and kinetics and on the product distribution are investigated. When naphtha, ethane, and the mixture are cracked under an equal molar dilution, the cocracking yields and selectivities can be quantitatively predicted from the separate cracking data, except for hydrogen, methane, and high molecular weight products. The combined effects of cocracking and partial pressure, occurring when naphtha, ethane, and the mixture are cracked under an equal weight dilution, are such that, if maximum olefins selectivities are desired, separate cracking is to be preferred. Some aspects of coke formation are addressed as well.