Direct crude oil cracking for producing chemicals: Thermal cracking modeling

- Thermal cracking of crude oil and its fractions was performed in the 560-640 °C temperature range.
- Yields of olefins above 20 wt% could be obtained directly from crude oil, maintaining low amounts of dry gas and coke.
- A 9-lumps scheme was used to model thermal cracking.

The direct cracking of crude oil is an interesting option for producing cheaply large amounts of petrochemicals. This may be carried out with catalyst and equipment similar to that of catalytic cracking, but at a temperature range between that of standard catalytic cracking and steam cracking. Thermal cracking will play a role in the conversion, but is rarely disclosed in experimental or modeling work. Thus, a crude oil and its fractions were thermally cracked and the products yields were modeled using a 9 lumps cracking scheme. It was found that heavy fraction cracks twice as fast as diesel fraction and ten times faster than gasoline fraction, with activation energies in the 140-200 kJ/mol range. Selectivity to ethylene, propylene and butenes were found similar in the operating range explored.

141