Catalytic cracking of light gas oil using microwaves as energy source

Catalytic cracking is a process of utmost importance in a refinery because it yields products of commercial interest from lower aggregate value oils. It is a high-return process and requires constant technological innovations to address environmental concerns. In this regard, an interesting alternative to conventional fluidized catalytic cracking processes, where the coke deposited on the particle surface is burned through combustion, is to heat the particles directly using microwave energy. Electromagnetic waves cause the dielectric heating of zeolite catalyst particles, providing the energy required for cracking reactions. Catalytic cracking experiments with microwaves were performed in a light gas oil obtained from vacuum distillation, in order to verify the effects of the feed temperature, catalyst mass, wave action time and nitrogen injection. The samples obtained were analyzed by gas chromatography and mass spectroscopy and sulfur determination was carried out by X-ray dispersion. It was demonstrated cracking reactions in the gas oil could be generated by using microwaves. An increase of 7.06 percentage points in the concentration of n-paraffins and isoparaffins could be obtained for volatile compounds at 200 °C, generating products with chemical characteristics similar to those of a commercial diesel. A significant decrease in the sulfur content also occurred, from 6751 to 2850 ppm. A spouted-bed reactor, inserted in a cavity designed to be multimodal, provided the best conditions of those evaluated for the reaction in a three-phase bed, operating with commercially used zeolite catalyst particles with an average size of around 68 μm.