Riser simulator test conditions

Tables 2.1 and 2.4 show the VGO-C feed quality properties and the test conditions of the Riser Simulator experiments. The three catalysts tested were the same ones used in the FFB reactor experiments. Temperature for the LZM catalyst was lower than for the other catalysts to reproduce typical conditions used for mid-distillate maximization in commercial units.

The test conditions for this Microscale Simulation Test (MST) correspond to the low vapor contact times as applied in today s FCC riser technology. An effective feed preheat and feed dispersion is ensured, while the isothermal reactor bed is set to the dominating kinetic temperature in the riser, being approximately the feed catalyst mix temperature. The MST conditions enable the testing of high Conradson Carbon residue feedstocks. 

Using equilibrium catalyst from commercial FCC units, we modified the MAT reactor conditions in order to meet the simulation criteria. This work was complemented with ARGO pilot riser plant tests, exploring the influence of the main process parameters such as residence time, mixing, reactor temperature and temperture profile. 

The results described in this review demonstrate the importance of novel tools for kinetic modelling and catalyst development. In this context it is proposed to adopt the Riser Simulator to effectively represent the catalytic cracking reactions which take place in a FCC riser reactor. The technique allows for similar conditions to be used such as temperature, catalyst to oil ratio, partial pressure of hydrocarbons, solids loading and reaction time as those used in commercial units. Moreover, the contacting of the hydrocarbons with the catalyst is more representative of riser cracking where the catalyst moves in time with the vapours, than that achieved in the MAT test. 

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