A riser based continuous pilot plant unit for fluid catalytic cracking (FCC) is also available in CERTH facilities. The unit has been recently used in the frame of EU collaborative projects for the upgrading of FT-waxes and BTL-naphtha for the production of high added value biofuels and chemicals.
The FCC pilot plant operates in full circulating mode with continuous regeneration. It consists of a vertical reactor (riser), a fluid bed regenerator, the stripper and the lift line. The reactions take place in the riser and the separation (stripping) of gases from the solid catalyst occurs in the stripper vessel. The solids flow through a second slide valve and through the spent catalyst lift line return to the reactor bottom following regeneration.
The fluid bed regenerator reactor is used to burn the carbon that covers the catalyst surface as a by-product of the cracking process. The fluidization gas (air) is introduced from the base of the regenerator and its flow rate is controlled by a mass flow controller. The spent catalyst enters the top of the fluid bed counter current to the air flow. The regenerator exit stream passes through cyclones that remove any entrained solids. The remaining products are cooled by a heat exchanger and subsequently their total flow is measured by a wet test meter and analyzed by a GC. Flue gases concentrations are measured on-line using an analyzer (Horriba, PG-250), which can measure the following flue gases: O2, CO2, CO, NO, NOx, SO2. The gas sample to this analyzer comes directly from the regenerator exit.