The Davison Circulating Riser (DCR) with its slide-valve, pressure balanced, adiabatic operation, is the leading, commercially available technology for small scale FCC pilot units.

Xytel offers a proprietary design of high severity/short contact downflow reactor (downer) based on a DCR pilot unit. High temperature, or high severity operation advantages include improved gasoline octane and increased light olefin production. Design and construction of the first modular 0.2 bpd downflow pilot plant was completed by Xytel in 1998. Data from the pilot plant confirm the advantages predicted by theory.