Fischer-tropsch process

Abstract

There is provided an improved system and process for the catalytic hydrogenation of carbon monoxide to form a mixture of hydrocarbons utilizing a plurality of reactors in series. Synthesis gas entering the system under pressure is partially converted in at least one initial stage reactor and the effluent therefrom introduced into a final stage reactor. In the at least one initial stage reactor, a portion of the catalyst is continuously or periodically removed with some hydrocarbons and treated to renew, or renew and enhance it, and returned. The treatment comprises reducing the hydrocarbon context of the withdrawn mixture, heating to a temperature above at least one of the metals in the catalyst thereby forming a melt, removing any slag forming on the melt, cooling the melt and reducing the particle size of the resulting solid to a fine powder of renewed catalyst. The renewed catalyst may be treated to further enhance its properties by slurry low temperature oxidation or passivated before being returned to the at least one initial stage reactor. The final stage reactor, which has a catalyst of the same type or differing from that in the at least one initial stage reactor, receives a feed therefrom having a substantially reduced level of impurities, thereby enhancing the efficiency and longevity of the catalyst contained therein. The system can further employ at least one intermediate stage reactor configured so that all stages are operably connected in series and all reactors with a given stage are operably connected in parallel.