Magnetic separation of iron catalysts from fischer-tropsch wax

摘要

This paper describes recent work in magnetic separation of precipitated iron catalysts particles from Fischer-Tropsch wax at 260 deg C in fields up to 0.2 Tesla employing a novel magnetic micro-particle separator (MM-PS patent pending) adapted from an earlier continuously operating magnetic particle separator (CO-MPS) described elsewhere.The MM-PS is scaled up by a factor of 29 from the bench scale CO-MPS.In processing nominal 20-25 wt% catalyst slurries,it has operated at a product rate of 7950 liters per day (Lpd) while producing concentrations as low as 0.35 wt% solids with filtration rates up to 250 kg/min/m~2.The upper limit of the filtration rate is not known.The MM-PS is designed to achieve isobaric and isothermal separation of the bulk of the catalyst for immediate return to the Fischer-Tropsch reactor.Catalyst concentrations of 100 ppm were obtained employing a second stage batch operated HGMS.While the feed to the first stage exhibited strongly magnetic behavior,the product of HGMS was diamagnetic.