Patent ID: 7378452

Claim:
A slurry hydrocarbon synthesis process for forming hydrocarbons, at least a portion of which are liquid, the invention comprises: (a) reacting a synthesis gas containing a mixture of H 2 and CO in the presence of a solid, particulate hydrocarbon synthesis catalyst in a slurry in a hydrocarbon synthesis reactor at reaction conditions effective to form hydrocarbons, at least a portion of which are liquid at said reaction conditions, wherein said slurry comprises said catalyst and gas bubbles in a hydrocarbon slurry liquid, and wherein said slurry hydrocarbon liquid comprises said liquid hydrocarbons; (b) contacting said slurry with a filter system comprised of one or more small pore filter elements having a mean pore size less than about 10 microns, and one or more large pore filter elements having a mean pore size 10 microns or greater; said small pore filter elements arrayed across a manifold connected to a filtrate conduit, with the interior of the elements, manifold and conduit in fluid communication with each other, and wherein the wall separating the interior of the elements from the slurry is permeable to said slurry hydrocarbon liquid but not said slurry solids; and said large pore filter elements arrayed across a separate manifold from said small pore filter elements and connected to a separate filtrate conduit, with the interior of the elements, manifold and conduit in fluid communication with each other, and wherein the wall separating the interior of the elements from the slurry is permeable to said slurry hydrocarbon liquid and particles less than about 10 microns, and wherein said larger pore filter elements are such that no more than about 1 wt % to about 25 wt % of slurry liquid is passed there-through; (c) passing said slurry hydrocarbon liquid through said small pore filter element walls and into said interior of said elements as a filtrate and then successively passing said filtrate through the interior of said manifold and said filtrate conduit and passing said filtrate from said conduit out of said reactor whereby said filtrate is substantially free of solids; and (d) passing said slurry hydrocarbon liquid and fines through said large pore filter element walls and into said interior of said elements as a filtrate and then successively passing said filtrate through the interior of said manifold and said filtrate conduit passing said filtrate from said conduit out of said reactor whereby the concentration of fines in the reactor is controlled.