US 6,476,086 B1 · Coalescence enhanced gravity separation of iron catalyst from Fischer-Tropsch catalyst/wax slurry

Abstract

Fine iron-based catalyst particles from. Fischer-Tropsch (F-T) synthesis processes are effectively separated from catalyst/liquid/wax slurry by contacting and/or mixing the slurry with a coalescence enhancing treating solution to facilitate gravity separation and settling of such catalyst, and thereby yield a substantially clean hydrocarbon liquid/wax product. The treating solution includes a surface tension reducing agent, an agglutinating agent, and a coalescing agent each in selected proportions in aqueous solution. Useful mixing and settling conditions are 10-250° C. temperature, 0-500 psig pressure and treating solution to slurry volume ratio of 0.5-5:1, with the settling time for at least about 90% and preferably substantially all of the catalyst fines after the mixing step being less than about 15 minutes. The treating solution can be desirably recovered and reused in the F-T synthesis process, and the recovered catalyst either recycled or disposed as desired.

Claims15

Dependent claims

A method for separating iron-based catalyst fines from hydrocarbon liquid/wax/catalyst slurry for Fischer-Tropsch (F-T) synthesis processes, comprising the steps of:

(a) providing in a pressurable container a slurry of iron-based catalyst fines and hydrocarbon liquid/wax product obtained from a F-T synthesis process, said catalyst fines having particle size smaller than about 100 micron;
(b) mixing said catalyst/liquid/wax slurry with an aqueous treating solution, said solution including an interfacial tension reducing component, an agglutinating component and a catalyst coalescing component, with the volume ratio of said treating solution to the catalyst/wax slurry being 0.5-5:1;
(c) maintaining in said pressurizable container catalyst mixing and settling conditions of 10-250° C. temperature and 0-500 psig pressure sufficient to maintain said treating solution in liquid form, and for sufficient time after said mixing to provide coalescence enhanced separation and gravity settling of at least about 90% of the catalyst fines in said container bottom portion;
and
(d) removing overhead from said container a hydrocarbon product stream, and withdrawing said treating solution and the resulting settled catalyst fines from said container lower portion.

2 more elements

Dependencies are inferred from the claim text.

Coalescence enhanced gravity separation of iron catalyst from Fischer-Tropsch catalyst/wax slurry

Life of this patent

Coalescence enhanced gravity separation of iron catalyst from Fischer-Tropsch catalyst/wax slurry

Life of this patent

Abstract

Claims15