Integrated multi-step solid/liquid separation system for fischer-tropsch processes

Abstract

A system for separating liquids from solids comprising an immobilization unit comprising an immobilization vessel containing a bed of magnetizable material and a magnet configured to produce a magnetic field within the immobilization vessel, wherein the immobilization vessel further comprises an immobilization vessel outlet and an immobilization vessel inlet for a fluid comprising liquid and metal-containing particles. A method for separating solid particles from liquid by introducing a fluid comprising liquid and a first concentration of solid particles into an immobilization unit comprising an immobilization vessel and at least one magnet configured to produce high density magnetic flux lines within the immobilization vessel and/or a high field gradient at or near the surface of the magnetizable material when powered, wherein the immobilization vessel contains therein a bed of magnetizable material; and removing from the immobilization unit a product having a second particle concentration less than the first particle concentration.

What is claimed is: 
     
         1 . A system for the separation of liquids from solids, the system comprising:
 an immobilization unit comprising an immobilization vessel containing a bed of magnetizable material and a magnet configured to produce a magnetic field within the immobilization vessel, wherein the immobilization vessel further comprises an immobilization vessel inlet for a fluid comprising liquid and metal-containing particles, and an immobilization vessel outlet for a reduced-solids liquid.   
     
     
         2 . The system of  claim 1  wherein the magnet is capable of producing high density magnetic flux lines within the immobilization vessel. 
     
     
         3 . The system of  claim 1  wherein the bed of magnetizable material comprises a plurality of interwoven fibers. 
     
     
         4 . The system of  claim 1  wherein the magnetizable material is configured as magnetizable steel wool. 
     
     
         5 . The system of  claim 1  further comprising a Fischer-Tropsch reactor, the Fischer-Tropsch reactor positioned upstream of the immobilization vessel, the Fischer-Tropsch reactor containing within it a metal-based Fischer-Tropsch catalyst, the Fischer-Tropsch reactor comprising an outlet for Fischer-Tropsch product comprising Fischer-Tropsch product wax and catalyst particles, the outlet in direct or indirect fluid communication with the immobilization unit. 
     
     
         6 . The system of  claim 5  wherein the catalyst is cobalt-based Fischer-Tropsch catalyst, iron-based Fischer-Tropsch catalyst, or a combination thereof. 
     
     
         7 . The system of  claim 6  wherein the catalyst comprises iron carbide. 
     
     
         8 . The system of  claim 5  further comprising a primary separator positioned upstream of the immobilization vessel, an inlet of the primary separator in fluid communication with the Fischer-Tropsch outlet and an outlet of the primary separator in fluid communication with the immobilization vessel inlet. 
     
     
         9 . The system of  claim 8  further comprising a surge drum between the primary separator and the immobilization vessel. 
     
     
         10 . The system of  claim 8  wherein the primary separator is a dynamic settler. 
     
     
         11 . The system of  claim 10  wherein the primary dynamic settler separator comprises a magnetic separation section. 
     
     
         12 . The system of  claim 8  wherein the primary separator comprises a cross-flow filtration unit. 
     
     
         13 . The system of  claim 8  further comprising upgrading apparatus downstream of the immobilization unit, wherein the upgrading apparatus is selected from hydrotreating apparatus, hydrocracking apparatus, isomerization apparatus, and combinations thereof. 
     
     
         14 . The system of  claim 13  wherein the upgrading apparatus is operable to provide a fuel selected from the group consisting of jet, diesel, naphtha, and combinations thereof. 
     
     
         15 . The system of  claim 8  wherein the reduced-solids liquid is suitable for direct use as a fuel. 
     
     
         16 . The system of  claim 8  further comprising at least one separation apparatus downstream of the immobilization unit, the at least one separation apparatus operable to provide a chemical product from the reduced-solids liquid. 
     
     
         17 . The system of  claim 16  wherein the chemical product is selected from the group consisting of olefins, alcohols, other oxygen-containing components, and combinations thereof. 
     
     
         18 . The system of  claim 1  comprising at least two immobilization units aligned in series. 
     
     
         19 . The system of  claim 1  comprising at least two immobilization units aligned in parallel. 
     
     
         20 . The system of  claim 1  comprising at least three immobilization units, with at least two of the immobilization units aligned in series.