Process to enhance catalyst life and removal of debris
View Patent ↗A process to optimize a slurry Fischer-Tropsch catalyst life and to further optimize removal of debris from a slurry Fischer-Tropsch process is provided. The process passes a part of a Fischer-Tropsch Reactor slurry inventory to another upstream Fischer-Tropsch Reactor where the Fischer-Tropsch reactors are connected in series. The process utilizes either multiple or a single transfer vessel and optionally, a motive gas.
1. A Fischer-Tropsch synthesis comprising the steps of:
(a) feeding synthesis gas into a first slurry FTR and recovering a first effluent comprised of C 4+ hydrocarbons, water and unreacted syngas;
(b) separating the unreacted syngas from the first effluent and feeding the unreacted syngas to a second slurry FTR;
(c) withdrawing a second slurry portion from the second FTR slurry and transferring the portion to a first transfer vessel;
(d) increasing the pressure of the second slurry portion in the first transfer vessel by feeding a motive gas to the transfer vessel wherein the motive gas has a pressure greater than the second FTR;
(e) feeding the second slurry portion from the first transfer vessel into the first FTR; and
(f) withdrawing a first slurry portion from the first FTR.
2. The process of claim 1 further comprising the step of (h) adding new catalyst to the regenerated slurry.
3. The process of claim 1 wherein the regeneration section comprises a process to reactivate chemically deactivated FT catalyst.
4. The process of claim 2 wherein the regeneration section comprises mixing new catalyst with the first slurry portion.
5. The process of claim 1 wherein the motive gas has a pressure of 5 psi or greater than that of the first FTR.
6. The process of claim 1 wherein the motive gas is injected at a bottom portion of the transfer vessel.
7. The process of claim 1 wherein the motive gas is selected from the group of syngas, high pressure process hydrogen, natural gas, and high-pressure process nitrogen.
8. The process of claim 1 further comprising the steps of:
(g) feeding the regenerated slurry to the second FTR.
9. The process of claim 1 further comprising the steps of:
(i) recovering from second FTR a second effluent from second FTR comprising C 4+ hydrocarbons, water and unreacted syngas; and
(ii) separating the unreacted syngas from the second effluent and feeding it to a third slurry FTR.
10. The process of claim 9 further comprising the steps of:
(iii) feeding the regenerated slurry to the third FTR.
11. The process of claim 10 further comprising the steps of:
(I) withdrawing a third slurry portion from the third FTR and transferring the third slurry portion to a second transfer vessel;
(II) third slurry portion to the second FTR.
12. The process of claim 11 wherein the first and second transfer vessels are the same vessel.
13. The process of claim 1 wherein the first slurry portion from the first FTR is transferred to a regeneration section to produce a regenerated slurry.