SLURRY BUBBLE COLUMN REACTOR FOR A FISCHER-TROPSCH PROCESS

Abstract

The disclosure deals with a slurry bubble column reactor for converting a gas mixture comprising carbon monoxide and hydrogen into liquid hydrocarbons. The slurry bubble column reactor features a slurry bed of catalyst particles, an inlet conduit for feeding the gas mixture into the slurry bed, a filtration zone for separating the liquid hydrocarbons from the catalyst particles and a liquid outlet conduit for withdrawing the separated hydrocarbons from the filtration zone. The filtration zone is situated in the slurry bubble column reactor such that the slurry bed is found in a first and a second heat exchange zone with the filtration zone arranged between the first and the second heat exchange zone.

Claims

1. A slurry bubble column reactor for converting a gas mixture comprising carbon monoxide and hydrogen into liquid hydrocarbons featuring a slurry bed of catalyst particles, an inlet conduit for feeding the gas mixture into the slurry bed, a filtration zone for separating the liquid hydrocarbons from the catalyst particles and an liquid outlet conduit for withdrawing the separated hydrocarbons from the filtration zone, at wherein the filtration zone is situated in the slurry bubble column reactor such that the slurry bed is found in a first and a second heat exchange zone with the filtration zone arranged between the first and the second heat exchange zone.

2. The slurry bubble column reactor according to claim 1 wherein each heat exchange zone features a separate heat exchanger.

3. The slurry bubble column reactor according to claim 1 wherein the slurry bubble column reactor comprises a bottom zone and the inlet conduit is fluently connected to the bottom zone.

4. The slurry bubble column reactor according to claim 3, wherein the first heat exchange zone is situated next to the bottom zone of the slurry bubble column reactor.

5. The slurry bubble column reactor according to claim 1, wherein the filtration zone comprises at least one hollow and enclosed filter element and at least one rinsing conduit for cleaning the filter element.

6. The slurry bubble column reactor according to claim 1, wherein the slurry bubble column reactor features a gas outlet conduit on top to withdraw gaseous products and unreacted synthesis gas.

7. The slurry bubble column reactor according to claim 1, wherein the filtration zone features a diameter similar to the slurry bubble column reactor diameter and that the beginning of the filtration zone measured from a lower tangent line (L.T.L) of the slurry bubble column reactor is between 20 and 60% of the height of the slurry bubble column reactor from the lower tangent line (L.T.L.) to an upper tangent line (U.T.L.).

8. The slurry bubble column reactor according to claim 1, wherein the heat exchange zones feature a diameter similar to the slurry bubble column reactor diameter and that the height of the first heat exchange zone is between 75 and 150% of the height of the second heat exchange zone.

9. A process for converting a gas mixture comprising carbon monoxide and hydrogen into liquid hydrocarbons, when the gas mixture is fed into a slurry bed in a slurry bubble column reactor, where at least part of the gas mixture is converted into liquid hydrocarbons on the catalyst particles in the slurry bed, wherein the obtained liquid hydrocarbons are separated from the catalyst particles in a filtration zone located in the slurry bubble column reactor and wherein at least parts of the separated liquid hydrocarbons are withdrawn from the filtration zone, wherein the gas mixture is converted in two heat exchange zones fluently connected via the filtration zone only.

10. The process according to claim 9, wherein the temperature inside the slurry bubble column reactor is between 200 and 260 C. and/or the pressure inside the slurry bubble column reactor is between 10 and 50 bar g.

11. The use of a slurry bubble column reactor according to claim 1 for performing a Fischer-Tropsch process.

Description

[0027] Preferred embodiments, advantages and possible applications of the invention can also be taken from the following description of the drawing. All features described and/or illustrated form the subject matter of the invention per se or in any combination, independent of their inclusion in the claims or their back reference.

[0028] FIG. 1 shows a slurry bubble column reactor according to the invention.

[0029] Via inlet conduit 14 a feed comprising carbon monoxide and hydrogen is fed into a bottom zone 24 of the slurry bubble column reactor 1. The bottom zone 24 is defined from the bottom 17 of the slurry bubble column reactor 1 up to its lower tangent line (L.T.L). The slurry bubble column reactor 1 is filled with a slurry bed 2 comprising suspended catalyst particles. Above the slurry bed is a disengagement zone 25. Further, a heat exchanger 21 is installed into a first heat exchange zone 11 to cool the slurry bed 2 which is heated due to the exothermic reactions taking place therein.

[0030] At least parts of the synthesis gas react on the catalyst particles, whereby at least one liquid product, often called wax, and gaseous products are formed. The liquid and gaseous products enter a filtration zone 13, whereby the solid catalyst particles are mainly separated in form of a filter cake on at least one filter element 19 inside the filtration zone 13.

[0031] Above the filtration zone 13, a second heat exchange zone 12 is located. The second heat exchange zone 12 also features a separate heat exchanger 22 to cool this part of the slurry bed 2. By entering the filtration zone 13 from the second heat exchange zone 12, also catalyst particles are separated at the at least one filter element 19 of the filtration zone 13.

[0032] As a result, the liquid product inside the filter element 19 is mainly free of catalyst particles and can be withdrawn via the liquid outlet conduit 16.

[0033] To clean the inside of the filter element 19, it is possible to feed a rinsing liquid via the rinsing conduit 15 into the filter element 19. The rinsing liquid can be withdrawn via the liquid outlet conduit 16.

[0034] After the rinsing step, a backflushing step is performed to dislodge the filter cake from the filter element 19 by a forced flow of the backflushing fluid from the inside of the filter element 19 into the slurry bed 2.

[0035] The slurry bubble column reactor 1 features a bottom 17 and a top 18. Gaseous products and unreacted synthesis gas can be withdrawn via the gas outlet conduit 23 from the top of the slurry bubble column reactor 1.

[0036] It is essential for the invention that the second heat exchange zone 12 above the filtration zone 13 is designed such that also in cases of emergency with a reduced gas hold up, the filtration zone 13 is fully submerged into the slurry bed 2.

REFERENCE LIST

[0037] 1 slurry bubble column reactor [0038] 2 slurry bed [0039] 11 first heat exchange zone [0040] 12 second heat exchange zone [0041] 13 filtration zone [0042] 14 inlet conduit [0043] 15 rinsing conduit [0044] 16 liquid outlet conduit [0045] 17 bottom [0046] 18 top [0047] 19 filter element [0048] 21, 22 heat exchanger [0049] 23 gas outlet conduit [0050] 24 bottom zone [0051] 25 disengagement zone [0052] L.T.L lower tangent line [0053] U.T.L upper tangent line