Syngas cleanup process

1 . A process for washing a syngas comprising:

cooling a syngas stream to a temperature below the dew point of water, the cooled syngas stream having at least a condensed-liquid phase and a gas phase, the condensed-liquid phase containing at least one nitrogen contaminant;

separating the condensed-liquid phase of the cooled syngas stream from the gas phase of the cooled syngas stream;

removing a majority of the at least one nitrogen contaminant from the condensed-liquid phase to produce a partially-decontaminated liquid stream; and

washing at least a portion of the separated gas phase of the cooled syngas stream with the partially-decontaminated liquid stream.

2 . The process of claim 1 , wherein a knockout drum is used to separate the condensed-liquid phase of the cooled syngas stream from the gas phase of the cooled syngas stream.

3 . The process of claim 1 , wherein the condensed-liquid phase is fed to a first stripper, the first stripper being adapted to remove at least a portion of the at least one nitrogen contaminant.

4 . The process of claim 3 , wherein the first stripper includes at least an upper portion and a lower portion.

5 . The process of claim 4 , wherein the upper portion of the first stripper is smaller in diameter than the lower portion of the first stripper.

6 . The process of claim 3 , wherein the condensed-liquid phase is fed to a second stripper after at least a portion of the at least one nitrogen contaminant has been removed by the first stripper, the second stripper being adapted to remove at least a second portion of the at least one nitrogen contaminant, the first and second strippers being adapted to remove the majority of the at least one nitrogen contaminant from the condensed-liquid phase.

7 . The process of claim 3 , wherein the condensed-liquid phase is run through a filter prior to being fed to the first stripper.

8 . The process of claim 7 , wherein the filter is adapted to filter out particulates in excess of 5 microns in size.

9 . The process of claim 1 further comprising cooling the partially-decontaminated liquid stream prior to washing the portion of the separated gas phase of the cooled syngas stream with the partially-decontaminated liquid stream.

10 . The process of claim 9 , wherein the partially-decontaminated liquid stream is cooled to less that 35° C.

11 . The process of claim 1 , wherein the cooling of the syngas stream and the separating of the condensed-liquid phase are performed by a water exchanger having a large disengagement area.

12 . The process of claim 11 further comprising collecting the separated condensed-liquid phase in a sump attached to the water exchanger.

13 . The process of claim 1 , wherein the separating of the condensed-liquid phase from the gas phase occurs within a scrubber having a lower portion, the separation of the condensed-liquid phase occurring within the lower portion of the scrubber.

14 . The process of claim 13 , wherein the scrubber includes a coalescer pad adapted to separate the condensed-liquid phase from the gas phase.

15 . The process of claim 13 , wherein the washing of the portion of the separated gas phase with the partially-decontaminated liquid stream occurs within the scrubber.

16 . A process for washing a syngas comprising:

providing a syngas stream having a plurality of phases;

cooling the syngas stream to a temperature below the dew point of water, the cooled syngas stream having at least a condensed-liquid phase and a gas phase, the condensed-liquid phase containing at least one nitrogen contaminant;

separating, via a liquid/gas phase separator, the condensed-liquid phase of the cooled syngas stream from the gas phase of the cooled syngas stream;

transferring the gas phase of the cooled syngas stream to a scrubber;

transferring the condensed-liquid phase of the cooled syngas stream including the at least one nitrogen contaminant to a stripper column;

removing a majority of the at least one nitrogen contaminant from the condensed-liquid phase via the stripper column, the stripper column producing a bottoms stream comprising a partially-decontaminated liquid stream;

transferring the partially-decontaminated liquid stream to the scrubber; and

washing, within the scrubber, at least a portion of the gas phase of the cooled syngas stream with the partially-decontaminated liquid stream.

17 . The process of claim 16 further comprising cooling the partially-decontaminated liquid stream prior to washing the portion of the separated gas phase of the cooled syngas stream with the partially-decontaminated liquid stream.

18 . The process of claim 17 , wherein the partially-decontaminated liquid stream is cooled to less that 35° C.

19 . The process of claim 16 further comprising filtering the condensed-liquid phase prior to transferring the condensed-liquid phase to the stripper column.