PROCESS FOR THE PRODUCTION OF SYNTHESIS GAS

Abstract

A process for producing synthesis gas, the process comprising the steps of a) reforming a hydrocarbon feed in a reforming section thereby obtaining a synthesis gas comprising CH4, CO, CO2, H2 and H2O and impurities comprising ammonia;b) shifting the synthesis gas in a shift section comprising one or more shift steps in series to a shifted synthesis gas; c) separating from the shifted synthesis gas a process condensate originating from cooling and optionally washing of the shifted synthesis gas;d) passing the process condensate to a condensate steam stripper, wherein dissolved shift byproducts comprising ammonia, methanol and amines formed during shifting the synthesis gas are stripped out of the process condensate using steam resulting in a stripper steam stream, e) adding a part of the stripper steam stream from the process condensate steam strip-per to the hydrocarbon feed and/or to the synthesis gas downstream the reforming section, up-stream the last shift step, wherein the remaining part of stripper steam is purged.

Claims

1. A process for producing synthesis gas, the process comprising the steps of a) reforming a hydrocarbon feed in a reforming section thereby obtaining a synthesis gas comprising CH.sub.4, CO, CO.sub.2, H.sub.2 and H.sub.2O and impurities comprising ammonia; b) shifting the synthesis gas in a shift section comprising one or more shift steps in series to a shifted synthesis gas; c) separating from the shifted synthesis gas a process condensate originating from cooling and optionally washing of the shifted synthesis gas; d) passing the process condensate to a condensate steam stripper, wherein dissolved shift byproducts comprising ammonia, methanol and amines formed during shifting the synthesis gas are stripped out of the process condensate using steam resulting in a stripper steam stream, e) adding a part of the stripper steam stream from the process condensate steam stripper to the hydrocarbon feed and/or to the synthesis gas downstream the reforming section, up-stream the last shift step, wherein the remaining part of stripper steam is purged.

2. The process of claim 1, wherein the condensate steam stripper is a medium pressure stripper.

3. The process of claim 1, wherein the purge stripper steam is passed to a hydrocarbon combustion step.

4. The process of claim 3, wherein the hydrocarbon combustion step is the fuel side of a steam reformer.

5. The process of claim 3, wherein the hydrocarbon combustion step is the fuel side of a fired heater.

6. The process of claim 3, wherein the purge stripper steam is mixed with the combustion air or hydrocarbon fuel before entering the hydrocarbon combustion step.

Description

EXAMPLE

[0034] Reference is made to FIG. 1

[0035] The stream numbers in the tables below refers to the reference numbers in FIG. 1 Table 1 shows a case for removing formed ammonia and amines by converting these in the reforming section by adding 8.4% of the stripped steam to this unit.

[0036] Table 2 shows a case for removing formed ammonia and amines by purging 8% of the process condensate.

[0037] There is in both cases the same built-up of ammonia and amines in the shift section. This built-up can be reduced or removed by admitting all the stripped steam to either the reforming section or the process condensate purge.

TABLE-US-00001 TABLE 1 Stream 1 2 3 4 5 6 7 9 10 11 Flow T/h 92 100 168 255 255 125 0 95 87 8 Ammonia Kg/g 0 40 42 482 480 480 0 480 440 40 Amines Kg/h 0 3 0 33 36 36 0 36 33 3

TABLE-US-00002 TABLE 2 Stream 1 2 3 4 5 6 7 9 10 11 Flow T/h 100 100 168 255 255 125 8 87 87 0 Ammonia Kg/g 0 0 42 480 478 478 40 438 438 0 Amines Kg/h 0 0 0 33 36 36 3 33 33 0