US 11,724,229 B2
Process and plant for removing disruptive components from raw synthesis gas
Robert Szabo, Frankfurt am Main (DE); and Sophia Schmidt, Frankfurt am Main (DE)
Assigned to L'Air Liquide, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude, Paris (FR)
Filed by L'Air Liquide, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude, Paris (FR)
Filed on Jun. 29, 2021, as Appl. No. 17/362,194.
Claims priority of application No. 20020304 (EP), filed on Jun. 29, 2020.
Prior Publication US 2021/0402347 A1, Dec. 30, 2021
Int. Cl. B01D 53/14 (2006.01); B01D 53/18 (2006.01); C10K 1/00 (2006.01); C10K 1/08 (2006.01)
CPC B01D 53/1425 (2013.01) [B01D 53/1462 (2013.01); B01D 53/18 (2013.01); C10K 1/004 (2013.01); C10K 1/005 (2013.01); C10K 1/08 (2013.01); B01D 2252/2021 (2013.01); B01D 2256/16 (2013.01); B01D 2256/20 (2013.01); B01D 2257/30 (2013.01); B01D 2257/504 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A process for purifying a raw synthesis gas containing hydrogen and carbon monoxide as target components and carbon dioxide and sulfur components as disruptive components by gas scrubbing with a physically acting, liquid scrubbing medium selective for carbon dioxide and sulfur components comprising the steps of:
a) providing an absorption apparatus comprising at least two absorption zones each provided with surface area-increasing internals, wherein in the gas flow direction of raw synthesis gas first passes through an absorption zone to remove at least one sulfur component and subsequently passes through an absorption zone to remove at least one carbon dioxide component
b) providing the raw synthesis gas stream to be purified, cooling the raw synthesis gas stream through indirect heat exchange with a first cooling medium, introducing the cooled raw synthesis gas stream to the at least absorption zone for removing at least one sulfur component,
c) contacting the cooled raw synthesis gas stream in the at least one sulfur components absorption zone under sulfur components absorption conditions with a first scrubbing medium stream, discharging a synthesis gas stream depleted in sulfur components from the at least one sulfur components absorption zone, discharging a scrubbing medium stream enriched in sulfur components from the at least one sulfur components absorption zone, introducing the synthesis gas stream depleted in sulfur components to the at least one carbon dioxide absorption zone,
d) contacting the synthesis gas stream depleted in sulfur components in the at least one carbon dioxide absorption zone under carbon dioxide absorption conditions with a second scrubbing medium stream, discharging a synthesis gas stream depleted in carbon dioxide from the at least one carbon dioxide absorption zone as pure synthesis gas, discharging a scrubbing medium stream enriched in carbon dioxide from the at least one carbon dioxide absorption zone,
e) supplying the scrubbing medium stream enriched in sulfur components to a first flash regeneration apparatus, discharging a third scrubbing medium stream containing sulfur components and depleted in carbon dioxide by flashing and at least one first carbon dioxide-containing gas stream from the first flash regeneration apparatus,
f) discharging at least one first carbon dioxide-containing gas stream from the absorption apparatus, introducing it to a multistage second flash regeneration apparatus, wherein the pressures in the individual flash stages decrease in the flow direction of the scrubbing medium stream, discharging a fourth scrubbing medium stream depleted in carbon dioxide through multistage flashing and at least one second carbon dioxide-containing gas stream from the second flash regeneration apparatus,
g) introducing the third and the fourth scrubbing medium stream into a reabsorber column, stripping the third scrubbing medium stream or the third and the fourth scrubbing medium stream in the reabsorber column with a first portion of a stripping gas, discharging a gaseous top product stream comprising carbon dioxide and stripping gas from the reabsorber column, discharging a liquid sump product stream from the reabsorber column, supplying the sump product stream to a hot regeneration apparatus and introducing it thereto,
h) hot regenerating the sump product stream from the reabsorber column in the hot regeneration apparatus under hot regeneration conditions, discharging a product gas stream enriched in sulfur components and a fifth scrubbing medium stream depleted in sulfur components from the hot regeneration apparatus, recycling at least a portion of the fifth scrubbing medium stream after cooling as a constituent of the first and/or second scrubbing medium stream to the absorption apparatus,
wherein,
i) a second portion of the stripping gas is introduced to the multistage second flash regeneration apparatus and an offgas stream comprising carbon dioxide and stripping gas is discharged therefrom.