Process for producing synthesis gas with reduced steam export
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
InventorsCharline GALLIOT, Marion David, Teja Schmid McGuinness
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Abstract
A process is proposed for producing synthesis gas with reduced steam export by catalytic steam reforming of a hydrocarbonaceous feed gas with steam in a multitude of reformer tubes in a burner-heated reformer furnace to form a steam reforming flue gas. This process includes a configuration of the reformer tubes as reformer tubes with internal heat exchange and the use of a structured catalyst. For amounts of export steam between 0 and 0.8 kg of export steam per mN3 of hydrogen produced, these features interact synergistically when particular steam reforming conditions are selected.
Claims12
A process for producing a synthesis gas containing hydrogen and carbon oxides with reduced steam export by catalytic steam reforming of a hydrocarbonaceous feed gas with steam under steam reforming conditions in a multitude of reformer tubes in a burner-heated reformer furnace, with formation of a steam reforming flue gas,
- the reformer tubes comprising the following constituents:
- (a) an outer, pressure-rated shell tube heated by means of the burners and having an inlet for a feed gas stream and an outlet for a crude synthesis gas product stream,
- (b) at least one structured catalyst which is catalytically active in respect of steam reforming and disposed within the shell tube, having an inlet end and an outlet end,
- (c) a heat exchanger tube which is disposed within the shell tube and within the structured catalyst, the inlet end of which is in fluid connection with the outlet end of the structured catalyst, and the outlet end of which is in fluid connection with the outlet for the crude synthesis gas product stream,
- (d) configured such that the feed gas stream is introduced into the shell tube via the inlet and flows first through the structured catalyst and subsequently through the heat exchanger tube in countercurrent, and the crude synthesis gas product stream produced is discharged from the shell tube via the outlet,
- (e) configured such that the heat exchanger tube and the gas stream that flows through it are in a heat-exchanging relationship with the structured catalyst and the gas stream that flows through it,
- the process comprising:
- (f) providing the hydrocarbonaceous feed gas and adding reforming steam and/or carbon dioxide,
- (g) at least partly catalytically converting the feed gas under steam reforming conditions in the reformer tubes to a crude synthesis gas product containing carbon oxides and hydrogen, wherein the steam reforming conditions comprise a reforming temperature Tref of at least 900° C., a steam/carbon ratio S/C of not more than 2.8 mol/mol and a normalized space velocity of the feed gas stream at the inlet into the reformer tubes between 2 and 5 mN3/(s*mcat3),
- (h) discharging the crude synthesis gas product from the reformer tubes,
- (i) discharging the reforming flue gas from the reformer furnace,
- (j) cooling at least a portion of the reforming flue gas and/or of the crude synthesis gas product by indirect heat exchange with cooling water to generate steam which can be discharged at least partly from the process as export steam, wherein the specific amount of export steam is between 0 and 0.8 kg of steam per mN3 of hydrogen generated.
Dependencies are inferred from the claim text.