Process for producing methanol
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et l'Eploitation des Procedes Georges Claude
InventorsLutz JANKO, Vincent PEÑA, Nina BLICKHAN
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Abstract
A process for producing methanol from a hydrogen-rich and a carbon dioxide-rich reactant gas stream. According to the invention a decompression gas stream obtained in a low-pressure separator and containing hydrogen and carbon dioxide is recycled to one of the two reactant gas streams or the decompression gas stream is divided over two substreams and the respective substreams are recycled to the respective reactant gas streams. Combination of these streams is carried out before compression to synthesis pressure and before formation of the actual synthesis gas stream.
Claims12
A process for producing methanol, wherein the process comprises the following process steps:
- (a) providing a first reactant gas stream rich in hydrogen;
- (b) providing a second reactant gas stream rich in carbon dioxide;
- (c) providing a decompression gas stream containing hydrogen and carbon dioxide;
- (d1) combining the decompression gas stream with the first reactant gas stream before compression to synthesis pressure to form a first mixed gas stream and forming a synthesis gas stream by combining the first mixed gas stream with the second reactant gas stream or
- (d2) combining the decompression gas stream with the second reactant gas stream before compression to synthesis pressure to form a second mixed gas stream and forming a synthesis gas stream by combining the first reactant gas stream with the second mixed gas stream or
- (d3) dividing the decompression gas stream into a first substream and a second substream and combining the first substream with the first reactant gas stream before compression to synthesis pressure to form a third mixed gas stream and combining the second substream with the second reactant gas stream before compression to synthesis pressure to form a fourth mixed gas stream and forming a synthesis gas stream by combining the third mixed gas stream with the fourth mixed gas stream;
- (e) reacting the synthesis gas stream at synthesis pressure in a reaction apparatus over a solid methanol synthesis catalyst to afford a methanol-containing product gas stream;
- (f) separating raw methanol from the product gas stream in a first separator to obtain a first raw methanol stream as a liquid phase and a stream of unreacted synthesis gas as a gaseous phase, wherein at least a portion of the stream of unreacted synthesis gas is recycled to an inlet of the reaction apparatus and the first raw methanol stream is discharged from the first separator;
- (g) introducing the first raw methanol stream into a second separator, wherein the pressure in the second separator is reduced relative to the pressure in the first separator, to obtain in the second separator a second raw methanol stream as a liquid phase and the decompression gas stream as a gaseous phase, wherein the second raw methanol stream and the decompression gas stream are discharged from the second separator and wherein the decompression gas stream is provided by the discharging from the second separator.
Dependencies are inferred from the claim text.