US 12,637,357 B2 · Process and plant for producing methanol and ammonia

Abstract

What is proposed is a process and a plant for parallel production of methanol and ammonia by heterogeneously catalyzed reaction of hydrogen and carbon oxides on the one hand and hydrogen and nitrogen on the other hand. This includes producing a raw synthesis gas stream and dividing it into two portions. A first raw synthesis gas substream is used as input for a methanol synthesis to obtain raw methanol and a methanol synthesis purge stream. A second raw synthesis gas substream is subjected to a CO conversion, a carbon dioxide separation and a liquid nitrogen scrubbing and then sent to an ammonia synthesis. According to the invention at least a portion of the methanol synthesis purge stream is sent to the ammonia synthesis and at least one substream obtained from the second raw synthesis gas substream is passed to the methanol synthesis.

A process for producing methanol and ammonia from an input stream comprising hydrocarbons, comprising:

(a) providing an input stream containing hydrocarbons,
(b) supplying the input stream containing hydrocarbons to a synthesis gas production plant comprising,
(b1) a steam reforming stage heated using burners and/or hot gases or
(b2) an autothermal reforming stage or
(b3) a partial oxidation stage or
(b4) a combination of at least two of the stages (b1) to (b3),
(c) at least partially converting the input stream containing hydrocarbons in the synthesis gas production plant under synthesis gas production conditions thereby producing a raw synthesis gas stream containing hydrogen, carbon monoxide and inert components,
(d) discharging the raw synthesis gas stream from the synthesis gas production plant and dividing the raw synthesis gas stream into a first raw synthesis gas substream and into a second raw synthesis gas substream,
(e) introducing at least a portion of the first raw synthesis gas substream into a methanol synthesis reactor, at least partially converting the first raw synthesis gas substream in the methanol synthesis reactor under methanol synthesis conditions, thereby producing a methanol-containing first reactor product stream,
(f) discharging the methanol-containing first reactor product stream from the methanol synthesis reactor, cooling the first reactor product stream to below its dew point and separating the cooled first reactor product stream in a phase separation apparatus into a first liquid product stream and a first residual gas stream containing unconverted synthesis gas constituents and inert components, discharging the first liquid product stream from the process as a raw methanol product stream,
(g) dividing the first residual gas stream into a methanol synthesis purge stream and into a recycle stream which is recycled to the methanol synthesis reactor,
(h) introducing at least a portion of the second raw synthesis gas substream into a carbon monoxide conversion plant comprising at least one carbon monoxide conversion stage, converting the portion of the second raw synthesis gas substream introduced into the carbon monoxide conversion plant under carbon monoxide conversion conditions to afford a converted synthesis gas stream, discharging the converted synthesis gas stream,
(i) introducing the converted synthesis gas stream into a sorption apparatus for removal of acidic gas constituents by means of a physical or chemical sorption process, discharging a deacidified synthesis gas stream and an acid gas stream containing acidic gas constituents from the sorption apparatus, discharging the acid gas stream from the process,
(j) introducing at least a portion of the deacidified synthesis gas stream into a liquid nitrogen scrubbing stage, separating the deacidified synthesis gas stream in the liquid nitrogen scrubbing stage into the following substreams:
(j1) an ammonia synthesis feed stream containing hydrogen and nitrogen as main constituents and carbon monoxide and inert components as trace constituents,
(j2) a second residual gas stream containing hydrogen and carbon monoxide as main constituents and inert components as trace constituents,
(j3) an inert gas stream which contains inert components as the main constituent and is discharged from the process,
(k) introducing the ammonia synthesis feed stream into an ammonia synthesis reactor, at least partially converting the ammonia synthesis feed stream in the ammonia synthesis reactor under ammonia synthesis conditions, discharging an ammonia product stream from the ammonia synthesis reactor,
(l) introducing at least a portion of the methanol synthesis purge stream into the sorption apparatus,
(m) introducing into the methanol synthesis reactor one or more gas streams selected from the following group of:
(m1) a portion of the converted synthesis gas stream from process step (h)
(m2) a portion of the deacidified synthesis gas stream from process step (i)
(m3) at least a portion of the second residual gas stream from process step (j2).

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Process and plant for producing methanol and ammonia

Life of this patent

Process and plant for producing methanol and ammonia

Life of this patent

Abstract

Claims6