System and process for preparing methanol through hydrogenation of carbon dioxide

Abstract

The invention discloses a system for preparing methanol through hydrogenation of carbon dioxide, wherein the system comprises at least three stages of methanol preparation units connected in series, and each methanol preparation unit comprises an in-tower preheater, a methanol synthesis tower, a methanol water cooler and a methanol separator; a raw material gas inlet of the in-tower preheater is communicated with a purified raw material mixed gas pipe, and a raw material gas outlet of the in-tower preheater is communicated with a gas inlet of the methanol synthesis tower; a gas outlet of the methanol synthesis tower is communicated with a high-temperature gas inlet of the in-tower preheater, a high-temperature gas outlet of the in-tower preheater is communicated with a feed port of the methanol water cooler, and a discharge port of the methanol water cooler is communicated with a feed port of the methanol separator; a gas outlet of the methanol separator of the previous-stage methanol preparation unit is communicated with a raw material gas inlet of the in-tower preheater of the next-stage methanol preparation unit; and the gas outlet of the methanol separator of the last-stage methanol preparation unit is communicated with the gas inlet of the methanol water washing tower. A recycle gas compressor is omitted, non-circulation of methanol preparation through hydrogenation of carbon dioxide is realized, and the compression work is saved.

Description

technical field

[0001] The invention relates to a system and process for preparing methanol by hydrogenation of carbon dioxide, belonging to the technical field of methanol preparation systems and processes. Background technique

[0002] Methanol is an important chemical basic raw material and an important fuel. Currently, it is mainly composed of natural gas or coal through synthesis gas (H 2 +CO) preparation. Recently, with the goal of "carbon peaking and carbon neutrality" proposed, as one of the large-scale utilization methods of carbon dioxide, the technical route of carbon dioxide hydrogenation to methanol has been paid more and more attention, and it also plays an important supporting role in the development of the CCUS industrial chain On the one hand, it can reduce greenhouse gas emissions and realize the recycling of carbon and hydrogen sources; on the other hand, it can be connected with new energy electrolytic hydrogen production, chlor-alkali and other industri...

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