PROCESS AND APPARATUS FOR SEPARATING A CARBON DIOXIDE-RICH GAS BY DISTILLATION

摘要

In a process for separating a gas rich in carbon dioxide by distillation, the gas rich in carbon dioxide is cooled in a heat exchanger and is sent to a distillation column, a gas depleted in carbon dioxide is withdrawn from the top of the column and a liquid enriched in carbon dioxide is withdrawn from the bottom of the column, a gas enriched in carbon dioxide is compressed in a compressor down to a first pressure and at least one portion of the gas enriched in carbon dioxide originating from the compressor is expanded from the first pressure to a second pressure lower than the first pressure, for example the pressure of the column, and the expanded gas is used to heat the bottom of the column.

主权项

1. A process for separating a feed gas comprising at least 50% of carbon dioxide by distillation, comprising:
i) Cooling the feed gas in a heat exchanger and transferring the cooled feed into a distillation column, ii) withdrawing carbon dioxide depleted gas from the top of the column and withdrawing a carbon dioxide enriched liquid relative to the carbon dioxide-rich gas from the column sump, iii) compressing a gas richer in carbon dioxide than the feed gas is in a compressor to a first pressure wherein the pressure of at least a part of the carbon dioxide enriched gas from the compressor is reduced from a first pressure to a second pressure lower than the first pressure, and the expanded gas is used to heat the column sump.