Method and apparatus for drying a flow rich in carbon dioxide

A method for drying a first wet gas stream containing at least 90 mol % CO2 on a dry basis, comprising:

• i) compressing the first wet gas stream to a first pressure in order to obtain a first wet gas stream at the first pressure,
• ii) drying the first wet gas stream in a water adsorption unit of the type implementing n adsorbers with, for each adsorber, a cycle comprising the following operating phases, which are offset from one adsorber to another by an nth of the duration (T) of the cycle:
• a. an adsorption phase comprising admission of the first wet gas stream into the adsorber via a first end of the adsorber, with circulation of the stream in the adsorber and simultaneous withdrawal, via a second end of the adsorber, of gas purified of water, and
• b. regeneration of the adsorber during which a regeneration gas regenerates the adsorber,
• removing water from the first wet gas stream in one of the adsorbers thereby producing a dried gas,
• sending the regeneration gas to another of the adsorbers, wherein the regeneration gas is produced in a separation apparatus that separates a gas containing carbon dioxide and at least one impurity by partial condensation and/or distillation at a temperature of less than 0° C., wherein the regeneration gas contains at least 90 mol % of carbon dioxide, and
• wherein the gas containing carbon dioxide and at least one impurity is not the dried gas and is not derived from the dried gas.