Method and apparatus for separating carbon dioxide from a residual gas in a fluidised bed catalytic cracking plant (fcc)

An apparatus for separating carbon dioxide from a waste gas of a fluid catalytic cracking installation containing carbon dioxide, nitrogen and carbon monoxide, comprising:

• a converter configured to convert at least a portion of the carbon monoxide of the waste gas into carbon dioxide to form a flow enriched in carbon dioxide by combustion,
• a separation unit for separating at least a portion of the flow enriched in carbon dioxide, comprising an adsorption separation unit configured to form a gas enriched in carbon dioxide and depleted in nitrogen and a gas rich in nitrogen and depleted in carbon dioxide,
• a separation apparatus for separating at least a portion of the gas enriched in carbon dioxide and depleted in nitrogen by separation at a temperature of less than 0° C. by partial condensation and/or by distillation, to form a fluid rich in carbon dioxide and a fluid depleted in carbon dioxide.
• a means for sending a gas containing at least 90% oxygen to the converter to take part in the combustion and
• a means for sending to the converter a gas containing at least 40% carbon dioxide, consisting either of a product of the separation of the flow enriched in carbon dioxide, or of a portion of the flow enriched in carbon dioxide.