A method for removing at least one contaminant from a feed stream (f) substantially comprising carbon dioxide, said method comprising the step of subjecting the feed stream (f) to a) a purification step in a column having a top, bottom and an intermediate section, the purification step provides a contaminant lean stream leaving the top section of the column and a contaminant rich liquid stream leaving, optionally the bottom section of, the column, said contaminant rich liquid stream being fed to a reboiler and wherein the contaminant lean stream leaving the top section of the column is further subjected to the steps b to d selected from one of the two options 1 and 2 where: option 1 comprises the steps of: b1) compressing the contaminant lean stream providing a compressed gaseous stream; and c1) cooling the compressed gaseous stream in the reboiler using the contaminant rich liquid providing at least a product stream (p), and a waste liquid stream and a gaseous stream respectively; and d1) feeding the gaseous stream to the column at the bottom section of the column; and option 2 comprises the steps of: b2) cooling the contaminant lean stream in a reboiler using the contaminant rich liquid providing at least a product stream (p) and a waste liquid stream and a gaseous stream; and c2) compressing the gaseous stream providing a cooled compressed gaseous stream (g4'); and d2) feeding the cooled compressed gaseous stream (g4') to the column at the bottom section of the column; and depressurising the contaminant rich liquid stream leaving at the bottom section of the column before entering the reboiler; wherein the purification step is selected from absorption using an absorbent when the feed stream is gaseous, and rectification having a liquid phase, when the feed stream is liquid, and wherein the absorbent and liquid phase is liquid carbon dioxide. a) a purification step in a column having a top, bottom and an intermediate section, the purification step provides a contaminant lean stream leaving the top section of the column and a contaminant rich liquid stream leaving, optionally the bottom section of, the column, said contaminant rich liquid stream being fed to a reboiler and wherein the contaminant lean stream leaving the top section of the column is further subjected to the steps b to d selected from one of the two options 1 and 2 where: option 1 comprises the steps of: b1) compressing the contaminant lean stream providing a compressed gaseous stream; and c1) cooling the compressed gaseous stream in the reboiler using the contaminant rich liquid providing at least a product stream (p), and a waste liquid stream and a gaseous stream respectively; and d1) feeding the gaseous stream to the column at the bottom section of the column; and option 2 comprises the steps of: b2) cooling the contaminant lean stream in a reboiler using the contaminant rich liquid providing at least a product stream (p) and a waste liquid stream and a gaseous stream; and c2) compressing the gaseous stream providing a cooled compressed gaseous stream (g4'); and d2) feeding the cooled compressed gaseous stream (g4') to the column at the bottom section of the column; and depressurising the contaminant rich liquid stream leaving at the bottom section of the column before entering the reboiler; wherein the purification step is selected from absorption using an absorbent when the feed stream is gaseous, and rectification having a liquid phase, when the feed stream is liquid, and wherein the absorbent and liquid phase is liquid carbon dioxide. option 1 comprises the steps of: b1) compressing the contaminant lean stream providing a compressed gaseous stream; and c1) cooling the compressed gaseous stream in the reboiler using the contaminant rich liquid providing at least a product stream (p), and a waste liquid stream and a gaseous stream respectively; and d1) feeding the gaseous stream to the column at the bottom section of the column; and b1) compressing the contaminant lean stream providing a compressed gaseous stream; and c1) cooling the compressed gaseous stream in the reboiler using the contaminant rich liquid providing at least a product stream (p), and a waste liquid stream and a gaseous stream respectively; and d1) feeding the gaseous stream to the column at the bottom section of the column; and option 2 comprises the steps of: b2) cooling the contaminant lean stream in a reboiler using the contaminant rich liquid providing at least a product stream (p) and a waste liquid stream and a gaseous stream; and c2) compressing the gaseous stream providing a cooled compressed gaseous stream (g4'); and d2) feeding the cooled compressed gaseous stream (g4') to the column at the bottom section of the column; and depressurising the contaminant rich liquid stream leaving at the bottom section of the column before entering the reboiler; b2) cooling the contaminant lean stream in a reboiler using the contaminant rich liquid providing at least a product stream (p) and a waste liquid stream and a gaseous stream; and c2) compressing the gaseous stream providing a cooled compressed gaseous stream (g4'); and d2) feeding the cooled compressed gaseous stream (g4') to the column at the bottom section of the column; and depressurising the contaminant rich liquid stream leaving at the bottom section of the column before entering the reboiler; wherein the purification step is selected from absorption using an absorbent when the feed stream is gaseous, and rectification having a liquid phase, when the feed stream is liquid, and wherein the absorbent and liquid phase is liquid carbon dioxide.