Process and plant for removing carbon dioxide and water from synthesis gas

A plant for removing carbon dioxide and water from synthesis gas, wherein the synthesis gas comprises at least hydrogen, carbon dioxide and water, comprising the following plant components in operative connection with one another:

• (a) a means for providing a physical absorption medium;
• (b) a scrubbing apparatus and a means for supplying the synthesis gas and for supplying absorption medium to the scrubbing apparatus, wherein the scrubbing apparatus is configured for removing water present in the synthesis gas by scrubbing the synthesis gas with absorption medium, thus making it possible to obtain in the scrubbing apparatus a synthesis gas at least partially freed of water and a mixture of absorption medium and water, and means for withdrawing the synthesis gas at least partially freed of water and the mixture of absorption medium and water from the scrubbing apparatus;
• c) a thermal separation apparatus and a means for supplying the mixture of absorption medium and water to the thermal separation apparatus, wherein the mixture of absorption medium and water is separable into water and absorption medium in the separation apparatus, and means for withdrawing the water from the thermal separation apparatus and means for withdrawing the absorption medium from the thermal separation apparatus and for supplying the absorption medium to the scrubbing apparatus according to (b) to remove the water present in the synthesis gas in the scrubbing apparatus;
• (d) an absorption apparatus and a means for supplying the synthesis gas at least partially freed of water to the absorption apparatus, wherein the absorption apparatus is configured such that carbon dioxide is removable from the synthesis gas by physical absorption of the carbon dioxide in the absorption medium at absorption pressure and wherein the absorption medium and the synthesis gas may be run in countercurrent in the absorption apparatus, thus making it possible to obtain an absorption medium laden at least with carbon dioxide and a synthesis gas at least partially freed of carbon dioxide and water, and means for withdrawing the absorption medium laden at least with carbon dioxide and the synthesis gas at least partially freed of carbon dioxide and water from the absorption apparatus;
• (e) a regeneration apparatus, wherein the regeneration apparatus is configured for removing carbon dioxide from the laden absorption medium withdrawable from the absorption apparatus by desorption of the carbon dioxide by pressure reduction relative to the absorption pressure, thus making it possible to obtain an at least partially regenerated absorption medium, means for withdrawing the desorbed carbon dioxide and the at least partially regenerated absorption medium from the regeneration apparatus and means for recycling the at least partially regenerated absorption medium to the absorption apparatus according to (d) for use as absorption medium.