| 摘要 |
The invention relates to a separation processing method for a product stream (g) of a reactor (4) used for the synthesis of dimethyl ether (z) from synthesis gas (e), said product stream containing at least dimethyl ether, methanol, water, carbon dioxide, carbon monoxide and hydrogen. The product stream (g) is fed into a liquid reflux-operated absorption column (6) at least partially in a gaseous state, wherein a gaseous top stream (m) is removed from the absorption column (6) at the top end, and a liquid bottom stream (p) is removed at the bottom end of the absorption column. At least part of the bottom stream (p) is fed into a first distillation column (5), wherein a gaseous transfer stream (q) containing dimethyl ether, and a stream (r) predominantly containing methanol and/or water are removed from the first distillation column (5). At least part of the top stream (m) is first cooled to a first temperature level and subsequently further cooled to one or more additional temperature levels, wherein a first condensate stream (n) is formed after the cooling to the first temperature level, and one or more additional condensate streams (s, t) are formed after the further cooling to the additional temperature level(s). Part of the first condensate stream (n) is used to form the liquid reflux, and at least part of the additional condensate stream(s) (s, t) are fed into an additional distillation column (9), from which a liquid stream (z) is removed at the bottom end, said liquid stream substantially containing dimethyl ether and having little or no carbon dioxide. The invention also relates to a corresponding separation plant and a plant (100) for producing dimethyl ether. |
