| 摘要 |
PURPOSE:To separate CO of high purity from a mixed gas consisting essentially of H2 and CO at a low cost, by using membrane modules having different separation degrees of H2/CO in combination. CONSTITUTION:CO of high purity is separated from a mixed gas, consisting essentially of H2, and obtained by decomposing heavy oil or coal, etc. using gas separation membranes. In the method, membrane modules having different separation degrees of H2/CO are used in combination. In the stage of a raw gas, i.e. a mixed gas consisting essentially of H2 and CO in a high H2 concentration, a membrane having a high separation degree of a rapidly permeating component gas (H2) from a slowly permeating component gas (CO) is used. After using the membrane, a membrane having a low separation degree of H2/CO is used in the stage of reduced H2 concentration. Thus, the aimed CO of high purity can be separated without requiring means of boosting the pressure of the raw gas side, reducing the pressure on the permeation side nor purging with the gas (CO) other than the component gas for permeation, etc. |
