| abstract |
The invention concerns a method of enriching a mine or waste tip gas containing from 20 to 65 % methane by the following steps: a) the mine and/or waste tip gas is removed (2) and compressed to between 5 and 15 bar (3, 4); b) CO2 and/or water (6, 8) is removed from the compressed gas; c) the compressed mine and/or waste tip gas is pre-cooled (A) such that the methane is partially condensed; and d) this gas/liquid mixture is separated by cryogenic separation (49) into a product gas, containing at least 85 % methane, and a residual gas. |