Natural gas from landfill gases

Based on the application of activated carbon, and a special carbon molecular sieve CMSC adsorption processes for the purification of landfill gases and subsequent recovery of substitute natural gas have been developed. By using different activated carbons trace contaminations (e.g. hydrogen sulfide, ammonia, mercury, halogenated hydrocarbons, higher alkanes and aromatics) are removed from landfill gas. The cleaned gas can then be processed by means of a pressure-swing adsorption process using molecular sieve CMSC into natural gas.

The adsorption processes can not only be applied to landfill gases but also waste water treatment plants and bioreactors. The processes are dry and almost maintenance-free. At the moment several pilot and demonstration plants are in operation in the Federal Republic of Germany and the Netherlands. Now several industrial-scale plants with gas flows of up to 1,500 m³/h (STP) are under consideration for various Dutch landfill sites and waste water treatment plants.

Compared to the competing scrubbing and diaphragm processes the pressure-swing adsorption process using the carbon molecular sieve CMSC has some essential advantages and technical realization can be expected in the near future.