3-step process

For applications where maximum methane yield and purity of the highest in the off-gas CO2 is to be achieved, should go in the 3-step process.

 

Here are the membrane modules arranged in such a way that both the product gas as well as off-gas are each concentrated several times to achieve an optimal separation. Permeanzverlust of the membrane over the lifetime is balanced by a vacuum pump and is held constant, an optimum operating point.

 

The three-stage process is characterized by very low methane content of the offgas - currently, approximately0.5% CH4 in CO2 achieved is a move towards 0.2%. Such a low methane slip is achieved by highly selective membrane in (through extensive trials in semi-industrial scale) optimized interconnection.