The SATTLER CENO’s combi-gas holder is an air supported gas holder with three membranes mounted on a tank. In principle, it works as a double membrane gas holder, but the raw gas and the clean gas chambers are sealed off from each other by a separating membrane.  In the combi-gas holder, the dirty biogas (also called raw gas) formed from the substrates lying at the bottom, is conducted into the standard biogas conduct. After the raw gas has undergone a gas cleaning procedure, it is stored temporarily in the upper part of the combi gas holder (clean gas holder), before it is directly conducted to the co-generation plant. The clean gas holder is designed for such large-scale capacities, that enough cleaned biogas is available for a multiple co-generation plant, thus ensuring a demand-oriented plant operation.

From an economic point of view, the combi-gas holder is also interesting, because by using it, a complex and cost-intensive expansion of the raw gas cleaning conducts can be avoided. Additionally, possible influences on the effectiveness of the gas cleaning procedure in the interval operation mode can also be avoided.

_{A Outer membrane   B Inner membrane = clean gas-storage membrane   C Raw gas-separating membrane   D AIRFLOW-SYSTEM^TM  D1 for gas inflow  |  D2 for gas outflow/for the circulation of gas  
E Brace system with a mast support in the centre   F Platform for gas inflow or outflow/inspection window (clean gas holder)   G  Supporting-air blower + air preservation valve (if necessary, redundancy)  
H Pressure controlling flap/gas outflow   I Safety valve (over-/low pressure), raw gas /clean gas chambers are sealed off   J Inspection window (supporting air chamber)   K Fill level measurement (various if necessary)   L Tanks/anchor ring   M Gas inflow and outflow into the membrane}