German company ETW Energietechnik has developed a new gas blending technology for combined heat and power systems.

The new equipment blends two gas streams of different qualities to fuel CHPs.

ETW said the equipment ’precisely blends the two gases to a homogeneous fuel mixture’. This makes the technology ideally suited for landfills that struggle with shrinking heating values and volumes of biogas along their lifetime.

This shrinking heating value can be compensated by gradually enriching biogas with natural gas (NG). The blending is completely automatized and designed to consume the lowest possible amounts of NG. Almost any CHP can easily be upgraded.

There are several advantages for the operator. At startups the CHP receives the perfectly balanced fuel, preventing startup problems caused by low CH4 concentration. That enables the operation of CHPs even with CH4 concentration lower than 30%, increasing its lifetime and availability, justifying its economic feasibility.

The CHP can be operated independently from the land-fill gas supply.