ETW Energietechnik GmbH has come up with an innovative solution that improves the feasibility of landfill gas and other combined heat and power (CHPs).
Already closed landfills struggle with shrinking gas qualities and quantities. Existing CHPs than have to be operated at reduced load or sequentially shut off when their operation becomes unfeasible. Yet, the biogas production of a landfill can hold on for many years. Enriching the “poor” biogas by blending it with natural gas enables the operation of the already existing (and financed) CHPs at full load, reducing the specific costs of cogeneration and increasing the CHP lifetime. Indeed, that combination ensures energy supply of self-consumers.
The new equipment developed by ETW blends two gas streams of different qualities to fuel CHPs. This equipment precisely blends the two gases to a homogeneous fuel mixture and is indicated 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, thus its economic feasibility. The CHP can be operated independently from the landfill gas supply.
The gas/fuel supply is composed of two parallel gas trains for Landfill gas and Natural gas respectively. After the gas trains both gases are mixed together. The dosing of Natural gas for the ideal blend is done according to the CH4 concentration in the outlet gas of the blending system. All variations of Natural and Biogas can be blended. This technology is commonly used by Landfill operators.
Catering to the European market and also to other countries on request, the ETW gas blending technology does not improve the already designed efficiency potential but enables to operate them at full load even at shrinking biogas qualities. The blender avoids the reduction of efficiency caused by an operation at a reduced load.
ETW Energietechnik GmbH has been developing and producing energy plants in Moers, Germany, since 1997. The company’s core business comprises the construction and maintenance of combined heat and power (CHP) plants in the output range of 400 to 4,600 kWel as well as highly efficient Biogas Upgrading plants that produce pure Biomethane out of raw Biogas using a high-end PSA technology.