Berliner Stadtreinigungsbetriebe (BSR) is relying on technology from the Rhineland and is delighted to be taking a decisive step towards environmental protection & climate neutrality with the biomethane plant from ETW Energietechnik GmbH in Moers. The full-service provider of biomethane plants & combined heat & power (CHP) plants has been awarded the contract for a plant that will process up to 700 Nm³/h of landfill gas into biomethane in the future. The plant concept was developed & planned by BSR in close cooperation with the planning office Rytec GmbH. Rytec brings extensive expertise in biogas production, biological & thermal waste treatment, energy technology & waste & landfill technology to the project.
ETW process converts landfill gas into biomethane
With the ETW treatment process specially developed for landfill gas with a downstream nitrogen reduction unit (NRU), landfill gas with nitrogen contents of over 22 per cent can be converted into biomethane suitable for feed-in. Following the consistently positive operating experience of our first reference plant in Taranto, Italy, which has been running successfully for over a year, this new contract confirms the market‘s confidence in our engineering expertise and plant technology,“ explains Alexander Szabo, Sales Manager at ETW Energietechnik.
Fluctuations in gas composition and quantity
Landfill gas is a special gas for processing. On the one hand, it has a very high concentration of trace pollutants (VOCs: volatile organic compounds) and siloxanes. On the other hand, the gas quality is not constant. This results in fluctuations in gas composition and gas volume. The longer a landfill site is in operation, the more methane is replaced by oxygen and nitrogen. In addition, the volume of gas is declining.
High demands on gas processing
This places very high demands on a biomethane plant for gas processing. The methane concentration is between 35 and 60 percent, the nitrogen and oxygen concentration is up to 23 percent, and the operating range – i.e. the partial load capacity of the plant – is between 40 and 100 percent capacity.
Additional CHP unit covers own electricity requirements
In order to minimise the external electricity requirements of the biomethane plant, ETW is also supplying a CHP unit for its own electricity supply, which is also operated with the offgas from the processing plant. This increases the methane yield of the entire plant to over 95 percent.
With the ETW treatment process specially developed for landfill gas with a downstream nitrogen reduction unit (NRU), landfill gas with nitrogen contents of over 22 per cent can be converted into biomethane suitable for feed-in.
