Validated a biogas purification technology to promote its use as an alternative energy

The European LIFE Biogasnet project has validated a new biogas purification technology, which allows improving the quality of this resource produced in urban solid waste treatment plants and wastewater treatment plants, as well as reducing the carbon footprint of the cycle energy and promote decarbonisation and the circular economy.

Specifically, the solution "is based on the application of biological, efficient and low-cost technologies, and allows to increase the quality of biogas to promote its use as an alternative energy source" , explains the project coordinator, Xavier Gamisans, professor at UPC Manresa School of Engineering .

The developed system has been tested for one year in an urban solid waste treatment plant located in Cádiz and subsequently in an urban solid waste treatment plant in the Attica region in Athens (Greece), two installations facilities in which different sources of ammonium-rich effluents have been used to desulfurize biogas with the aim of validating the technology and its operation in various environments and conditions.

At the same time, "exhaustive studies on the environmental impact of the technology have been carried out to demonstrate objectively which are the most favorable scenarios for its implementation" , explains the director of the Waste, Energy and Environmental Impact Unit from the Eurecat technology center, Frederic Clarens . In this sense, "scaling studies have been carried out for installations other than those where the project system has been installed and operated, for example, in waste water treatment plants".

According to the director of Eurecat's Water, Air and Soil Unit, Xavier Martínez , this project "is a clear example of how biological technologies for gas treatment are becoming more robust and attractive for the its implementation in the industry" .

Validation in two real waste treatment facilities

For its validation, the technology installed in Cádiz has included an anoxic bioreactor for the removal of hydrogen sulphide from biogas with yields above 97%. The removal of hydrogen sulphide is carried out using nitrate and/or nitrite which is obtained in a nitrification bioreactor using the landfill leachate itself as an ammonium source. Hydrogen sulphide is mostly oxidized to elemental sulphur, a by-product that can be revalued.

With regard to the installation at the Athens plant, the process consisted, initially, of capturing the ammonia present in the extraction gases of a composting plant in a liquid stream by a washer This stream has been nitrified to nitrite and/or nitrate to be used in an anoxic percolator biofilter to lead to the elimination of hydrogen sulphide through its majority oxidation to sulphate. Finally, this sulfate is combined with some of the ammonium-rich liquid to produce ammonium sulfate in a CSTR reactor, effectively converting the waste gas into a useful product.

The LIFE Biogasnet consortium included the Universitat Politècnica de Catalunya (project coordinator), the Eurecat technology center, the University of Cadiz and the National Technical University of Athens, and the companies AERIS Tecnologies Ambientals and Bioreciclaje de Cádiz.

More information

• "Experiències en sistemes de purificació de biogàs i prospectiva de futur" - Workshop final del projecte LIFE BIOGASNET
• Seminari web organitzat per LIFE ECOdigestion 2.0 dins de la Setmana de les Regions de la UE
• Congrés Internacional de Bioenergia celebrat dins del Saló de Gasos Renovables
• Workshop - Industrial experiences in biogas desulfurisation
• Visita a les instal·lacions de l''Association of Municipalities in the Attica Region' a Atenes on s'instal·larà el prototip LIFE Biogasnet
• En el marc del projecte LIFE BIOGASNET s'ha celebrat un primer taller “Experiències de consorci en sistema de depuració de biogàs”
• Desenvoluparan un sistema de purificació que impulsa el biogàs com a energia alternativa
• Welcome Meeting dels projectes LIFE 2018