Electrochaea’s two-step biomethanation process starts with the production of hydrogen by electrolysis using renewable power. The renewable hydrogen is combined with carbon dioxide and fed into the reactor which houses the biocatalyst – a methanogenic archaea. The product that leaves the reactor is renewable methane.
The archaea do the job of synthesizing methane from the two substrates, hydrogen and carbon dioxide. The renewable methane and water are the products of the reaction.
How the Technology Works
Electrochaea employs a patented biocatalyst to convert renewable electricity and carbon dioxide into pipeline-grade renewable gas. This gas can be directly injected into the existing natural gas grid or used immediately. The core of our power-to-gas (P2G) technology is the proprietary biocatalyst that can be deployed in a simple and cost-effective energy conversion system.
Electrochaea’s proprietary biocatalyst is a selectively evolved – not genetically modified – strain of methanogenic archaea, a single-celled microorganism that has populated Earth for billions of years. These organisms can be found in a broad range of habitats, including some of the most extreme environments on the planet, such as volcanic hot springs, salt lakes, in addition to that, oceans and soils, among others. The strain of archaea used in our P2G process has been adapted for industrial application by Prof. Laurens Mets at the University of Chicago.
Our archaea exhibit several unique properties including high mass conversion efficiency, tolerance to many contaminants typically found in industrial CO2-sources (oxygen, hydrogen sulfide, particulates), high selectivity in methane production, and very fast reaction kinetics that enable scale-up to commercial application. In addition, the microorganisms are self-replicating and self-maintaining.
Electrochaea is currently pursuing energy storage via a two-step P2G system that uses an off-the-shelf electrolyzer to produce hydrogen. This hydrogen is then fed into a separate bioreactor containing the archaea along with carbon dioxide from a biogenic or industrial source. The organisms are indifferent to the source of CO2 and can use commonly available sources such as raw biogas from anaerobic digesters, fermentation off-gas from breweries and ethanol plants, and flue gas from combustion processes.
Because of the high selectivity of the archaea, minimal post-reaction gas treatment is needed before the product gas is injected into the gas grid. Oxygen and heat are by-products from the process and can be sold in a broad range of different markets, either on-site or off-site.
Technological Development Milestones
Pre-Commercial Project in Foulum, Denmark
With a grant of $1.2 million from the Danish Energy Agency (EUDP), we tested our P2G technology using a 10,000-liter reactor vessel and raw biogas as a CO2source. The system ran continuously for more than 3,200 hours between August and December 2013 at Aarhus University’s Biogas Research Center in Foulum, Denmark. Supported by Aarhus University, E.ON, Energie 360° (formerly Erdgas Zürich), ewz (the City of Zurich’s utility), and NEAS Energy, the project demonstrated the efficiency, productivity, robustness, and responsiveness of Electrochaea’s P2G technology.
Commercial Scale BioCat Project in Avedøre, Denmark
Electrochaea’s BioCat project has demonstrated commercial scale P2G technology to address Europe’s needs to integrate renewable power, gas and energy storage. The overall objective of the project was to design, engineer, and construct a commercial-scale P2G facility and show its capabilities to provide energy storage services to the Danish energy system.
The core of the BioCat project was Electrochaea’s BioCat methanation system, which employs a unique biological catalyst that stores renewable energy in the form of methane. The system includes a commercial scale methanation reactor and balance of plant, an electrolyzer, gas polishing system and gas grid injection station, all located at the BIOFOS wastewater treatment facility in Avedøre, near Copenhagen.
Biogas produced on-site at Avedøre via anaerobic digestion delivered the carbon dioxide required for methanation to the reactor. Heat generated in the P2G process was captured and utilized in the BIOFOS on-site operations. The system has flexible operational modes and responds rapidly to available energy, so it could also provide frequency regulation services to the Danish power grid. The first grid injection took place in September 2019.
Commercial Scale STORE&GO Project in Solothurn, Switzerland
STORE&GO stands for innovative large-scale energy STORagE technologies AND power-to-Gas concepts after Optimization. The international project was launched in 2016 as part of Horizon 2020, the European Union’s research and innovation program. 27 project partners from six European countries were involved in developing and advancing power-to-gas technology. Three different Power-to-Gas concepts at three locations in Germany, Italy and Switzerland.
While other STORE&GO research projects were developing chemical processes, Electrochaea together with Regio Energie Solothurn (RES), the Hochschule für Technik Rapperswil (HSR), the Ecole polytechnique fédérale Lausanne (EPFL), the Eidgenössische Materialprüfungs- und Forschungsanstalt (EMPA) and the Swiss Gas and Water Industry Association (SVGW), built and operated a biomethanation plant in Solothurn, Switzerland. The automated plant, with a basis for design of 1 MW, could be operated remotely. Comprehensive training materials were used in operator training classes.
The research facility was officially opened in January 2019. A few months later, in May 2019, renewable methane was produced for the first time and the injection into the Swiss gas network took place.
Electrochaea carried out intensive tests and optimizations. At the end of the STORE&GO Project, Electrochaea and its partners had accomplished:
- >1200 hours of operation with >13800 Nm3 renewable methane injected
- Gas grid injection within 96 h of startup (gas quality exceeded standards for grid injection without any post-purification)
- Load factor tests: 0%-100% capacity testing achieved (at > 97% CH4 in product gas)
- Process flexibility: on/off cycles with immediate recovery after various shut-down periods
The STORE&GO Project demonstrated that Electrochaea’s technology is ready for scale up and market entry.
The biocatalyst is available for commercial projects. Within the scope of these projects for the storage of gas, liquid fuels and electricity, Electrochaea provides the proprietary system design and engineering and oversees the construction and design of structures for the storage of gas, liquid fuels and electricity. Our services include system design, project management and system commissioning.