Microbial biomethane on the way to industrial maturity

© M. Thema
© M. Thema

ORBIT field test successfully completed

In December, the test operation of the ORBIT biomethanisation plant in Ibbenbüren ended and with it a research project for the further development of power-to-gas technology, which is becoming more and more important. ORBIT stands for “Optimierung eines Rieselbett-Bioreaktors für die dynamische mikrobielle Biosynthese von Methan mit Archaeen in Power-to-Gas-Anlagen” or “Optimisation of a trickle bed bioreactor for the dynamic microbial biosynthesis of methane with archaea in power-to-gas plants” in English. The research project had been running since July 2017 and was funded by the Federal Ministry for Economic Affairs and Energy (BMWi) with 1.14 million euros. Within a short time, it was possible to set up a functioning system. This is now to be expanded into a complete system for industrial use in further development steps.

Methanation is a process in which regeneratively produced hydrogen and CO2 are converted into biomethane by methane-producing archaea. These micro-organisms are among the oldest living organisms on earth. Methanogenic archaea occur naturally in oxygen-free habitats such as bogs and swamps, geothermal springs or the deep sea, but also in the digestive tract of humans and other mammals.

The overall goal of the joint project was to develop new technological options for the biological methanation process with archaea. Efficient energy storage and sector coupling technology should be taken to the next level and a new process developed therein from scratch, from technology maturity level (TRL) 3 to 7.

In contrast to technically mature chemical-catalytic methanation, there is still potential here for optimising process engineering and biological processes. On the one hand, the focus was on optimising, simulating and setting up a trickle bed bioreactor and preparing it for upscaling. On the other hand, optimally suitable micro-organisms were selected and their behaviour and suitability in the reactor and for the process were analysed.

18-month test operation

The project was divided into several phases. After the initial construction of the methanation plant at the FAU Erlangen-Nuremberg, it completed a successful 18-month test operation on the joint campus of the OTH and the University of Regensburg. “In the early phases of the project in Regensburg, various micro-organisms were tested in the laboratory in interaction with different material samples from the structural part of the plant, while in the meantime the plant was set up in Nuremberg and then structurally further developed in Regensburg,” project coordinator Martin Thema explains the first project steps. Afterwards, the project partners further developed the interaction of process technology and biology for semi-automated operation in the pilot plant. The gas supply in this project phase was by bottled gas.

… Read more in the latest H2-International e-Journal, Aug 2021

Author: Michael Nallinger

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