TY - JOUR A1 - Kaul, Anja A1 - Boellmann, Andrea A1 - Thema, Martin A1 - Kalb, Larissa A1 - Stoeckl, Richard A1 - Huber, Harald A1 - Sterner, Michael A1 - Bellack, Annett T1 - Combining a robust thermophilic methanogen and packing material with high liquid hold-up to optimize biological methanation in trickle-bed reactors JF - Bioresource technology N2 - The hydrogen gas-to-liquid mass transfer is the limiting factor in biological methanation. In trickle-bed reactors, mass transfer can be increased by high flow velocities in the liquid phase, by adding a packing material with high liquid hold-up or by using methanogenic archaea with a high methane productivity. This study developed a polyphasic approach to address all methods at once. Various methanogenic strains and packings were investigated from a microbial and hydrodynamic perspective. Analyzing the ability to produce high-quality methane and to form biofilms, pure cultures of Methanothermobacter performed better than those of the genus Methanothermococcus. Liquid and static hold-up of a packing material and its capability to facilitate attachment was not attributable to a single property. Consequently, it is recommended to carefully match organism and packing for optimized performance of trickle-bed reactors. The ideal combination for the ORBIT system was identified as Methanothermobacter thermoautotrophicus IM5 and DuraTop (R). KW - BIOCATALYTIC METHANATION KW - CARBON-DIOXIDE KW - hydrogen KW - Liquid hold-up maximization KW - MASS-TRANSFER KW - Methane production KW - Methanothermobacter KW - Methanothermococcus KW - Optimized packing-organism combination KW - THERMOAUTOTROPHICUS Y1 - 2022 U6 - https://doi.org/10.1016/j.biortech.2021.126524 VL - 345 PB - Elsevier ER - TY - INPR A1 - Kaul, Anja A1 - Böllmann, Andrea A1 - Thema, Martin A1 - Kalb, Larissa A1 - Stöckl, Richard A1 - Huber, Harald A1 - Sterner, Michael A1 - Bellack, Annett T1 - Identification of Robust Thermophilic Methanogenic Archaea and Packing Material for High Liquid Hold-Up at Low Volumetric Gas Flow Rates for Use in Trickle-Bed Reactors for Biological Methanation T2 - SSRN Electronic Journal N2 - he hydrogen gas-to-liquid mass transfer is the limiting factor in biological methanation. In a trickle-bed reactor, mass transfer can be increased by high flow velocities in the liquid phase, by adding a packing material with high liquid hold-up, or by choosing methanogenic archaea with a high methane productivity. This study analyzed various packings and methanogenic strains from a hydrodynamic and microbial perspective. By analyzing twelve pure cultures of thermophilic methanogens for their ability to produce high quality methane and to form biofilms on different packings, strains of Methanothermobacter were found to perform better than thus of the genus Methanothermococcus. Best methane production and adherence was observed on DuraTop®, Bioflow 9, and filter foam. DuraTop® and Bioflow 9 had also a high dynamic liquid hold-up, but the maximum hold-up was determined for expanded clay. The ideal combination for use in the ORBIT-trickle-bed reactor was identified as Methanothermobacter thermoautotrophicus IM5 and DuraTop®. KW - Liquid hold-up maximization KW - Methane production KW - Methanothermobacter KW - Methanothermococcus KW - Optimized packing-organism combination Y1 - 2021 U6 - https://doi.org/10.2139/ssrn.3940878 N1 - final peer reviewed article published under: https://doi.org/10.1016/j.biortech.2021.126524 ER - TY - GEN A1 - Thema, Martin A1 - Bellack, Annett A1 - Weidlich, Tobias A1 - Huber, Harald A1 - Karl, Jürgen A1 - Sterner, Michael T1 - Optimierung biologischer CO2-Methanisierung im Rieselbett-Reaktor BT - das ORBIT-Projekt T2 - 4. Regensburger Energiekongress, Regensburg 26.-27.02.2019 KW - biologische Methanisierung KW - Archaeen KW - Power-to-Gas KW - Erneuerbare Energien KW - Rieselbett-Bioreaktor Y1 - 2019 ER - TY - CHAP A1 - Thema, Martin A1 - Bellack, Annett A1 - Weidlich, Tobias A1 - Huber, Harald A1 - Karl, Jürgen A1 - Sterner, Michael ED - Held, Jörgen T1 - Optimizing biological CO2-methanation in a trickle-bed reactor BT - the ORBIT-Project T2 - 6th International Conference on Renewable Energy Gas Technology, 20-21 May 2019, Malmö, Sweden. Conference proceedings KW - Biologische Methanisierung KW - Power-to-Gas KW - Erneuerbare Energien KW - Rieselbett-Bioreaktor KW - Archaeen Y1 - 2019 SP - 93 EP - 94 PB - Renewable Energy Technology International AB CY - Lund, Sweden ER - TY - JOUR A1 - Thema, Martin A1 - Weidlich, Tobias A1 - Hörl, Manuel A1 - Bellack, Annett A1 - Mörs, Friedemann A1 - Hackl, Florian A1 - Kohlmayer, Matthias A1 - Gleich, Jasmin A1 - Stabenau, Carsten A1 - Trabold, Thomas A1 - Neubert, Michael A1 - Ortloff, Felix A1 - Brotsack, Raimund A1 - Schmack, Doris A1 - Huber, Harald A1 - Hafenbradl, Doris A1 - Karl, Jürgen A1 - Sterner, Michael T1 - Biological CO2-Methanation: An Approach to Standardization JF - Energies N2 - Power-to-Methane as one part of Power-to-Gas has been recognized globally as one of the key elements for the transition towards a sustainable energy system. While plants that produce methane catalytically have been in operation for a long time, biological methanation has just reached industrial pilot scale and near-term commercial application. The growing importance of the biological method is reflected by an increasing number of scientific articles describing novel approaches to improve this technology. However, these studies are difficult to compare because they lack a coherent nomenclature. In this article, we present a comprehensive set of parameters allowing the characterization and comparison of various biological methanation processes. To identify relevant parameters needed for a proper description of this technology, we summarized existing literature and defined system boundaries for Power-to-Methane process steps. On this basis, we derive system parameters providing information on the methanation system, its performance, the biology and cost aspects. As a result, three different standards are provided as a blueprint matrix for use in academia and industry applicable to both, biological and catalytic methanation. Hence, this review attempts to set the standards for a comprehensive description of biological and chemical methanation processes. KW - Biological methanation KW - bubble column reactor KW - CO2-methanation KW - CSTR KW - membrane reactor KW - methanation KW - Power-to-Gas KW - Power-to-Methane KW - standardization KW - Trickle-bed reactor Y1 - 2019 U6 - https://doi.org/10.3390/en12091670 N1 - Corresponding author: Martin Thema VL - 12 IS - 9 SP - 1 EP - 32 PB - MDPI ER - TY - JOUR A1 - Thema, Martin A1 - Weidlich, Tobias A1 - Kaul, Anja A1 - Böllmann, Andrea A1 - Huber, Harald A1 - Bellack, Annett A1 - Karl, Jürgen A1 - Sterner, Michael T1 - Optimized biological CO2-methanation with a pure culture of thermophilic methanogenic archaea in a trickle-bed reactor JF - Bioresource Technology N2 - In this study, a fully automated process converting hydrogen and carbon dioxide to methane in a high temperature trickle-bed reactor was developed from lab scale to field test level. The reactor design and system performance was optimized to yield high methane content in the product gas for direct feed-in to the gas grid. The reaction was catalyzed by a pure culture of Methanothermobacter thermoautotrophicus IM5, which formed a biofilm on ceramic packing elements. During 600 h in continuous and semi-continuous operation in countercurrent flow, the 0.05 m3 reactor produced up to 95.3 % of methane at a methane production rate of 0.35 mCH43mR-3h-1. Adding nitrogen as carrier gas during startup, foam control and dosing of ammonium and sodium sulfide as nitrogen and sulfur source were important factors for process automation. KW - Biological methanation KW - Power-to-Gas KW - Reactor concept KW - Thermophilic archaea KW - Trickle-bed reactor Y1 - 2021 U6 - https://doi.org/10.1016/j.biortech.2021.125135 IS - 333 PB - Elsevier ER -