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 -