Suchergebnisse

Renewable energies will represent an increasing share of the electricity supply, while flue and gasification-derived gases can be a promising CO2 feedstock with a heat load. In this study, microbial electrosynthesis of organic compounds from CO2 at high temperature was proposed as an alternative for valorising energy surplus and decarbonizing the economy. The unremitting fluctuation of renewable energy sources was assessed using two bioreactors at 50 °C, under circumstances of continuous and intermittent power supply (ON-OFF; 8-16 h), simulating an off-grid photovoltaic system. Results highlighted that maximum acetate production rate (43.27 g m−2 d−1) and columbic efficiency (98%) were achieved by working with an intermittent energy supply, while current density was reduced three times. This boosted the production of acetate per unit of electricity provided up to 138 g kWh−1 and reinforced the robustness of the technology by showing resilience to tolerate perturbations and returning to its initial state ; This work was supported by the European Union's Horizon 2020 research and innovation program under the grant agreement No 760431 (BioRECO2VER). L.R-A acknowledges the support by the Catalan Government (2018 FI-B 00347) in the European FSE program (CCI 2014ES05SFOP007). S.P is a Serra Húnter Fellow (UdG-AG-575) and acknowledges the funding from the ICREA Academia award. LEQUIA has been recognized as consolidated research groups by the Catalan Government (2017-SGR-1552)

Anaerobic gas fermentation is a promising approach to transform carbon dioxide (CO2) into chemical building blocks. However, the main operational conditions to enhance the process and its selectivity are still unknown. The main objective of this study was to trigger chain elongation from a joint perspective of thermodynamic and experimental assessment. Thermodynamics revealed that acetic acid formation was the most spontaneous reaction, followed by n-caproic and n-butyric acids, while the doorway for alcohols production was bounded by the selected conditions. Best parameters combinations were applied in three 0.12L fermenters. Experimentally, n-caproic acid formation was boosted at pH 7, 37°C, Acetate:Ethanol mass ratio of 1:3 and low H2 partial pressure. Though these conditions did not match with those required to produce their main substrates, the unification of both perspectives yielded the highest n-caproic acid concentration (> 11 g L-1) so far from simple substrates, accounting for 77% of the total products ; The authors acknowledge funding from the Agency for Business Competitiveness of the Government of Catalonia (ACCIÓ; COMRDI16-1-0061) and the Spanish Ministry of Science and Innovation (RTI2018-098360-B-100 and PLEC2021-007802). LEQUIA (http://www.lequia.udg.edu/) has been recognized as a consolidated research group by the Catalan Government (2017-SGR-1552). L.R.-A. acknowledge the support by the Catalan Government (2018 FI-B 00347) in the European FSE program (CCI 2014ES05SFOP007). M.R.-C. is grateful for the support of the Spanish Government (FPU20/01362). S.P is a Serra Hunter Fellow (UdG-AG-575) and acknowledges the funding from the ICREA Academia award

Many industrial combustion processes produce carbon dioxide (CO2) at high temperature, which may be electrically recycled into valuable chemicals using microorganisms as catalysts. However, little attention has been paid to handle the remaining heat of these processes as an alternative to increase CO2 fixation and production rates. Thus, this study was aimed at steering electro bio-CO2 recycling into organic compounds under thermophilic conditions. A mesophilic anaerobic sludge was adapted in lab-scale reactors at 50 °C, developing a resilient biocathode. High amounts of acetate (5250 mg L−1) were accumulated during a long-term operation period (150 days). The maximum production rate was 28 g acetate per m2 per d, with columbic efficiencies over 80%. In terms of carbon (C) conversion, 0.31 kg of C as acetate were obtained per 1 kg of C as CO2 inlet, with an energy demand of 24 kW h per 1 kg of acetate. Thermoanaerobacterales appeared to dominate the cathodic chambers, though they were compartmentalized by distinct bacterial communities in the electrode biofilm compared to the bulk liquid. This research delves into the sustained ability of a mixed microbial culture to electrochemically produce organic compounds at 50 °C and considers the possibility of using CO2-saturated effluents from industrial heated point sources to bring the technology closer to its scale-up. ; This study has received funding from the European Union's Horizon 2020 research and innovation program under the grant agreement no. 760431. L. R.-A. acknowledges the support from the Catalan Government (2018 FI-B 00347) in the European FSE program (CCI 2014ES05SFOP007). E. P.-V. is grateful for the Research Training grant from the University of Girona (IFUdG2018/52). S. P. is a Serra Húnter Fellow (UdG-AG-575) and acknowledges the funding from the ICREA Acadèmia award. LEQUIA and IEA have been both recognized as consolidated research groups by the Catalan Government (2017-SGR-1552 and 2017-SGR-548)

Decarbonisation of the economy has become a priority at the global level, and the resulting legislative pressure is pushing the chemical and energy industries away from fossil fuels. Microbial electrosynthesis (MES) has emerged as a promising technology to promote this transition, which will further benefit from the decreasing cost of renewable energy. However, several technological challenges need to be addressed before the MES technology can reach its maturity. The aim of this review is to critically discuss the bottlenecks hampering the industrial adoption of MES, considering the whole production process (from the CO2 source to the marketable products), and indicate future directions. A flexible stack design, with flat or tubular MES modules and direct CO2 supply, is required for site-specific decentralised applications. The experience gained for scaling-up electrochemical cells (e.g. electrolysers) can serve as a guideline for realising pilot MES stacks to be technologically and economically evaluated in industrially relevant conditions. Maximising CO2 abatement rate by targeting high-rate production of acetate can promote adoption of MES technology in the short term. However, the development of a replicable and robust strategy for production and in-line extraction of higher-value products (e.g. caproic acid and hexanol) at the cathode, and meaningful exploitation of the currently overlooked anodic reactions, can further boost MES cost-effectiveness. Furthermore, the use of energy storage and smart electronics can alleviate the fluctuations of renewable energy supply. Despite the unresolved challenges, the flexible MES technology can be applied to decarbonise flue gas from different sources, to upgrade industrial and wastewater treatment plants, and to produce a wide array of green and sustainable chemicals. The combination of these benefits can support the industrial adoption of MES over competing technologies ; This work was performed on the framework of the Science Foundation Ireland (SFI) Pathfinder ...