TY - JOUR A1 - Conti, Fosca A1 - Saidi, Abdessamad A1 - Goldbrunner, Markus T1 - Evaluation Criteria and Benefit Analysis of Mixing Process in Anaerobic Digesters of Biogas Plants JF - Environmental and Climate Technologies N2 - A valid method to evaluate decisions of a project proposal is the so-called cost-benefit analysis. Criteria are selected and properly weighted to determine if the project is effective and feasible. The present research study is focused on methodical selection of design parameters to install two propeller mixers inside anaerobic digesters of biogas plants. A cylindrical tank of 1400 m3 was considered. For the model-based optimisation, the substrate was considered as a non-Newtonian fluid with a density of 1090 kg/m3. The Oswald-de Waele power-law model was selected to account for the rheological behaviour of the fluid. Installation parameters of the mixers were rotational angles and heights of the shafts of the two propellers. A computational model was developed to simulate the fluid dynamics depending on the mixing process inside the tank. Several configurations were analysed according to evaluating criteria such as the value of the fluid velocity, its distribution along the three spatial dimensions, and the power consumption to rotate the mixers. The maximum fluid velocity and minimum power consumption were observed when the propellers are located at intermediate height inside the tank and with the shafts perpendicular to the tank radius. With this configuration, the fluid reaches a maximum velocity of 0.28 m/s. According to the investigation, it is evident that mixing systems with propeller shafts deep-seated and parallel to the tank radius should be avoided, both in term of efficiency of the fluid mixing distribution and in term of power consumption. UR - https://doi.org/10.2478/rtuect-2020-0105 KW - Anaerobic digester KW - biomass KW - computational fluid dynamics (CFD) KW - Cost-Benefit Analysis (CBA) KW - evaluation criteria KW - flow velocity KW - full scale biogas digester KW - mixing KW - propeller Y1 - 2020 UR - https://doi.org/10.2478/rtuect-2020-0105 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-9274 SN - 2255-8837 VL - 24 IS - 3 SP - 305 EP - 317 PB - De Gruyter Poland CY - Warsaw ER - TY - JOUR A1 - Conti, Fosca A1 - Saidi, Abdessamad A1 - Goldbrunner, Markus T1 - Numeric Simulation-Based Analysis of the Mixing Process in Anaerobic Digesters of Biogas Plants JF - Chemical Engineering & Technology N2 - Stirring systems with two rotational three-bladed propellers were analyzed using computational fluid dynamics. The propellers are located at three heights and seven angles in a tank with 9 m radius. The fluid was characterized by non-Newtonian rheology and simulated by applying the k-ε turbulence model and the standard k-ω model. Reynolds numbers were estimated. High fluid speeds were obtained with the propellers located at a height of 2 m and oriented at 90° with respect to the tank radius. In the top regions of the tank, the fluid velocity was generally less intense and less affected by the angle setting. The configurations identified as good mixing systems showed power consumptions broadly distributed around 30 kW. UR - https://doi.org/10.1002/ceat.201900650 KW - Anaerobic digester KW - Biogas plant KW - Biomass KW - Fluid dynamics KW - Mixing Y1 - 2020 UR - https://doi.org/10.1002/ceat.201900650 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-9379 SN - 1521-4125 VL - 43 IS - 8 SP - 1522 EP - 1529 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Saidi, Abdessamad A1 - Conti, Fosca A1 - Karl, Jürgen A1 - Goldbrunner, Markus ED - Thrän, Daniela ED - Pfeiffer, Diana T1 - Biogastankstelle für die Landwirtschaft – Gegenüberstellende ökonomische Bewertung unterschiedlicher Verfahren für die dezentrale partielle Biogasaufbereitung T2 - 8. Statuskonferenz Bioenergie Reader Y1 - 2019 UR - https://www.energetische-biomassenutzung.de/veranstaltungen/statuskonferenzen/8-statuskonferenz/programm SN - 978-3-946629-27-6 SN - 2698-6809 SP - 78 EP - 79 PB - DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH CY - Leipzig ER - TY - CHAP A1 - Conti, Fosca A1 - Saidi, Abdessamad A1 - Goldbrunner, Markus ED - Thrän, Daniela ED - Pfeiffer, Diana T1 - Verbesserung der Durchmischung in Biogasfermentern T2 - 8. Statuskonferenz Bioenergie Reader Y1 - 2019 UR - https://www.energetische-biomassenutzung.de/veranstaltungen/statuskonferenzen/8-statuskonferenz/programm SN - 978-3-946629-27-6 SN - 2698-6809 SP - 105 PB - DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH CY - Leipzig ER - TY - JOUR A1 - Wiedemann, Leonhard A1 - Conti, Fosca A1 - Saidi, Abdessamad A1 - Sonnleitner, Matthias A1 - Goldbrunner, Markus T1 - Modeling Mixing in Anaerobic Digesters with Computational Fluid Dynamics Validated by Experiments JF - Chemical Engineering & Technology UR - https://doi.org/10.1002/ceat.201800083 KW - Anaerobic digesters KW - Biomass KW - Computational fluid dynamics KW - Mixing KW - Rheology Y1 - 2018 UR - https://doi.org/10.1002/ceat.201800083 SN - 1521-4125 VL - 41 IS - 11 SP - 2101 EP - 2110 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Conti, Fosca A1 - Wiedemann, Leonhard A1 - Saidi, Abdessamad A1 - Sonnleitner, Matthias A1 - Goldbrunner, Markus T1 - Mixing of a Model Substrate in a Scale-down Laboratory Digester and Processing with a Computational Fluid Dynamics Model T2 - EUBCE 2018 Online Conference Proceedings UR - https://doi.org/10.5071/26thEUBCE2018-2CV.5.34 KW - anaerobic digestion KW - biomass KW - cellulose KW - laboratory digester KW - mixing process KW - fluid dynamic Y1 - 2018 UR - https://doi.org/10.5071/26thEUBCE2018-2CV.5.34 SN - 978-88-89407-18-9 SN - 2282-5819 SP - 811 EP - 815 PB - ETA s.r.l. CY - Florenz ER - TY - JOUR A1 - Conti, Fosca A1 - Wiedemann, Leonhard A1 - Sonnleitner, Matthias A1 - Saidi, Abdessamad A1 - Goldbrunner, Markus T1 - Monitoring the mixing of an artificial model substrate in a scale-down laboratory digester JF - Renewable Energy UR - https://doi.org/10.1016/j.renene.2018.08.013 KW - Laboratory digester KW - Anaerobic digestion KW - Artificial chemical substrate KW - Mixing KW - Particle image velocimetry (PIV) KW - Acoustic Doppler velocimetry (ADV) Computational fluid dynamics (CFD) Y1 - 2018 UR - https://doi.org/10.1016/j.renene.2018.08.013 SN - 0960-1481 VL - 2019 IS - 132 SP - 351 EP - 362 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Saidi, Abdessamad A1 - Trinkl, Christoph A1 - Conti, Fosca A1 - Goldbrunner, Markus A1 - Karl, Jürgen T1 - Partially Upgraded Biogas: Potential forDecentralized Utilization in AgriculturalMachinery JF - Chemical Engineering & Technology UR - https://doi.org/10.1002/ceat.201800100 KW - Agriculture KW - Biogas KW - Combustion KW - Fuel KW - Upgrading Y1 - 2018 UR - https://doi.org/10.1002/ceat.201800100 SN - 1521-4125 VL - 41 IS - 11 SP - 2111 EP - 2119 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Conti, Fosca A1 - Wiedemann, Leonhard A1 - Sonnleitner, Matthias A1 - Goldbrunner, Markus T1 - Thermal behaviour of viscosity of aqueous cellulose solutions to emulate biomass in anaerobic digesters JF - New Journal of Chemistry UR - https://doi.org/10.1039/C7NJ03199H Y1 - 2017 UR - https://doi.org/10.1039/C7NJ03199H SN - 1369-9261 VL - 42 IS - 2 SP - 1099 EP - 1104 PB - RSC CY - London ER - TY - JOUR A1 - Saidi, Abdessamad A1 - Conti, Fosca A1 - Sonnleitner, Matthias A1 - Goldbrunner, Markus T1 - Membrane separation process for small scaled partial biogas upgrading JF - IOP Conference Series: Materials Science and Engineering N2 - Biogas upgrading is actually limited to the production of biomethane as natural gas substitute. To realize the according gas quality a cost intensive methane enrichment is required, wherefore biogas upgrading is actually merely cost-efficient in case of high production rates. Since the energy and cost effort disproportionately increases with the required product gas purity partial biogas upgrading for decentralized utilization represents a promising utilization approach for farm based applications. Among the available technologies for CO2-separation the gas permeable membrane has high potential for small scaled biogas upgrading. Within the present study a model based analysis to determine the savings potential of a membrane based upgrading system is performed. UR - https://doi.org/10.1088/1757-899X/446/1/012012 Y1 - 2018 UR - https://doi.org/10.1088/1757-899X/446/1/012012 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-28012 SN - 1757-899X VL - 2018 IS - 446 PB - IOP Publishing CY - London ER -