@article{ContiSaidiGoldbrunner2020, author = {Conti, Fosca and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Evaluation Criteria and Benefit Analysis of Mixing Process in Anaerobic Digesters of Biogas Plants}, volume = {24}, journal = {Environmental and Climate Technologies}, number = {3}, publisher = {De Gruyter Poland}, address = {Warsaw}, issn = {2255-8837}, doi = {https://doi.org/10.2478/rtuect-2020-0105}, pages = {305 -- 317}, year = {2020}, abstract = {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.}, language = {en} } @article{ContiSaidiGoldbrunner2020, author = {Conti, Fosca and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Numeric Simulation-Based Analysis of the Mixing Process in Anaerobic Digesters of Biogas Plants}, volume = {43}, journal = {Chemical Engineering \& Technology}, number = {8}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.201900650}, pages = {1522 -- 1529}, year = {2020}, abstract = {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.}, language = {en} } @inproceedings{SaidiContiKarletal.2019, author = {Saidi, Abdessamad and Conti, Fosca and Karl, J{\"u}rgen and Goldbrunner, Markus}, title = {Biogastankstelle f{\"u}r die Landwirtschaft - Gegen{\"u}berstellende {\"o}konomische Bewertung unterschiedlicher Verfahren f{\"u}r die dezentrale partielle Biogasaufbereitung}, booktitle = {8. Statuskonferenz Bioenergie Reader}, editor = {Thr{\"a}n, Daniela and Pfeiffer, Diana}, publisher = {DBFZ Deutsches Biomasseforschungszentrum gemeinn{\"u}tzige GmbH}, address = {Leipzig}, isbn = {978-3-946629-27-6}, issn = {2698-6809}, url = {https://www.energetische-biomassenutzung.de/veranstaltungen/statuskonferenzen/8-statuskonferenz/programm}, pages = {78 -- 79}, year = {2019}, language = {de} } @inproceedings{ContiSaidiGoldbrunner2019, author = {Conti, Fosca and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Verbesserung der Durchmischung in Biogasfermentern}, booktitle = {8. Statuskonferenz Bioenergie Reader}, editor = {Thr{\"a}n, Daniela and Pfeiffer, Diana}, publisher = {DBFZ Deutsches Biomasseforschungszentrum gemeinn{\"u}tzige GmbH}, address = {Leipzig}, isbn = {978-3-946629-27-6}, issn = {2698-6809}, url = {https://www.energetische-biomassenutzung.de/veranstaltungen/statuskonferenzen/8-statuskonferenz/programm}, pages = {105}, year = {2019}, language = {de} } @article{WiedemannContiSaidietal.2018, author = {Wiedemann, Leonhard and Conti, Fosca and Saidi, Abdessamad and Sonnleitner, Matthias and Goldbrunner, Markus}, title = {Modeling Mixing in Anaerobic Digesters with Computational Fluid Dynamics Validated by Experiments}, volume = {41}, journal = {Chemical Engineering \& Technology}, number = {11}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.201800083}, pages = {2101 -- 2110}, year = {2018}, language = {en} } @inproceedings{ContiWiedemannSaidietal.2018, author = {Conti, Fosca and Wiedemann, Leonhard and Saidi, Abdessamad and Sonnleitner, Matthias and Goldbrunner, Markus}, title = {Mixing of a Model Substrate in a Scale-down Laboratory Digester and Processing with a Computational Fluid Dynamics Model}, booktitle = {EUBCE 2018 Online Conference Proceedings}, publisher = {ETA s.r.l.}, address = {Florenz}, isbn = {978-88-89407-18-9}, issn = {2282-5819}, doi = {https://doi.org/10.5071/26thEUBCE2018-2CV.5.34}, pages = {811 -- 815}, year = {2018}, language = {en} } @article{ContiWiedemannSonnleitneretal.2018, author = {Conti, Fosca and Wiedemann, Leonhard and Sonnleitner, Matthias and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Monitoring the mixing of an artificial model substrate in a scale-down laboratory digester}, volume = {2019}, journal = {Renewable Energy}, number = {132}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0960-1481}, doi = {https://doi.org/10.1016/j.renene.2018.08.013}, pages = {351 -- 362}, year = {2018}, language = {en} } @article{SaidiTrinklContietal.2018, author = {Saidi, Abdessamad and Trinkl, Christoph and Conti, Fosca and Goldbrunner, Markus and Karl, J{\"u}rgen}, title = {Partially Upgraded Biogas: Potential forDecentralized Utilization in AgriculturalMachinery}, volume = {41}, journal = {Chemical Engineering \& Technology}, number = {11}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.201800100}, pages = {2111 -- 2119}, year = {2018}, language = {en} } @article{ContiWiedemannSonnleitneretal.2017, author = {Conti, Fosca and Wiedemann, Leonhard and Sonnleitner, Matthias and Goldbrunner, Markus}, title = {Thermal behaviour of viscosity of aqueous cellulose solutions to emulate biomass in anaerobic digesters}, volume = {42}, journal = {New Journal of Chemistry}, number = {2}, publisher = {RSC}, address = {London}, issn = {1369-9261}, doi = {https://doi.org/10.1039/C7NJ03199H}, pages = {1099 -- 1104}, year = {2017}, language = {en} } @article{SaidiContiSonnleitneretal.2018, author = {Saidi, Abdessamad and Conti, Fosca and Sonnleitner, Matthias and Goldbrunner, Markus}, title = {Membrane separation process for small scaled partial biogas upgrading}, volume = {2018}, pages = {012012}, journal = {IOP Conference Series: Materials Science and Engineering}, number = {446}, publisher = {IOP Publishing}, address = {London}, issn = {1757-899X}, doi = {https://doi.org/10.1088/1757-899X/446/1/012012}, year = {2018}, abstract = {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.}, language = {en} }