@article{DotzauerPfeifferLaueretal.2019, author = {Dotzauer, Martin and Pfeiffer, Diana and Lauer, Markus and Pohl, Marcel and Mauky, Eric and B{\"a}r, Katharina and Sonnleitner, Matthias and Z{\"o}rner, Wilfried and Hudde, Jessica and Schwarz, Bj{\"o}rn and Faßauer, Burkhardt and Dahmen, Markus and Rieke, Christian and Herbert, Johannes and Thr{\"a}n, Daniela}, title = {How to measure flexibility - Performance indicators for demand driven power generation from biogas plants}, series = {Renewable Energy}, journal = {Renewable Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0960-1481}, doi = {10.1016/j.renene.2018.10.021}, pages = {135 -- 146}, year = {2019}, language = {en} } @article{CheenakulaGriebelMontagetal.2023, author = {Cheenakula, Dheeraja and Griebel, Kai and Montag, David and Gr{\"o}mping, Markus}, title = {Concept development of a mainstream deammonification and comparison with conventional process in terms of energy, performance and economical construction perspectives}, series = {Frontiers in Microbiology}, volume = {14}, journal = {Frontiers in Microbiology}, number = {11155235}, editor = {Huang, Xiaowu}, publisher = {Frontiers}, issn = {1664-302X}, doi = {10.3389/fmicb.2023.1155235}, pages = {1 -- 15}, year = {2023}, abstract = {Deammonification for nitrogen removal in municipal wastewater in temperate and cold climate zones is currently limited to the side stream of municipal wastewater treatment plants (MWWTP). This study developed a conceptual model of a mainstream deammonification plant, designed for 30,000 P.E., considering possible solutions corresponding to the challenging mainstream conditions in Germany. In addition, the energy-saving potential, nitrogen elimination performance and construction-related costs of mainstream deammonification were compared to a conventional plant model, having a single-stage activated sludge process with upstream denitrification. The results revealed that an additional treatment step by combining chemical precipitation and ultra-fine screening is advantageous prior the mainstream deammonification. Hereby chemical oxygen demand (COD) can be reduced by 80\% so that the COD:N ratio can be reduced from 12 to 2.5. Laboratory experiments testing mainstream conditions of temperature (8-20°C), pH (6-9) and COD:N ratio (1-6) showed an achievable volumetric nitrogen removal rate (VNRR) of at least 50 gN/(m3∙d) for various deammonifying sludges from side stream deammonification systems in the state of North Rhine-Westphalia, Germany, where m3 denotes reactor volume. Assuming a retained Norganic content of 0.0035 kgNorg./(P.E.∙d) from the daily loads of N at carbon removal stage and a VNRR of 50 gN/(m3∙d) under mainstream conditions, a resident-specific reactor volume of 0.115 m3/(P.E.) is required for mainstream deammonification. This is in the same order of magnitude as the conventional activated sludge process, i.e., 0.173 m3/(P.E.) for an MWWTP of size class of 4. The conventional plant model yielded a total specific electricity demand of 35 kWh/(P.E.∙a) for the operation of the whole MWWTP and an energy recovery potential of 15.8 kWh/(P.E.∙a) through anaerobic digestion. In contrast, the developed mainstream deammonification model plant would require only a 21.5 kWh/(P.E.∙a) energy demand and result in 24 kWh/(P.E.∙a) energy recovery potential, enabling the mainstream deammonification model plant to be self-sufficient. The retrofitting costs for the implementation of mainstream deammonification in existing conventional MWWTPs are nearly negligible as the existing units like activated sludge reactors, aerators and monitoring technology are reusable. However, the mainstream deammonification must meet the performance requirement of VNRR of about 50 gN/(m3∙d) in this case.}, language = {en} } @article{BlockViebahnJungbluth2024, author = {Block, Simon and Viebahn, Peter and Jungbluth, Christian}, title = {Analysing direct air capture for enabling negative emissions in Germany: an assessment of the resource requirements and costs of a potential rollout in 2045}, series = {Frontiers in Climate}, volume = {6}, journal = {Frontiers in Climate}, publisher = {Frontiers}, address = {Lausanne}, issn = {2624-9553}, doi = {10.3389/fclim.2024.1353939}, pages = {18 Seiten}, year = {2024}, abstract = {Direct air capture (DAC) combined with subsequent storage (DACCS) is discussed as one promising carbon dioxide removal option. The aim of this paper is to analyse and comparatively classify the resource consumption (land use, renewable energy and water) and costs of possible DAC implementation pathways for Germany. The paths are based on a selected, existing climate neutrality scenario that requires the removal of 20 Mt of carbon dioxide (CO2) per year by DACCS from 2045. The analysis focuses on the so-called "low-temperature" DAC process, which might be more advantageous for Germany than the "high-temperature" one. In four case studies, we examine potential sites in northern, central and southern Germany, thereby using the most suitable renewable energies for electricity and heat generation. We show that the deployment of DAC results in large-scale land use and high energy needs. The land use in the range of 167-353 km2 results mainly from the area required for renewable energy generation. The total electrical energy demand of 14.4 TWh per year, of which 46\% is needed to operate heat pumps to supply the heat demand of the DAC process, corresponds to around 1.4\% of Germany's envisaged electricity demand in 2045. 20 Mt of water are provided yearly, corresponding to 40\% of the city of Cologne's water demand (1.1 million inhabitants). The capture of CO2 (DAC) incurs levelised costs of 125-138 EUR per tonne of CO2, whereby the provision of the required energy via photovoltaics in southern Germany represents the lowest value of the four case studies. This does not include the costs associated with balancing its volatility. Taking into account transporting the CO2 via pipeline to the port of Wilhelmshaven, followed by transporting and sequestering the CO2 in geological storage sites in the Norwegian North Sea (DACCS), the levelised costs increase to 161-176 EUR/tCO2. Due to the longer transport distances from southern and central Germany, a northern German site using wind turbines would be the most favourable.}, language = {en} } @inproceedings{AugensteinKuperjansLucas2002, author = {Augenstein, Eckardt and Kuperjans, Isabel and Lucas, K.}, title = {EUSEBIA - Decision-Support-System for Technical, Economical and Ecological Design and Evaluation of Industrial Energy Systems}, series = {ECOS 2002 : proceedings of the 15th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems, Berlin, Germany July 3 - 5, 2002. - Vol. 1}, booktitle = {ECOS 2002 : proceedings of the 15th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems, Berlin, Germany July 3 - 5, 2002. - Vol. 1}, editor = {Tsatsaronis,, Georgios}, publisher = {Techn. Univ., Inst. for Energy Engineering}, address = {Berlin}, isbn = {3-00-009533-0}, pages = {446 -- 453}, year = {2002}, language = {en} } @inproceedings{AugensteinHerbergsKuperjansetal.2005, author = {Augenstein, Eckardt and Herbergs, S. and Kuperjans, Isabel and Lucas, K.}, title = {Simulation of industrial energy supply systems with integrated cost optimization}, series = {Proceedings of ECOS 2005, the 18th International Conference on Efficiency, Cost, Optimization, Simulation, and Environmental Impact of Energy Systems : Trondheim, Norway, June 20 - 22, 2005. - Vol. 2}, booktitle = {Proceedings of ECOS 2005, the 18th International Conference on Efficiency, Cost, Optimization, Simulation, and Environmental Impact of Energy Systems : Trondheim, Norway, June 20 - 22, 2005. - Vol. 2}, editor = {Kjelstrup, Signe}, publisher = {Tapir Academic Press}, address = {Trondheim}, isbn = {82-519-2041-8}, pages = {627 -- 634}, year = {2005}, language = {en} }