@article{JablonowskiKollmannNabeletal.2016, author = {Jablonowski, Nicolai David and Kollmann, Tobias and Nabel, Moritz and Damm, Tatjana and Klose, Holger and M{\"u}ller, Michael and Bl{\"a}sing, Marc and Seebold, S{\"o}ren and Krafft, Simone and Kuperjans, Isabel and Dahmen, Markus and Schurr, Ulrich}, title = {Valorization of Sida (Sida hermaphrodita) biomass for multiple energy purposes}, series = {GCB [Global Change Biology] Bioenergy}, volume = {9}, journal = {GCB [Global Change Biology] Bioenergy}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1757-1707 (online)}, doi = {10.1111/gcbb.12346}, pages = {202 -- 214}, year = {2016}, abstract = {The performance and biomass yield of the perennial energy plant Sida hermaphrodita (hereafter referred to as Sida) as a feedstock for biogas and solid fuel was evaluated throughout one entire growing period at agricultural field conditions. A Sida plant development code was established to allow comparison of the plant growth stages and biomass composition. Four scenarios were evaluated to determine the use of Sida biomass with regard to plant development and harvest time: (i) one harvest for solid fuel only; (ii) one harvest for biogas production only; (iii) one harvest for biogas production, followed by a harvest of the regrown biomass for solid fuel; and (iv) two consecutive harvests for biogas production. To determine Sida's value as a feedstock for combustion, we assessed the caloric value, the ash quality, and melting point with regard to DIN EN ISO norms. The results showed highest total dry biomass yields of max. 25 t ha⁻¹, whereas the highest dry matter of 70\% to 80\% was obtained at the end of the growing period. Scenario (i) clearly indicated the highest energy recovery, accounting for 439 288 MJ ha⁻¹; the energy recovery of the four scenarios from highest to lowest followed this order: (i) ≫ (iii) ≫ (iv) > (ii). Analysis of the Sida ashes showed a high melting point of >1500 °C, associated with a net calorific value of 16.5-17.2 MJ kg⁻¹. All prerequisites for DIN EN ISO norms were achieved, indicating Sida's advantage as a solid energy carrier without any post-treatment after harvesting. Cell wall analysis of the stems showed a constant lignin content after sampling week 16 (July), whereas cellulose had already reached a plateau in sampling week 4 (April). The results highlight Sida as a promising woody, perennial plant, providing biomass for flexible and multipurpose energy applications.}, language = {en} } @inproceedings{RuppKuperjansSchulze2016, author = {Rupp, Matthias and Kuperjans, Isabel and Schulze, Sven}, title = {Energetische und {\"o}kologische Bewertung hybrider Antriebe im st{\"a}dtischen Busverkehr}, series = {Commercial vehicle technology 2016 : proceedings of the 4th Commercial Vehicle Technology Symposium (CVT 2016), March 8-10, 2016, University of Kaiserslautern, Kaiserslautern, Germany}, booktitle = {Commercial vehicle technology 2016 : proceedings of the 4th Commercial Vehicle Technology Symposium (CVT 2016), March 8-10, 2016, University of Kaiserslautern, Kaiserslautern, Germany}, editor = {Berns, Karsten}, publisher = {Shaker}, address = {Aachen}, organization = {Internationales Commercial Vehicle Technology Symposium <4, 2016, Kaiserslautern>}, pages = {227 -- 237}, year = {2016}, abstract = {In Anbetracht weltweit zunehmend strengerer klimapolitischer Ziele steigt auch der Druck f{\"u}r Nutzfahrzeughersteller, effizientere und umweltfreundlichere Technologien zu entwickeln. Den Blick bei der Bewertung dieser ausschließlich auf die Fahrzeugnutzung zu richten, ist l{\"a}ngst nicht mehr zufriedenstellend. Im Rahmen dieser Analyse wird ein gegenw{\"a}rtig auf dem Markt erwerblicher und in deutschen St{\"a}dten bereits seit Jahren betriebener Hybridbus energetisch und {\"o}kologisch mit einem konventionell angetriebenen, nahezu baugleichen Modell entlang des Lebensweges bewertet. Nach Definition von Ziel und Untersuchungsrahmen wird ein {\"U}berblick auf bereits durchgef{\"u}hrte Lebenszyklusanalysen zu Hybridbussen im Stadtverkehr gegeben und Schlussfolgerungen f{\"u}r die anschließende Analyse abgeleitet. Diese wird im Rahmen einer energetischen und {\"o}kologischen Bewertung beider Produktsysteme anhand der Parameter "Prim{\"a}renergieeinsatz" und "CO2{\"a}q Emissionen" praktiziert. Der Fahrzeugrumpf beider Fahrzeuge des gleichen Modells wird dabei als einheitlich angenommen, sodass bei dem Vergleich der Herstellung vereinfacht nur die sich unterscheidenden Komponenten des Antriebstranges ber{\"u}cksichtigt werden. Die Resultate der Wirkungsabsch{\"a}tzung werden als Differenz des Hybridbusses gegen{\"u}ber dem Referenzfahrzeug {\"u}ber die einzelnen Lebenszyklusphasen dargestellt. Schließlich werden Prognosen getroffen, ab welcher Strecke die bei der Herstellung erzeugten h{\"o}heren CO2{\"a}q Emissionen des Hybridantriebstranges gegen{\"u}ber dem Referenzmodell ausgeglichen werden.}, language = {de} } @article{RuppRiekeHandschuhetal.2020, author = {Rupp, Matthias and Rieke, Christian and Handschuh, Nils and Kuperjans, Isabel}, title = {Economic and ecological optimization of electric bus charging considering variable electricity prices and CO₂eq intensities}, series = {Transportation Research Part D: Transport and Environment}, volume = {81}, journal = {Transportation Research Part D: Transport and Environment}, number = {Article 102293}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1361-9209}, doi = {10.1016/j.trd.2020.102293}, year = {2020}, abstract = {In many cities, diesel buses are being replaced by electric buses with the aim of reducing local emissions and thus improving air quality. The protection of the environment and the health of the population is the highest priority of our society. For the transport companies that operate these buses, not only ecological issues but also economic issues are of great importance. Due to the high purchase costs of electric buses compared to conventional buses, operators are forced to use electric vehicles in a targeted manner in order to ensure amortization over the service life of the vehicles. A compromise between ecology and economy must be found in order to both protect the environment and ensure economical operation of the buses. In this study, we present a new methodology for optimizing the vehicles' charging time as a function of the parameters CO₂eq emissions and electricity costs. Based on recorded driving profiles in daily bus operation, the energy demands of conventional and electric buses are calculated for the passenger transportation in the city of Aachen in 2017. Different charging scenarios are defined to analyze the influence of the temporal variability of CO₂eq intensity and electricity price on the environmental impact and economy of the bus. For every individual day of a year, charging periods with the lowest and highest costs and emissions are identified and recommendations for daily bus operation are made. To enable both the ecological and economical operation of the bus, the parameters of electricity price and CO₂ are weighted differently, and several charging periods are proposed, taking into account the priorities previously set. A sensitivity analysis is carried out to evaluate the influence of selected parameters and to derive recommendations for improving the ecological and economic balance of the battery-powered electric vehicle. In all scenarios, the optimization of the charging period results in energy cost savings of a maximum of 13.6\% compared to charging at a fixed electricity price. The savings potential of CO₂eq emissions is similar, at 14.9\%. From an economic point of view, charging between 2 a.m. and 4 a.m. results in the lowest energy costs on average. The CO₂eq intensity is also low in this period, but midday charging leads to the largest savings in CO₂eq emissions. From a life cycle perspective, the electric bus is not economically competitive with the conventional bus. However, from an ecological point of view, the electric bus saves on average 37.5\% CO₂eq emissions over its service life compared to the diesel bus. The reduction potential is maximized if the electric vehicle exclusively consumes electricity from solar and wind power.}, language = {en} } @inproceedings{PaulsenHoffstadtKrafftetal.2020, author = {Paulsen, Svea and Hoffstadt, Kevin and Krafft, Simone and Leite, A. and Zang, J. and Fonseca-Zang, W. and Kuperjans, Isabel}, title = {Continuous biogas production from sugarcane as sole substrate}, series = {Energy Reports}, volume = {6}, booktitle = {Energy Reports}, number = {Supplement 1}, publisher = {Elsevier}, doi = {10.1016/j.egyr.2019.08.035}, pages = {153 -- 158}, year = {2020}, abstract = {A German-Brazilian research project investigates sugarcane as an energy plant in anaerobic digestion for biogas production. The aim of the project is a continuous, efficient, and stable biogas process with sugarcane as the substrate. Tests are carried out in a fermenter with a volume of 10 l. In order to optimize the space-time load to achieve a stable process, a continuous process in laboratory scale has been devised. The daily feed in quantity and the harvest time of the substrate sugarcane has been varied. Analyses of the digester content were conducted twice per week to monitor the process: The ratio of inorganic carbon content to volatile organic acid content (VFA/TAC), the concentration of short-chain fatty acids, the organic dry matter, the pH value, and the total nitrogen, phosphate, and ammonium concentrations were monitored. In addition, the gas quality (the percentages of CO₂, CH₄, and H₂) and the quantity of the produced gas were analyzed. The investigations have exhibited feasible and economical production of biogas in a continuous process with energy cane as substrate. With a daily feeding rate of 1.68gᵥₛ/l*d the average specific gas formation rate was 0.5 m3/kgᵥₛ. The long-term study demonstrates a surprisingly fast metabolism of short-chain fatty acids. This indicates a stable and less susceptible process compared to other substrates.}, language = {en} } @article{Kuperjans1996, author = {Kuperjans, Isabel}, title = {Exergetische und exergo{\"o}konomische Analyse thermischer Prozesse}, series = {Arbeitsbericht / Institut f{\"u}r Wirtschaftswissenschaften, Rheinisch-Westf{\"a}lische Technische Hochschule Aachen}, journal = {Arbeitsbericht / Institut f{\"u}r Wirtschaftswissenschaften, Rheinisch-Westf{\"a}lische Technische Hochschule Aachen}, number = {06}, year = {1996}, language = {de} } @inproceedings{KasparGroebelKuperjansetal.2013, author = {Kaspar, K. and Groebel, Simone and Kuperjans, Isabel and Dielmann, Klaus-Peter and Selmer, Thorsten}, title = {Charakterisierung der Bioz{\"o}nose von Biogasfermentern in Abh{\"a}ngigkeit verschiedener Substrate}, series = {Biogas 2013 : 6. Innovationskongress, 23. - 24.05.2013, Osnabr{\"u}ck, Tagungsband}, booktitle = {Biogas 2013 : 6. Innovationskongress, 23. - 24.05.2013, Osnabr{\"u}ck, Tagungsband}, publisher = {Profair Consult+Project}, address = {Hildesheim}, issn = {978-3-9813776-3-7}, pages = {69 -- 74}, year = {2013}, language = {de} } @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} } @inproceedings{KueppersGroebelKuperjansetal.2011, author = {K{\"u}ppers, Christine and Groebel, Simone and Kuperjans, Isabel and Dielmann, Klaus-Peter}, title = {Molekulargenetische Analysen zur Optimierung der Biogasgewinnung}, series = {Biogas 2011 : 4. Innovationskongress ; Effizienzsteigerung von Biogasanlagen ; Vorstellung der 17 besten Biogas-Innovationen der letzten 12 Monate ; 12. - 13. Mai 2011, im ZUK der Deutschen Bundesstiftung Umwelt ; Tagungsband}, booktitle = {Biogas 2011 : 4. Innovationskongress ; Effizienzsteigerung von Biogasanlagen ; Vorstellung der 17 besten Biogas-Innovationen der letzten 12 Monate ; 12. - 13. Mai 2011, im ZUK der Deutschen Bundesstiftung Umwelt ; Tagungsband}, publisher = {Profair Consult+Project}, address = {Hildesheim}, isbn = {978-3-9813776-1-3}, pages = {45 -- 48}, year = {2011}, language = {de} } @inproceedings{AugensteinHerbergsKuperjans2006, author = {Augenstein, Eckardt and Herbergs, S. and Kuperjans, Isabel}, title = {Planung und Bewertung der Geb{\"a}udeenergieversorgung mit TOP-Energy}, series = {Heizungs- und Raumlufttechnik : 1. Fachtagung Leonberg, 31. Januar bis 1. Februar 2006. - (VDI-Berichte ; Nr. 1921)}, booktitle = {Heizungs- und Raumlufttechnik : 1. Fachtagung Leonberg, 31. Januar bis 1. Februar 2006. - (VDI-Berichte ; Nr. 1921)}, publisher = {VDI-Verl.}, address = {D{\"u}sseldorf}, isbn = {3-18-091921-3}, pages = {57 -- 60}, year = {2006}, language = {de} } @inproceedings{KuperjansSchreiberDetermannetal.1998, author = {Kuperjans, Isabel and Schreiber, M. and Determann, L. and Schreiber, R.}, title = {Entscheidungsunterst{\"u}tzung bei der Gestaltung der betrieblichen Energieversorgung und -nutzung}, series = {Innovationen bei der rationellen Energieanwendung : neue Chancen f{\"u}r die Wirtschaft ; Tagung Dortmund, 3. und 4. M{\"a}rz 1998. - (VDI-Berichte ; 1385)}, booktitle = {Innovationen bei der rationellen Energieanwendung : neue Chancen f{\"u}r die Wirtschaft ; Tagung Dortmund, 3. und 4. M{\"a}rz 1998. - (VDI-Berichte ; 1385)}, publisher = {VDI-Verl.}, address = {D{\"u}sseldorf}, isbn = {3-18-091385-1}, pages = {79 -- 94}, year = {1998}, language = {de} }