TY - JOUR A1 - Wahab, M. A. A1 - Kebelmann, Katharina A1 - Schartel, Bernhard A1 - Griffiths, G. T1 - Improving bio-oil chemical profile of seaweeds through anaerobic fermentation pre-treatment N2 - Biomass pre-treatments for bio-oil quality improvement are mainly based on thermal and chemical methods which are costly and hence reduce the sustainability of pyrolysis-based refineries. In this paper, anaerobic digestion (AD) and dark fermentation (DF) are proposed as alternative ‘green’ pre-treatments to improve this situation. For this purpose, three seaweeds namely Sargassum polycystum, (Phaephyta), Gracilaria tenuistipitata, (Rhodophyta) and Ulva reticulata, (Chlorophyta) with high ash and oxygen contents were pre-treated to improve their composition and structure prior to pyrolysis. The results reveal that both biological pre-treatments affected, positively, the composition and structure of the seaweed biomass with AD pre-treatment reducing N and S contents by 86% and 63%, respectively. DF was more efficient in terms of ash and moisture reduction with 25% and 70%, respectively. In addition, oxygen (O) reduction by 27% was observed after DF which was evidenced by FTIR spectroscopy indicating the reduction of most oxygen-containing functional groups in the biomass. On the other hand, the carbon (C) content increased in DF pre-treated seaweeds up to 42%, almost two times higher relative content than C in the raw seaweed. The changes in the composition of pre-treated seaweeds resulted in changes in their thermal degradation and the volatile profiles produced during pyrolysis. Interestingly, anhydrosugars and furans which account for some 70% (by area) in raw seaweeds markedly declined or become undetectable after DF pre-treatment and correspondingly more acetic acid and hydrocarbons were produced while after AD more aromatics with high toluene content (ca.17%) were generated. The results indicate that biooil with profiles more similar to petroleum-based composition i.e. rich in hydrocarbons and low in anhydrosugars, N and S can be generated by AD and DF pre-treatments and opens up the possibility of these approaches to effect cost reduction in the overall generation of bio-based fuels. KW - Anaerobic digestion KW - Dark fermentation KW - Pyrolysis KW - Seaweeds KW - Thermogravimetric analysis KW - Pyrolysis volatiles PY - 2021 DO - https://doi.org/10.1016/j.enconman.2021.114632 SN - 0196-8904 VL - 245 SP - 1 EP - 12 PB - Elsevier CY - Amsterdam AN - OPUS4-53136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fahmy, Alaa A1 - Kolmangadi, Mohamed Aejaz A1 - Schönhals, Andreas A1 - Friedrich, J. T1 - Structure of plasma‐deposited copolymer films preparedfrom acrylic acid and styrene: Part III sulfonation andelectrochemical properties N2 - Acrylic acid-styrene copolymer films were deposited plasma-chemically more gently using the pulsed plasma mode instead of the continuous mode, with linear and some slightly branched chains and marginal crosslinking. Then, the styrene unit of copolymers was wet-chemically sulfonated by chlorosulfuric acid. On exposure to air, the formed 4-chlorosulfonic acid groups hydrolyze to sulfonic acid groups (-SO3H). FTIR, XPS and broadband dielectric spectroscopy were employed to characterize the composition, the structure, the functional groups, and the electrochemical performance for the copolymers. A high concentration of sulfonic acid-containing groups was obtained in the sulfonated PS sample. The values of the DC conductivity DC for the sulfonated sample of the AA/S copolymer are ca. five orders of magnitude higher than that of the not-sulfonated copolymer materials. KW - Plasma Polymers KW - Electrolyte membrane PY - 2022 DO - https://doi.org/10.1002/ppap.202100222 SP - 1 EP - 12 PB - Wiley VHC-Verlag AN - OPUS4-54539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wahab, M. A. A1 - Kebelmann, Katharina A1 - Schartel, Bernhard A1 - Griffiths, G. T1 - Valorization of macroalgae digestate into aromatic rich bio-oil and lipid rich microalgal biomass for enhanced algal biorefinery performance N2 - The valorization of macroalgae digestate as a secondary resource for high value chemicals and nutrients will promote the sustainability and circularity of anaerobic digestion based biorefinery. In this study, three digestates from A. nodosum C.linum and L. digitata were separated into liquid and solid fractions to investigate the production of high value added chemicals through pyrolysis using Pyrolysis Gas Chromatography Mass Spectroscopy (Py-GC/MS) while the filtered liquid fractions were tested as an alternative culture media to grow C. sorokiniana under mixotrophic conditions. The digestates showed different thermal degradation and an improvement of bio-oil profiles compared to the starter material. Pyrolyzates from raw macroalgae were characterized by a high anhydrosugar content in contrast to high aromatics observed in the case of their digestates. Toluene, benzofuran and vinylphenol, base chemicals for many industries, represented together 30–37% of the total chemicals produced during pyrolysis of the three macroalgae digestate. On the other hand, C. sorokiniana cultured on digestate-based media showed a higher lipid content with an increase in monounsaturated fatty acids and a lower poly-unsaturated fatty acid content in comparison to microalgae grown in standard tris-acetate-phosphate media. Thus, the acyl composition was shifted in a direction more suitable for biodiesel production by this process. In addition, the increase of Chemical Oxygen Demand and Volatile Fatty Acids concentration in the digestate was found to reduce ammonium toxicity. Finally, 94% of Chemical Oxygen Demand and 83% of ammonium were removed by microalgae from the digestate-based media which will reduce the pollution risk of the biorefinery. Overall, the results indicate that using macroalgae solid digestates can generate improvements in the quality of products obtained by pyrolysis and the liquid digestate can positively influence microalgae growth and its products. KW - Macroalgae KW - Anaerobic digestion KW - Aromatics KW - Microalgae culture KW - Biorefinery PY - 2022 DO - https://doi.org/10.1016/j.jclepro.2022.130925 SN - 0959-6526 VL - 341 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-54365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Frisch, M. A1 - Raza, M. H. A1 - Ye, M.-Y. A1 - Sachse, René A1 - Paul, B. A1 - Gunder, R. A1 - Pinna, N. A1 - Kraehnert, R. T1 - ALD-coated mesoporous iridium-titanium mixed oxides: Maximizing iridium utilization for an outstanding OER performance N2 - With the increasing production of renewable energy and concomitant depletion of fossil resources, the demand for efficient water splitting electrocatalysts continues to grow. Iridium (Ir) and iridium oxides (IrOₓ) are currently the most promising candidates for an efficient oxygen evolution reaction (OER) in acidic medium, which remains the bottleneck in water electrolysis. Yet, the extremely high costs for Ir hamper a widespread production of hydrogen (H₂) on an industrial scale. Herein, the authors report a concept for the synthesis of electrode coatings with template-controlled mesoporosity surface-modified with highly active Ir species. The improved utilization of noble metal species relies on the synthesis of soft-templated metal oxide supports and a subsequent shape-conformal deposition of Ir species via atomic layer deposition (ALD) at two different reaction temperatures. The study reveals that a minimum Ir content in the mesoporous titania-based support is mandatory to provide a sufficient electrical bulk conductivity. After ALD, a significantly enhanced OER activity results in dependency of the ALD cycle number and temperature. The most active developed electrocatalyst film achieves an outstanding mass-specific activity of 2622 mA mg(Ir)⁻¹ at 1.60 V(RHE) in a rotating-disc electrode (RDE) setup at 25 °C using 0.5 m H₂SO₄ as a supporting electrolyte. KW - Acidic oxygen evolution reaction KW - Atomic layer deposition KW - Electrocatalysis KW - Iridium oxide KW - Soft-templated mesoporous films PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542651 DO - https://doi.org/10.1002/admi.202102035 SN - 2196-7350 SP - 1 EP - 11 PB - Wiley-VCH CY - Weinheim AN - OPUS4-54265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rütters, H. A1 - Fischer, S. A1 - Le, Quynh Hoa A1 - Bettge, Dirk A1 - Bäßler, Ralph A1 - Maßmann, J. A1 - Ostertag-Henning, C. A1 - Wolf, J. L. A1 - Pumpa, M. A1 - Lubenau, U. A1 - Knauer, S. A1 - Jaeger, P. A1 - Neumann, A. A1 - Svensson, K. A1 - Pöllmann, H. A1 - Lempp, C. A1 - Menezes, F. F. A1 - Hagemann, B. T1 - Towards defining reasonable minimum composition thresholds – Impacts of variable CO2 stream compositions on transport, injection and storage N2 - To set up recommendations on how to define “reasonable minimum composition thresholds” for CO2 streams to access CO2 pipeline networks, we investigated potential impacts of CO2 streams with different and temporally variable compositions and mass flow rates along the CCS chain. All investigations were based on a generic “CCS cluster scenario” in which CO2 streams captured from a spatial cluster of eleven emitters (seven fossil-fired power plants, two cement plants, one refinery and one steel mill) are collected in a regional pipeline network. The resulting CO2 stream (19.78 Mio t impure CO2 per year) is transported in a trunk line (onshore and offshore) and injected into five generic replicate storage structures (Buntsandstein saline aquifers) offshore. Experimental investigations and modeling of selected impacts revealed beneficial as well as adverse impacts of different impurities and their combinations. Overall, no fundamental technical obstacles for transporting, injecting and storing CO2 streams of the considered variable compositions and mass flow rates were observed. We recommend to define minimum composition thresholds for each specific CCS project through limiting i) the overall CO2 content, ii) maximum contents of relevant impurities or elements, iii) acceptable variability of concentrations of critical impurities, and defining impurity combinations to be avoided. KW - Impurities KW - CO2 quality KW - Pipeline network KW - Whole-chain CCS scenario KW - Recommendations PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543004 DO - https://doi.org/10.1016/j.ijggc.2022.103589 SN - 1750-5836 VL - 114 SP - 1 EP - 14 PB - Elsevier CY - New York, NY AN - OPUS4-54300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nehrig, Marko A1 - Scheidemann, Robert A1 - Wille, Frank A1 - Ballheimer, Viktor T1 - Investigation of the internal impact during a 9 m drop test of an accident-safe waste package N2 - The safety assessment of packages for the transport of radioactive material follows the IAEA regulations and guidance. The specified regulatory tests cover severe accidents and demonstrate the package containment system integrity. Special attention must be drawn to the behaviour of the content which could move inside the package due to unpreventable gaps caused by the loading procedure and the structure of the content. A possible internal impact of the content which occurs during the drop tests onto the lid system is investigated. The IAEA regulations SSR-6 and the Guidance SSG-26, revised recently, consider input from Germany and France related to the significance of internal gaps. In the context of a waste package design assessment, a model was equipped with a representative content to conduct a drop test with an internal impact. The weight and kinetic impact of this content covered all possible real contents. The objective of the test was to maximize the load onto the lid system and to prove the mechanical integrity by complying with the required leak tightness. The test was conducted conservatively at a package temperature lower than -40 °C at the BAM Test Site Technical Safety. This paper gives an overview of efforts to address internal gaps and their consequences, and the BAM efforts with the implementation of this topic into IAEA regulations and guidance material. The paper then focuses on the conduction of a drop test and investigation of internal component impact. T2 - ASME 2021 Pressure Vessels & Piping Conference (PVP2021) CY - Online meeting DA - 13.07.2021 KW - Internal gaps KW - Drop test KW - IAEA PY - 2021 SN - 978-0-7918-8535-2 DO - https://doi.org/10.1115/PVP2021-60996 SP - 1 EP - 6 PB - American Society of Mechanical Engineers (ASME) CY - New York, NY, USA AN - OPUS4-54742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jiang, C. A1 - Xie, G. A1 - Wu, Dejian A1 - Yan, T. A1 - Chen, S. A1 - Zhao, P. A1 - Wu, Z. A1 - Li, W. T1 - Experimental investigation on an energy-efficient floor heating system with intelligent control: A case study in Chengdu, China N2 - The space heating system accounts for 20%~50% of building energy consumption, and may lead to energy waste due to unreasonable controls. In this study, an energy-efficient floor heating system with intelligent control was proposed to improve energy efficiency of the system. In order to validate the concept of the proposed intelligent control, an experimental system was designed and constructed in Chengdu, China. Temperature, control cycle and energy consumption were then studied under different control strategies. The result shows that a larger flow rate of supply water will result in a longer control cycle and a lower control frequency, i.e., the average control cycle at 7 L min−1 is 1.7 h during the test day, while it is 1.5 h at 5 L min−1. Moreover, adopting water with a higher temperature and flow rate could achieve a higher efficiency of the system. The energy consumptions in case 1 (5 L min−1, 50 °C), case 2 (5 L min−1, 55 °C), case 5 (7 L min−1, 55 °C) and case 6 (7 L min−1, 60 °C) are 4746 kJ, 3534 kJ, 3093 kJ and 3028 kJ, respectively. Based on the experimental data, the supply water temperature is suggested to set lower than 60 °C considering human comfort. KW - Floor heating KW - Intelligent control KW - Experimental KW - Energy consumption KW - Control strategy PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550522 DO - https://doi.org/10.1016/j.csite.2021.101094 SN - 2214-157X VL - 26 SP - 1 EP - 14 PB - Elsevier Ltd. AN - OPUS4-55052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stamm, Michael A1 - Krankenhagen, Rainer T1 - Weather-dependent passive thermography of unheated wind turbine blades N2 - Up to now, the inspection of wind turbines with industrial climbers has been considered ”state of the art”. However, ever-larger wind turbines and advancing digitization make modern and automated inspection methods indispensable. Passive thermography can serve as such a digital and atomized method while it is well known for its applications in the inspection of buildings or electrical circuits. However, its application relies on thermal gradients in the inspected object such that a temperature contrast exists between damaged and sound areas. This also holds for unheated structures like rotor blades of wind turbines which show no intrinsic temperature gradient and can hardly be heated. Under certain weather conditions with sufficient solar loading and diurnal temperature variations, passive thermography is suitable for the in-service inspection of rotor blades. However, for a reliable use of passive thermography on ”thermal passive” components, the incorporation of these environmental conditions in the planning and evaluation of thermal inspections is crucial. Additionally, the complex inner structure of wind turbine blades in comparison to other objects and buildings require a specific method referencing the individual rotor blades to each other. This allows the distinction between the thermal response of design-specific structural features and damages or irregularities between the three blades. We show thermal signatures of damage in rotor blades and contrast them with structural characteristics by comparing the three blades. In addition to measurements in industrial environments, laboratory measurements are shown and compared to simulations. The long-term goal is to simulate the influence of different weather parameters and thus gain a better understanding of measurements in the field. The results shown here can be seen as one step towards industrial application. T2 - SPIE Defense + Commercial Sensing CY - Orlando, Florida, USA DA - 03.04.2022 KW - Passive thermography KW - Wind energy KW - FEM simulations PY - 2022 DO - https://doi.org/10.1117/12.2618740 VL - 12109 SP - 1 EP - 8 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) AN - OPUS4-54943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Amano, K. A1 - Hahn, S. A1 - Tschirschwitz, Rico A1 - Rappsilber, Tim A1 - Krause, U. T1 - An Experimental Investigation of Thermal Runaway and Gas Release of NMC Lithium-Ion Pouch Batteries Depending on the State of Charge Level N2 - In this study, 19 experiments were conducted with 25 pouch cells of NMC cathode to investigate thermal runaway and the release of gases from lithium-ion batteries (LIBs). Single cells, double cells, and a four-cell battery stack were forced to undergo thermal runaway inside an air-tight reactor vessel with a volume of 100 dm3 . The study involved two series of tests with two types of ignition sources. In the Series 1 tests, a heating plug was used to initiate thermal runaway in LIBs in the ranges of 80–89% and 90–100% SOC. In the Series 2 tests, a heating plate was used to trigger thermal runaway in LIBs in the ranges of 30–50%, 80–89%, and 90–100% SOC. Thermal runaway started at an onset temperature of 344 ± 5 K and 345 K for the Series 1 tests and from 393 ± 36 K to 487 ± 10 K for the Series 2 tests. Peak reaction temperatures ranged between 642 K and 1184 K, while the maximum pressures observed were between 1.2 bar and 7.28 bar. Thermal runaway induced explosion of the cells and lead to a rate of temperature increase greater than 10 K/s. The amounts of gases released from the LIBs were calculated from pressures and temperatures measured in the reactor. Then, the gas composition was analyzed using a Fourier transform infrared (FTIR) spectrometer. The highest gaseous production was achieved at a range of 90–100% SOC and higher battery capacities 72 L, 1.8 L/Ah (Series 1, battery stack) and 103 L, 3.2 L/Ah (Series 2, 32 Ah cell)). Among the gases analyzed, the concentration of gaseous emissions such as C2H4 , CH4 , and C2H6 increased at a higher cell capacity in both series of tests. The study results revealed characteristic variations of thermal behavior with respect to the type of ignition source used. KW - Lithium-ion batteries KW - Battery KW - Pouch cell KW - NMC Cathode KW - Thermal runaways PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548601 DO - https://doi.org/10.3390/batteries8050041 VL - 8 IS - 5 SP - 1 EP - 16 PB - MDPI CY - Basel, Switzerland AN - OPUS4-54860 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, J. A1 - Gong, M. A1 - Zhang, W. A1 - Mehmood, Asad A1 - Zhang, J. A1 - Ali, G. A1 - Kucernak, A. T1 - Simultaneously incorporating atomically dispersed Co-Nₓ sites with graphitic carbon layer-wrapped Co₉S₈ nanoparticles for oxygen reduction in acidic electrolyte N2 - A facile yet robust synthesis is reported herein to simultaneously incorporate atomically dispersed Co-Nₓ sites with graphitic layer-protected Co₉S₈ nanoparticles (denoted as Co SACs+Co₉S₈) as an efficient electrocatalyst for oxygen reduction in acidic solution. The Co SACs+Co₉S₈ catalyst shows low H₂O₂ selectivity (∼5 %) with high half-wave potential (E1/2) of ∼0.78 V(RHE) in 0.5 M H₂SO₄. The atomic sites of the catalyst were quantified by a nitrite stripping method and the corresponding site density of the catalyst is calculated to be 3.2×10¹⁸ sites g⁻¹. Besides, we also found the presence of a reasonable amount of Co₉S₈ nanoparticles is beneficial for the oxygen electrocatalysis. Finally, the catalyst was assembled into a membrane electrode assembly (MEA) for evaluating its performance under more practical conditions in proton exchange membrane fuel cell (PEMFC) system. KW - Co−N-Cs KW - Fuel cells KW - Single-atom catalysts KW - Oxygen reduction reaction KW - PGM-free catalysts PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575993 DO - https://doi.org/10.1002/celc.202300110 SN - 2196-0216 VL - 10 IS - 12 SP - 1 EP - 9 PB - Wiley-VCH CY - Weinheim AN - OPUS4-57599 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -