04 Fakultät Energie-, Verfahrens- und Biotechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/5
Browse
5 results
Search Results
Item Open Access Novel metal mesh filter using water-based regeneration for small-scale biomass boilers(2020) Baumgarten, Björn; Grammer, Peter; Ehard, Ferdinand; Winkel, Oskar; Vogt, Ulrich; Baumbach, Günter; Scheffknecht, Günter; Thorwarth, HaraldParticulate matter emissions are a key issue of modern biomass boilers. A novel gas cleaning method using a metal mesh filter combined with water-based cleaning was developed and tested. The filter was tested batch-wise. Flue gas of a commercial 50-kW boiler was filtered until a pressure drop of 2000 Pa was reached. Afterwards, the filter was regenerated. The initial prototype used ultrasound in order to remove the filter cake from the filter candles. Regeneration was complete and, even after boiler malfunctions producing tar, the filter cake could still be removed. Given the good results, a second cleaning mode, flushing the filter candles with water, was tested. The results were as good as with ultrasonic cleaning. Peak mass collection efficiency was very high with 98 ± 2% (burning wood pellets). However, directly after cleaning, the first layer of filter cake has to be developed. In this initial phase, collection efficiency is low. Service time until maximum pressure drop was reached depended on the gas velocity. Using pellets as fuel, at a gas velocity of 66.6 m/h, 12-h service time was reached and 4.1 g dust was collected per square meter filter surface, while at 33.3 m/h, service time increased to 55 h and collected dust to 13.9 g/m2. Using low-quality wood chips, the raw gas dust loading was much higher but also the maximum loading of the filter was higher with 13.3 to 28.9 g dust separated per square meter. Still, the service time decreased to 3.4 respective 38 h. Peak collection efficiency increased to 99.5 ± 0.8%. The overall collection efficiency including the buildup of the filter cake depends on the gas velocity and fuel. It ranges from 74 ± 4 to 91 ± 1%. The feasibility of the filter concept could be proven, and further development towards a commercial application is in progress. Metal mesh filters with countercurrent cleaning showed a high potential given their simple and robust design, as well as high collection efficiency.Item Open Access Ganzheitliche Bewertung von Holzheizungen(Stuttgart : Zentrum für Energieforschung Stuttgart, 2016) Huang, Ganlin; Schmid, Dorothea; Friedrich, Rainer; Vogt, Ulrich; Mahami, Golnoosh; Struschka, Michael; Juschka, WinfriedHolzfeuerungen emittieren nur wenige Treibhausgasemissionen, aber erhebliche Mengen an Feinstaub und Stickoxiden. Überwiegen die Vorteile des Klimaschutzes die Nachteile, nämlich die Gesundheitsrisiken durch die Luftschadstoffbelastung? Um dies zu klären, werden die sozialen Kosten, also die Summe aus Kosten, monetarisierten Klimaschäden und monetarisierten Gesundheitsschäden von Holzheizungen denen von Erdgas- und Ölheizungen gegenübergestellt. Es zeigt sich, dass in Stuttgart - als Beispiel für eine Großstadt -, Erdgas- und Ölheizungen niedrigere soziale Kosten aufweisen als Holz- und Pelletfeuerungen, selbst wenn diese mit Partikelfiltern versehen wären; in Städten sollten Holzfeuerungen daher nicht verwendet werden. Auf dem Land weisen dagegen mit Partikelfiltern versehene Holzheizungen günstigere soziale Kosten auf als Feuerungen für fossile Brennstoffe.Item Open Access Application of the urban climate model PALM-4U to investigate the effects of the diesel traffic ban on air quality in Stuttgart(2024) Samad, Abdul; Caballero Arciénega, Ninoska Alejandra; Alabdallah, Talal; Vogt, UlrichThe air pollution situation in the German city of Stuttgart is very important, as high pollutant concentrations are measured here compared to other German cities. This is mainly due to Stuttgart’s geographical location as it is in a basin covered by hills on three sides. This leads to reduced wind speeds that inhibit pollutant dispersion. One of the main contributors to the pollutant concentrations in Stuttgart is local traffic. To improve the air quality in Stuttgart, a diesel traffic ban was introduced on 1 January 2019, and is ongoing. In this study, the urban climate model PALM-4U was applied to obtain the pollutant distribution along the federal highways B14 and B27 of Stuttgart to evaluate the impact of the diesel traffic ban on air quality. The simulations were carried out in two areas of the city, namely the city center and Kaltental Valley, with domain sizes of 3.2 km × 2 km and 3.2 km × 1.6 km, respectively, and with a grid size of 10 m for each domain. The influence of traffic emissions on the air quality of Stuttgart was studied for a typical summer day. The results showed that air pollutant concentrations were highest near federal highways B14 and B27 (e.g., NO2 concentration peaks of around 200 µg/m3). Also, a significant reduction of around four times in air pollutant concentrations was observed in the study area after the diesel traffic ban was introduced.Item Open Access Messung und Bewertung der Schadstoffemissionen von Holzfeuerungen in Innenräumen(Stuttgart : Universität Stuttgart, Institut für Energiewirtschaft und Rationelle Energieanwendung, 2019) Li, Naixin; Huang, Ganlin; Friedrich, Rainer; Vogt, Ulrich; Schürmann, Stefan; Straub, DieterHolzöfen in Wohnräumen verursachen nicht nur Emissionen von Schadstoffen über den Schornstein in die Außenluft, vielmehr tragen sie auch zur Schadstoffkonzentration in Innenräumen bei. Diese gelangen insbesondere beim Öffnen der Ofentür beim Anfeuern oder beim Nachlegen von Holzscheiten in die Innenraumluft. Allerdings liegen hierfür bisher noch keine Emissionsfaktoren vor. In diesem Bericht werden Ergebnisse von Messungen an einem modernen Holzofen vorgestellt, die die Emissionen von Feinstaub (PM1, PM2.5, PM10, UFP) und Stickoxiden für Prozesse wie Anfeuern und Nachlegen mit verschiedenen Türöffnungsgeschwindigkeiten repräsentieren. Mit den so gewonnenen Emissionsfaktoren werden dann die entstehenden Gesundheitsschäden ermittelt und monetarisiert. Wird nur mit Holzöfen geheizt, steigen die Gesundheitsrisiken durch Feinstaub um ca. 5%, bei gelegentlicher Nutzung des Holzofens ergibt sich ein um ca. 1% höheres Risiko.Item Open Access Contribution of airplane engine emissions on the local air quality around Stuttgart airport during and after COVID-19 lockdown measures(2022) Samad, Abdul; Arango, Kathryn; Chourdakis, Ioannis; Vogt, UlrichAir quality investigations at airports have shown that aircrafts cause a significant increase in air pollution at and around the vicinity of the airport, which can cause adverse effects on human health. The objective of this research was to investigate the aircraft-sourced pollutant levels at the Stuttgart airport and in the surrounding areas during and after COVID-19 lockdown measures. Three phases of stationary measurements of ultrafine particles (UFP), particulate matter (PM), black carbon (BC), CO2, O3, NO, and NO2 were made at various points on the east and west sides of the airport in the extension of the airport runway. In first phase of measurement, the airport was closed for construction, and no air traffic took place. In the second phase, the airport was reopened with limited operation due to a lockdown period at the beginning of the COVID-19 pandemic. Finally, in the third phase, measurements were performed during the peak summer holiday travel season to measure the air quality during maximum air traffic, after the end of the first lockdown period. While there were fewer notable changes in the BC concentrations, coarse PM fractions, and gases across the three phases, there were significant increases in the UFP concentrations from aircraft emissions. Throughout the three phases, the peak particle concentration decreased from between 27 and 86 nm in phase 1. to between 27 and 35 nm in phase 2, to finally 11 nm in phase 3 on all days in which the aircraft plumes were measured. During flight arrivals, definite increases in UFP particle number concentration (PNC) were observed, with the majority of the particles being in the 10 nm size class. These results were measured repeatedly on both sides of the airport in the direct prolongation of the runway and even at distances of up to 3 km away in nearby neighbouring communities. While the overall PM and UFP levels are affected by vehicular traffic, the freeway measurements showed particles from aircrafts and vehicles are distinguishable using the parameters PNC and Dp. The BC concentrations were rarely influenced by aircraft activity, while only some NO and NO2 peaks were measured depending on the consistency of the wind.