Speech by dr. Robert Baars at the official inauguration as Professor in Climate Smart Dairy Value Chains at Van Hall Larenstein University of Applied Sciences, 24th September 2021, Dairy Campus, Leeuwarden, The Netherlands.
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Managing dairy excreta as slurry can result in significant emissions of ammonia (NH3) and greenhouse gases (GHGs) during storage and thereafter. Additionally, slurry often has an imbalanced nitrogen (N) to phosphorus (P) ratio for crop fertilization. While various treatments exist to address emissions and nutrient imbalances, each has trade-offs that can result in pollution swapping. An integrated management system, starting with source segregation (SS) in-house to separate faeces and urine into two manageable streams followed by step-wise complementary treatments has been designed to manage nutrients and reduce emissions in the whole chain, but its effect on emissions in storage remains untested. This study investigated NH3, nitrous oxide (N2O), and methane (CH4) emissions and total N losses from integrated storage systems combining SS, mesophilic or thermophilic anaerobic digestion (AD), acidification, drying and zeolite addition and an impermeable cover. These systems were compared to two reference slurry storage systems: in-house uncovered (US) and outside covered (CS). A 30-day lab-scale experiment was conducted at 10 °C, monitoring emissions using an INNOVA1412 gas analyser, while total N losses were assessed using mass balance. Results indicated that the SS fractions treated before covered storage exhibited significantly lower emissions (NH3 or CH4 or both) compared to both reference slurry storage systems (US and CS). Source segregation combined with acidification of urine and AD of faeces at 35 °C and an impermeable cover allowed for a 99% reduction in NH3 emissions, a 45% reduction in CH4 emissions and had no effect on N2O emissions as compared to US. When AD of faeces was conducted at 55 °C instead of 35 °C, the CH4 emission was reduced by 77% compared to US. This study concludes that SS combined with urine and faeces treatment allows a more effective and simultaneous reduction of all emissions in storage as compared to slurry storage systems, while also effectively separating nutrients allowing more precise N and P fertilization with dairy excreta. Further research is necessary to assess emissions and fertilizer value of treated fractions after field application, in addition to the associated costs.
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Greenhouse gas emissions from air transport, and methods to calculate them, are notwell defined in the current literature. While calculating the direct emissions of CO2 is already causefor some debate, the contribution of other emissions and impacts – like nitrogen oxides (NOx),contrails, water vapour – to climate change still lacks a reliable metric. As aviation is the largestemitter of greenhouse gases within tourism, accurate estimates of carbon and non-carbon emissions are important. This paper presents some standardisation as well as general insights to assistresearchers assessing the impact of aviation on climate change in scenario studies or evaluatingmitigation policies. The IPCC introduced a radiative forcing index (RFI) to measure the role of aviation in climate change, which is in scenario studies or evaluations of policies often used as a kind ofconstant ‘equivalence factor’. The paper shows this to be inaccurate and proposes ways to accountfor both carbon and non-carbon climate impacts of air transport
The growing awareness of consumers of the increasing problem with livestock and meat production due to the high nitrogen emissions and the related impact on climate change drives consumption of plant based vegetarian alternatives. Similarly there is also an increasing demand for animal-free, eco-friendly alternative vegan leather. Consequently there has been significant interest in developing leather-like vegan materials from multiple plant sources, such as mango, pineapple and mushroom based materials. However, the commercialization and the growth of sustainable vegan leather production is hampered significantly by the difficulty of achieving the needed quality for the various consumer products as well as the high prices of the vegan alternatives. In the Growing Leather project two SMEs, BioscienZ and B4Plastics, will combine forces with Avans University of Applied Sciences to develop vegan leather from the mushroom based material called mycelium. BioScienZ is a biotech company with strong expertise and capacity to produce low-cost and consistent quality mycelium. B4Plastics is a material development company, with strengths in designing and distributing eco-plastic products. In this project Avans University will use several mycelium types (produced by BioscienZ), and with the guidance of B4Plastics, it will test various additives under many different conditions, to ultimately develop an environmentally friendly, vegan material that will have comparable material characteristics to animal leather and is competitive in price.
The reclaiming of street spaces for pedestrians during the COVID-19 pandemic, such as on Witte de Withstraat in Rotterdam, appears to have multiple benefits: It allows people to escape the potentially infected indoor air, limits accessibility for cars and reduces emissions. Before ordering their coffee or food, people may want to check one of the many wind and weather apps, such as windy.com: These apps display the air quality at any given time, including, for example, the amount of nitrogen dioxide (NO2), a gas responsible for an increasing number of health issues, particularly respiratory and cardiovascular diseases. Ships and heavy industry in the nearby Port of Rotterdam, Europe’s largest seaport, exacerbate air pollution in the region. Not surprisingly, in 2020 Rotterdam was ranked as one of the unhealthiest cities in the Netherlands, according to research on the health of cities conducted by Arcadis. Reducing air pollution is a key target for the Port Authority and the City of Rotterdam. Missing, however, is widespread awareness among citizens about how air pollution links to socio-spatial development, and thus to the future of the port city cluster of Rotterdam. To encourage awareness and counter the problem of "out of sight - out of mind," filmmaker Entrop&DeZwartFIlms together with ONSTV/NostalgieNet, and Rotterdam Veldakademie, are collaborating with historians of the built environment and computer science and public health from TU Delft and Erasmus University working on a spatial data platform to visualize air pollution dynamics and socio-economic datasets in the Rotterdam region. Following discussion of findings with key stakeholders, we will make a pilot TV-documentary. The documentary, discussed first with Rotterdam citizens, will set the stage for more documentaries on European and international cities, focusing on the health effects—positive and negative—of living and working near ports in the past, present, and future.
Stringent nitrogen oxide (NOx) regulations are crucial for minimizing environmental harm and enhancing public health. The Selective Non-Catalytic Reduction (SNCR) technique is an effective after-treatment method for reducing NOx emissions in combustion systems. By injecting a reagent, typically ammonia or urea, into the flue gas within a specified temperature window, SNCR facilitates the chemical reaction that converts NOx into harmless nitrogen and water. The optimal temperature range for this reaction is critical for maximizing efficiency and effectiveness. The primary advantage of the SNCR technique is its lower installation and operating costs in comparison to other after-treatment methods. The partners involved in this proposal are highly interested in implementing the SNCR method to reduce NOx emissions from heavy-duty engines. This proposal aims to develop a numerical model to evaluate the NOx reduction potential in heavy-duty engine applications using the SNCR method. The model will enable the analysis of key parameters, including the injection site temperature and the reagent-to-NOx concentration ratio, to determine their impact on NOx reduction.
