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Bioplastics are alternatives of conventional petroleum-based plastics. Bioplastics are polymers processed from renewable sources and are biodegradable. This study aims at conducting an environmental impact assessment of the bioprocessing of agricultural wastes into bioplastics compared to petro-plastics using an LCA approach. Bioplastics were produced from potato peels in laboratory. In a biochemical reaction under heating, starch was extracted from peels and glycerin, vinegar and water were added with a range of different ratios, which resulted in producing different samples of bio-based plastics. Nevertheless, the environmental impact of the bioplastics production process was evaluated and compared to petro-plastics. A life cycle analysis of bioplastics produced in laboratory and petro-plastics was conducted. The results are presented in the form of global warming potential, and other environmental impacts including acidification potential, eutrophication potential, freshwater ecotoxicity potential, human toxicity potential, and ozone layer depletion of producing bioplastics are compared to petro-plastics. The results show that the greenhouse gases (GHG) emissions, through the different experiments to produce bioplastics, range between 0.354 and 0.623 kg CO2 eq. per kg bioplastic compared to 2.37 kg CO2 eq. per kg polypropylene as a petro-plastic. The results also showed that there are no significant potential effects for the bioplastics produced from potato peels on different environmental impacts in comparison with poly-β-hydroxybutyric acid and polypropylene. Thus, the bioplastics produced from agricultural wastes can be manufactured in industrial scale to reduce the dependence on petroleum-based plastics. This in turn will mitigate GHG emissions and reduce the negative environmental impacts on climate change.

Abstract A variety of novel, recyclable and reusable, construction materials has already been studied within literature during the past years, aiming at improving the overall energy efficiency ranking of the building envelope. However, several studies show that a delicate control of indoor climating elements can lead to a significant performance improvement by exploiting the building’s savings potential via smart adaptive HVAC regulation to exogenous uncertain disturbances (e.g. weather, occupancy). Building Optimization and Control (BOC) systems can be categorized into two different groups: centralized (requiring high data transmission rates at a central node from every corner of the overall system) and decentralized 1 (assuming an intercommunication among neighboring constituent systems). Moreover, both approaches can be further divided into two subcategories, respectively: model-assisted (usually introducing modeling oversimplifications) and model-free (typically presenting poor stability and very slow convergence rates). This paper presents the application of a novel, decentralized, agent-based , model-free BOC methodology (abbreviated as L4GPCAO) to a modern non-residential building (E.ON. Energy Research Center’s main building), equipped with controllable HVAC systems and renewable energy sources by utilizing the existing Building Management System (BES). The building testbed is located inside the RWTH Aachen University campus in Aachen, Germany. A combined rule criterion composed of the non-renewable energy consumption (NREC) and the thermal comfort index – aligned to international comfort standards – was adopted in all cases presented herein. Besides the limited availability of the specified building testbed, real-life experiments demonstrated operational effectiveness of the proposed approach in BOC applications with complex, emerging dynamics arising from the building’s occupancy and thermal characteristics. L4GPCAO outperformed the control strategy that was designed by the planers and system provider, in a conventional manner, requiring no more than five test days.

SummaryThe German government has adopted a law that requires sewage plants to go beyond the recovery of phosphorus from wastewater and to promote recycling. We argue that there is no physical global short‐ or mid‐term phosphorus scarcity. However, we also argue that there are legitimate reasons for policies such as those of Germany, including: precaution as a way to ensure future generations’ long‐term supply security, promotion of technologies for closed‐loop economics in a promising stage of technology development, and decrease in the current supply risk with a new resource pool.

Abstract Rare earth permanent magnets are important components for modern (energy) technologies and are employed to reduce GHG emissions and combat climate change. The process of extracting these minerals from the ore has contentious economic, environmental and social implications. While the environmental impacts of their production have already been analyzed in several studies, the economic and the social perspective is still under-researched. The Social Life Cycle Assessment (S-LCA) approach employed in the present research explores whether there is a difference in social risks for rare earth permanent magnet production from three different rare earth ore production locations and the associated value chains. While one is located completely in China, another is composed of processes in Australia and Malaysia. The third process chain combines processes in the United States and Japan. The Product Social Impact Life Cycle Assessment (PSILCA) 2.0 database is used to assess the social implications. The analysis focuses on value chain actors, a stakeholder group of great interest to businesses but often underrepresented in S-LCA research. The impact categories describing this stakeholder group pertain to issues of social responsibility along the value chain, fair competition and corruption. Overall, the US value chain indicates the lowest level of social risk along the supply chain. However, in order to gain a deeper understanding of the social risks a sectoral and geographical analysis is conducted. Across all three cases, the mineral, fossil fuel and chemical sectors are shown to be problematic.

Abstract Since the adoption of the Kyoto protocol in 1997 and its entry into force in 2005, as well its aftermath such as the Doha amendment and Paris agreement, national policies have become more conscious of the usage of clean energy, mostly the different forms of renewable energy and nuclear energy. Ratifying countries and signatories had committed themselves to binding targets for the reduction of greenhouse emissions by 8% with respect to 1990 levels until 2012, also based on the particular contribution to global emissions from each country. This paper examines the integrational properties of clean energy consumption from eight emerging economies which are also high greenhouse gas emitters. The empirical results show that the clean energy consumption is stationarity for Brazil and Philippines by using a quantile unit root test without smooth breaks (Koenker and Xiao, 2004). However, after capturing the smooth breaks (Bahmani-Oskooee et al., 2018), we find the clean energy consumption of China, Pakistan and Thailand are stationary. The time-varying deterministic trend with smooth breaks is more fitted to the path of clean energy consumption in comparison to the deterministic trend without smooth breaks. The paper suggests economic insights useful for policy making.

Abstract Waste disposal is a core issue worldwide. Different researches are being carried out in order to handle waste materials, generated in industrial production and application processes, e.g. paint residue from metal coating in the automobile industry. Often waste is disposed in landfills at substantial economic and environmental cost. Combustion is another way to get rid of possibly hazardous waste. Pulverized fuel combustion is one of the latest combustion technologies. However, pulverized fuel combustion faces severe problems if the waste (fuel) contains components with low melting point. Having a low melting point, it gets difficult to manage and convey the pulverized material to the hot combustion chamber. The melting of fuel causes clogging in the fuel transport nozzle used to convey the material into the combustion chamber. In this work, a new technology for combustion of materials with low melting points is proposed, focusing on apparatus and nozzle design to prevent clogging. For this purpose, different nozzle designs were evaluated by multi-phase CFD simulations. Two sets of nozzle air flow rates were used in four nozzles. Effect of different flow rates and fuel particle size on combustion temperatures are also discussed. It was noted that nozzle air flow rate has a strong influence on the temperature distributions. Small fuel particle sizes result in wider combustion zones while larger particles give longer combustion zones. The results come up with optimized nozzle design and nozzle air flow for transportation of pulverized material with low melting point.

Technical and economic developments in battery and fast-charging technologies could soon make fuel cell electric vehicles, which run on hydrogen, superfluous in road transport

Abstract The most pressing global challenges have been summarized in the UN Sustainable Development Goals. Given the complex feedbacks and interdependencies among them, fulfilling these goals requires a holistic approach leading to profound transitions. The food-energy-water nexus is often proposed to be one such holistic approach. However, to date no consistent definition of the nexus concept exists, while research interest in the nexus rapidly grows. Therefore, in this paper, the nexus is defined as a concept of systems thinking. A nexus systems thinking test is developed that can be used as a new way of categorizing nexus research. To examine the test's viability and suitability, it is applied to a sample data set of nexus-related research papers. By means of a multi- and mixed methods document analysis it is analyzed if the papers conceptualize the nexus approach as a systems thinking concept. The results show that all papers meet the four system criteria. Different emphasis, however, is put on certain aspects. The nexus systems thinking test proved to be a viable systematic method to investigate if and in which way nexus research incorporates a systems thinking perspective. It does not only offer a new way of categorizing nexus related research, but also allows assessing its quality from a comprehensive nexus perspective. The test thus provides valuable and systematic understanding of a rapidly developing, central research field within sustainability science.

Abstract This paper examines the impact of climate targets which have been adapted to individuals’ behavior based on global political events. As the global climate targets of the Paris Agreement are largely supported by society, we investigate the potential of these targets to lead to personal and social norms concerning individual contributions to the Paris Agreement´s climate goals. We assume that these norms mediate the influence of personal involvement in the Paris agreement and of environmental values on greenhouse gas avoiding decisions. Also, we expect that these norms predict greenhouse gas avoiding behavior, rather than norms related to climate change. The research is based on a laboratory study with students conducted in December 2017 in Germany (n = 226). The main results show for the students surveyed in the research that norms in favor of contribution to the Paris Agreement substantially influence objective carbon offsetting, as well as consumption of local food and green electricity; and these norms partially mediate the influence of personal involvement in the Paris Agreement and of environmental values on decision-making.