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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 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.

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.

Following the impressive economic achievements in the past decades, China is faced with energy and environmental challenges. To carry out more effective and targeted energy policies, the heterogeneities of different industrial sectors are of great importance. The energy consumption of China’s light industry in 2012 was 316 million tons of coal equivalents, which is about the energy consumption of South Korea. The paper explored the substitution relationships between various input factors and fuel sources, and showed that electricity price reform is crucial for energy conservation in China’s light industry. Then, the dynamics of energy intensity change is examined by decomposing energy intensity into budget effect, substitution effect, output effect and technology advance effect. The result revealed that the substitution effect between input factors is a key driving force. However, technology progress seems to contribute very little. For future energy policy alternatives, promoting the implementation of new conservation technology and electricity price reform may be effective measures.

Abstract To ensure techno-economically suitable installation of ground source heat pump (GSHP) systems, thermal and hydrogeological properties of the subsoil need to be investigated. In this paper, the geothermal potential for three types of GSHP installations in the urban area of Wuhan city is assessed based on preliminary geological investigations. The potential for shallow geothermal energy is evaluated for surface water heat pump systems (SWHP), groundwater heat pump systems (GWHP) and ground coupled heat exchanger heat pump systems (GCHP). The mapped shallow geothermal potentials provide essential information for the installation of GSHPs and for the management of geothermal resources of Wuhan city. Furthermore, the heat transfer rates for some typical configured borehole heat exchanger (BHE) are tested by field Thermal Response Tests (TRT). In order to understand the techno-economic feasibility of the GSHPs, different types of the installed systems are measured and analyzed.