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Abstract To ensure long-term availability of mobility and to keep the effects of humanity on global climate limited, politics, research, and industry currently search for ways to reduce greenhouse gas (GHG) emissions caused by it. A potential reduction could be achieved by transitioning towards more efficient transport modes, optimally powered by renewable energy. Based on mobility (commutes), population, and weather data from Switzerland, we present a model to compute energy savings due to a (hypothetical) widespread deployment of electric bicycles. In different scenarios, we analyze the dependence of the commuting energy demand on users’ preferences about when to take the bike, such as an aversion to biking on cold and rainy days. Our study shows that GHG emission reductions of up to approx. 10% of the total emissions from diesel and gasoline are possible. In combination with a widespread deployment of electric vehicles, further savings of up to 17.5% could be achieved. In particular, the willingness to drive longer commutes by e-bike influences the potential GHG emission reductions, followed by the willingness to use the bicycle at temperatures below 10°C. Using these results, we identify the spatial energy and greenhouse gas savings potential and thus regions that are particularly suited for e-bike use. The identification of regions with high saving potentials allows for targeted marketing, transition-supporting incentives, or infrastructural changes to maximize the reduction of emissions.

This paper discusses the influence of time horizon on dynamic optimization of small-size wastewater treatment plants alternating aerobic and anoxic processes. The optimization problem consists in determining the aeration policy (air-on and air-off periods) that minimizes the energy dissipated by the aeration system subject to both effluent and operating constraints. Optimization over short time horizons is first considered and reductions of the energy consumption up to 30% are obtained with respect to the usual operating mode of the process. But the application of such aeration strategies eventually results in a biomass wash-out when applied over long time periods. Here, it is shown that long time horizon optimized policies guarantee a durable functioning of the treatment plant. The resulting energy consumption savings are however lower (up to 15%), but are still important.

A simple framework for environmental life-cycle assessment (LCA) based on physical measures is presented and applied to the comparison of long-distance energy transport systems, including high-voltage alternating and direct current transmission lines, pipelines for gas and oil, inland waterway, road and rail transportation. Quantitative indicators for fossil-energy consumption, air-emission impacts, land use, audible noise impacts, and visual impacts are developed. These can be used in the context of existing planning or decision making instruments, such as integrated resource planning, technology assessment, LCA, regional planning, line and power plant siting. To reduce all information to a single indicator, the concept of the equivalent impacted area is introduced for land use, audible noise and visual impacts. It is shown that pipelines are the environmentally most favourable option in the case of oil and gas transport. In the case of coal transport, early conversion to electricity and transmission by high-voltage lines can lead to significant impact reductions compared to coal transport with barges and trains. For long transport distances, high-voltage direct current lines yield particularly good results.

Abstract Chemists, biologists, ecologists, and engineers have been developing a data-base to identify and evaluate risks to humans and the environment and strategies to minimize potential risks from large-scale coal liquefaction. Coal-liquids produced by various processes and under various stages of design and operating conditions have been screened for potential health and environmental effects. Toxicologically active materials have been fractionated and chemical constituents of biologically active fractions have been identified, and the environmental fate of problematic agents is being determined. Results indicate that coal-derived liquids are generally more toxicologically active than shale oil and petroleum crudes. Bioactive agents include primary aromatic amines (PAA), polynuclear aromatic hydrocarbons (PAH), phenolics, and others. Some components of coal-derived materials are taken up by biota and metabolized. Hydrotreating reduces PAA, PAH, and phenol content, as well as toxicological response to coal-liquids. Selective distillation restricts PAA and PAH content, and mutagenicity and carcinogenicity to high-boiling-range materials. Other process conditions and environmental factors also influence chemical characteristics and toxicological activity of coal-derived liquids. Recent findings indicate that biological responses to a given coal-derived liquid component vary, depending on whether that material is presented to the organism or environment as a pure compound or in a complex mixture. The data-base described provides input for assessment and has been used by developers when selecting process modifications and product slates that minimize risk to humans and the environment. These data have also been used in developing occupational health and industrial hygiene practices and may aid in selection of control technologies, mitigative strategies, special handling and accident prevention procedures, or spill-clean-up options to enhance the environmental acceptability of a coal liquefaction industry.

Current indicator-based sustainability assessment approaches usually have three shortcomings: (i) ecological aspects are mostly overrepresented in relation to importance and complexity of economic and social aspects; (ii) they center on filling important gaps in scientific knowledge, but miss on utilization and implementation; and (iii) the assessment results themselves are difficult to implement in decision-making, as conflicting goals and the interaction between indicators have not been sufficiently considered. We propose an approach that fulfills systemic criteria, i.e., sufficient representation of the system including functional interaction among indicators; normative criteria, i.e., considering the different value perspectives of stakeholders by including them in the process and designing sustainability ranges rather; and (iii) procedural criteria, i.e. pursuing the assessment in a true transdisciplinary process. We present the SSP and its application for the Swiss milk value added chain. The system is described with a set of 8 ecological and 9 socio-economic indicators. The sustainability ranges were obtained through literature research and stakeholder interviews. The relationship among the indicators was elicited in a transdisciplinary workshop. The SSP program takes a geometric approach to determine the intersection space corresponding to the satisfaction of the normative ranges while taking into account the functional interactions of the indicators.

AbstractDevelopment of catalytically active materials from biowaste represents an important aspect of sustainable chemical research. Three heterogeneous materials were synthesized from inexpensive biomass‐based chitosan and abundant Co(OAc)2 using complexation followed by pyrolysis at various temperatures. These materials were applied in the catalytic hydrogenation of nitroarenes using molecular hydrogen. A variety of diversely functionalized nitroarenes including some pharmaceutically active compounds were converted into aromatic amines in high yields, with high selectivity, and with excellent functional group tolerance. This green protocol has also been implemented for the synthesis of a biologically important TRPC3 inhibitor.

Domestic heating represents the most dominant energy function in Dutch households nowadays. Using district heat from CHP (combined heat and power) by means of a NGCC (natural gas-fired combined cycle) plants is generally acknowledged as an effective option to reduce primary energy consumption for heating. However, methods to calculate energy savings from CHP differ widely. This paper compares a number of different methods, including the method from the EU CHP Directive, to estimate primary energy savings in comparison with the typically used domestic gas-fired condensing boiler. Real hourly CHP plant performance data is used. An estimation of the CO2 mitigation cost of delivering district heat to Dutch dwellings is made. We find that supplying dwellings with district heat from an NGCC-CHP saves energy, regardless of the calculation method and for a rather wide range of reference efficiencies. CO2 mitigation costs are acceptable from a social perspective (at discount rates up to 4%, excluding fuel taxes) and negative from a private perspective (at discount rates up to 10%, including fuel taxes).

The paper reports on the methodology and results of several studies on the long-term efficiency potentials in the two energy transformation steps from primary energy to final and useful energy and, more importantly, from useful energy to energy services. The examination of these potentials considers the lifetimes and periods of refurbishment of manufactured artefacts: Buildings and infrastructure that will save or waste energy in 2050 that are being built or restored today. The paper emphasises the enormous size of energy conservation potentials achievable not only by reducing energy losses but also by decreasing the specific activity levels for several energy services through improved material efficiency and intensified use of products, plants, and vehicles. It also reports on major definitive conclusions on R&D needs and challenges to R&D-policies as well as immediate policy action in OECD-countries in order to realise the vision of reducing primary energy use per capita by two thirds in industrialised countries within the next five decades.

Abstract The adoption of blended cements to reduce the carbon footprint has increased significantly over the last decades. Clays containing kaolinite are a promising choice due to their widespread availability. Kaolinite content is the major factor controlling the performance of blended cements incorporating calcined clay, for example in LC3-50 (50% clinker, 30% calcined clay, 15% limestone and 5% gypsum) clays with a kaolinite above about 40% are needed to achieve similar strength to reference OPCs at 7 days. Materials with low contents of kalinite are often considered unsuitable. This study compares two fractionation techniques to increase the kaolinite content of a low-grade clay (30% kaolinite content). The results show that kaolinite remains concentrated in the fine particles after grinding. Both wet sedimentation and air separation were effective to increase the reactivity of the material as a combined result of increased fineness and kaolinite content. For the air separation process, it was observed that a significant amount of kaolinite remained in the rejected fraction after processing due to agglomeration of the powder. It was shown that the use of grinding aids before the separation process can further improve the results.