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The selection of an appropriate “optimal” recycling alternative has to take into consideration both the ecological and economic effects of the entire life-cycle. The aim of this paper is to compare different waste management systems by means of a life-cycle assessment (LCA) and a cost comparison. The analysis uses data regarding the amount of household waste generated, collected and treated in a selected area in Austria. For this purpose, model-based scenarios with recycling and separate collection as well as scenarios without recycling were created. The database covers the amounts of household waste generated in the different collection schemes, the transport distances by private delivery and by regional waste management companies and data on the waste treatment processes that are widely employed throughout Austria and Germany. The resulting life-cycle inventories have been assessed according to three impact categories relevant to this topic—the global warming potential (GWP), the acidification potential (AP) and the net energy use (NEU). The results include ecological impact analyses and cost comparisons for the overall waste management systems and the waste management systems for the individual waste types—waste paper, plastic packaging, metal packaging and waste glass. Finally, a sensitivity analysis should prove the validity of the results for regions with transport distances differing from those in the area under analysis. © 2003 Elsevier B.V. All rights reserved.

Is it true that a nuclear technology approach to generate electric energy offers a clean, safe, reliable and affordable, i.e., sustainable option? In principle yes, however a technology impact on the environment strongly depends on the actual implementation bearing residual risks due to technical failures, human factors, or natural catastrophes. A full response is thus difficult and can be given first when the wicked multi-disciplinary issues get well formulated and “resolved”. These problems are lying at the interface between: the necessary R&D effort, the industrial deployment and the technology impact in view of the environmental sustainability including the management of produced hazardous waste. As such, this problem is clearly of multi-dimensional nature. This enormous complexity indicates that just a description of the problem might cause a dilemma. The paper proposes a novel holistic approach applying Multi-Criteria Decision Analysis to assess the potential of nuclear energy systems with respect to a sustainable performance. It shows how to establish a multi-level criteria structure tree and examines the trading-off techniques for scoring and ranking of options. The presented framework allows multi-criteria and multi-group treatment. The methodology can be applied to support any pre-decisional process launched in a country to find the best nuclear and/or non-nuclear option according to national preferences and priorities. The approach addresses major aspects of the environmental footprint of nuclear energy systems. As a case study, advanced nuclear fuel cycles are analyzed, which were previously investigated by the Nuclear Energy Agency (NEA/OECD) expert group WASTEMAN. Sustainability facets of waste management, resource utilization and economics are in focus.

AbstractThermochemical biorefineries for the production of chemicals and materials can play an important role in the bioeconomy. However, their economic viability is often questioned under the premise of the economy of scale. This paper presents a regional, modular biorefinery concept for the production of the platform chemicals hydroxymethylfurfural (HMF), furfural and phenols from the lignocellulosic perennial miscanthus, which can be cultivated on marginal and degraded areas. The paper focuses on the question of the minimum selling price of HMF and the optimal plant size for this purpose, using the region of Baden‐Württemberg, Germany, as an example. Based on small pilot plant results, a scalable process simulation was created via AspenPlus. This allows different scenarios and process combinations of this multi‐output biorefinery concept to be compared with each other. Using this, a minimum sales price for the main product HMF is calculated using methods of dynamic investment cost calculation according to the net present value method. Based on this, the plant capacity was scaled. The scenarios and sensitivity analyses show that, with an accuracy of ±15%, regional biorefineries could already offer platform chemicals at prices of 2.21–2.90 EUR/kg HMF at the current stage of development. This corresponds to three to four times the price of today's comparative fossil base chemicals and is thus a competitive option from the authors’ point of view. The local biomass and the heat prices were identified as the main influencing factors. As a result, the selection of the location will have a decisive influence on the economic viability of such concepts in the case of further development and optimization of the process in first demonstration plants.

Reducing methane (CH4) emission from paddy rice production is an important target for many Asian countries in order to comply with their climate policy commitments. National greenhouse gas (GHG) inventory approaches like the Tier-2 approach of the Intergovernmental Panel on Climate Change (IPCC) are useful to assess country-scale emissions from the agricultural sector. In paddy rice, alternate wetting and drying (AWD) is a promising and well-studied water management technique which, as shown in experimental studies, can effectively reduce CH4 emissions. However, so far little is known about GHG emission rates under AWD when the technique is fully controlled by farmers. This study assesses CH4 and nitrous oxide (N2O) fluxes under continuous flooded (CF) and AWD treatments for seven subsequent seasons on farmers’ fields in a pumped irrigation system in Central Luzon, Philippines. Under AWD management, CH4 emissions were substantially reduced (73% in dry season (DS), 21% in wet season (WS)). In all treatments, CH4 is the major contributor to the total GHG emission and is, thus, identified as the driving force to the global warming potential (GWP). The contribution of N2O emissions to the GWP was higher in CF than in AWD, however, these only offset 15% of the decrease in CH4 emission and, therefore, did not jeopardize the strong reduction in the GWP. The study proves the feasibility of AWD under farmers’ management as well as the intended mitigation effect. Resulting from this study, it is recommended to incentivize dissemination strategies in order to improve the effectiveness of mitigation initiatives. A comparison of single CH4 emissions to calculated emissions with the IPCC Tier-2 inventory approach identified that, although averaged values showed a sufficient degree of accuracy, fluctuations for single measurement points have high variation which limit the use of the method for field-level assessments.

Abstract Despite the comparatively limited stock of vehicles, heavy-duty road transport is responsible for a major share of CO2 emissions from the European transport sector. Electric trucks powered by overhead lines, so-called trolley trucks or catenary hybrid trucks, have been proposed as a potential GHG mitigation option. However, from the perspective of the energy system, trolley trucks constitute an additional and inflexible electricity demand. Here, we analyse scenarios with an ambitious European market diffusion of trolley trucks and their impact on the electricity system and CO2 emissions. Our results show that trolley trucks can noteworthily reduce the CO2 emissions from heavy road transport even when the additional CO2 emissions from electricity generation are taken into account. Furthermore, the actual impact of the additional load from trolley trucks on the total energy system is limited. Compared to the anticipated electricity demand from passenger cars in 2030, trolley trucks require less energy and the load is more equally distributed over daytime. Our findings thus show that electric trucks are an interesting option for CO2 mitigation in heavy road transport.

The advantages of fast-spectrum reactors consist not only of an efficient use of fuel through the breeding of fissile material and the use of natural or depleted uranium, but also of the potential reduction of the amount of actinides such as americium and neptunium contained in the irradiated fuel. The first aspect means a guaranteed future nuclear fuel supply. The second fact is key for high-level radioactive waste management, because these elements are the main responsible for the radioactivity of the irradiated fuel in the long term. The present study aims to analyze the hypothetical deployment of a Gen-IV Sodium Fast Reactor (SFR) fleet in Spain. A nuclear fleet of fast reactors would enable a fuel cycle strategy different than the open cycle, currently adopted by most of the countries with nuclear power. A transition from the current Gen-II to Gen-IV fleet is envisaged through an intermediate deployment of Gen-III reactors. Fuel reprocessing from the Gen-II and Gen-III Light Water Reactors (LWR) has been considered. In the so-called advanced fuel cycle, the reprocessed fuel used to produce energy will breed new fissile fuel and transmute minor actinides at the same time. A reference case scenario has been postulated and further sensitivity studies have been performed to analyze the impact of the different parameters on the required reactor fleet. The potential capability of Spain to supply the required fleet for the reference scenario using national resources has been verified. Finally, some consequences on irradiated final fuel inventory are assessed. Calculations are performed with the Monte Carlo transport-coupled depletion code SERPENT together with post-processing tools.

The average antimony concentration in municipal solid waste is estimated to be about 10-60 ppm. Thermodynamical models predict a volatile behavior for antimony compounds, yet literature mass balances show that about 50% of the antimony input remains in the grate ashes. This fact can be explained by the formation of thermally stable antimonates in the fuel bed due to interactions with alkali or earth-alkali metals. Thermogravimetric experiments revealed an increased thermal stability for antimony oxide in presence of oxygen and calcium oxide. Spiking experiments on the test incinerator TAMARA showed that chlorination processes have a strong effect on antimony volatilization whereas high fuel-bed temperatures and addition of antimony oxide only have a moderate effect. In the grate ashes, antimony shows a pH-depending leaching property, which is typical for anionic species. This fact supports the thesis that antimony is present in the grate ashes in an anionic speciation.