Liselotte Schebek

Social aspects for sustainability assessment of technologies—challenges for social life cycle assessment (SLCA)

PurposeTechnologies can contribute to sustainable development (e.g., improving living conditions) and at the same time cause sustainability problems (e.g., emissions). Decisions on alternative technologies should thus ideally be based on the principle to minimize the latter. Analyzing environmental, economic, and social aspects related to technologies supports decisions by identifying the “more sustainable” technology. This paper focuses on social issues. First, it discusses the applicability of the social life cycle assessment (SLCA) guidelines for a comparative technology analysis, taking the example of two case studies in developing countries. Indicating technologies as “sustainable” also means that they are indeed operated over the expected lifetime, which, in development projects, is often not guaranteed. Consequently, social aspects related to implementation conditions should be considered in an SLCA study as well. Thus, a second focus is laid on identifying appropriate indicators to address these aspects.MethodsFirst, the SLCA guidelines were examined with regard to applying this product-related approach to two real case studies (analysis of technologies/plants for water supply and for decentralized fuel production) for a comparative technology analysis. Suitable indicators are proposed. To address the second focus, a literature research on technology assessment and implementation in developing countries was conducted. Moreover, socioeconomic studies in the investigation areas of the case studies were consulted. Based on this, indicators addressing implementation conditions were identified from the SLCA guidelines and additional literature.Results and discussionThe study shows social issues and indicators found in the SLCA guidelines and considered suitable for a comparative technology analysis in the case studies. However, for a sustainability assessment of technologies, especially in developing countries, further indicators are required to address technology implementation conditions. A set of additional social indicators like reported trust in institutions or fluctuation of personnel is proposed. Though these indicators were derived based on specific case studies, they can also be suggested to other technologies and are not necessarily limited to developing countries.ConclusionsThe study pointed out that an application of the SLCA guidelines considering the whole life cycle was not (yet) feasible for the case studies considered. This is mainly due to the lack of data. Regarding technology implementation, it was examined which indicators are available in this SLCA approach and which could additionally be integrated and applied. This is relevant as a potential contribution of technologies to sustainable development can only be achieved when the technologies are successfully implemented.

Closed-loop recycling of construction and demolition waste in Germany in view of stricter environmental threshold values:

Recycling of construction and demolition waste contributes decisively to the saving of natural mineral resources. In Germany, processed mineral construction and demolition waste from structural engineering is used nearly exclusively in civil engineering (earthwork and road construction sector) as open-loop recycling. Due to the planned stricter limit values for the protection of soil and water, however, this recycling path in civil engineering may no longer be applicable in the future. According to some new guidelines and standards adopted recently, recycled aggregates may also be used for concrete production in the structural engineering sector (closed-loop recycling). Wastes from the structural engineering sector can thus be kept in a closed cycle, and their disposal on a landfill can be avoided. The present report focuses on the determination of maximum waste volumes that may be handled by this new recycling option. Potential adverse effects on the saving of resources and climate protection have been analysed. For this purpose, materials flow analysis and ecobalancing methods have been used.

Using Life-Cycle Assessment in Process Design

Summary This article presents the application of life-cycle assessment in early phases of process design in the context of technology that employs a bio-based material. The goal is to identify hot spots in the process chains with regard to environmental impacts by performing a dominance analysis. By focusing his activities on the hot spots identified, the designer is given the opportunity to efficiently improve environmental performance. This approach is illustrated for the case of supercritical water gasification, a novel technology for the treatment of organic feedstock with high moisture content. In the reactor under supercritical conditions, organic components are converted into a high-caloric synthesis gas, with hydrogen, methane, and carbon dioxide as the main products. The data used for the assessment are obtained from laboratory tests and the literature, completed by assumptions for missing data. The scope of assessment ranges from the extraction of raw materials to the product, that is, hydrogen (cradle to gate) with sewage sludge of a municipal wastewater treatment plant used as feedstock. The assessment identifies the main sources of environmental impacts. The predominant process step in terms of global warming potential is the supply of the gasification process with additional heat. The production of a blending agent in the dewatering step is the main source of the impact category of acidification, whereas the wastewater treatment plant is the origin of emissions that lead to eutrophication. The revealed sources are analyzed further and options for reducing the environmental impacts are discussed.

Volkswagen slimLCI: a procedure for streamlined inventory modelling within life cycle assessment of vehicles

One of the key prerequisites of environmentally-friendly product design is a quantitative assessment of the environmental profile of product design options. Life Cycle Assessment (LCA) is a tool for evaluating the environmental performance of goods and services over the whole life cycle. Yet, the effort involved remains one major obstacle for its wide-spread use. It is well-known that collecting and processing the relevant data is the most time-consuming part while conducting an LCA study of complex systems. It is possible to reduce the workload significantly by automating these process steps, which also offers advantages in terms of LCA quality.

Organotin in the Tagus estuary

The tri(n-butyl)tin (TBT) moiety has been shown to have complex ecotoxicological effects on estuarine populations. In the Tagus the massive die-off of the Portuguese oyster (Crassostrea angulata Lmk), has been attributed to the introduction and use of this contaminant by shipyards. This paper reviews previous work by others and reassesses our results obtained in water and sediments of the Tagus estuary, as a contribution to the understanding of tin geochemistry and organotin speciation in this estuary. Contrary to earlier results, the latest surveys show that in the open waters of the Tagus measurable concentrations of all the three butyltin species occur, exhibiting peak concentrations at two locations that indicate two previously undetected sources of TBT. TBT also presents a peak concentration in sediments near the Lisnave shipyards, as previously suggested. The latest surveys still detected methylated forms of tin, particularly monomethyltin (Me Sn3+), in Tagus sediments, with maximum concentrations in the vicinity of urban effluent discharges. The concentrations for TBT and its degradation products found in the Tagus are potentially harmful to the populations of gastropods and endemic bivalves.

Determination of Methyltin and Butyltin Compounds in Environmental Water and Sediment Samples

Abstract Although today most techniques for the determination of organotin compounds provide adequate precision, problems concerning the accuracy of data obtained from actual environmental samples still exist. Two important sources of error are the storage of samples and the extraction of organotin compounds from environmental matrices. The stability of methyl- and butyltin compounds in freshwater samples stored in polycarbonate containers was examined: storage at + 10°C and freezing at − 20°C both conserved original concentrations for some days, but resulted in losses after prolonged storage. For sediment samples, freeze-drying was found to be a reliable method of conservation. Extraction efficiency was evaluated for the extraction of sediment samples by refluxing in methanol/hydrochloric acid. Spiking and re-extracting a sediment may result in an overestimate of extraction efficiency. More accurate data can be obtained by using a method based on extracting sediment with varying volumes of solvent. Our d...

Substitution knapper Metalle – ein Ausweg aus der Rohstoffknappheit?

A growing number of metals is used in many technical applications. As several metals are essential for specific products, concerns are growing that limited resource availability may be an important constraint for technology development. Thus, a sustainable resource use is required to secure raw material supply for key technologies. Substitution of scarce metals might be a successful strategy for that; however, the question arises of which contribution is possible.

German network on life cycle inventory data

Reliability of Life Cycle Assessment (LCA) results depends on the availability and quality of Life Cycle Inventory (LCI) data. In order to provide high-quality LCI data for background systems in LCA and to make it applicable to a wider range of fields, harmonization strategies for already existing datasets and databases are required. In view of the high significance of LCI data as a basis of major fields of action within a sustainability strategy, the German Helmholtz Association (HGF), under the leadership of the Forschungszentrum Karlsruhe (FZK) has taken up this issue in its research programme. In 2002, the FZK conducted a preliminary study on ‘Quality Assurance and User-oriented Supply of a Life Cycle Inventory Data’ funded by the Federal Ministry of Education and Research (BMBF). Within the framework of this study, a long-term concept for improving the scientific fundamentals and practical use of LCI data was developed in association with external experts. The focus is on establishing a permanent German ‘Network on Life Cycle Inventory Data’ which will serve as the German information and cooperation platform for all scientific and non-scientific actors in the field of life cycle analysis. This network will integrate expertise on LCA in Germany, harmonise methodology and data, and use the comprehensive expert panel as an efficient basis for further scientific development and practical use of LCA. At the same time, this network will serve as a platform for cooperation on an international level. Current developments address methodological definitions for the initial information infrastructure. As a novel element, user needs are differentiated in parallel according to the broad application fields of LCI-data from product declaration to process design. Case studies will be used to define tailored interfaces for the database, since different data quality levels will be encountered.

Extraction of medium chain fatty acids from organic municipal waste and subsequent production of bio-based fuels.

This paper provides an overview on investigations for a new technology to generate bio-based fuel additives from bio-waste. The investigations are taking place at the composting plant in Darmstadt-Kranichstein (Germany). The aim is to explore the potential of bio-waste as feedstock in producing different bio-based products (or bio-based fuels). For this investigation, a facultative anaerobic process is to be integrated into the normal aerobic waste treatment process for composting. The bio-waste is to be treated in four steps to produce biofuels. The first step is the facultative anaerobic treatment of the waste in a rotting box namely percolate to generate a fatty-acid rich liquid fraction. The Hydrolysis takes place in the rotting box during the waste treatment. The organic compounds are then dissolved and transferred into the waste liquid phase. Browne et al. (2013) describes the hydrolysis as an enzymatically degradation of high solid substrates to soluble products which are further degraded to volatile fatty acids (VFA). This is confirmed by analytical tests done on the liquid fraction. After the percolation, volatile and medium chain fatty acids are found in the liquid phase. Concentrations of fatty acids between 8.0 and 31.5 were detected depending on the nature of the input material. In the second step, a fermentation process will be initiated to produce additional fatty acids. Existing microorganism mass is activated to degrade the organic components that are still remaining in the percolate. After fermentation the quantity of fatty acids in four investigated reactors increased 3-5 times. While fermentation mainly non-polar fatty acids (pentanoic to octanoic acid) are build. Next to the fermentation process, a chain-elongation step is arranged by adding ethanol to the fatty acid rich percolate. While these investigations a chain-elongation of mainly fatty acids with pair numbers of carbon atoms (acetate, butanoic and hexanoic acid) are demonstrated. After these three pre-treatments, the percolate is brought to a refinery to extract the non-polar fatty acids using bio-diesel, which was generated from used kitchen oil at the refinery. The extraction tests in the lab have proved that the efficiency of the liquid-liquid-extraction is directly linked with the chain length and polarity of the fatty acids. By using a non-polar bio-diesel mainly the non-polar fatty acids, like pentanoic to octanoic acid, are extracted. After extraction, the bio-diesel enriched with the fatty acids is esterified. As a result bio-diesel with a lower viscosity than usual is produced. The fatty acids remaining in the percolate after the extraction can be used in another fermentation process to generate biogas.

The utilization of light weight boards for reducing air emissions by the German wood industry – a perspective?

BackgroundResource saving product development is one competitive advantage for companies. Forestbased industries try to realize this amongst others with lightweight board solutions.Using lightweight boards is discussed in the wood industry for several years and could be technically realized nowadays on an industrial scale. Advantages by using lightweight boards are expected in costs due to reduced wood requirements as well as in respect to logistics. In discussion are potential environmental advantages of an enhanced use of lightweight boards.The objective of the paper is to identify and quantify the environmental impacts due to an increased use of lightweight boards in the furniture industry. The focus rests on the so-called Kyoto greenhouse gas emissions, NMVOC and formaldehyde.ResultsThe study grounds on a process-based material flow model, which depicts the use of forest resources in Germany. The situation in 2005 is compared with a scenario, which describes a partial substitution of conventional boards by lightweight boards using sandwich design.Overall the greenhouse gas emissions will decrease, even though the overall decline is rather small.ConclusionsBy this lightweight boards could be a perspective for the German wood-industry to reduce emissions into air noteworthy. The main causes are a reduced requirement for adhesives and binders, logistics and thermal use of residuals.ZusammenfassungBackgroundRessourcenschonende Produktentwicklungen sind ein entscheidender Wettbewerbsvorteil für Unternehmen. In der Holzindustrie wird dies u.a. mit Leichtbauplatten verfolgt.Der Einsatz leichter Holzwerkstoffplatten wird seit Jahren in der Holzindustrie diskutiert und ist heute technisch ausgereift. Erwartet werden unternehmensabhängig Kostenvorteile durch einen geringeren Holzeinsatz, aber auch Vorteile in der Logistik. Offen ist, welche ökologischen Konsequenzen, ggf. Vorteile mit dem Einsatz von Leichtbauplatten verbunden sind.Das Ziel des Beitrags ist die Identifikation und die Quantifizierung der ökologischen Wirkungen eines verstärkten Einsatzes von Leichtbauplatten in der Holzindustrie. Hierbei konzentriert sich der Beitrag auf die im Kioto-Protokoll reglementierten Treibhausgase, sowie NMVOCs und Formaldehyd.ResultsFür die Analyse wird mit Hilfe eines prozessbasierten Materialflussmodells, welches die Nutzung forstlicher Ressourcen in Deutschland abbildet, die Situation in 2005 als Referenz mit einem Szenario verglichen, in dem Spanplatten partiell durch Leichtbauplatten in Sandwichbauweise substituiert werden.Im Ergebnis sinken die Treibhausgasemissionen durchgängig, wenn die Minderungen auch gering ausfallen.ConclusionsDamit stellen leichte Holzwerkstoffplatten für die deutsche Holzindustrie eine Perspektive, ihre Luftemissionen zu senken. Die Ursachen für die Senkungen sind zu wesentlichen Teilen im Bereich der Klebstoffe und Bindemittel, der Logistik und der thermischen Nutzung von Produktionsresten zu finden.