Bengt Steen

Non-aqueous electrolytes for sodium-ion batteries

The first review of the various electrolytes currently used and developed for sodium-ion batteries (SIBs), both in terms of materials and concepts, is presented. In contrast to the Li-ion battery (LIB), which is a mature technology for which a more or less unanimously accepted “standard electrolyte” exists: 1 M LiPF6 in EC/DMC, the electrolyte of choice for SIBs has not yet fully conformed to a standard. This is true for both materials: salts, solvents, or additives, and concept, using the main track of organic solvents or aiming for other concepts. SIB research currently prospers, benefitting from using know-how gained from 30 years of LIB R&D. Here the currently employed electrolytes are emphasized and their effects on practical SIB performance are outlined, scrutinizing the rationale for specific choices made, salts, solvents, additives, concentrations, etc. for each specific cell set-up and usage conditions.

On uncertainty and sensitivity of LCA-based priority setting

Abstract Life-cycle assessments are normally made without quantitative estimations of their uncertainty. More interest has been focused on sensitivity analysis. In ISO 14040, LCA standard and SETACs ‘code of practice’ sensitivity and uncertainty analysis are recommended or even requested. In the EPS system, an analysis of significance and sensitivity has been carried out for several years. The article describes this procedure in ISO terms and generalises it for other types of life-cycle assessments.

Experiences of environmental performance evaluation in the cement industry. Data quality of environmental performance indicators as a limiting factor for Benchmarking and Rating

Abstract Although ISO 14031 gives guidelines for environmental performance evaluation, there is limited experience of applying the standard in the area of benchmarking and external rating, especially when limitations of data quality are considered. This paper evaluates the importance of the data quality of operational performance indicators (OPIs, in this case emission factors) as a limiting factor for benchmarking and external rating between six cement plants in Sweden, Norway and Finland for three types of emissions, dust, NO x and SO 2 . Monthly emission factors for 1993–1999 were collected for these plants and a quality assurance process was undertaken to eliminate factors that decreased comparability. The data were tested against six hypotheses concerning different aspects of the variation of the emission factors. One of the findings was that there is no sharp limit when the quality of emission factors is high enough to make it possible to compare, since quality is a qualitative conception in itself. Instead, organisations using emission factors should strive to adapt a system with quality assurance of emission factors, resulting in widely accpeted emission factors suitable for comparison between plants. This is achieved with a sector specific methodology which can handle irrelevant differences and reflects real differences in environmental performance.

Environmental costs and benefits in life cycle costing

Purpose – From a methodological point of view, life cycle costing (LCC) is well developed with respect to conventional costs. However, when it comes to costs related to environmental issues, neither the items nor their estimation have been well developed. This paper aims at investigating the possibilities of using life cycle assessment (LCA) results to identify and estimate environmental costs or benefits in an LCC.Design/methodology/approach – The paper begins by looking at the driving forces for introducing environmental costs in companies, continues by identifying external and internal environmental cost issues, and concludes with an attempt to estimate the internal costs.Findings – Some of the items of an LCC have to do with increased/decreased sales, others with good will. Both are difficult to estimate, but LCA or LCA‐like investigations may be helpful in identifying relevant issues. Future costs to the product system may also be estimated, for example, with a distance‐to‐target type of weighting. L...

Reducing epistemological uncertainty in life cycle inventory

Abstract Life Cycle Assessment is very dependent on data of good quality. LCA data should ideally be accessible, relevant and reliable. Common sources of data for LCA-practitioners are databases of different kinds. The use of the information in databases for LCI introduces an epistemological uncertainty—since the system where the data is to be used (the unit process in question for the LCA) may differ from the system where the data was generated (the unit process in the database). Information about data, metadata, is often used to provide knowledge about the applicability and relevance of data, but the practitioner has limited possibilities to evaluate any differences between the required data and the available data. An analysis is made in this article where the problem is treated from two sides, the compiler of information (the database compiler) and the receiver of information (LCA-practitioner). To structure the relevance aspect of LCI-data, a methodology is suggested where the most frequent LCI-emissions are considered to have three different phases; primary emission mechanism, conversion in process, and end-of-pipe measures. An analysis is made for each of these stages with its governing parameters, which regulates the amount of the emission. A table is presented with all the common LCI emissions with their governing parameters. The methodology enables the practitioner to evaluate differences between unit processes and also gives information about the spread in emission factors between different variants of a unit process. The methodology is then applied to cement production, showing how the knowledge of governing parameters should be handled. A set of questions is compiled which elucidates the epistemological uncertainty for cement production.

An estimation of the cost of sustainable production of metal concentrates from the earth's crust

Abstract An attempt has been made to estimate the value of present ores to future generations. The direct costs for the producer and the external environmental costs for the society of a sustainable production of ore-like metal concentrates are investigated. In a technical scenario, granite, granodiorite and basalt rock are mined, crushed and ground to give fine powders. The powders are acid leached and the extracted metals precipitated using hydrogen sulphide and sodium hydroxide to form the ore-like concentrates. All chemicals are produced in a sustainable way. Leaching efficiencies and use of energy-ware (ISO standard term for oil, coal, electricity, etc.) and chemicals are important factors in the cost estimation, as well as the number of metals mined at the same time. It is assumed that 10 different metal concentrates are produced at the same time. The technical scenario uses state-of-the-art technology. No new technical achievements are assumed. The estimated costs exceed current prices by orders of magnitude. In cost estimation for individual metals, the main uncertainty lies in the allocation of costs amongst the metals produced at the same time.

Lci data modelling and a database design

A large scale operative data format for transparent storage, administration and retrieval of environmental Life Cycle Inventory (LCI) data has been implemented by applying data modelling and database design.Key concepts in the design are ‘activity’ and flow’: An activity is a technical system, such as a process or a transport, or an aggregate of different processes or transports. A flow is any matter entering or leaving an activity, such as natural resources, energywarc, raw material, emission, waste or products.Any numerical data set on an activity can he thoroughly described by supplying meta data. Meta data fields are prepared for a wide set of commonly known LCA-data aspects, such as descriptions of data acquisition methods, system boundary conditions and relevant dates.

An Approach for Handling Geographical Information in Life Cycle Assessment Using a Relational Database

A new data model has been developed to handle information relevant to site-specific life cycle assessments (LCA). The model is orientated towards GIS-representations of three generalised subsystems; the technical, the environmental and the social subsystems. The technical and environmental systems are mainly linked through flows of energy and matter, which are the causes of environmental impacts, which subsequently is perceived, evaluated and acted upon by the social subsystem. For all three systems important differences, attributable to geographical locations can be determined. With the new data model a possibility to enhance LCA and reach more relevant results emerge due to a higher site specificity. The high level data model is expressed as relations between different entities using the entity relationship (ER) modelling language. An existing LCA-database, SPINE, which is already used by several companies for decision support in product development, can be utilised since the structure of the database supports geographical information. So far, applications with GIS-data are limited, but examples of area specific LCA impact characterisation factors exist.

A selection of safeguard subjects and state indicators for sustainability assessments

PurposeThe purpose of this work is to identify and select safeguard subjects and state indicators that are suitable for sustainability assessment in product and production development, using an interpretation of the Brundtland definition of sustainable development. The purpose is also to investigate how indicators selected in this way differ from other selections in the literature.MethodsWe use a top-down approach, which starts with reviewing the Brundtland definition of sustainability and identifying the corresponding human basic needs to be satisfied. For each basic need, we identify relevant satisfiers, and for each satisfier, a number of safeguard subjects. The safeguard subjects represent critical resources for making satisfiers available. For each safeguard subject, a number of state indicators (=endpoint category indicators) are selected that are relevant for describing impacts from product life cycles on the safeguard subject.Results and discussionEcosystem services, access to water, and abiotic resources are identified as environmental safeguard subjects. Technology for transports, environment, textiles, housing, food, information, and energy, together with income, are identified as economical safeguard subjects. Human health, land availability, peace, social security, continuity, knowledge, jobs/occupation, and culture are identified as social safeguard subjects. In comparison with the other selections of safeguard subjects in literature, our safeguard subjects are structured differently and delimited in scope, but there are also many similarities. The best agreement is on environmental issues, but we classify human health as a social issue. For social issues, we identify fewer safeguard subjects and state indicators than recommendations from UNEP/SETAC. For economic issues, we diverse from current LCC and approach UNECE measures of sustainability.ConclusionsIdentification and selection of safeguard subjects and state indicators benefit from a clear definition of sustainability, needs to be satisfied, and satisfiers. The interpretation of the sustainability concept has a large influence on which safeguard subjects that are included and which indicators that are needed to describe their state. Capacity building is an important sustainability indicator, which should be developed further for use in life cycle sustainability assessment. The top-down approach offers a good arena for a further research and discussions on how to structure and focus LCSA. Our results shall be seen as one example of which safeguard subject that may be identified with the top-down approach presented here.

Carbon Dioxide Capture from Ambient Air Using Amine-Grafted Mesoporous Adsorbents

Anthropogenic emissions of carbon dioxide (CO2) have been identified as a major contributor to climate change. An attractive approach to tackle the increasing levels of CO2 in the atmosphere is direct extraction via absorption of CO2 from ambient air, to be subsequently desorbed and processed under controlled conditions. The feasibility of this approach depends on the sorbent material that should combine a long lifetime with nontoxicity, high selectivity for CO2, and favorable thermodynamic cycling properties. Adsorbents based on pore-expanded mesoporous silica grafted with amines have previously been found to combine high CO2 adsorption capacity at low partial pressures with operational stability under highly defined laboratory conditions. Here we examine the real potential and functionality of these materials by using more realistic conditions using both pure CO2, synthetic air, and, most importantly, ambient air. Through a combination of thermogravimetric analysis and Fourier transform infrared (TGA-FTIR) spectroscopy we address the primary functionality and by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy the observed degradation of the material on a molecular level.