Development of Innovating Materials for Distributing Mixtures of Hydrogen and Natural Gas. Study of the Barrier Properties and Durability of Polymer Pipes

International audienceWith the growing place taken by hydrogen, a question still remains about its delivery and transport from the production site to the end user by employing the existing extensive natural gas pipelines. Indeed, the key challenge is the significant H 2 permeation through polymer infrastructures (PolyEthylene (PE) pipes, components such as connecting parts). This high flow rate of H 2 through PE has to be taken into account for safety and economic requirements. A 3-year project was launched, the aim of which was to develop and assess material solutions to cope with present problems for hydrogen gas distribution and to sustain higher pressure compared to classical high density polyethylene pipe. This project investigated pure hydrogen gas and mixtures with natural gas (20% of CH 4 and 80% of H 2) in pipelines with the aim to select engineering polymers which are more innovative than polyethylene and show outstanding properties, in terms of perme-ation, basic mechanical tests but also more specific characterizations such as long term ageing and behaviour. The adequate benches, equipments and scientific approach for materials testing had been developed and validated. In this context, the paper will focus on the evaluation of the barrier properties of 3 polymers (PE, PA11 and PAHM). Experiments were performed for pure H 2 and CH 4 and also in the presence of mixtures of hydrogen and natural gas in order to study the possible mixing effects of gases. It will report some round-robin tests that have been carried out. Secondly, by comparing data obtained on film, polymer membrane and on pipe section, the influence of the polymer processing will be studied. Innovative multilayers systems will be proposed and compared on the basis of the results obtained on monolayer systems. Finally, the evolution of the transport properties of the studied polymers with an ageing under representative service conditions will be discussed

Social impacts and life cycle assessment: proposals for methodological development for SMEs in the European food and drink sector

Purpose: Small and medium enterprises (SMEs) account for 99 % of companies operating in the European food and drink industry and, often, are part of highly fragmented and complex food chains. The article focuses on the development of a social impact assessment methodology for SMEs in selected food and drink products as part of the EU-FP7 SENSE research project. The proposed methodology employs a top-down and bottom-up approach and focuses on labour rights/working conditions along the product supply chain as the key social impact indicator, limiting key stakeholder classification to workers/employees and local communities impacted by the production process. Problems related to this emerging field are discussed, and questions for further research are expounded. Methods: The article reviews both academic and 'grey' literature on life cycle assessment (LCA) and its relationship to social LCA (S-LCA) and SMEs at the beginning of 2013 and includes case study evidence from the food sector. A pilot questionnaire survey sent to European food and drink sector SMEs and trade associations (as partners in the research project) about their knowledge, experience and engagement with social impacts is presented. Proposals are elaborated for a social impact assessment methodology that identifies the key data for SMEs to collect. Results and discussion: The literature reveals the complexity of the S-LCA approach as it aims to unite disparate and often conflicting interests. Findings from the pilot questionnaire are discussed. Using a top-down and bottom-up approach, the proposed methodology assesses data from SMEs along the supply chain in order to gauge social improvements in the management of labour-related issues for different product sectors. Issues relating to the 'attributional' choice of a social impact indicator and key stakeholder categories are discussed. How 'scoring' is interpreted and reported and what the intended effect of its use will be are also elaborated upon. Conclusions: Whilst recognising the difficulty of devising a robust social impact assessment for SMEs in the food and drink sector, it is argued that the proposed methodology makes a useful contribution in this fast-emerging field

Life cycle assessment (LCA) of sustainable building materials: An overview

The construction industry is one of the largest exploiters of both renewable and non-renewable natural resources. It was inevitable that it would find itself at the centre of concerns regarding environmental impact. The process and operation of building construction consumes a great deal of materials throughout its service life cycle. The selection and use of sustainable building materials play an important role in the design and construction of green building. This chapter sets out to present an overview of sustainable building materials and their impacts on the environment. It also discusses the life cycle assessment as a methodological principle and framework, and its limitations for the analysis of sustainable building materials. © 2014 Woodhead Publishing Limited All rights reserved

Introduction to polymer spectroscopy

VII+190hlm.;24c

Nanotechnology and Life Cycle Assessment: A Systems Approach

[Life Cycle Assessment (LCA)] can be used to evaluate how a product or material—from the start of production through end-of-life—affects ecosystems and human health. LCA is already widely used internationally by scientists, engineers, and product designers in universities and businesses. If applied in the nanotechnology realm, the tool has the potential to guide researchers, policymakers, and companies as they seek to realize the commercial and practical benefits of a nanoproduct, while avoiding potential risks.

Introduction to polymer spectroscopy

xii, 190 p.; 25 cm

FLUORESCENCE AND LIFETIME STUDIES OF EXCIMERS IN POLYVINYL CARBAZOLE.

Author Institution: Battelle-Institut, Frankfurt a.The fluorescence spectrum of solid-state polyvinyl carbazole (PVCA) is of the excimer type whereas in solution both mirror-image and excimer-fluorescence spectra can be observed. The excimer-fluorescence decay time after flash excitation was found to be approximately $4\times 10^{-8}$ sec. Small amounts of perylene, hexachloro-p-xylene, and trinitro fluorenone in PVCA reduce the quantum efficiency (y) of the PVCA fluorescence but leave the decay time unaffected. The quenching factor $Q = yo/y(c)-1$ depends linearly on the guest concentration (c). The results are interpreted in terms of energy transfer by monomer-exciton diffusion involving two competitive traps: excimer forming sites and guest molecules