Entity

Time filter

Source Type

Warrington, United Kingdom

Broom D.P.,Hiden Isochema Ltd.
Green Energy and Technology | Year: 2011

In this concluding chapter we firstly discuss interlaboratory studies, which can be used to demonstrate the reproducibility of a measurement technique, or to compare the results of different techniques, and hence to assess the accuracy of the characterisation process. In particular, we discuss the results of a recent relevant interlaboratory study on hydrogen adsorption. We then discuss reference materials, which can be used to characterise and corroborate both sorption instrument performance and experimental methodology, before describing some provisional measurement guidelines, which provide both a guide to best practice in hydrogen sorption measurement and serve as a useful practical summary of the discussion of the experimental considerations in Chap. 6 10.1007/978-0-85729-221-6_6. We conclude by emphasising the importance of future research into hydrogen sorption measurement accuracy, in order to aid our understanding of the interaction of hydrogen with matter and to help reduce the variation in the reported hydrogen sorption properties of new materials, as the search for a solution to the hydrogen storage problem continues. © Springer-Verlag London Limited 2011. Source


Broom D.P.,Hiden Isochema Ltd.
Green Energy and Technology | Year: 2011

In this chapter we cover some of the common complementary techniques used for hydrogen storage material characterisation. We begin with thermal analysis and calorimetry, which can be used to determine the thermodynamic properties that can also be measured using hydrogen sorption techniques, as well as activation energies and characteristic temperatures of absorption and desorption. Gas adsorption methods, such as BET (Brunauer-Emmett-Teller) surface area measurement and DFT (Density Functional Theory) based pore size distribution determination, are commonly used to characterise the properties of porous hydrogen adsorbents and so these are then covered, with a focus on the data analysis methods used in each case. We then consider neutron and X-ray powder diffraction and small angle scattering, which can complement hydrogen sorption measurements for both hydrides and porous adsorbents. Different types of spectroscopy are then covered including Inelastic Neutron Scattering (INS), proton (1H) Nuclear Magnetic Resonance (NMR) and Variable Temperature Infrared (VTIR) spectroscopy. A number of other techniques that do not fit readily into the above categories are also briefly covered. © Springer-Verlag London Limited 2011. Source


Broom D.P.,Hiden Isochema Ltd.
Green Energy and Technology | Year: 2011

In this chapter, we discuss many of the practical issues that can affect the accuracy of gas phase hydrogen sorption measurement techniques. We begin with some relevant properties of gaseous hydrogen, such as the description of its compressibility as a function of temperature and pressure, the Joule-Thomson effect, thermal conductivity and the gas purity. We then cover some of the properties of materials that can affect hydrogen sorption measurement, including our knowledge of the sample volume, density and mass, the sensitivity of materials to air and moisture, the history and purity of samples, and gaseous impurity gettering. General instrumentation issues, such as the vacuum and pressure handling capability of apparatus, its thermal stability and homogeneity, and the accuracy of pressure and temperature measurement, are then discussed. Two aspects of experimental measurement methodology, namely sample degassing and activation, and equilibration times, are then covered. The last three sections of the chapter then discuss a series of issues that can affect the volumetric, gravimetric and thermal desorption methods, respectively. Source


Broom D.P.,Hiden Isochema Ltd.
Green Energy and Technology | Year: 2011

In this chapter we introduce the main gas sorption techniques applied to the characterisation of the hydrogen sorption properties of potential hydrogen storage materials. We begin with volumetric techniques, with a focus on the commonly used manometric (Sieverts') method, but also cover some of the alternative approaches, such as the flowing and differential volumetric methods. We then describe the gravimetric technique, including a discussion of vacuum microbalances and the requirements for high pressure hydrogen operation. Thermal desorption techniques are then covered, including Thermogravimetric Analysis (TGA) and Thermal Desorption Spectroscopy (TDS), in which the temperature-programmed desorption of hydrogen can be detected in a number of ways, including quadrupole mass spectrometry. The chapter concludes with a practical comparison of the different gas sorption measurement techniques. © Springer-Verlag London Limited 2011. Source


Broom D.P.,Hiden Isochema Ltd.
Green Energy and Technology | Year: 2011

This chapter presents an overview of the various materials that are currently being considered as potential solid state storage media. We concentrate on the physical and chemical properties of the materials relevant for the characterisation of their hydrogen storage properties and their practical use in storage devices, as opposed to the materials synthesis methods. The chapter looks first at microporous materials, including activated and nanostructured carbons, zeolites, organic microporous polymers and metal-organic frameworks. Secondly, we cover the alloys and intermetallic compounds that form interstitial hydrides at practical storage temperatures and hydrogen pressures. The complex hydrides, including alanates and lithium-based materials, such as LiNH2 and LiBH4, are then discussed before concluding with a look at some materials that do not fit readily into the above categories. © Springer-Verlag London Limited 2011. Source

Discover hidden collaborations