Measurement of the Thermodynamic Properties of Single Phases

Anthony Goodwin, KN Marsh, WA Wakeham

• Publisher: Elsevier Science
• Year: 2003
• ISBN:
  9780080531441
• Topic: Physical Sciences
• Subtopic: Physical & Theoretical Chemistry

This title is a revision of Experimental Thermodynamics Volume II, published in 1975, reflecting the significant technological developments and new methods introduced into the study of measurement of thermodynamic quantities.The editors of this volume were assigned the task of assembling an international team of distinguished experimentalists, to describe the current state of development of the techniques of measurement of the thermodynamic quantities of single phases. The resulting volume admirably fulfils this brief and contains a valuable summary of a large variety of experimental techniques applicable over a wide range of thermodynamic states with an emphasis on the precision and accuracy of the results obtained. Those interested in the art of measurements, and in particular engaged in the measurement of thermodynamic properties, will find this material invaluable for the guidance it provides towards the development of new and more accurate techniques.·Provides detailed descriptions of experimental chemical thermodynamic methods·Strong practical bias and includes both detailed working equations and figures for the experimental methods·Most comprehensive text in this field since the publication of Experimental Thermodynamics II

1

Introduction

A.R.H. Goodwin Schlumberger-Doll Research Ridgefield Connecticut, USA

W.A. Wakeham University of Southampton Southampton, UK

K.N. Marsh University of Canterbury, NZ

Commission 1.2 of the International Union of Pure and Applied Chemistry (IUPAC) has been responsible for numerous texts in fields encompassed by its title. The most recent, Chemical Thermodynamics [1], is one of eleven monographs in the IUPAC series Chemistry for the 21st Century [2] and demonstrates the importance of chemical thermodynamics in current areas of industrial significance and scientific research. Chemical Thermodynamics covered separation technology (including membrane techniques, solvent extraction and super-critical properties), colloids and microemulsions, electrolytes, adsorption, high temperature effects, nuclear applications, dielectrics, theoretical and quantum chemistry, polymer science, microgravity, new materials (including amorphous materials and glasses), enzyme catalyzed reactions, molecular and cell biology, medicine and pharmacy, food science, protein folding and design, as well as petroleum chemistry. Some experimental aspects were included in this volume.

The Commission has been responsible within IUPAC for a series of monographs summarizing the state of knowledge with regard to experimental techniques in thermodynamics and thermochemistry. Two monographs [3,4] reporting methods in thermochemistry formed the first series and were updated in a text concerned with combustion calorimetry [5]. The present volume is the sixth in a series of volumes [6–10] issued by IUPAC Commission 1.2 on Thermodynamics concerned with methods of measuring the thermophysical properties of substances. The first volume was concerned with calorimetry of non-reacting systems [6], while the fourth monograph the calorimetry of reacting fluids. Volume three [8] continued the theme of non-reacting systems with measurements of properties characteristic of the relaxation of a fluid from a non-equilbrium state: the transport properties. The fifth volume [10] presented the theoretical basis for equations of state of both fluids and fluid mixtures along with practical uses of each equation type. The second volume in the series, [7] focused on measurements of a broader class of thermodynamic properties and state variables over a wide range of temperature and pressure including techniques with industrial applications for chemically non-reacting systems including: pressure, p; temperature, T; (p, V, T), where V is volume; sound speed; refractive index; relative permittivity; vapor pressure; critical state; solubility; phase equilibria; molten salts; fluid metals; surface tension; adsorption; and equations of state. A very considerable effort was expended to collect a diligent set of authors who contributed to this seminal work. The entire book had a gestation period of about 10 years, drew upon 53 authors and comprised 1318 pages. It is perhaps not surprising that many of the techniques described therein remain valid today. However, there have been technical developments completely independent of thermodynamics that have profoundly affected some earlier measurement techniques and other approaches hitherto not possible have become feasible. The technical developments to which we refer include digital electronics, which has provided numerous signal analysis tools, along with materials, such as quartz and silicon. The measurement of frequency, which can now be determined with a relative precision of 10⁻¹¹, has transformed the determination of thermophysical properties. Indeed, researchers appear to prefer methods of determining thermodynamic properties that rely on the measurement of frequency. This philosophy is reflected in the content of this volume. At the same time, the industrial demand for thermodynamic properties of fluids and solids is insatiable, requiring more properties, often of higher precision, of an ever-expanding number of materials over a wide range of temperature and pressure. However, economic reality dictates that it is not practical for any single industrial organization to maintain the breath of expertise required to perform these measurements. At the same time, in the academic research environment, the measurement of thermophysical properties has become an expensive and relatively unpopular activity. Hence, the capability to perform these measurements throughout the world has decreased, in favour of simulation techniques. IUPAC Commission 1.2 therefore felt that it was essential in this environment to establish a source book of the current state-of-the-art for both present and future generations of experimentalists.

A survey sponsored by IUPAC Commission 1.2 of 70 individuals active in experimental thermodynamics within academia, industry, and government confirmed this preliminary view. Having had a firm endorsement of the idea from practitioners in the field the Commission formally initiated IUPAC project 120/16/97 in 1997. The intention was to continue the theme of non-reacting systems and to provide an up-to-date presentation of thermodynamic measurement techniques with a strong practical bias and full working equations. The success of Volume II [7] implied that a new book should also be comprehensive, covering the thermodynamic properties of solids, liquids, and gases as well as the equilibrium between them. On the other hand, many techniques described in the first book remain valid and have undergone only minor development rather than major change and in some cases have been reported in other monographs [11,12]. The Commission therefore sought to develop a text complementary to, rather than as a replacement for reference [7], concentrating on new developments and significant enhancements of earlier techniques. Even so the material that falls into these categories are more than can be accommodated in one modern monograph. Thus, the Commission determined that the total volume of material should be divided into two parts. Of course, the separation could have been performed in many ways but, after much deliberation, the Commission decided to divide the material into two volumes, one describing the properties of single phases and the other multiple phases. This volume, Volume VI, covers experimental methods primarily for single phases while Volume VII, Measurement of the Thermodynamic Properties of Multiple Phases, edited by R.D. Weir and T.W. de Loos [13], is concerned with systems containing more than one phase. The principal purpose of both volumes is to serve as a guide to the scientist or technician who are contemplating measurements of the thermodynamic properties of fluids. Emphasis is placed on those methods for which good, theoretically-based, working equations are available or with the potential for industrial application. Additionally, the volumes will also be of interest to the data evaluator who needs to make an assessment of the reliability of experimental data obtained with specific techniques. General experimental methods, not described in either of the current volumes, can be found in reference [14].

The editors of the present volume were therefore assigned the task of assembling an international team of distinguished experimentalists to describe recent developments in the techniques for measurement of thermodynamic quantities for single phases consisting of both pure fluids and compositionally complex mixtures over a wide range of conditions. Many of the authors were found among the members of Commission 1.2, but considerable effort was expended to locate appropriate expertise elsewhere. This volume fulfills the brief given to the editors by the Commission and contains a summary of a large variety of experimental techniques applicable over a wide range of thermodynamic states. The precision and accuracy of the results obtained from each method, which is so much part of the remit of the Commission on Thermodynamics itself, was regarded as an essential element of the descriptions. Throughout the text we have adopted the quantities, units and symbols of physical chemistry defined by IUPAC in the text commonly known as the Green Book [15]. We have also adopted the ISO guidelines for the expression of uncertainty [16] and vocabulary in metrology [17]. Values of the fundamental constants and atomic masses of the elements have been obtained from references [18] and [19] respectively. In the remainder of the introduction an overview of the chapters is presented.

Although pressure and temperature measurements have been covered elsewhere they are fundamental to thermodynamic measurements. Since the publication of reference [7] the temperature scale has been updated from the International Practical Temperature Scale of 1968 (IPTS-68) to the International Temperature Scale of 1990 (ITS-90). Pressure measurement methods have enjoyed considerable enhancement from those reported in reference [7]. The new techniques, which often rely on devices constructed with silicon technology and the measurement of frequency, provide the capability to determine pressure in extreme conditions with harsh fluids.

From a measurement perspective, pure fluids are far easier to handle than are multicomponent mixtures. Although measurements on pure fluids, particularly argon, are essential for validating new techniques and working equations, they have received rhetorical comments from theorists and industrialists – why are you still measuring the properties of argon? [20]. We have therefore included a chapter which covers the important area of mixture preparation and the acquisition of samples of natural fluids that are representative of the those found in sub-surface strata under extreme conditions.

The methods for the determination of volume discussed in reference [7] have changed little so that we concentrate on density metrology in Chapter 5. The notable exception to this statement is the measurement of volume of a single silicon sphere, which is both new and essential to density measurement. In this chapter a section is devoted to absolute density standards, which have achieved unforeseen precision.

Measurements of the density, described in Chapter 5, of gases, liquids, and solids were not covered in the first volume. Some entirely new techniques and the use of modern electronics (in some established approaches) have brought entirely new perspective to old measurement techniques.

Acoustic measurements can be used to probe the thermophysical properties of systems to obtain both the speed and attenuation of sound. This is an example of a technique that was possible but not routinely performed at the time of writing of reference [7]. Acoustic measurements, which rely on the determination of frequency, can now be performed with extremely high precision. Sound speed measurements can be used to determine both equation o...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright page
• Dedication
• List of Contributors
• Foreword
• Acknowledgments
• 1: Introduction
• 2: Temperature
• 3: Pressure
• 4: Mixture Preparation and Sampling Hydrocarbon Reservoir Fluids
• 5: Density
• 6: Speed of Sound
• 7: Calorimetry
• 8: Properties of Mixing
• 9: Relative Permittivity and Refractive Index
• 10: Extreme Conditions
• Index