Tài liệu Chromatography in the petroleum industry docx

[...]... freestanding account of a particular topic It was interesting to reread the comments of the editors of the only other book dedicated to the subject of petroleum analysis by chromatography published 15 years ago These editors spent some time describing the reasons for the choice of the title of their book In this context, it is interesting that the original title intended for their book was the one used... Although the spectacular development of gas chromatography in the 1950s and 1960s is now a fading memory of a golden era, there are still advances being made in apparatus, technique and applications The petroleum industry makes use of all the variants of chromatography as should be clear from the present volume, but gas chromatography in particular is the most important analytical technique in petroleum. .. been since its first announcement by James and Martin in 1952 Indeed it is no exaggeration to claim that many of the major advances in gas chromatography in that golden era emanated from the laboratories of the petroleum industry This book is intended primarily for those concerned with the analysis of crude oil and its products but many of the chapters have much broader applications It is hoped, therefore,... isomers as if their sum was represented by the n-alkane of that carbon number Since the n-alkane has the highest boiling point of the series, this approach will over-estimate the contributions to dewpoint temperature, and so has the advantage of a built -in safety margin A more accurate approach is to input data for groups of components as that of fractions rather than components, assuming that the program... combination of their decreasing concentrations and increasing peak widths makes their measurement more and more difficult (In this and subsequent figures, only the n-alkanes are identified, to avoid clutter) Backflushing to recombine all hydrocarbons above C, and pass the combined peak (C,+) to the detector has two advantages: the recombined peak will be larger than the individual ones, and the analysis... and they in turn retain CO, for so long as to make it unmeasurable The solution then is to cut the N, and CH,, with any 0, which may be present, onto a molecular sieve column, leaving the CO, and C, on the porous polymer Figure 1.1 1 shows the configuration, where the additional valve 3 includes or isolates the molecular sieve The procedure is similar to the previous one, starting with all columns in. .. Against this, we cannot make exact allowance for the contribution of all the individual components, but must make some assumptions about the bulk properties Figure 1.7 shows the valve system which allows rapid backflushing and measurement of C,i The original boiling point column is separated into a short (0.75 m) and a long (5.25 m) section The valve both alters the sequence of these sections, and The. .. ionization detector (FID) are the two most commonly used for hydrocarbon gases in the petroleum industry Because many of the gases contain non-hydrocarbon components, the TCD, as a universal detector, is essential Its dynamic range allows it to be used also for all the major and many of the minor components of most mixtures The FID, while the most commonly used detector in gas chromatography generally,... detectors The chromatogram in Fig 1.12 illustrates the use of two detectors, TCD and FID in series The presence of N,and CO, makes the use of the TCD necessary, and it is sufficiently sensitive for measurement of the lighter hydrocarbons To include pentanes, however, means choosing a larger sample size than would be desirable for linear measurement of the major components Using an FID in series with the. .. analysis is clearly targeted upon a few components, probably using a selective detector, and the composition of the main components is without interest, except insofar as they may interfere with the measurement Calculation of properties is the most common need for analysis, with calorific value the most usual target The following is a list of some of the properties of natural gas which are calculable from . 21 1,1000AE Amsterdam, The Netherlands Library of Congress Cataloging -in- Publication Data Chromatography in the petroleum industry / edited by. it is interesting that the original title intended for their book was the one used here. In concluding this foreword, I should like to thank all the