Preface

The need for, and the acceptance of, the use of the viscous feedstocks as refinery feedstocks oil has increased substantially during the second half of the 20th century. Thus, attempts to understand and manipulate refinery processes have persisted over centuries, with an explosion of technological innovation and research occurring in the last 100?years. The majority of these efforts have focused on using the knowledge gained to produce a useful product and achieve a perceived improvement in the performance of that product.

The laws of science will ultimately dictate what can or cannot be done with feedstocks to provide the needed products. The science of analytical chemistry is at the core of understanding of both the problems of processing various feedstocks. This book will examine through a presentation discussion of the way that the analytical science has been applied to defining the properties and behavior of the different feedstocks that are used in the heavy crude oil, extra heavy crude oil, and tar sand bitumen (known collectively in this text as viscous feedstocks) refining industry.

In the 20th century and at the beginnings of the 21th century, scientists and engineers have become increasingly well-versed in utilizing chemical knowledge to better understand the nature of the feedstocks that arbitrarily fall under the term "heavy oil" but are more correctly known as viscous feedstocks (which include heavy crude oil, extra heavy crude oil, and tar sand bitumen) and the influence of each feedstock on refining scenarios and on product slate. Definitions of processing do's and don'ts abound in the scientific and engineering literature but the essence of these rules depends on analytical chemical measurements.

Heavy crude oil, extra heavy crude oil, and tar sand bitumen exhibit a wide range of physical properties and a wide range of tests have been (and continue to be) developed to provide an indication of the means by which a particular feedstock should be processed. Initial inspection of the nature of the viscous feedstocks will provide deductions about the most logical means of refining or correlation of various properties to structural types present and hence attempted classification of the viscous feedstocks. Proper interpretation of the data resulting from the inspection of crude oil requires an understanding of their significance.

Evaluation of heavy crude oil, extra heavy crude oil, and tar sand bitumen for use as refinery feedstocks usually involves an examination of one or more of the physical properties of the material. By this means, a set of basic characteristics can be obtained that can be correlated with utility. Consequently, various standards organizations, such as the American Society for Testing and Materials in North America have devoted considerable time and effort to the correlation and standardization of methods for the inspection and evaluation of the products from the viscous feedstocks.

The acceptance of the viscous feedstocks by refineries has meant that the analytical techniques used for the lighter feedstocks have had to evolve to produce meaningful data that can be employed to assist in defining refinery scenarios for processing the feedstocks. In addition, selection of the most appropriate analytical procedures will aid in the predictability of feedstock behavior during refining. This same rationale can also be applied to feedstocks behavior during recovery operations.

Because of the wide range of chemical and physical properties, a wide range of tests have been (and continue to be) developed to provide an indication of the means by which a particular feedstock should be processed. Initial inspection of the nature of the heavy crude oil, extra heavy crude oil, and tar sand bitumen will provide deductions about the most logical means of refining or correlation of various properties to structural types present and hence attempted classification of the viscous feedstocks. Proper interpretation of the data resulting from the inspection of crude oil requires careful consideration and an understanding of the significance of the data.

It is for these reasons that understanding the composition of the viscous feedstocks, as well as the chemical and physical properties of these feedstocks, is extremely important. Thus, an efficient evaluation of a feedstock requires the application of tests than specifications. These are then used to provide adequate control of product quality without being over restrictive with the minimum of testing effort.

Product quality is judged by the performance during service. The performance of any product in particular service applications is therefore the ultimate criterion of quality. It is therefore necessary to find properties that allow assessment of the service performance, especially those tests that correlate closely with the service conditions. Sometimes the inspection tests attempt to measure these properties, for example, the research octane number test that was devised to measure the antiknock performance of motor fuel or, in many cases, the significant property is obtained indirectly from the inspection test results.

However, where the specified property is not measured directly, it is important to ensure that a suitable combination of inspection tests is selected to give a high degree of correlation with the specified property.

Although the focus on this book is on the relevant ASTM test methods with the numbers given, where possible the corresponding IP test method number is also presented. As an aside, the ASTM or the IP may have withdrawn some of the tests noted herein. Nevertheless, the method is still included because of its continued use, for whatever reason, by analysts and also for historical (not hysterical) reference purposes!

Thus, this book will deal with the various aspects of the analysis (and properties) of the viscous feedstocks and will provide a detailed explanation of the necessary standard tests and procedures that are applicable to feedstocks in order to help define predictability of behavior. In addition, the application of test methods for determining instability and incompatibility as well as test methods related to environmental regulations will be described.

More important, the book will provide details of the meaning of the various test results and how they might be applied to predict feedstock behavior. In fact, analytical techniques for chemical analysis of crude oil and the viscous feedstocks as well as the transformation products formed by photochemical processes and biological processes is a necessary next step after a spill. In addition to the standard test method present elsewhere in this text, the spilled material can be investigated by advanced gas chromatography (GC) techniques such as comprehensive two-dimensional GC (GC-GC), pyrolysis GC with mass spectrometry (MS), and GC with tandem mass spectrometry (GC-MS/MS) which will provide a greater understanding at the molecular level of composition and complexity of the spilled material and any chemical changes that occur to the spilled material.

Analytical chemists represent a rich resource for the various aspects of feedstock refining and recognize that while the recent decades of experience have enhanced analytical knowledge, they have also revealed large gaps in the kind of data needed to thoroughly understand the nature of heavy crude oil, extra heavy crude oil, and tar sand bitumen as feedstocks for refineries.

The significance of a particular test is not always apparent by reading the procedure, and sometimes can only be gained through a working (i.e., a hands-on) familiarity with the test. The following tests are commonly used to characterize asphalts but these are not the only tests used for determining the property and behavior of an asphaltic binder. As in the petroleum industry, a variety of tests are employed having evolved through local, or company, use.

The development of laboratory instrumentation over the last 50?years has been one of the forces shaping analytical standards and improved instrumentation is already changing approaches to the analysis of viscous feedstocks. Like the twin strands of the famous DNA double helix, technology and analytical science and regulation will continue their closely linked relationship.

The prime focus of the book is the emphasis of the analytical methods applied to heavy crude oil, extra heavy crude oil, and tar sand bitumen with lesser emphasis on product analysis. Although product analysis is an extremely important aspect of the science and technology of the viscous feedstocks, it is felt that the move to these feedstocks for refinery operations requires that more emphasis be placed on the analysis and properties of refinery feedstocks.

Furthermore, while the focus of this chapter is on the sampling and preparation of the viscous feedstocks for refining, it is worthwhile (because of the similarity of the methods) to consider the application of the sampling and measurement methods to situations where the feedstock has been spilled into the environment. In fact, the spills of crude oil and viscous feedstocks can occur anywhere that the material is being stored, transported, transferred from one tank to another, or refined. Thus, methods that are applicable to both refining and environmental issues are cited in this chapter. This will save unnecessary repetition of the methods at other parts of the book.

This book will assist the reader to gain an understanding of the criteria for determining the quality and processability of heavy crude oil, extra heavy crude oil, and tar sand bitumen and the...