Handbook of Industrial Hydrocarbon Processes

By James G. Speight

Handbook of Industrial Hydrocarbon Processes, Second Edition, provides an analysis of the process steps required to produce hydrocarbons from various raw materials and how the choice of a process depends not only on technology, but also on external effects, such as social and economic developments, political factors affecting the availability of raw materials, and environmental legislation. This book qualitatively examines chemical processes and plant design by showing the factors determining process structures, including the underlying chemistry, feedstock, product specifications and reactor design. The book also compares the processes for different products based on raw materials and manufacturing processes based on their respective applications.

With the addition of useful flowcharts that present an overview of the chemical processes, process design and equipment, this book is a valuable resource to industry professionals on how to understand how hydrocarbons are produced from different raw materials and how to develop an instinct for the right process development strategy.

• Provides a qualitative analysis of chemical processes and plant design by showing the factors determining process structures
• Presents chemical processes in an organized, easy-to-read and understandable manner with the use of useful flowcharts and concise descriptions
• Includes updates on changes in existing technological and chemical processes, as well as possible future improvements or changes to other more economic or more readily available feedstocks

• Language: English
• Publisher: Elsevier Science
• Release date: Nov 21, 2019
• ISBN: 9780128099247

James G. Speight

Dr. Speight is currently editor of the journal Petroleum Science and Technology (formerly Fuel Science and Technology International) and editor of the journal Energy Sources. He is recognized as a world leader in the areas of fuels characterization and development. Dr. Speight is also Adjunct Professor of Chemical and Fuels Engineering at the University of Utah. James Speight is also a Consultant, Author and Lecturer on energy and environmental issues. He has a B.Sc. degree in Chemistry and a Ph.D. in Organic Chemistry, both from University of Manchester. James has worked for various corporations and research facilities including Exxon, Alberta Research Council and the University of Manchester. With more than 45 years of experience, he has authored more than 400 publications--including over 50 books--reports and presentations, taught more than 70 courses, and is the Editor on many journals including the Founding Editor of Petroleum Science and Technology.

Book preview

Handbook of Industrial Hydrocarbon Processes

Second Edition

James G. Speight, PhD, DSc, PhD

CD & W Inc. Laramie, WY, United States

Table of Contents

Cover image

Title page

Copyright

About the Author

Preface

Chapter 1. Chemistry and chemical technology

1. Introduction

2. Organic chemistry

3. Chemical engineering

4. Chemical technology

5. Hydrocarbons

6. Isomers

7. Nonhydrocarbons

8. Properties of hydrocarbons

Chapter 2. Sources of hydrocarbons

1. Introduction

2. Natural sources

3. Unconventional sources

Chapter 3. Hydrocarbons from crude oil

1. Introduction

2. Gaseous products

3. Naphtha

4. Gasoline

5. Kerosene and related fuels

6. Diesel fuel

7. Gas oil and fuel oil

8. Lubricating oil

9. Wax

Chapter 4. Hydrocarbons from natural gas and natural gas hydrates

1. Introduction

2. Gas processing

3. Natural gas hydrates

4. Hydrocarbon products

Chapter 5. Hydrocarbons from coal

1. Introduction

2. Occurrence and reserves

3. Formation and types

4. Mining and preparation

5. Properties

6. Hydrocarbon products

Chapter 6. Hydrocarbons from oil shale

1. Introduction

2. History

3. Origin

4. Occurrence

5. Oil shale types

6. Composition and properties

7. Kerogen

8. Hydrocarbon products

Chapter 7. Hydrocarbons from biomass

1. Introduction

2. Biomass feedstocks

3. Hydrocarbons from biomass

4. Production of Hydrocarbons by conversion

Chapter 8. Hydrocarbons from synthesis gas

1. Introduction

2. Coal gasification

3. Gasification of crude oil fractions

4. Gasification of other feedstocks

5. Fischer-Tropsch process

Chapter 9. Chemical and physical properties of hydrocarbons

1. Introduction

2. Stereochemistry

3. Molecular weight

4. Chemical properties

5. Physical properties

Chapter 10. Combustion of hydrocarbons

1. Introduction

2. Combustion chemistry

3. Process parameters

4. Combustion of hydrocarbons

Chapter 11. Reactions of hydrocarbons

1. Introduction

2. Thermal reactions

3. Catalytic decomposition

4. Hydrogenation

5. Dehydrogenation

6. Dehydrocyclization

7. Chemical reactions

Chapter 12. Petrochemicals

1. Introduction

2. Chemicals from paraffin hydrocarbons

3. Chemicals from olefin hydrocarbons

4. Chemicals from aromatic hydrocarbons

5. Chemicals from acetylene

6. Chemicals from natural gas

7. Chemicals from synthesis gas

Chapter 13. Pharmaceuticals

1. Introduction

2. History

3. Hydrocarbon pharmaceuticals

4. Pharmaceuticals based on hydrocarbons

Chapter 14. Monomers, polymers, and plastics

1. Introduction

2. Polymerization

3. Polymers

4. Plastics

5. Synthetic rubber

6. Thermosetting plastics

7. Synthetic fibers

Chapter 15. Hydrocarbons in the environment

1. Introduction

2. Release into the environment

3. Biodegradation

4. Analysis of hydrocarbons in the environment

5. Toxicity hazards

6. Remediation of hydrocarbon spills

Conversion Factors

Glossary

Index

Copyright

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Notices

Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.

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About the Author

Dr James G. Speight has doctorate degrees in chemistry, geological sciences, and petroleum engineering and is the author of more than 80 books in petroleum science, petroleum engineering, environmental sciences, and ethics.

He has more than 50 years of experience in areas associated with (1) the properties, recovery, and refining of reservoir fluids, conventional petroleum, heavy oil, and tar and bitumen; (2) the properties and refining of natural gas, gaseous fuels, (3) the production and properties of petrochemicals; (4) the properties and refining of biomass, biofuels, biogas, and the generation of bioenergy; and (5) the environmental and toxicological effects of fuels. His work has also focused on safety issues, environmental effects, remediation, and reactors associated with the production and use of fuels and biofuels.

Although he has always worked in private industry with emphasis on contract-based work, Dr Speight was a visiting professor in the College of Science, University of Mosul, Iraq, and has also been a visiting professor in chemical engineering at the following universities: University of Missouri-Columbia, the Technical University of Denmark, and the University of Trinidad and Tobago.

In 1996, Dr Speight was elected to the Russian Academy of Sciences and awarded the Gold Medal of Honor that same year for outstanding contributions to the field of petroleum sciences. In 2001, he received the Scientists Without Borders Medal of Honor of the Russian Academy of Sciences and was also awarded the Einstein Medal for outstanding contributions and service in the field of Geological Sciences. In 2005, Dr Speight was awarded the Gold Medal—Scientists Without Frontiers, Russian Academy of Sciences, in recognition of Continuous Encouragement of Scientists to Work Together Across International Borders. In 2007, Dr. Speight received the Methanex Distinguished Professor award at the University of Trinidad and Tobago in recognition of excellence in research. In 2018, he received the American Excellence Award for Excellence in Client Solutions from the United States Institute of Trade and Commerce, Washington, DC.

Preface

The success of the First Edition of this text has been the primary factor in the decision to publish an updated Second Edition.

The hydrocarbon industry had its modern origins in the later years of the 19th century. By the time that the 19th century had dawned, it was known that kerosene, a fuel for heating and cooking, was the primary product of the crude oil industry in the 1800s. Rockefeller and other refinery owners considered gasoline a useless by-product of the distillation process. But all of that changed around 1900 when electric lights began to replace kerosene lamps and automobiles came on the scene. New hydrocarbon fuels were also needed to power the ships and airplanes used in World War I. After the war, an increasing number of farmers began to operate tractors and other equipment powered by oil. The growing demand for petrochemicals and the availability of crude oil and natural gas caused the industry to quickly expand in the 1920s and 1930s. During World War II, vast amounts of crude oil were produced and converted into hydrocarbon fuels and lubricants.

The term hydrocarbons (compounds which contain carbon and hydrogen only) represents a large group of chemicals manufactured from crude oil and natural gas as distinct from fuels and other products that are also derived from crude oil and natural gas by a variety of processes and used for a variety of commercial purposes. Hydrocarbons lead to products which include such items as plastics, soaps and detergents, solvents, drugs, fertilizers, pesticides, explosives, synthetic fibers and rubbers, paints, epoxy resins, and flooring and insulating materials. Hydrocarbons are also used to produce chemicals as diverse as aspirin, luggage, boats, automobiles, aircraft, polyester clothes, and recording discs and tapes. It is the changes in product demand that have been largely responsible for the evolution of the hydrocarbon industry from the demand for the hydrocarbonaceous asphalt mastic used in ancient times to the current high demand for gasoline and other hydrocarbon fuels as well as increasing demand for a wide variety of petrochemical products.

As a result, the hydrocarbon industry is a huge field that encompasses many commercial chemicals and polymers. The organic chemicals produced in large volumes are methanol, ethylene, propylene, butadiene, benzene, toluene, and the xylene isomers. Ethylene, propylene, and butadiene, along with butylenes, are collectively called olefins, which belong to a class of unsaturated aliphatic hydrocarbons, having the general formula CnH2n. Olefins contain one or more double bonds, which make them chemically reactive. Benzene, toluene, and the xylene isomers, commonly referred to as aromatics (BTX), are unsaturated cyclic hydrocarbons containing one or more rings. Olefins, aromatics, and methanol are precursors to a variety of chemical products and are generally referred to as primary petrochemicals. Furthermore, because ethylene and propylene are the major building blocks for petrochemicals, alternative ways for their production have always been sought. The main route for producing ethylene and propylene is steam cracking, which is an energy extensive process.

Basic hydrocarbon chemicals are the key building blocks for manufacture of a wide variety of durable and nondurable consumer goods. Considering the items that are encountered every day—clothes, construction materials used to build our homes and offices, a variety of household appliances and electronic equipment, food and beverage packaging, and many products used in various modes of transportation—hydrocarbons provide the fundamental building blocks that enable the manufacture of the vast majority of these goods. Demand for chemicals and plastics is driven by global economic conditions, which are directly linked to demand for consumer goods.

The search for alternative ways to produce monomers and chemicals from sources other than crude oil. In fact, Fisher Tropsch technology, which produces low molecular weight olefins in addition to hydrocarbon fuels, could enable non–crude oil feedstocks (such as extra heavy oil, tar and bitumen, coal, oil shale, and biomass) to be used as feedstocks for petrochemicals.

In addition, the continued high demand for hydrocarbon products, such as liquid fuels (gasoline and diesel fuel) and petrochemical feedstocks (such as aromatic derivatives and olefin derivatives), is increasing throughout the world. Traditional markets such as North America and Europe are experiencing a steady increase in demand, whereas emerging Asian markets, such as India and China, are witnessing a rapid surge in demand for hydrocarbons. This has resulted in a tendency for existing refineries to seek fresh refining approaches to optimize efficiency and throughput. Furthermore, the increasing use of the heavier feedstocks for refineries is forcing technology suppliers/licensors to revamp their refining technologies in an effort to cater to the growing customer base.

The evolution in product specifications caused by various environmental regulations plays a major role in the development of crude oil refining technologies. In many countries, especially in the United States and Europe, gasoline and diesel fuel specifications have changed radically in the past decades and will continue to do so in the future. Currently, reducing the sulfur levels of hydrocarbon fuels is the dominant objective of many refiners. There is also an increasing demand for hydrocarbon derivatives for other uses. This is pushing the technological limits of hydrocarbon production to the maximum, and the continuing issue is the processes that will increase hydrocarbon production and purity.

Refineries must, and indeed are eager to, adapt to changing circumstances and are amenable to trying new technologies that are radically different in character. Currently, refineries are also looking to exploit heavy (more viscous) crude oils and tar and bitumen (sometimes referred to as extra heavy crude oil) provided they have the refinery technology capable of handling such feedstocks. Transforming the higher boiling constituents of these feedstock components into single hydrocarbon derivative as well as hydrocarbon fuels is becoming a necessity.

The reader might also be surprised at the number of older references that are included. The purpose of this is to remind the reader that there is much valuable work cited in the older literature. Work that is still of value and, even though in some cases, there has been similar work performed with advanced equipment, the older work has stood the test of time. Many of the ideas are still pertinent and should not be forgotten in terms of the valuable contributions they have made to crude oil science and technology. However, many of the older references included in previous editions of this book have been deleted—unavailability of the source for the general scientific researcher and the current lack of a substantiated sources (other than the files collected by the author) have been the root cause of such omissions.

Therefore, it is the purpose of this book to provide the reader with a detailed overview of the production and properties of hydrocarbon derivatives and hydrocarbon fuels as the world evolves into the 21st century. With this in mind, many of the chapters that appeared in the First Edition have been rewritten to include the latest developments related to hydrocarbon products. Updates on the evolving processes and new processes as well as the various environmental regulations are presented. However, the text still maintains its initial premise, that is, to introduce the reader to the hydrocarbon science and technology as well as the production of a wide variety of products and petrochemical intermediates. However, the text will also prove useful for those scientists and engineers already engaged in the crude oil industry as well as in the catalyst manufacturing industry who wish to gain a general overview or update of the science of crude oil.

Thus, the book focuses on the interfaces between chemical technology and biotechnology especially where these impact on health and safety and the environment. Also, the book has been adjusted, polished, and improved for the benefit of new readers as well as for the benefit of readers of the four previous editions.

Dr. James G. Speight

Laramie, Wyoming, USA

June, 2019

Chapter 1

Chemistry and chemical technology

Abstract

Chemistry is the science of matter and is concerned with the composition, behavior, structure, and properties of matter, as well as the changes matter undergo during chemical reactions. Chemistry is a physical science and is used for the investigation of atoms, molecules, crystals, and other assemblages of matter whether in isolation or combination, which incorporates the concepts of energy and entropy in relation to the spontaneity or initiation of chemical reactions or chemical processes.

The definitions of technology vary from one discipline to another. However, in the current context, chemical technology is the practical application of chemistry and chemical engineering to the needs of commerce or industry and is a multicomponent discipline which, in this context, deals with the application of chemical knowledge to the solution of practical. Chemical technology is also a human action that involves the generation of knowledge and (usually innovative) processes to develop systems that solve problems and extend human capabilities.

This chapter explains the various aspects of chemistry and technology and prepares the reader for the terms used throughout the book.

Keywords

Bonding in carbon-based systems; Chemical technology; Hydrocarbons; Nonhydrocarbons; Properties of hydrocarbons

1. Introduction

Chemistry (from the Arabic al khymia) is the science of matter and is concerned with the composition, behavior, structure, and properties of matter, as well as the changes matter undergo during chemical reactions. Chemistry is a physical science and is used for the investigation of atoms, molecules, crystals, and other assemblages of matter whether in isolation or combination, which incorporates the concepts of energy and entropy in relation to the spontaneity or initiation of chemical reactions or chemical processes.

Disciplines within chemistry are traditionally grouped by the type of matter being studied or the kind of study and include the following (presented alphabetically): (i) analytical chemistry, which is the analysis of material samples to gain an understanding of their chemical composition and structure, (ii) biochemistry, which is the study of substances found in biological organisms, (iii) inorganic chemistry, which is the study of inorganic matter (inorganic chemicals, such as minerals), (iv) organic chemistry, which is the study of organic matter (inorganic chemicals, such as hydrocarbon derivatives), and (v) physical chemistry, which is the study of the energy relations of chemical systems at macro, molecular, and submolecular scales.

In fact, the history of human culture can be viewed as the progressive development of chemical technology through evolution of the scientific and engineering disciplines in which chemistry and chemical engineering have played major roles in producing a wide variety of industrial chemicals, especially industrial organic chemicals (Ali et al., 2005). Chemical technology, in the context of the present book, relies on chemical bonds of hydrocarbon derivatives. Nature has favored the storage of solar energy in the hydrocarbon bonds of plants and animals, and the evolution of chemical technology has exploited this hydrocarbon energy profitably.

The focus of this book is hydrocarbon derivatives and the chemistry associated with these organic compounds which will be used to explain the aspects of hydrocarbon properties, structure, and manufacture. The book will provide information relating to the structure and properties of hydrocarbon derivatives and their production through process chemistry and chemical technology to their conversion into commercial products.

2. Organic chemistry

Organic chemistry is a discipline within chemistry that involves study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of carbon-based compounds (in this context—hydrocarbon derivatives).

On the other hand, inorganic chemistry is the branch of chemistry concerned with the properties and behavior of inorganic compounds. This field covers all chemical compounds except the myriad of carbon-based compounds (such as the hydrocarbon derivatives), which are the subjects of organic chemistry. The distinction between the two disciplines is far from absolute, and there is much overlap, most importantly in the subdiscipline of organometallic chemistry in which organic compounds and metals form distinct and stable products. An example is tetraethyl lead which was formerly used in gasoline (until it was banned by various national environmental agencies) as an octane enhancer to prevent engine knocking or pinging during operation. Other than this clarification and brief mention here, neither inorganic chemistry nor organometallic chemistry will be described further in this text.

2.1. Organic chemicals

Organic compounds are structurally diverse, and the range of application of organic compounds is enormous. In addition, organic compounds may contain any number of other elements, including nitrogen, oxygen, sulfur, halogens, phosphorus, and silicon. They form the basis of, or are important constituents of, many products (such as plastics, drugs, petrochemicals, food, explosives, and paints) and, with very few exceptions, they form the basis of all life processes and many industrial processes.

Organic compounds—of which the hydrocarbon derivatives are a subgroup—are classified according to the presence of functional groups in the molecule (Table 1.1, Table 1.2, Table 1.3, Table 1.4). A functional group is a molecular moiety that typically dictates the behavior (reactivity) of the organic compound in the environment and the reactivity of that functional group is assumed to be the same in a variety of molecules, within some limits and if steric effects (that arise from the three-dimensional structure of the molecule) do not interfere. Thus, most organic functional groups feature heteroatoms (atoms other than carbon and hydrogen, such as: nitrogen, oxygen, and sulfur). The concept of functional groups is a major concept in organic chemistry, both to classify the structure of organic compounds and to predict the physical and chemical properties especially, in the context of this book, those properties that relate to behavior and reactivity in technological processes.

Table 1.1

For example, when comparing the properties of ethane (CH3CH3) with the properties of propionic acid (CH3CH2CO2H), which is a chemical that is formed due to the replacement of a hydrogen atom in the ethane molecule by a carboxylic acid functional group (CO2H) the change in properties and behavior is spectacular. Alternatively, the replacement of a methyl group (CH3) into the ethane molecule by the carboxylic acid function to produce acetic acid (CH3CO2H) (or the replacement of a hydrogen in the methane molecule (CH4) by the carboxylic acid function) produces significant changes in the properties of the product vis-à-vis the original molecule.

Thus, organic chemicals from very simple compounds such as methane (CH4) to organic chemicals that contain more than one carbon atom, as many as 10 carbon atoms to chemicals that contain hundreds or more carbon atoms that are linked in carbon–carbon bonds. Those that contain only carbon and hydrogen are called hydrocarbons; a simple example is H3C(CH2)3CH3 (pentane). Organic chemicals commonly contain other elements too, such as oxygen, nitrogen, or sulfur. An organometallic chemical has a carbon atom bonded to a metal as in tetraethyl lead. Some organometallic chemicals are found naturally.

Many organic chemicals are synthetic, i.e., produced not by living creatures, but manufactured by human beings. However, the feedstocks from which the chemicals are made come from nature. Commonly synthetic organic chemicals are made from crude oil or natural gas feedstocks, which are referred to as petrochemicals (Speight, 2014, 2017). Coal or wood also sometimes serve as feedstocks for organic chemicals. Plastics are synthetic organic chemicals and the so-called bioplastics, which humans produce from plant materials, involve some synthetic chemistry. Some commercial organic chemicals are produced too by cultures of molds or bacteria; such chemicals must then be purified from these cultures by human actions.

Table 1.2

Table 1.3

Table 1.4

Finally, for clarification, a biochemical is an organic chemical synthesized by a living creature. Proteins, fats, and carbohydrates are biochemicals. Sucrose (table sugar) and the acetic acid (CH3CO2H) in vinegar are examples of simple biochemicals. Many biochemicals can also be made synthetically, not only simple chemicals such as vinegar or the sugars, sucrose, and xylose, but also complex ones. If the structure of a chemical made by synthetic means is exactly the same as that found in nature, it is indeed the same chemical—the body treats both in exactly the same way so there is no biological difference between them. Chemicals synthesized by living creatures can also be extensively manipulated during extraction and purification and still legally be called natural.

2.2. The chemical bond

The most basic concept in all of chemistry is the chemical bond. The chemical bond is essentially the sharing of electrons between two atoms, a sharing which holds or bonds the atoms together.

Atoms have three components: protons, neutrons, and electrons. Protons have a positive charge of +1, neutrons have 0 charge, and electrons have a negative charge of −1. The protons and neutrons occupy the center of the atom as a piece of solid matter called the nucleus. The electrons exist in orbitals surrounding the nucleus. In reality, it is impossible to tell the precise trajectory of an electron and the best that can be achieved is to describe the probability of locating the electron in a region of space.

The simplest case is when the nucleus is surrounded by just one electron (for example, the hydrogen atom). In this case, the probability of finding an electron in its lowest energy, or most stable, state is it being distributed in a spherically symmetric way around the nucleus. The probability of finding the electron is highest at the nucleus and decreases as the distance from the nucleus increases.

The spherically symmetric 1s orbital is the lowest energy orbital that an electron can occupy, but several higher energy orbitals are significant in organic chemistry. The next lowest energy orbital that an electron can occupy is the 2s orbital, which looks much like the 1s orbital except that the electron is more likely to be found farther from the nucleus. The third lowest energy orbital is the 2p orbital. The major and highly important difference between a p orbital and an s orbital is that the p orbital is not spherically symmetric and is oriented along a specific axis in space. There are three p orbitals, which are oriented along the x, y, and z axes.

2.3. Bonding in carbon-based systems

A chemical bond is essentially the sharing of electrons between two atoms. Since electrons are negatively charged and exert an attractive force on nuclei, they serve to hold the atoms together if they are located between two nuclei.

When two atoms approach each other, their atomic orbitals overlap. The overlapped atomic orbitals can add together to form a molecular orbital (linear combination of atomic orbitals, LCAO). The area of greatest overlap between the original atomic orbitals represents the chemical bond that is formed between them. Since the sharing of electrons is the basis of the chemical bond, the molecular orbitals formed represent chemical bonds.

For example, in the case of hydrogen, the two 1s orbitals gradually come closer together until there is a good deal of overlap between them. At this point, the area in space of greatest electron density will be between the two nuclei, which themselves were at the center of the original atomic orbitals. This electron density, now part of a new molecular orbital, represents the chemical bond. When the area of greatest overlap occurs directly between the two nuclei on an axis containing the nuclei of both atoms (internuclear axis), the bond is a sigma bond (σ bond) (Fig. 1.1).

More than one atomic orbital from a single atom can be used to form new molecular orbitals. For example, a 2s orbital and a 2p orbital from one atom might add together and overlap with one or more orbitals from a second atom to form new molecular orbitals. Second, parts of orbitals can possess a sign (+or -). The s orbital has the same sign throughout, while in the p orbitals, one lobe is + and the other lobe is -. Signs do not matter with respect to electron density, but they must be considered when orbitals are added or subtracted. If two orbitals of the same sign are added, electron density will increase, while if two orbitals of opposite signs (charges) are added, the shared electron density will cancel out.

Carbon has six electrons—only two electrons can occupy an s orbital at a time. The first two electrons in carbon occupy the 1s orbital and the next two occupy the higher-energy, but similarly shaped 2s orbital while the final two electrons occupy the 2p orbitals.

Figure 1.1 Two hydrogen 1s atomic orbitals overlap to form a hydrogen molecular orbital.

In carbon, the electrons in the 1s orbital are too low in energy to form bonds. Thus, electrons used to form bonds must come from the 2s and 2p orbitals. Carbon very often makes four bonds by redistribution of the 2p electrons:

When it does so, these bonds are arranged so that they are as far away from each other as possible. This arrangement is referred to as a tetrahedral bond (Fig. 1.2).

The individual 2s orbital and the 2p orbital cannot form bonds in this arrangement due to their geometry. The 2s orbital is completely symmetric, while the 2p orbitals are aligned along specific axes. None of these orbitals is well-equipped to form bonds in the tetrahedral geometry alone.

Since a chemical bond does not have to be formed from individual atomic orbitals, but can be formed from a combination of several atomic orbitals from the same atom, each bond that is made in the tetrahedral geometry, a part of the 2s and a part of each of the 2p orbitals will contribute, resulting in a tetrahedral arrangement and there is a 109.5 degrees angle between each of the bonds (Fig. 1.2). To achieve this geometry, both the 2s and all three of the 2p orbitals (2p x , 2p y , and 2p z ) must contribute. The new bonds that are formed are called sp ³  bonds, since 1 s orbital and 3 p orbitals were used to form the bonds.

Carbon sometimes makes three bonds instead of four. In this case, not all of the 2p orbitals combine with the 2s orbital to form bonds. Instead, a combination of the 2s orbital and two of the 2p orbitals make three sp ²  bonds, while the other p orbital does not participate in this combination and can make a fourth bond on its own.

Like the sp ³ bonds, the sp ² bonds are oriented such that they are as far away from each other as possible (trigonal planar geometry). Each of the bonds points to one of the vertices of a triangle, but all three bonds are located in the same plane. The other 2p orbital, the one which did not add to make sp ² bonds exists perpendicular to the plane in which the sp ² bonds form. It too is able to form bonds, and it does so independently of the sp ² bonds.

When two carbon atoms with sp ² orbitals form a bond to each other using their sp ² orbitals, a σ bond is formed between then. Moreover, the extra p orbitals, which exist above and below each carbon atom, also overlap with each other. This overlap between p orbitals leads to the formation of a second bond in addition to the σ bond formed between the sp ² orbitals. This second bond which does not occur directly between the nuclei on the internuclear axis but above and below the internuclear axis is a π bond (pi bond). When a σ bond and a π bond form together between two atoms, it leads to the formation of a double bond (Fig. 1.3).

Figure 1.2 Tetrahedral geometry as exhibited by the carbon atom surrounded by four hydrogen atoms (methane).

Briefly, many inorganic compounds are ionic compounds, consisting of cations and anions joined by ionic bonding. Examples of salts (which are ionic compounds) are magnesium chloride (MgCl2) which consists of magnesium cations (Mg²+) and chloride anions (Cl − ). In any salt, the proportions of the ions are such that the electric charges cancel out, so that the bulk compound is electrically neutral. Important classes of inorganic compounds are the oxides, the carbonates, the sulfates, and the halides. Many inorganic compounds are characterized by high melting points, ease of crystallization, and solubility— where some salts (such as sodium chloride, NaCl) are highly soluble in water, others (such as silica, silicon oxide, SiO2) are insoluble in water.

Figure 1.3 The molecule ethylene is formed from two carbon atoms and four hydrogen atoms— a σ bond is formed from two sp ² orbitals and a π bond is formed from two 2p orbitals to comprise a double bond.

3. Chemical engineering

Chemical engineering is the branch of engineering that deals with the application of physical science (such as chemistry) to the process of converting raw materials (for example, crude oil) or chemicals into more useful or valuable forms.

Chemical engineering largely involves the design, improvement, and maintenance of processes involving chemical transformations for large-scale manufacture. Chemical engineers (process engineers) ensure the processes are operated safely, sustainably, and economically. Chemical engineering is applied in the manufacture of a wide variety of products. The chemical industry manufactures inorganic and organic industrial chemicals, ceramics, fuels and petrochemicals, agrochemicals (fertilizers, insecticides, herbicides), plastics and elastomers, oleo-chemicals, explosives, detergents and detergent products (soap, shampoo, cleaning fluids), fragrances and flavors, additives, dietary supplements, and pharmaceuticals. Closely allied or overlapping disciplines include wood processing, food processing, environmental technology, and the engineering of crude oil, glass, paints, and other coatings, inks, sealants, and adhesives.

Chemical engineers design processes to ensure the most economical operation in which the entire production chain must be planned and controlled for costs. A chemical engineer can both simplify and complicate showcase reactions for an economic advantage. Using a higher pressure or temperature makes several reactions easier; ammonia, for example, is simply produced from its component elements in a high-pressure reactor. On the other hand, reactions with a low yield can be recycled continuously (recycled to extinction in which no further product is made), which would be complex, arduous work if done by hand in the laboratory. It is not unusual to build 6-step, or even 12-step evaporators to reuse the vaporization energy for an economic advantage. In contrast, laboratory chemists evaporate samples in a single step.

The individual processes used by chemical engineers (e.g., distillation or filtration) are called unit operations and consist of chemical reactions, mass-transfer operations, and heat transfer operations. Unit operations are grouped together in various configurations for the purpose of chemical synthesis and/or chemical separation. Some processes are a combination of intertwined transport and separation unit operations, such as reactive distillation in which the product is formed as the still temperature is raised and the product distills from the reaction mixture.

Three basic physical laws that underlie chemical engineering design are (i) conservation of mass, (ii) conservation of energy, and (iii) conservation of momentum.

3.1. Conservation of mass

The law of conservation of mass (principle of mass/matter conservation) states that the mass of a closed system (in the sense of a completely isolated system) remains constant over time. The mass of an isolated system cannot be changed as a result of processes acting inside the system but while mass cannot be created or destroyed, it may be rearranged in space, and changed into different types of particles. Put simply, the law states that matter cannot be created or destroyed in a chemical reaction. This implies that for any chemical process in a closed system, the mass of the reactants must equal the mass of the products.

The law implies that mass can neither be created nor destroyed, although it may be rearranged in space, or the entities associated with it may be changed in form. This is illustrated in chemical reactions example in which the mass of the chemical components before the reaction is equal to the mass of the components after the reaction. Thus, during any chemical reaction and low-energy thermodynamic processes in an isolated system, the total mass of the reactants (the starting materials) will be equal to the mass of the reaction products. For example, using the molecular proportions as the weights of the reactants and the products:

CH4 + 2O2 → CO2 + 2H2O

16   +   (2   ×   32) → 44   +   (2   ×   18)

Mass of the reactants   =   mass of the products

The change in mass of certain kinds of open systems where atoms or massive particles are not allowed to escape, but other types of energy (such as light or heat) were allowed to enter or escape, went unnoticed during the 19th century, because the mass-change associated with addition or loss of the fractional amounts of heat and light associated with chemical reactions, was very small. Mass is also not generally conserved in open systems (even if only open to heat and work), when various forms of energy are allowed into, or out of, the system. Mass conservation for closed systems continues to be true exactly. The mass-energy equivalence theorem states that mass conservation is equivalent to energy conservation, which is the first law of thermodynamics. The mass-energy equivalence formula requires closed systems, since if energy is allowed to escape a system, mass will escape also.

3.2. Conservation of energy

The law of conservation of energy states that the total amount of energy in an isolated system remains constant over time. A consequence of this law is that energy can neither be created nor destroyed; it can only be transformed from one state to another. The only thing that can happen to energy in a closed system is that it can change form, such as a transformation of chemical energy to kinetic energy.

Conservation of energy refers to the conservation of the total system energy over time. This energy includes the energy associated with the mass of the reactants as well as all other forms of energy in the system. In an isolated system, although mass and energy (heat and light) can be converted to one another, both the total amount of energy and the total amount of mass of such systems remain constant over time. If energy in any form is allowed to escape such systems, the mass of the system will decrease in correspondence with the loss. The conservation of energy is a fundamental concept of physics along with the conservation of mass and the conservation of momentum. Within some problem domain, the amount of energy remains constant and energy is neither created nor destroyed. Energy can be converted from one form to another (potential energy can be converted to kinetic energy) but the total energy within the domain remains fixed.

Thus, energy conservation is the effort made to reduce the consumption of energy by using less of an energy service. This can be achieved either by using energy more efficiently (using less energy for a constant service) or by reducing the amount of service used (for example, by driving less). Energy can be conserved by reducing wastage and losses, improving efficiency through technological upgrades, and improving operation and maintenance. However, energy can only be transformed from one form to another.

3.3. Conservation of momentum

Momentum is the product of the mass and the velocity of an object. The conservation of momentum is a fundamental law of physics which states that the momentum of a system is constant if there are no external forces acting on the system. Momentum is a conserved quantity insofar as the total momentum of any closed system (a system not affected by external forces) cannot change. One of the consequences of the law is that the center of mass of any system of objects will always continue with the same velocity unless acted on by a force from outside the system. In an isolated system (one where external forces are absent) the total momentum will be constant, which dictates that the forces acting between systems are equal in magnitude, but opposite in sign, is due to the conservation of momentum.

Thus, for two objects (A and B) colliding in an isolated system, the total momentum before and after the collision is equal—the momentum lost by one object is equal to the momentum gained by the other. By Newton's third law of thermodynamics, for every action there is an equal but opposite reaction. Hence, the force exerted by object A on object B is equal but opposite to the force that object B exerts on object A. Then by Newton's second law of thermodynamics, this force is equal to the product of the mass and the acceleration of the objects. Hence, the product of the mass and acceleration of object A is equal but opposite to the product between the mass and acceleration of object B. in other words, momentum is conserved.

4. Chemical technology

The definitions of technology vary from one discipline to another. However, in the current context, chemical technology is the practical application of chemistry and chemical engineering to the needs of commerce or industry and is a multicomponent discipline which, in this context, deals with the application of chemical knowledge to the solution of practical problems (Badger and Baker, 1941; Henglein, 1969; Jess and Wasserscheid, 2013). Chemical technology is also a human action that involves the generation of knowledge and (usually innovative) processes to develop systems that solve problems and extend human capabilities.

In chemical technology, when a reaction not studied before is planned, it is of the utmost importance to know and to calculate the equilibrium, that is, the equilibrium constants at various temperatures, before expensive equipment for experimental studies is installed. It is the aim of chemical thermodynamics to answer technically important questions, such as the final state of chemical transformations, reaction mechanisms (passing intermediate stages), and reaction rates.

4.1. Historical aspects

Historically, the word technology is a modern term and rose to prominence during the industrial revolution when it became associated with science and engineering. The word technology can also be used to refer to a collection of techniques, which refers to the current state of humanity's knowledge of how to combine resources to produce desired products, to solve problems, fulfill needs, or satisfy wants; it includes technical methods, skills, processes, techniques, tools, and raw materials. The distinction between science, engineering, and technology is not always clear. However, technologies are not usually exclusively products of science because they have to satisfy requirements, such as utility.

In the context of technology as a technical endeavor, engineering technology is the process of designing and making tools and systems to exploit natural phenomena for practical human means, often (but not always) using results and techniques from chemistry and other sciences. Thus, the development of technology may draw upon many fields of knowledge from the scientific and engineering disciplines in order to achieve a practical result.

To some, technology is often a consequence of science and engineering—in this sense, scientists and engineers may both be considered technologists; the three fields are often considered as one for the purposes of research and reference.

Chemical technology is the study of technology related to chemistry. To be more specific, chemical technology takes chemistry beyond the laboratory and into the industrial world where products are made through knowledge of chemistry. Thus, chemical technology also involves various aspects of chemical engineering such as reactor design and performance. This differs from chemistry itself because the focus is also on the means by which chemistry can be employed to make useful products. Chemical technologists are more likely than technicians to participate in the actual design of experiments, and may be involved in the interpretation of experimental data. They may also be responsible for the operation of chemical processes in large plants, and may even assist chemical engineers in the design of the same.

Within technology falls the concept of innovation, which is the change in the thought process for performing a scientific or engineering task that will lead to (i) a new process, (ii) a new product, or (iii) a new use for an old product. In fact, innovation may refer to incremental or radical changes in products and/or processes and the goal of innovation is a positive change in a product or process. Innovation is considered to be a major driver of the economy, especially when it leads to new product categories or increasing productivity.

For example, using the crude oil industry as an example, innovative use of crude oil and its derivatives (particularly as an asphalt mastic) started 6000 years ago; current innovations can be considered to have commenced in the 1860s and continue to this day (Table 1.5) to the point where heavy oil (once considered a difficult-to-refine feedstock) is now refined on a very regular basis (Ancheyta and Speight, 2007; Speight, 2014).

4.2. Technology and human culture

The use of technology in the form of the development of tools and harnessing the energy of fire has often been regarded as the defining characteristic of Homo sapiens, and is a means of defining the species. Furthermore, the history of human culture can be viewed as the progressive development of new energy sources and their associated conversion technologies (Hall et al., 2003). Most of these energy technologies rely on the properties (i.e., the chemical bonds) of hydrocarbon derivatives.

Technology, the systematic application of scientific and engineering knowledge in developing and applying technology, has grown immensely. Technological knowledge provides a means of estimating what the behavior of things will be even before they are made or observed in service. Moreover, technology often suggests new kinds of behavior that had not even been imagined before, and so leads to strategies of design, to solve practical problems.

Although the development of hunting weapons can be considered a key event in the evolution of human culture, harnessing the energy of fire was probably the most seminal event of human history. This, more than any other event, assisted humans in their exploitation of colder, more northerly ecosystems.

The principal energy sources of antiquity were all derived directly from the sun: human and animal muscle power, wood, flowing water, and wind. In the mid-to-late 18th century the industrial revolution began with stationary wind-powered and water-powered technologies, which were essentially replaced by fossil hydrocarbon derivatives: coal in the 19th century, oil since the 20th century, and now, increasingly, natural gas (Speight, 2014, 2017). Furthermore, hydrocarbon-based energy has a strong connection with economic activity for industrialized and developing economies (Hall et al., 2001; Tharakan et al., 2001).

Technology provides the raison d’être of science and engineering. Technology is essential to science and engineering for purposes of measurement, data collection, treatment of samples, computation, transportation to research sites, sample collection, protection from hazardous materials, and communication. More and more new instruments and techniques are being developed through technology that makes it possible to advance various lines of scientific research.

Table 1.5

However, technology does not just provide tools for science; it also may provide motivation and direction for theory and research. Scientists and engineers see patterns in phenomena to make the world as understandable as possible and being able to be manipulated. Technology also pushes scientists and engineers to show that theories fit the data and to show logical proof of abstract connections as well as demonstrable designs that work.

Technology affects the social system and culture with immediate implications for the success or failure of human enterprises and for personal benefit and harm. Technological decisions, whether in designing an irrigation system or a crude oil recovery project, inevitably involve social and personal values as well as scientific and engineering judgments. This leads to the issues regarding the supply of hydrocarbon derivatives (in the form of crude oil and natural gas) and the future of these valuable chemicals (Speight, 2014, 2017).

The rumors of the death of the hydrocarbon culture are greatly exaggerated (to paraphrase Mark Twain who observed, "The rumors of my death are greatly exaggerated"). The world is not about to run out of hydrocarbon derivatives, and perhaps it is not going to run out of crude oil or natural gas from unconventional sources any time soon. However, cheap crude oil will be difficult to obtain because the reserves that remain are not only difficult to recover but the crude oil is a low-grade and will be more difficult (costly) to refine to produce the desired hydrocarbon fuels (Speight, 2010, 2014).

As conventional oil becomes less important, it is important to invest in a different source of energy, one freeing us for the first time from our dependence on hydrocarbon derivatives (Speight, 2008). However, renewable energy technologies require further development but some do show advantages over hydrocarbon derivatives in terms of economic reliability, accessibility, and environmental benefits. With proper attention to environmental concerns, biomass-based energy generation is competitive in some cases relative to conventional hydrocarbon-based energy generation. By contrast, liquid-fuel production from grain and solar thermal power has a relatively low economic return on investment. But is does depend on the investment required to keep a fleet on alert offshore of various oil producing countries as well as the willingness of the population to pay an additional per gallon of gasoline or per gallon of fuel oil amount for a higher measure of energy independence.

Government intervention, in concert with ongoing private investment, will speed up the process of sorting the wheat from the chaff in the portfolio of feasible renewable energy technologies. It is time to think about possibilities other than the next cheapest hydrocarbon derivatives. If for no other reason than to protect the environment, all of the available technologies should be brought to bear on this task.

5. Hydrocarbons

A hydrocarbon is an organic compound consisting of carbon and hydrogen only. The inclusion of any atom other than carbon and hydrogen disqualified the compound from being considered as a hydrocarbon. The majority of hydrocarbon derivatives found naturally occur in crude oil (crude oil) and natural gas, where decomposed organic matter provides an abundance of many individual varieties of hydrocarbon derivatives. Hydrocarbon derivatives are the simplest organic compounds—they can be straight-chain, branched chain, or cyclic molecules (Fig. 1.4). Nevertheless, in spite of the variations in molecular structure of the various hydrocarbon derivatives, there are five specific families for hydrocarbon derivatives: (i) alkanes, (ii) alkenes, (iii) alkynes, (iv) cycloalkanes, and (v) aromatic hydrocarbon derivatives, also called arenes.

1. Alkanes (paraffins) are saturated hydrocarbon derivatives in which all of the four valence bonds of carbon are satisfied by hydrogen or by another carbon. Alkanes can have straight or branched chains, but without any ring structure.

2. Alkenes (olefinsC) between carbon atoms. Alkenes have the general formula CnH2n, assuming there are no ring structures in the molecule. Alkenes may have more double than one double bond between carbon atoms, in which case the formula is reduced by two hydrogen atoms for each additional double bond. For example, an alkene with two double bonds in the molecule has the general formula CnH2n. Because of their reactivity and the time involved in crude oil maturation, alkenes do not usually occur in crude oil.

Figure 1.4  Types of hydrocarbons and their interrelationship.

3. Alkyne derivatives (acetylene derivatives) are hydrocarbon derivatives which contain a triple bond (CC) and have the general formula CnH2n-2. Acetylene hydrocarbon derivatives are highly reactive and, as a consequence, are very rare in crude oil.

4. Cycloalkane derivatives (naphthene derivatives) are saturated hydrocarbon derivatives containing one or more rings, each of which may have one or more paraffinic side chains (more correctly known as alicyclic hydrocarbon derivatives). The general formula for a saturated hydrocarbon containing one ring is CnH2n.

5. Aromatic hydrocarbon derivatives (arenes or arene derivatives) are hydrocarbon derivatives containing one or more aromatic nuclei, such as benzene, naphthalene, and phenanthrene ring systems, which may be linked up with (substituted) naphthene rings and/or paraffinic side chains.

5.1. Bonding in hydrocarbons

Since carbon adopts the tetrahedral geometry when there are four σ bonds, only two bonds can occupy a plane simultaneously. The other two bonds are directed to the rear or to the front of the plane. In order to represent the tetrahedral geometry in two dimensions, solid wedges are used to represent bonds pointing out of the plane of the drawing toward the viewer, and dashed wedges are used to represent bonds pointing out of the plane or to the rear of the plane.

For example, in a representation of the methane molecule, the hydrogen connected by a solid wedge points to the front of the plane and the hydrogen connected by the dashed wedge points to the rear of the paper while the two hydrogen joined by solid single lines are in the plane (of the paper in this case):

Fortunately, while there is the need to understand such stereochemistry (the existence of molecules in space), hydrocarbon derivatives can be represented in a shorthand notation called a skeletal structure.

In a skeletal structure, only the bonds between carbon atoms are represented. Individual carbon and hydrogen atoms are not drawn, and bonds to hydrogen are not drawn. In the case that the molecule contains just single bonds (sp³ bonds), these bonds are drawn in a zigzag fashion. This is because in the tetrahedral geometry all bonds point as far away from each other as possible and the structure is not linear. For example:

Structure of propane

Skeletal structure of propane

Only the bonds between carbons have been drawn, and these have been drawn in a zigzag manner and there is no evidence of hydrogen atoms in a skeletal structure. Since, in the absence of double or triple bonds, carbon makes four bonds total, the presence of hydrogens is implicit. Whenever an insufficient number of bonds to a carbon atom are specified in the structure, it is assumed that the rest of the bonds are made to hydrogens.

For example, if the carbon atom makes only one explicit bond, there are three hydrogens implicitly attached to it. If it makes two explicit bonds, there are two hydrogens implicitly attached, etc. Two lines are sufficient to represent three carbon atoms. It is the bonds only that are being drawn out, and it is understood that there are carbon atoms (with three hydrogens attached to each) at the terminal ends of the structure.

5.2. Nomenclature

The large number of organic compounds identified with each passing day, together with the fact that many of these compounds are isomers of other compounds, requires that a systematic nomenclature system be developed. Just as each distinct compound has a unique molecular structure which can be designated by a structural formula, each compound must be given a characteristic and unique name. As organic chemistry developed, many compounds were given trivial names, which are now commonly used and recognized.

The IUPAC (International Union of Pure and Applied Chemistry) systematic approach to nomenclature is a rational nomenclature system that should do at least two things. First, it should indicate how the carbon atoms of a given compound are bonded together in a characteristic lattice of chains and rings. Second, it should identify and locate any functional groups present in the compound. Since hydrogen is such a common component of organic compounds, its amount and locations can be assumed from the tetravalency of carbon, and need not be specified in most cases.

The IUPAC nomenclature system is a set of logical rules devised and used by organic chemists to circumvent problems caused by arbitrary nomenclature. Knowing these rules and given a structural formula, one should be able to write a unique name for every distinct compound. Likewise, given an IUPAC name, one should be able to write a structural formula. In general, an IUPAC name will have three essential features: (i) a root or base indicating a major chain or ring of carbon atoms found in the molecular structure, (ii) a suffix or other element(s) designating functional groups that may be present in the compound, and (iii) the names of substituent groups, other than hydrogen, that complete the molecular structure.

As defined by the IUPAC nomenclature of organic chemistry, the classifications for hydrocarbons are:

1. Saturated hydrocarbons are the simplest of the hydrocarbon species. They are composed entirely of single bonds and are saturated with hydrogen. The formula for acyclic saturated hydrocarbons (alkanes) is CnH2n+2 (Table 1.5). The most general form of saturated hydrocarbons is CnH2n+2(1-r), where r is the number of rings. Those with exactly one ring are the cycloalkane derivatives. Saturated hydrocarbons are the basis of fuels from crude oil and are found as either linear or branched species. Substitution reaction is their characteristic property (such as chlorination to form chloroform). Hydrocarbon derivatives with the same molecular formula but different structural formula are called structural isomers. The number of structural isomers increases phenomenally with the number of carbon atoms in the molecule (Table 1.6)

2.