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Handbook of Industrial Hydrocarbon Processes

Second Edition James G. Speight, PhD, DSc, PhD CD & W Inc. Laramie, WY, United States

Gulf Professional Publishing is an imprint of Elsevier 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States The Boulevard, Langford Lane, Kidlington, Oxford, OX5 1GB, United Kingdom Copyright Ó 2020 Elsevier Inc. All rights reserved.

No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions.

This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

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.

To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN: 978-0-12-809923-0 For information on all Gulf Professional Publishing publications visit our website at https://www.elsevier.com/books-and-journals

Publisher: Joe Hayton Acquisition Editor: Katie Hammon Editorial Project Manager: Aleksandra Packowska Production Project Manager: Surya Narayanan Jayachandran Cover Designer: Mark Rogers Typeset by TNQ Technologies

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 MissouriColumbia, 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 MedaldScientists 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.

xv

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

xvii

xviii Preface

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 daydclothes, 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 transportationdhydrocarbons 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 nonecrude 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

Preface

xix

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 deleteddunavailability 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 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 Handbook of Industrial Hydrocarbon Processes. https://doi.org/10.1016/B978-0-12-809923-0.00001-1 Copyright © 2020 Elsevier Inc. All rights reserved.

1

2 Handbook of Industrial Hydrocarbon Processes

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 contextdhydrocarbon 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 compoundsdof which the hydrocarbon derivatives are a subgroupdare 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

Chemistry and chemical technology Chapter | 1

3

TABLE 1.1 General classes of hydrocarbons.

Chemical class

Group

Formula

Alkane

Alkyl

R(CH2)nH

Alkene

Alkenyl

R2C ¼ CR2

Alkyne

Alkynyl

R1ChCR2

Benzene derivative

Phenyl

RC6H5

Structural formulae

book, those properties that relate to behavior and reactivity in technological processes.

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 carbonecarbon 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

4 Handbook of Industrial Hydrocarbon Processes

TABLE 1.2 General classes of oxygen compounds.

Chemical class

Group

Formula

Alcohol

Hydroxyl

ROH

Ketone

Carbonyl

RCOR0

Aldehyde

Aldehyde

RCHO

Acyl halide

Haloformyl

RCOX

Carbonate

Carbonate ester

ROCOOR

Carboxylate

Carboxylate

RCOO

Carboxylic acid

Carboxyl

RCOOH

Ester

Ester

RCOOR0

Methoxy

Methoxy

ROCH3

Structural formula

Chemistry and chemical technology Chapter | 1

5

TABLE 1.3 General classes of nitrogen compounds.

Class

Group

Formula

Amide

Carboxamide

RCONR2

Amines

Primary amine

RNH2

Secondary amine

R2NH

Tertiary amine

R3N

4 degrees ammonium ion

R4Nþ

Primary ketimine

RC(¼NH)R0

Secondary ketimine

RC(¼NR)R0

Primary aldimine

RC(¼NH)H

Imine

Structural formula

Continued

6 Handbook of Industrial Hydrocarbon Processes

TABLE 1.3 General classes of nitrogen compounds.dcont’d Class

Group

Formula 0

Secondary aldimine

RC(¼NR )H

Imide

Imide

(RCO)2NR0

Azide

Azide

RN3

Azo compound

Azo (di-imide)

RN2R0

Cyanates

Cyanate

ROCN

Isocyanate

RNCO

Nitrate

Nitrate

RONO2

Nitrile

Nitrile

RCN

Isonitrile

RNC

Nitrite

Nitroso-oxy

RONO

Nitro compound

Nitro

RNO2

Structural formula

Chemistry and chemical technology Chapter | 1

TABLE 1.4 General classes of sulfur compounds.

Chemical class

Group

Formula

Thiol

Sulfhydryl

RSH

Sulfide (thioether)

Sulfide

RSR0

Disulfide

Disulfide

RSSR0

Sulfoxide

Sulfinyl

RSOR0

Sulfone

Sulfonyl

RSO2R0

Sulfinic acid

Sulfino

RSO2H

Sulfonic acid

Sulfo

RSO3H

Thiocyanate

Thiocyanate

RSCN

Isothiocyanate

RNCS

Thione

Carbonothioyl

RCSR0

Thial

Carbonothioyl

RCSH

Structural formula

7

8 Handbook of Industrial Hydrocarbon Processes

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.

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 chemicaldthe 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 þ1, 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.

Chemistry and chemical technology Chapter | 1

9

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 (s 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 (þor -). The s orbital has the same sign throughout, while in the p orbitals, one lobe is þ 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 electronsdonly 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.

S+S

+

AO

AO

LCAO MO

MO

build up of electron density

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

10 Handbook of Industrial Hydrocarbon Processes

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 (2px, 2py, and 2pz) must contribute. The new bonds that are formed are called sp3 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 sp2 bonds, while the other p orbital does not participate in this combination and can make a fourth bond on its own.

Like the sp3 bonds, the sp2 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 sp2 bonds exists perpendicular to the plane in which the sp2 bonds form. It too is able to form bonds, and it does so independently of the sp2 bonds.

When two carbon atoms with sp2 orbitals form a bond to each other using their sp2 orbitals, a s 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 s bond formed between the sp2 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 p bond (pi bond). When a s

Chemistry and chemical technology Chapter | 1

11

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

bond and a p bond form together between two atoms, it leads to the formation of a double bond (Fig. 1.3).

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 (Mg2þ) and chloride anions (Cl ). In any salt, the proportions of the

12 Handbook of Industrial Hydrocarbon Processes FIGURE 1.3 The molecule ethylene is formed from two carbon atoms and four hydrogen atomsd a s bond is formed from two sp2 orbitals and a p bond is formed from two 2p orbitals to comprise a double bond.

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 solubilityd where some salts (such as sodium chloride, NaCl) are highly soluble in water, others (such as silica, silicon oxide, SiO2) are insoluble in water.

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

Chemistry and chemical technology Chapter | 1

13

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 12step 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, masstransfer 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

14 Handbook of Industrial Hydrocarbon Processes

components after the reaction. Thus, during any chemical reaction and lowenergy 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 þ 2O2 / CO2 þ 2H2O 16 þ (2 32) / 44 þ (2 18) Mass of the reactants ¼ 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.

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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 equaldthe 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.

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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 engineeringdin 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

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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 windpowered 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’eˆtre of science and engineering. Technology is essential to science and engineering for purposes of measurement, data collection, treatment of samples, computation, transportation to research

Alkadiene

Number of C atoms

Alkane (single bond)

Alkene (double bond)

Alkyne (triple bond)

Cycloalkane

1

Methane

d

d

d

2

Ethane

Ethylene (ethene)

Acetylene (ethyne)

d

d

3

Propane

Propylene (propene)

Propyne

Cyclopropane

Propadiene

4

Butane

Butylene (butene)

Butyne

Cyclobutane

Butadiene

5

Pentane

Pentene

Pentyne

Cyclopentane

Pentadiene

6

Hexane

Hexene

Hexyne

Cyclohexane

Hexadiene

7

Heptane

Heptene

Heptyne

Cycloheptane

Heptadiene

8

Octane

Octene

Octyne

Cyclooctane

Octadiene

9

Nonane

Nonene

Nonyne

Cyclononane

Nonadiene

10

Decane

Decene

Decyne

Cyclodecane

Decadiene

11

Undecane

Undecene

Undecyne

Cycloundecane

Undecadiene

12

Dodecane

Dodecene

Dodecyne

Cyclododecane

Dodecadiene

d

18 Handbook of Industrial Hydrocarbon Processes

TABLE 1.5 Simple hydrocarbons and the variations.

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BIFURCATION

We were two lovers; let me lie by her, My tomb beside her tomb. On hers inscribe— "I loved him; but my reason bade prefer Duty to love, reject the tempter's bribe Of rose and lily when each path diverged, And either I must pace to life's far end As love should lead me, or, as duty urged, Plod the worn causeway arm-in-arm with friend.

So, truth turned falsehood: 'How I loathe a flower, How prize the pavement!' still caressed his ear— The deafish friend's—through life's day, hour by hour, As he laughed (coughing) 'Ay, it would appear!'

But deep within my heart of hearts there hid Ever the confidence, amends for all, That heaven repairs what wrong earth's journey did, When love from life-long exile comes at call.

Duty and love, one broad way, were the best— Who doubts? But one or other was to choose, I chose the darkling half, and wait the rest In that new world where light and darkness fuse."

Inscribe on mine—"I loved her: love's track lay O'er sand and pebble, as all travellers know.

Duty led through a smiling country, gay With greensward where the rose and lily blow.

'Our roads are diverse: farewell, love!' said she: ''T is duty I abide by: homely sward And not the rock-rough picturesque for me!

Above, where both roads join, I wait reward.

Be you as constant to the path whereon I leave you planted!' But man needs must move, Keep moving—whither, when the star is gone Whereby he steps secure nor strays from love?

No stone but I was tripped by, stumbling-block But brought me to confusion. Where I fell, Th I l fl t if di i d th k

There I lay flat, if moss disguised the rock, Thence, if flint pierced, I rose and cried 'All's well!

Duty be mine to tread in that high sphere Where love from duty ne'er disparts, I trust, And two halves make that whole, whereof—since here One must suffice a man—why, this one must!'"

Inscribe each tomb thus: then, some sage acquaint The simple—which holds sinner, which holds saint!

NUMPHOLEPTOS The Browning Society became so puzzled over the interpretation of this poem that through Dr. Furnivall it applied to the poet for an explanation and he replied: "Is not the key to the meaning of the poem in its title νυμφόληπτος [caught or rapt by a nymph] not γυναικεραστής [a woman lover]? An allegory, that is, of an impossible ideal object of love, accepted conventionally as such by a man who, all the while, cannot quite blind himself to the demonstrable fact that the possessor of knowledge and purity obtained without the natural consequences of obtaining them by achievement—not inheritance,—such a being is imaginary, not real, a nymph and no woman; and only such an one would be ignorant of and surprised at the results of a lover's endeavor to emulate the qualities which the beloved is entitled to consider as pre-existent to earthly experience, and independent of its inevitable results. I had no particular woman in my mind; certainly never intended to personify wisdom, philosophy, or any other abstraction; and the orb, raying color out of whiteness, was altogether a fancy of my own.

The 'seven spirits' are in the Apocalypse, also in Coleridge and Byron,—a common image."

Still you stand, still you listen, still you smile!

Still melts your moonbeam through me, white awhile, Softening, sweetening, till sweet and soft Increase so round this heart of mine, that oft I could believe your moonbeam-smile has past The pallid limit, lies, transformed at last To sunlight and salvation—warms the soul It sweetens, softens! Would you pass that goal, Gain love's birth at the limit's happier verge, And, where an iridescence lurks, but urge The hesitating pallor on to prime Of dawn!—true blood-streaked, sun-warmth, action-time, By heart-pulse ripened to a ruddy glow Of gold above my clay—I scarce should know From gold's self, thus suffused! For gold means love.

What means the sad slow silver smile above My clay but pity, pardon?—at the best, But acquiescence that I take my rest, Contented to be clay, while in your heaven The sun reserves love for the Spirit-Seven Companioning God's throne they lamp before, —Leaves earth a mute waste only wandered o'er By that pale soft sweet disempassioned moon Which smiles me slow forgiveness! Such, the boon I beg? Nay, dear, submit to this—just this Supreme endeavor! As my lips now kiss Your feet, my arms convulse your shrouding robe, My eyes, acquainted with the dust, dare probe Your eyes above for—what, if born, would blind Mine with redundant bliss, as flash may find The inert nerve, sting awake the palsied limb, Bid with life's ecstasy sense overbrim And suck back death in the resurging joy— Love, the love whole and sole without alloy!

V i l ! Th

i

ith

!I

l

Vainly! The promise withers! I employ Lips, arms, eyes, pray the prayer which finds the word, Make the appeal which must be felt, not heard, And none the more is changed your calm regard: Rather, its sweet and soft grow harsh, and hard— Forbearance, then repulsion, then disdain.

Avert the rest! I rise, see!—make, again Once more, the old departure for some track Untried, yet through a world which brings me back Ever thus fruitlessly to find your feet, To fix your eyes, to pray the soft and sweet Which smile there—take from his new pilgrimage Your outcast, once your inmate, and assuage With love—not placid pardon now—his thirst For a mere drop from out the ocean erst He drank at! Well, the quest shall be renewed.

Fear nothing! Though I linger, unembued With any drop, my lips thus close. I go!

So did I leave you, I have found you so, And doubtlessly, if fated to return, So shall my pleading persevere and earn Pardon—not love—in that same smile, I learn, And lose the meaning of, to learn once more, Vainly!

What fairy track do I explore?

What magic hall return to, like the gem Centuply-angled o'er a diadem?

You dwell there, hearted; from your midmost home Rays forth—through that fantastic world I roam Ever—from centre to circumference, Shaft upon colored shaft: this crimsons thence, That purples out its precinct through the waste.

Surely I had your sanction when I faced, Fared forth upon that untried yellow ray Whence I retrack my steps? They end to-day Where they began before your feet beneath

Where they began, before your feet, beneath Your eyes, your smile: the blade is shut in sheath, Fire quenched in flint; irradiation, late Triumphant through the distance, finds its fate, Merged in your blank pure soul, alike the source And tomb of that prismatic glow: divorce Absolute, all-conclusive! Forth I fared, Treading the lambent flamelet: little cared If now its flickering took the topaz tint, If now my dull-caked path gave sulphury hint Of subterranean rage—no stay nor stint To yellow, since you sanctioned that I bathe, Burnish me, soul and body, swim and swathe In yellow license. Here I reek suffused With crocus, saffron, orange, as I used With scarlet, purple, every dye o' the bow Born of the storm-cloud. As before, you show Scarce recognition, no approval, some Mistrust, more wonder at a man become Monstrous in garb, nay—flesh disguised as well, Through his adventure. Whatsoe'er befell, I followed, wheresoe'er it wound, that vein You authorized should leave your whiteness, stain Earth's sombre stretch beyond your midmost place Of vantage,—trode that tinct whereof the trace On garb and flesh repel you! Yes, I plead Your own permission—your command, indeed, That who would worthily retain the love Must share the knowledge shrined those eyes above, Go boldly on adventure, break through bounds O' the quintessential whiteness that surrounds Your feet, obtain experience of each tinge That bickers forth to broaden out, impinge Plainer his foot its pathway all distinct From every other. Ah, the wonder, linked With fear, as exploration manifests What agency it was first tipped the crests

What agency it was first tipped the crests Of unnamed wildflower, soon protruding grew Portentous 'mid the sands, as when his hue Betrays him and the burrowing snake gleams through; Till, last ... but why parade more shame and pain?

Are not the proofs upon me? Here again I pass into your presence, I receive Your smile of pity, pardon, and I leave ...

No, not this last of times I leave you, mute, Submitted to my penance, so my foot May yet again adventure, tread, from source To issue, one more ray of rays which course Each other, at your bidding, from the sphere Silver and sweet, their birthplace, down that drear Dark of the world,—you promise shall return Your pilgrim jewelled as with drops o' the urn The rainbow paints from, and no smatch at all Of ghastliness at edge of some cloud-pall Heaven cowers before, as earth awaits the fall O' the bolt and flash of doom. Who trusts your word Tries the adventure: and returns—absurd As frightful—in that sulphur-steeped disguise Mocking the priestly cloth-of-gold, sole prize The arch-heretic was wont to bear away Until he reached the burning. No, I say: No fresh adventure! No more seeking love At end of toil, and finding, calm above My passion, the old statuesque regard, The sad petrific smile!

O you—less hard And hateful than mistaken and obtuse Unreason of a she-intelligence!

You very woman with the pert pretence To match the male achievement! Like enough!

Ay, you were easy victors, did the rough Straightway efface itself to smooth the gruff

Straightway efface itself to smooth, the gruff Grind down and grow a whisper,—did man's truth Subdue, for sake of chivalry and ruth, Its rapier-edge to suit the bulrush-spear Womanly falsehood fights with! O that ear All fact pricks rudely, that thrice-superfine Feminity of sense, with right divine To waive all process, take result stain-free From out the very muck wherein ...

Ah me!

The true slave's querulous outbreak! All the rest Be resignation! Forth at your behest I fare. Who knows but this—the crimson-quest— May deepen to a sunrise, not decay To that cold sad sweet smile?—which I obey.

APPEARANCES And so you found that poor room dull, Dark, hardly to your taste, my dear?

Its features seemed unbeautiful: But this I know—'t was there, not here, You plighted troth to me, the word Which—ask that poor room how it heard.

And this rich room obtains your praise Unqualified,—so bright, so fair, So all whereat perfection stays?

Ay, but remember—here, not there, The other word was spoken!—Ask This rich room how you dropped the mask!

ST. MARTIN'S SUMMER

No protesting, dearest!

Hardly kisses even!

Don't we both know how it ends?

How the greenest leaf turns serest, Bluest outbreak—blankest heaven, Lovers—friends?

You would build a mansion, I would weave a bower —Want the heart for enterprise.

Walls admit of no expansion: Trellis-work may haply flower Twice the size.

What makes glad Life's Winter?

New buds, old blooms after.

Sad the sighing "How suspect Beams would ere mid-Autumn splinter, Rooftree scarce support a rafter, Walls lie wrecked?"

You are young, my princess!

I am hardly older: Yet—I steal a glance behind!

Dare I tell you what convinces Timid me that you, if bolder, Bold—are blind?

Where we plan our dwelling Glooms a graveyard surely!

Headstone, footstone moss may drape,— Name, date, violets hide from spelling,— But, though corpses rot obscurely, Ghosts escape.

Ghosts! O breathing Beauty,