Contents

Preface to the Second Updated Edition

Acronyms and Initialisms

Units and their Abbreviations

1 Introduction

2 History of Coal in the Industrial Revolution and Beyond

3 History of Petroleum Oil and Natural Cas

3.1 Oil Extraction and Exploration

3.2 Natural Gas

4 Fossil Fuel Resources and Their Use

4.1 Coal

4.2 Petroleum Oil

4.3 Unconventional Oil Sources

4.4 Natural Gas

4.5 Coalbed Methane

4.6 Tight Sands and Shales

4.7 Methane Hydrates

4.8 Outlook

5 Diminishing Oil and Natural Cas Reserves

6 The Continuing Need for Carbon Fuels, Hydrocarbons and their Products

6.1 Fractional Distillation

6.2 Thermal Cracking

7 Fossil Fuels and Climate Change

7.1 Effects of Fossil Fuels on Climate Change

7.2 Mitigation

8 Renewable Energy Sources and Atomic Energy

8.1 Introduction

8.2 Hydropower

8.3 Geothermal Energy

8.4 Wind Energy

8.5 Solar Energy Photovoltaic and Thermal

8.6 Bioenergy

8.7 Ocean Energy Tidal, Wave and Thermal Power

8.8 Nuclear Energy

8.9 Future Outlook

9 The Hydrogen Economy and its Limitations

9.1 Hydrogen and its Properties

9.2 Development of Hydrogen Energy

9.3 Production and Uses of Hydrogen

9.4 The Challenge of Hydrogen Storage

9.5 Centralized or Decentralized Distribution of Hydrogen?

9.6 Hydrogen Safety

9.7 Hydrogen as a Transportation Fuel

9.8 Fuel Cells

9.9 Outlook

10 The “Methanol Economy”: General Aspects

11 Methanol and Dimethyl Ether as Fuels and Energy Carriers

11.1 Background and Properties

11.2 Chemical Uses of Methanol

11.3 Methanol as a Transportation Fuel

11.4 Dimethyl Ether as a Transportation Fuel

11.5 DME Fuel for Electricity Generation and as a Household Gas

11.6 Biodiesel Fuel

11.7 Advanced Methanol-Powered Vehicles

11.8 Hydrogen for Fuel Cells Based on Methanol Reforming

11.9 Direct Methanol Fuel Cell (DMFC)

11.10 Fuel Cells Based on Other Methanol Derived Fuels and Biofuel Cells

11.11 Regenerative Fuel Cell

11.12 Methanol and DME as Marine Fuels

11.13 Methanol and DME for Static Power and Heat Generation

11.14 Methanol and DME Storage and Distribution

11.15 Price of Methanol and DME

11.16 Safety of Methanol and DME

11.17 Emissions from Methanol- and DME-Powered Vehicles

11.18 Environmental Effects of Methanol and DME

11.19 Beneficial Effect of Chemical CO₂ Recycling to Methanol on Climate Change

12 Production of Methanol: From Fossil Fuels and Bio-Sources to Chemical Carbon Dioxide Recycling

12.1 Methanol from Fossil Fuels

12.2 Methanol through Methyl Formate

12.3 Methanol from Methane without Producing Syn-Gas

12.4 Methanol from Biomass, Including Cellulosic Sources

12.5 Chemical Recycling of Carbon Dioxide to Methanol

13 Methanol-Based Chemicals, Synthetic Hydrocarbons and Materials

13.1 Methanol-Based Chemical Products and Materials

13.2 Methyl tert-butyl Ether and DME

13.3 Methanol Conversion into Light Olefins and Synthetic Hydrocarbons

13.4 Methanol to Olefrn (MTO) Processes

13.5 Methanol to Gasoline (MTG) Processes

13.6 Methanol-Based Proteins

13.7 Outlook

14 Conclusions and Outlook

14.1 Where We Stand Now

14.2 The “Methanol Economy”, a Solution for the Future

References

For Further Reading and Information

Index

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Authers

Prof. Dr. George Olah

Dr. Alain Goeppert

Prof. Dr. G. K. Surya Prakash

Loker Hydrocarbon Research Institute

University of Southern California

837 W. 37th. Street

Los Angeles, CA 90089-1661

USA

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A catalogue record for this book is available from the British Library.

Bibliographic information published by the Deutsche Nationalbibliothek

The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available on the Internet at http://dnb.d-nb.de.

© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

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Cover Design

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ISBN: 978-3-527-32422-4

Preface to the Second Updated Edition

After just three years since the publication of the first edition of our book it is rewarding that favorable reception and interest prompted our publisher to suggest an updated edition. The concept of our proposed “Methanol Economy” in the intervening time has made progress from extended research to practical development in countries around the world. From smaller demonstration plants to full-scale methanol and derived dimethyl ether (DME) plants, practical industrial applications are growing in this field. These include carbon dioxide to methanol (and DME) conversion plants but also large million metric tonnes per year, coal or natural gas based mega-plants using still available large coal and natural gas resources. The full potential of the Methanol Economy will be realized, however, when the chemical recycling of natural and industrial carbon dioxide sources into methanol and its derived products are widely implemented, making their use environmentally carbon neutral and regenerative. This will allow us to mitigate the grave environmental problems linked to global warming. At the same time chemical carbon dioxide recycling, eventually from the air itself, will provide humankind with an inexhaustible carbon source available everywhere on earth. The needed hydrogen for the conversion of CO₂ into methanol can be produced from water using any renewable or atomic energy source. This conversion will allow the continued production of convenient transportation and household fuels, and synthetic hydrocarbons and their products on which we all so much depend on. It should be emphasized that methanol is not an energy source but only a convenient way to store, transport and use any form of energy. We are not suggesting that this approach is necessarily in all aspects the only solution for the future. The Methanol Economy, however, is a new feasible and realistic approach, warranting further development and increasing practical application.

Los Angeles, August 2009

George A. Olah
Alain Goeppert
G.K. Surya Prakash

Acronyms and Initialisms

AFC	alkaline fuel cell
BP	British Petroleum
BWR	boiling water reactor
CEA	Commissariat à l'Energie Atomique (France)
CEC	California Energy Commission
CI	compression ignition
CIA	Central Intelligence Agency
DME	dimethyl ether
DMFC	direct methanol fuel cell
DOE	Department of Energy (United States)
EDF	Electricité de France
EIA	Energy Information Administration (DOE)
EPA	Environmental Protection Agency (United States)
EPRI	Electric Power Research Institute
EU	European Union
GDP	gross domestic product
GHG	greenhouse gas
IAEA	International Atomic Energy Agency
ICE	internal combustion engine
IEA	International Energy Agency
IGCC	integrated gasification combined cycle
IPCC	International Panel on Climate Change
ITER	International Thermonuclear Experimental Reactor
JAERI	Japan Atomic Energy Research Institute
LNG	liquefied natural gas
MCFC	molten carbonate fuel cell
MTBE	methyl-tert-butyl ether
NRC	National Research Council (United States)
NREL	National Renewable Energy Laboratory (United States)
OECD	Organization for Economic Cooperation and Development
OPEC	Organization of Petroleum Exporting Countries
ORNL	Oak Ridge National Laboratory
OTEC	ocean thermal energy conversion
PAFC	phosphoric acid fuel cell
PEMFC	proton exchange membrane fuel cell
PFBC	pressurized fluidized bed combustion
PV	photovoltaics
PWR	pressurized water reactor
R/P	reserve over production ratio
SUV	sport utility vehicle
TPES	total primary energy supply
UNO	United Nations Organization
UNSCEAR	United Nations Scientific Committee on Effects of Atomic Radiation
UNEP	United Nation Environmental Program
URFC	unitized regenerative fuel cell
USCB	United States Census Bureau
USGS	United States Geological Survey
WCD	World Commission on Dams
WCI	World Coal Institute
WEC	World Energy Council
WMO	World Meteorological Organization
ZEV	zero emission vehicle

Units and their Abbreviations

atm	atmosphere
b and bbl	barrel
btu	British thermal unit
°C	degree Celsius
cal	calorie
g	gram
h	hour
ha	hectare
kWh	kilowatt-hour
m	meter
Mb	megabarrel (106 barrels)
ppm	parts per million
s	second
Sv	Sievert
t	metric tonne
toe	tonne oil equivalent
W	watt

Prefixes

p-	micro 10 6
m	milli 1(T3
k	kilo 103
M	mega 106
G	giga 109
T	tera 1012
P	peta 1015
E	exa 1018

Conversion of Units

Volume

1 tonne of crude oil = 7.33 barrels of oil
1 gallon = 3.785 liters
1 barrel of oil = 42 U.S. gallons = 159 liters
1 m³ = 1000 liters
1 m³ = 35.3 cubic feet (ft³)

Energy

1 kcal = 4.1868 kj = 3.968 Btu
1 kj = 0.239 kcal = 0.948 Btu
1 kWh = 860 kcal = 3600 kj
1 toe = 41.87 GJ
Quadrillion Btu, QBtu = 1 x 10¹⁵ Bt

1

Introduction

Ever since our distant ancestors managed to light fire for providing heat, means for cooking and many essential purposes, humankind’s life and survival has been inherently linked with an ever-increasing thirst for energy. From burning wood, vegetation, peat moss and other sources to the use of coal, followed by petroleum oil and natural gas (fossil fuels), we have thrived using Nature’s resources [1]. Fossil fuels include coal, oil and gas – all composed of hydrocarbons with varying ratios of carbon and hydrogen.

Hydrocarbons derived from petroleum oil, natural gas or coal are essential in many ways to modern life and its quality. The bulk of the world’s hydrocarbons are used as fuels for propulsion, electrical power generation and heating. The chemical, petrochemical, plastics and rubber industries also depend upon hydrocarbons as raw materials for their products. Indeed, most industrially significant synthetic chemicals are derived from petroleum sources. The overall use of oil in the world is now close to 12 million metric tons per day [2]. An ever-increasing world population (presently nearing 7 billion and projected to increase to 8–11 billion by the middle of the twenty-first century [3]; Table 1.1) and energy consumption, compared with our finite non-renewable fossil fuel resources, which will be increasingly depleted, are clearly on a collision course. New solutions will be needed for the twenty-first century to sustain the standard of living to which the industrialized world has become accustomed and to which the developing world is striving to achieve.

The rapidly growing world population, which stood at 1.6 billion at the beginning of the twentieth century, is now approaching 7 billion. With an increasingly technological society, the world’s resources have difficulty keeping up with demands. Satisfying our society’s needs while safeguarding the environment and allowing future generations to continue to enjoy planet Earth as a hospitable home is one of the major challenges that we face today. Man needs not only food, water, shelter, clothing and many other prerequisites but also increasingly huge amounts of energy. In 2004 the world used some 1.13 × 10²⁰ calories per year (131 Petawatt-hours), equivalent to a continuous power consumption of about 15 terawatts (TW), which is comparable to the production of 15 000 nuclear power plants each of 1 GW output [4]. With increasing world population, development and higher standards of living, this demand for energy is expected to grow to 21 TW in 2025 (Figure 1.1). In 2050 the demand is expected to reach 30 TW.

Our early ancestors discovered fire and began to burn wood. The industrial revolution was fueled by coal, and the twentieth century added oil and natural gas and introduced atomic energy.

When fossil fuels such as coal, oil or natural gas (i.e., hydrocarbons) are burnt to generate electricity in power plants, or to heat our houses, propel our cars, airplanes, and so on, they form carbon dioxide and water as the combustion products. They are thus used up, and are non-renewable on the human timescale.

Nature has given us, in the form of oil and natural gas, a remarkable gift. It has been determined that a single barrel of oil has the energy equivalent of 12 people working all year, or 25000 man hours [5]. With each American consuming on average about 25 barrels of oil per year, this would amount to each of them having 300 people working all year long to power the industries and man their households to maintain their current standard of living. Considering the present cost of oil, this is truly a bargain. What was created over the ages, however, mankind is consuming rather rapidly. Petroleum and natural gas are used on a massive scale to generate energy, and also as raw materials for diverse man-made materials and products such as the plastics, pharmaceuticals and dyes that have been developed during the twentieth century. The United States energy consumption is heavily based on fossil fuels, with atomic energy and other sources (hydro, geothermal, solar, wind, etc.) representing only a modest 15% of the energy mix (Table 1.2) [6].

With regard to electricity generation, coal still represents about half of the fuel used, with some 19% for natural gas and 19% for nuclear energy (Table 1.3).

Other industrialized countries, in contrast, obtain between 20% and 90% of their electrical energy from non-fossil sources (Table 1.4) [7].

Oil use has grown to the point where the world consumption is around 85 million barrels (1 barrel equals 42 gallons, i.e., some 160 L) a day, or almost 12 million metric tonnes [2]. Fortunately, we still have significant worldwide reserves left, including heavy oils, oil shale and tar-sands and even larger deposits of coal (a mixture of complex carbon compounds more deficient in hydrogen than oil and gas). Our more plentiful coal reserves may last for 200–300 years, but at a higher socio-economical and environmental cost. It is not suggested that our resources will run out in the near future, but it is clear that they will become even scarcer, much more expensive, and will not last for very long. With a world population nearing 7 billion and still growing (as indicated earlier, it may reach 8–11 billion), the demand for oil and gas will only increase. It is also true that, in the past, dire predictions of rapidly disappearing oil and gas reserves have always been incorrect (Table 1.5) [2, 8]. Until fairly recently the reserves have been growing, but lately they seem to have leveled off.

The question is, however, what is meant by “depletion” and what is the real extent of our reserves? Proven oil reserves, instead of being depleted, have in fact almost doubled during the past 30 years and now exceed 150 billion tonnes (more than one trillion barrels) [2]. This seems so impressive that many people assume that there is no real oil shortage in sight. However, increasing consumption due to increasing standards of living, coupled with a growing world population, makes it more realistic to consider per-capita reserves. Based on this consideration, it becomes evident that our known accessible reserves will not last for much more than this century. Even if all other factors are taken into account (new findings, savings, alternate sources, etc.) our overall reserves will inevitably decrease, and thus we will increasingly face a major shortage. Oil and gas will not become exhausted overnight, but market forces of supply and demand will start to drive the prices up to levels that nobody even wants to presently contemplate. Therefore, if we do not find new solutions, we will face a real crisis.

Table 1.5 Proven oil and natural gas reserves (in billion tonnes oil equivalent).

Source for 1995–2006: BP Statistical Review of World Energy [2].

Year	Oil	Natural gas
1960	43	15
1965	50	22
1970	78	33
1975	87	55
1980	91	70
1986	95	87
1987	121	91
1988	124	95
1989	137	96
1990	137	108
1995	140	130
2002	160	160
2003	162	162
2004	162	161
2005	164	162
2006	165	163

Humankind wants the advantages that an industrial society can give to all of its citizens. We essentially rely on energy, but the level of consumption varies vastly in different parts of the world (industrialized versus developing and underdeveloped countries). At present for example, the annual oil consumption per capita in China is still only two to three barrels, whereas it is about ten-fold this level in the United States [2]. China’s oil use is expected to at least double during the next decade, and this alone equals roughly the United States consumption – reminding us of the size of the problem that we will face. Not only the world population growth but also the increasing energy demands from China, India and other developing countries is already putting great pressure on the world’s oil reserves, and this in turn contributes to price escalation. Large price fluctuations, with temporary sharp drops, can be expected, but the upward long-term trend in oil prices is inevitable.

Even though the generation of energy by massive burning of non-renewable fossil fuels (including oil, gas and coal) is feasible only for a relatively short period in the future, it is generating serious environmental problems (vide infra). The advent of atomic energy opened up a fundamental new possibility, but also created dangers and concerns regarding the safety of radioactive by-products. Regrettably, these considerations brought any further development of atomic energy almost to a standstill, at least in most of the Western world. Whether we like it or not, we clearly have few alternatives and will rely on using nuclear energy, albeit making it safer and cleaner. Problems, including those of the storage and disposal of radioactive waste products, must be solved. Pointing out difficulties and hazards as well as regulating them, within reason, is necessary, but solutions to overcome them are essential and certainly feasible.

As we continue to burn our hydrocarbon reserves to generate energy at an alarming rate, diminishing resources and sharp price increases will inevitably lead to the need to supplement or replace them by feasible alternatives. Alternative energy and fuel sources and synthetic oil products are, however, more costly. Nature’s petroleum oil and natural gas are the greatest gifts we will ever have. However, with a barrel of oil presently priced between $30 and $150, within wide market fluctuations, some synthetic manufacturing processes are already becoming economically viable. Regardless, it is clear that we will need to get used to higher prices, not as a matter of any government policy but as a fact of market forces over which free societies have limited control.

Synthetic oil products are feasible. Their production was proven via synthesis-gas (syn-gas), a mixture of carbon monoxide and hydrogen obtained from the incomplete combustion of coal or natural gas, which, however, are themselves non-renewable. Coal conversion was used in Germany during World War II and in South Africa during the boycott years of the Apartheid era [9]. Nevertheless, the size of these operations hardly amounted to 0.3% of the present United States consumption alone. This route – the so-called Fischer–Tropsch synthesis – is also highly energy consuming, giving complex product mixtures and generating large amounts of carbon dioxide, thereby contributing to global warming. It thus can hardly be seen on its own as the technology of the future. To utilize still-existing large natural gas reserves, their conversion into liquid fuels through syn-gas is presently being developed; for example, on a large scale in Qatar, where Shell is spending over $10 billion on the construction of gas-to-liquid (GTL) facilities, to produce about 140 000 barrels per day of liquid hydrocarbon products, mainly sulfur-free diesel fuel. Chevron in partnership with Sasol has already built a GTL unit in Qatar with a capacity of 34 000 barrels per day. However, even when running at full capacity, these plants will provide only a daily total of some 180 000 barrels, compared with present world use of transportation fuels alone in excess of 45 million barrels per day. These figures demonstrate the enormity of the problem that we face. New and more efficient processes are clearly needed. Some of the required basic science and technology is already being developed. As will be discussed below, still abundant natural gas can be, for example, directly converted, without first producing syn-gas, into gasoline or hydrocarbon products. Using our even larger coal resources to produce synthetic oil could extend its availability, but new approaches based on renewable resources are essential for the future. The development of biofuels, primarily by the fermentative conversion of agricultural products (derived from sugar cane, corn, etc.) into ethanol is evolving. Whereas ethanol can be used as a gasoline additive or alternative fuel, the enormous amounts of transportation fuel needed clearly limits the applicability to specific countries and situations. Other plant-based oils are also being developed as renewable equivalents of diesel fuel, although their role in the total energy picture is again limited. Biofuels have also started to affect food prices by competing for the same agricultural resources [10].

When hydrocarbons are burned, as pointed out, they produce carbon dioxide (CO₂) and water (H₂O). It is a great challenge to reverse this process and to chemically produce, efficiently and economically, hydrocarbon fuels from CO₂ and H₂O. Nature, in its process of photosynthesis, recycles CO₂ with water into new plant life using the Sun’s energy. While fermentation and other processes can convert plant life into biofuels and products, the natural formation of new fossil fuels takes a very long time, making them non-renewable on the human timescale.

The “Methanol Economy®” [11] – the subject of our book – elaborates a new approach of how humankind can decrease and eventually liberate itself from its dependence on diminishing oil and natural gas (and even coal) reserves while mitigating global warming caused by the carbon dioxide released by their excessive combustion. The “Methanol Economy” is in part based on the more efficient direct conversion of still-existing natural gas resources into methanol or dimethyl ether, and most importantly on their production by chemical recycling of CO₂ from the exhaust gases of fossil fuel-burning power plants as well as other industrial and natural sources. Eventually, even atmospheric CO₂ itself can be captured and recycled using catalytic or electrochemical methods. This represents a chemical regenerative carbon cycle alternative to natural photosynthesis [12]. Methanol and dimethyl ether (DME) are both excellent transportation and industrial fuels on their own for internal combustion engines and household uses, replacing gasoline, diesel fuel and natural gas. Methanol is also a suitable fuel for fuel cells, being capable of producing electric energy by reaction with atmospheric oxygen contained in the air. It should, however, be emphasized that the “Methanol Economy” per se is not producing energy. In the form of methanol or DME it only stores energy more conveniently and safely compared to extremely difficult to handle and highly volatile alternative hydrogen gas, which is the basis of the so-called “hydrogen economy” [13, 14]. Besides being most convenient energy storage materials and suitable transportation fuels, methanol and DME can also be catalytically converted into ethylene and/or propylene, the building blocks of synthetic hydrocarbons and their products presently obtained from our diminishing oil and gas resources.

The far-reaching applications of the new “Methanol Economy” approach clearly have great implications and societal benefit for humankind. As mentioned, the world is presently consuming about 85 million barrels of oil each day, and about two-thirds as much natural gas equivalent, both being derived from our declining and non-renewable natural sources. Oil and natural gas (as well as coal) were formed by Nature over the eons in scattered and frequently increasingly difficult-to-access locations such as under desert areas, in the depths of the seas, the inhabitable reaches of the Polar Regions, and so on. In contrast, the recycling of CO₂ from industrial exhausts or natural sources, and eventually from the air itself, which belongs to everybody, opens up an entirely new vista. The energy needs of humankind will, in the foreseeable future, come from any available source, including alternative sources and atomic energy. As we still cannot store energy efficiently on a large scale, new ways of storing energy are also needed. The production of methanol offers a convenient means of energy storage. Even now, our existing power plants, during off-peak periods, could, by the electrolysis of water, generate the hydrogen needed to produce methanol from CO₂. Other means of cleaving water by thermal, biochemical (enzymatic) or photovoltaic (using energy from the Sun, our ultimate clean energy source) pathways are also evolving.

Initially, CO₂ will be recycled from high level industrial emissions to produce methanol and to derive synthetic hydrocarbons and their products. CO₂ accompanying natural gas, geothermal and other natural sources will also be used. The CO₂ content of these emissions is high and can be readily separated and captured. In contrast, the average CO₂ content of air is very low (0.038%) (Table 1.6). Atmospheric CO₂ is therefore presently difficult to utilize on an economic basis. However, these difficulties can be overcome by ongoing developments using selective absorption or other separation technologies. Humankind’s ability to technologically recycle CO₂ to useful fuels and products will eventually provide an inexhaustible renewable carbon source.

Carbon dioxide can readily be recovered from industrial sources, such as flue gas emissions of power plants burning carbonaceous fossil fuels (coal, oil and natural gas), fermentation processes, the calcination of limestone in cement production, production of steel and aluminum, and so on, as well as natural CO₂ accompanying natural gas, geothermal sources and others. As these plants and operations emit very large amounts of CO₂ they contribute to the increasing “greenhouse warming effect” of our planet, which is causing grave environmental concern. The relationship between the atmospheric CO₂content and temperature was first studied scientifically by Arrhenius as early as 1895 [15]. The climate change and warming/cooling trends of our Earth can be evaluated only over longer time periods, but there is clearly a relationship between the CO₂ content in the atmosphere and Earth’s surface temperature.

Table 1.6 Composition of air.

Nitrogen	78%
Oxygen	20.90%
Argon	0.90%
Carbon dioxide	0.038%
Water	Few % (variable)
Methane, nitrogen oxides, ozone	Trace amounts of each

Recycling excess CO₂ evolving from human activities into methanol and dimethyl ether, and further developing and transforming them into useful fuels and synthetic hydrocarbons and products, will thus not only help to alleviate the question of our diminishing fossil fuel resources but at the same time help to mitigate global warming caused by human-made greenhouse gases.

One highly efficient method of producing electricity directly from varied fuels is achieved in fuel cells via their catalytic electrochemical oxidation, primarily that of hydrogen (Equation 1.1).

(1.1)

The principle of fuel cells was first recognized by William Grove during the early 1800s, but their practical use was only recently developed. Most fuel cell technologies are still based on Grove’s approach, that is, hydrogen and oxygen (air) are combined in an electrochemical cell-like device, producing water and electricity. The process is clean, giving only water as a by-product. Hydrogen itself, however, must be first produced in an energy-consuming process, using at present mainly fossil fuels and to a lesser extent the electrolysis of water. The handling of highly volatile hydrogen gas is not only technically difficult, but also dangerous. Nonetheless, the use of hydrogen-based fuel cells is gaining application in static installations or in specific cases, such as space vehicles. Currently, hydrogen gas is produced mainly from still-available fossil fuel sources using reformers, which converts them into a mixture of hydrogen and carbon monoxide from which hydrogen is then separated. Although this process relies mostly on our diminishing fossil fuel sources, electrolysis or other processes to cleave water can also provide hydrogen without any reliance on fossil fuels. Hydrogen-burning fuel cells, by necessity, are still limited in their applicability. In contrast, a new approach (discussed in Chapter 11) uses, directly, convenient liquid methanol, or its derivatives, in fuel cells without first converting it into hydrogen. The direct oxidation liquid-fed methanol fuel cell (DMFC) has been developed in a cooperative effort between our group at the University of Southern California and Caltech-Jet Propulsion Laboratory of NASA, who for a long time developed fuel cells for the U.S. space programs [16, 17]. In such a fuel cell, methanol reacts with oxygen present in the air over a suitable metal catalyst, producing electricity while forming CO₂ and H₂O:

(1.2)

More recently, it was found that the process could also be reversed. Methanol and related oxygenates can be made from CO₂ via aqueous electrocatalytic reduction without prior electrolysis of water to produce hydrogen in what is termed a “regenerative fuel cell.” This process can convert CO₂ and H₂O electrocatalytically into oxygenated fuels (i.e., formic acid, formaldehyde and methanol), depending on the electrode material and potential used in the fuel cell in its reverse operation.

The reductive conversion of CO₂ into methanol is primarily carried out by catalytic hydrogenation using hydrogen produced by electrolysis of water (using any available energy sources such as atomic, solar, wind, geothermal, etc.) or other means of cleavage (photolytic, enzymatic, etc.):

(1.3)

Natural gas, when available, can also be used for the CO₂ to methanol conversion, including improved processes such as our proposed bi-reforming (Chapter 10) [18]:

(1.4)

As mentioned, methanol is a convenient energy storage material and an excellent transportation fuel. It is a liquid, with a boiling point of 64.6°C, allowing it to be transported easily and stored using existing infrastructure. Methanol can also be readily converted into dimethyl ether, which has a higher calorific value and is an excellent diesel fuel and household gas substitute:

(1.5)

Methanol and DME produced directly from methane (natural gas) without going to syn-gas or by recycling of CO₂ can subsequently also be used to produce ethylene as well as propylene (Equation 1.6):

(1.6)

These are the building blocks in the petrochemical industry for the ready preparation of synthetic aliphatic and aromatic hydrocarbons, and for the wide variety of derived products and materials, obtained presently from oil and gas, on which we rely so much in our everyday life.

2

History of Coal in the Industrial Revolution and Beyond

Coal was formed during the Carboniferous Period – roughly 360 to 290 million years ago – from the anaerobic decomposition of then-living plants. These plants ended up as coal because, upon their death, they failed to decompose in the usual way, by the action of oxygen to form eventually CO₂ and water. As the carboniferous plants died they often fell into oxygen-poor swamps or mud, or were covered by sediments. Because of the lack of oxygen they only partially decayed. The resulting spongy mass of carbon-rich material first became peat. Then, by action of the heat and pressure of geological forces, peat eventually hardened into coal.

During this process, the plant’s carbon content was trapped in coal, together with the sun’s energy used in the photosynthesis of plants, and accumulated over millions of years. This energy source was buried until modern man dug it up and made use of it. It is only very recently on the Earth’s timescale that humankind has started to use coal. Historically, the use of coal began when the Romans invaded Britain [19]. While it was used occasionally for heating purposes, the main use of this “black stone” was to make jewelry, since it could be easily carved and polished. It was only during the late twelfth century that coal re-emerged as a fuel along the river Tyne in Britain, especially around the rich coal fields of Newcastle. The widespread use of coal, however, would not be significant before the middle of the sixteenth century. At that time, England’s population – and that of London especially – was growing rapidly. As the city grew, the nearby land was deforested to a degree where wood had to be hauled from increasingly distant locations. Wood was used not only for home heating and cooking purposes but also in most industries, such as breweries, iron smelters and ship building. As the shortage of wood became increasingly pronounced, its price increased such that the poorest of the population were increasingly unable to afford it. These were particularly hard times because Europe had just entered into a so-called “little ice age,” which would last until the eighteenth century. However, a severe energy crisis never materialized thanks to coal, which became increasingly the country’s main source of fuel by the beginning of the seventeenth century. This conversion to coal was not without problems; coal’s thick smoke upon burning made London’s air quality one of the poorest in all of Europe. On some days, the sun was hardly able to penetrate the coal smoke, and travelers could smell the city miles before they actually saw it.

What really brought about the power of coal as an energy source came along in the early eighteenth century with the invention of the steam engine. The steam engine was at the heart of the resulting industrial revolution [20], and it was fueled by coal. At the time, one of the main problems facing coal mining was water seepage and flooding from various sources. Rainwater seeping down from the surface accumulated in the tunnels, and once the mines reached below the water table the surrounding groundwater also contributed to the problem. Consequently, the mines became slowly submerged in water. If the mine was located on a hill, simple draining shafts could be used, but as the mines were pushed deeper into the ground, the water had to be removed by other means. The earliest method relied on miners hauling the water up in buckets strapped to their backs. As this was not really convenient, various ways were designed to increase the effectiveness of the human labor. Among these were chains of buckets or primitive forms of pumps powered not only by human muscle but also in some cases by windmills, waterwheels (Figure 2.1) or horse power. However, none of these was very convenient or economical.

One of the most pressing challenges for contemporary England was to find a way to keep its coal mines dry. This led eventually to the introduction of a device invented by Thomas Newcomen, who was not a scholar but a very inventive small-town ironmonger [1]. His device consisted of a piston that moved up by steam generated by heating water with burning coal, and down by reduced pressure resulting from the condensation of steam with cold water. The piston was connected to the rod of a pump used to pump water.

In 1712, one of these Newcomen engines was first used in a coal mine and became an almost immediate hit among mine operators, largely because it was much cheaper to operate than horses and could pump water from a much greater depth than ever before. The drawback was that the engine needed large amounts of coal to generate the steam necessary to keep it operating, and therefore found little use outside of the coal mines.

At about this time James Watt, a carpenter’s son from Scotland, improved Newcomen’s steam engine dramatically. Watt realized that as steam was injected and then cooled with water, heat was wasted in the constant reheating and cooling of the cylinder. The installation of a separate condenser immersed in cold water connected to the cylinder kept it hot and avoided unnecessary heat losses (Figure 2.2). This improved the efficiency of the steam engine by at least a factor of four, and allowed it to move out from the coal mines and find its place in factories.

To really move the industrial revolution ahead, however, another technological advance was needed: the manufacture of iron using coal-based coke. Until that time, the iron needed to build engines and factories was essentially made using charcoal obtained by burning huge amounts of wood, which was increasingly becoming scarcer in Britain. Charcoal provided both the heat and the carbon needed for the reduction of the iron ore. The use of coal to smelt iron was hindered by the impurities it contained, which made it unsuitable. After more than a century of experimentation, however, the key to making iron using coal was found. In the same way that wood was turned into charcoal, coal had first to be baked to drive off the volatiles and form coke. By the 1770s, the technology had advanced to the point where coke could be used in all stages of iron production. With this breakthrough, Britain, rather than being dependent upon iron imports, became in just a few years the most efficient iron producer in the world. This technological advance allowed it to build its powerful industries at home and its vast empire worldwide.

The “coal economy” resulted in a concentration of the ever-larger and mechanized factories, as well as their workforces, into urban areas, making them more efficient. The epicenter of this industrial revolution was Manchester, which became the premier center of manufacture in England. The city also became home of the first steam locomotive-driven public railway, the Liverpool and Manchester Railway, which opened in 1830 (Figure 2.3). The “father of the railways” was George Stephenson, who first envisioned moving large quantities of coal over land. It was through the steam locomotive that this transport became possible, although this invention would in time have revolutionary consequences far beyond the coal industry.

The Liverpool and Manchester Railway became a huge success, transporting hundreds of thousands of passengers during the first months of operation. This success established a bright future for railway as a transportation system and triggered massive investment in this industry. Although other European nations followed its example, Britain had a good 50 years head start in industrialization, and maintained its lead for most of the nineteenth century. In 1830, Britain produced 80% of the world’s coal and, in 1848, more than half of the iron of the world, making the nation the most powerful on Earth until the end of the nineteenth century. Across the Atlantic, however, the United States – having even more coal and other resources than England – also began to undergo an even faster industrial transformation.

Historically, coal has probably been the most important fossil fuel, as it triggered the industrial revolution that led to our present-day modern industrial society. During the twentieth century, coal has been supplemented and displaced progressively by oil and natural gas, as well as nuclear power, for electricity generation. Coal was increasingly considered as a “dirty fuel” of the past, and was deemed to have a limited future. Only with the energy crisis in the 1970s, and the growing concerns about the safety of nuclear energy, did coal again become an attractive energy source, especially for electricity production. Because the reserves of coal are geographically widespread and coal is a heavy and bulky solid which is costly to transport, it is mainly utilized close to its source. The economically recoverable proven coal reserves are enormous, and estimated as being in the order of one trillion tonnes [2, 21, 22] – enough at current rates of consumption to supply our needs for more than 150 years. The reserve over production (R/P) ratio is more than two times as large as that for natural gas, and about four times as high as that for oil. Unlike oil and natural gas, our coal resources should last at least for the next two centuries. Our total coal resources are estimated to be more than 6.2 trillion tonnes [23]. The main reason why the R/P ratio for coal is not even higher is the limited incentive to find new exploitable reserves, given the size of already-known reserves. Production has increased ten-fold over the past 100 years, without any significant increase in coal price. In contrast, the implementation of advanced mining technologies has improved, and will continue to improve productivity and steadily lower the cost of coal extraction and treatment. The efficiency of coal transportation, which can represent as much as 50% of the import cost into Europe or Japan, is also improving [24]. Furthermore, large reserves, coupled with competition between coal-producing countries, make a sustained price increase unlikely and should result in relatively flat coal prices in the foreseeable future. In the case of coal, neither the abundant resources nor the competitive prices are determining factors in the fuel’s future. The rate of extraction of coal is presently only a function of its relatively limited demand. In industrialized countries, where coal is used mainly to generate electricity, the demand will be governed by the ability of coal to compete with natural gas, not only from an economic point of view but also increasingly from environmental considerations. One of the reasons why we no longer rely more heavily on coal is that, from an environmental aspect, it is the most polluting fossil fuel compared to oil and gas. It usually emits significant levels of pollutants, especially sulfur dioxide, nitrogen oxides and particulates. Heavy metals such as mercury, lead, arsenic and even uranium are difficult to remove from coal, and are generally released into the air upon combustion [25]. Interestingly, these concerns about pollution are as old as the use of coal itself. An ordinance from 1273 prohibiting the use of coal in London as prejudicial to health is the earliest known attempt to reduce smoke pollution [26]. Present efforts to ban or reduce the use of coal are thus not revolutionary or new.

In a continuous effort to diminish the environmental impact of coal burning, the development and progressive introduction of new separation technologies applied to existing or new power plants can greatly reduce or nearly eliminate the emissions of SO₂, NO_x and particulates [27]. Emission regulations for mercury and other impurities present in coal are under evaluation in several nations, including the United States. Most significantly, the combustion of coal also generates large amounts of CO₂, a harmful greenhouse gas that contributes to a large extent to human-caused global warming. The only presently considered technology to mitigate CO₂ emissions is to capture and subsequently sequester it in underground formations or at the bottom of the seas [27]. At present, however, there are no CO₂ emission capture technologies operating at large-scale power plants. Given the growing concerns about global warming, coal-burning power plants represent a major challenge. Compared to oil and gas, coal is the fuel that produces the most CO₂ and other pollutants per unit of energy released. To tackle this problem, so-called “clean coal technologies” are being developed to improve the thermal efficiency and reduce emissions and, consequently, the environmental impact of coal-fired power plants [23, 28]. Among these technologies, some are already commercially available.

₂₂

From an energy perspective, coal has a major advantage as its resources are still vast and are widely distributed around the world. Furthermore, the outlook for coal supply and prices is subject to less fluctuation than for oil and gas. However, coal could be penalized for its high carbon content, and the key uncertainty affecting the future of coal is the impact of environmental policies. Longer-term prospects for coal may therefore depend on the development and introduction of clean coal technologies and carbon dioxide recycling that would reduce or even eliminate carbon emissions. In any case, coal resources will not last for more than two or three centuries – longer than oil and gas, but still a short period on the timescale of humanity.

As coal (and all other carbon containing fossil fuels) upon combustion forms carbon dioxide, a major greenhouse gas contributing to global warming, serious attacks have recently been directed by environmentalist groups and individuals to abandon altogether coal as a fuel. These attacks are part of an effort to “cure” society from its carbon addiction. We do not consider this a realistic goal, at least in the short term, as with our large coal reserves, lasting centuries, humankind will hardly be able to avoid the use of coal as an energy source, and also as a source for synthetic hydrocarbons and products. A more feasible and practical solution seems to be to capture and chemically recycle carbon dioxide to methanol and derived products as part of our “Methanol Economy” [12]. Capturing and sequestering carbon dioxide emission is already being considered and is starting to be implemented. Sequestering of CO₂ is, however, only a temporary and potentially dangerous solution for the disposal of CO₂ in contrast with its chemical recycling in the context of the “Methanol Economy” (Chapters 10–14).