Hydrogen & Fuel Cells

Advances in Transportation and Power

Michael Frank Hordeski

• Publisher: River Publishers
• Year: 2020
• eBook ISBN: 9781000356137
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

The hydrogen car has been proposed as the solution to our oil problems, but how would it work, and what potential problems associated with it? This book addresses these questions and provides specifics about current developments toward a hydrogen-based energy infrastructure. It offers the reader an informed look at the current state of fuel cell power and transportation technology, and where it's headed.

Chapter 1

The Energy Evolution

When oil prices increase, the interest in alternatives increases. Recent hydrogen demonstration programs are being conducted by states such as California where the concern of air quality is high which makes finding solutions more urgent.

Alternate energy becomes more popular but major questions remain to be answered on which fuel or fuels will emerge and to what extent alternative sources will replace gasoline as the main product of crude oil.

Oil and other non-renewable fossil fuels are being quickly consumed, which is creating major impacts on air and water pollution as well as concern on global climate change. A shift to zero-carbon emission solar hydrogen systems could fundamentally resolve these energy supply and environmental problems. Hydrogen can be manufactured from water with algae and other microorganism, as well as with any source of electricity. New electrical production options include coal and nuclear power plants or solar technologies, such as photovoltaic, wind and ocean thermal systems.

Civilization has experienced exceptional developments during the last 200 years. This was spurred by the discovery and use of fossil fuels and resulted large productivity gains. Humans now number over 6 billion persons, more than 6 times the population that existed before the discovery of fossil fuels. Even persons with moderate incomes in industrialized countries have, in many aspects, much more disposable energy, more comfortable homes, far better appliances, better health care choices, and more enjoyable living conditions than the most wealthy king or queen that reigned before fossil fuels were exploited. Millions of average citizens regularly drive cars and trucks on improved roadways with sufficient power to comfortably travel 300 miles at 60 MPH. More millionaires and billionaires now exert their economic reigns than at any previous time in history.

Progress was always possible when better tools were invented. Inventions that emphasized lighter, stronger and potentially more useful alloys defined the Iron Age of progress.

New inventions are rapidly progressing that will enable a solar hydrogen society to enter a non-carbon age of material excellence. Renewable energy for this advancement will be converted into safely storable, efficiently transportable, and clean usable hydrogen.

Hydrogen is a universal fuel that could power automobiles, aircraft, spacecraft, power plants and appliances, including gas stoves that can operate on mountain-tops. Since it is a zero-carbon emission fuel, carbon emissions that may effect pollution and global climate change are eliminated. Shifting to hydrogen energy can have a profound positive impact on the Earth’s biological systems.

Every product has a basic energy cost and the rising consumption of fossil fuels makes it difficult to predict energy costs in the future. Shifting to hydrogen will reduce future cost and supply uncertainties and significantly improve the U.S. balance of trade.

Many relate hydrogen fuel use, which involves a chemical change, with hydrogen weapons, which involves a thermonuclear reaction. Many people do not realize that most of the passengers and crew of the Hindenburg survived, and that extensive testing and utilization evidence by NASA & BMW show hydrogen to be safer in many ways than gasoline and other petrocarbon fuels when accidents do occur.

HYDROGEN THE BASIC ELEMENT

The chronicle of hydrogen begins with the Big Bang theory of universe creation 15 billion years ago, when hydrogen atoms were first formed. Gravity acted as the primitive force that caused the hydrogen to condense into vast clouds that collapsed into stars, which consume the hydrogen as fuel. When the larger stars with adequate mass no longer have enough hydrogen, a supernova is formed which then transforms into heavier elements. These giant molecular cloud formations, consisting almost entirely of hydrogen, are the most massive objects within galaxies. Gravity eventually causes the hydrogen to compress until it fuses into heavier elements.

Without the energy emitted by the sun, life as we know it could not exist. The primary fuel for the sun and other stars is hydrogen while the force that allows the sun and other stars to burn is gravity. Our sun consumes about 600 million tons of hydrogen every second. As this hydrogen is fused into helium, photons of electromagnetic energy are released and eventually find their way through the earth’s atmosphere as solar energy. This solar energy is the aftermath of nuclear fusion, while nuclear fission occurs in commercial nuclear reactors. Without this energy there would be no life, there would be no fossil fuels or wind or even elements in our world.

Hydrogen was discovered in 1766 when the English chemist Henry Cavendish observed what he called an inflammable air rising from a zinc-sulfuric acid mixture. It was identified and named in the 18th century by Antoine Lavoisier, who demonstrated that this inflammable air would burn in air to form water. He identified it as a true element, and called it hydrogen, which is Greek for water former. Hydrogen is the simplest, lightest and most abundant of the 92 elements in the universe. It makes up over 90% of the universe and 60% of the human body in the form of water. As the most basic element, it can never be exhausted since it recycles in a relatively short time.

Protons and electrons are the basic components of the hydrogen atom and these atoms are the basic building blocks of the other 91 elements that occur naturally. The atomic number of an atom equals the number of protons, hydrogen nuclei, or electrons of the element. Hydrogen with one proton and one electron, has an atomic number of 1. Carbon has six protons and six electrons and an atomic number of 6. The proton’s positive electrical charge and the electron’s negative charge have a natural attraction for each other.

Hydrogen atoms and other subatomic particles would have continued to expand away from each other from the force of the big bang, but gravity caused these particles to cluster in large masses. As the mass increased, the force of gravity increased and eventually, the force and pressure became great enough for the interstellar clouds of hydrogen to collapse causing the hydrogen and other particles to collide.

These collisions result in high enough temperatures of 45 million degrees Fahrenheit and pressures to fuse the hydrogen into helium and the birth of a star takes place. As the star feeds on this supply of hydrogen, four hydrogen nuclei are fused into one heavier helium nucleus.

The heavier helium atoms form a dense, hot core. When the star has consumed most of its hydrogen, it begins to burn or fuse the helium, converting it to carbon and then to oxygen.

The more massive a star is, the higher the central temperatures and pressures are in the later stages. When the helium is consumed, the star fuses the carbon and oxygen into heavier atoms of neon, magnesium, silicon and even silver and gold. In this way, all the elements of the earth except hydrogen and some helium were formed billions of years ago in stars.

The transition from nonrenewable fossil fuel should consider the development of technologies that can use the available energy of the sun. It is reasonable to assume that solar energy will eventually serve as a primary energy source. As we attempt to use solar energy to replace the use of fossil and nuclear fuels, this relationship between solar energy and hydrogen returns and one may not effectively work without the other.

Hydrogen is the most abundant element in the universe and our sun alone consumes 600 million tons of it each second. Unlike oil, widespread underground reservoirs of hydrogen are not to be found on earth. While hydrogen is the simplest element and most plentiful gas in the universe, it never occurs by itself and always combines with other elements such as oxygen and carbon. The hydrogen atoms are bound together in molecules with other elements and it takes energy to extract the hydrogen.

Hydrogen is not a primary energy source, but it can be used like electricity as a method of exchange for getting energy to where it is needed. As a sustainable, non-polluting source of power hydrogen could be used in many mobile and stationary applications. As an energy carrier, hydrogen could increase our energy diversity and security by reducing our dependence on hydrocarbon-based fuels.

HYDROGEN CHARACTERISTICS

Hydrogen is different than other energy options like oil, coal, nuclear or solar. Solar technology is renewable, modular and generally pollution free, but it has some disadvantages, such as not always being available at the right time.

Hydrogen and electricity are complementary and one can be converted into the other. Hydrogen can be viewed as a type of energy currency that does not vary in quality depending on origin or location. A molecule of hydrogen made by the electrolysis of water is the same as hydrogen manufactured from green plant biomass, paper, coal gasification or natural gas.

Hydrogen is a primary chemical feedstock in the production of gasoline, fuel oils, lubricants, fertilizers, plastics, paints, detergents, electronics and pharmaceutical products. It is also an excellent metallurgical refining agent and an important food preservative.

Hydrogen can be extracted from a range of sources since it is in almost everything, from biological tissue and DNA, to petroleum, gasoline, paper, human waste and water. It can be generated from nuclear plants, solar plants, wind plants, ocean thermal power plants or green plants.

When hydrogen is burned in a combustion chamber instead of a conventional boiler, high-pressure superheated steam can be generated and fed directly into a turbine. This could cut the capital cost of a power plant by one half. While hydrogen is burned, there is essentially no pollution. Expensive pollution control systems, which can be almost one third of the capital costs of conventional fossil fuel power plants are not required. This should also allow plants to be located closer to residential and commercial loads, reducing power transmission costs and line losses.

Since hydrogen burns cleanly and reacts completely with oxygen to produce water vapor, this makes it more desirable than fossil fuels for essentially all industrial processes. For example, the direct reduction of iron or copper ores could be done with hydrogen rather than smelting by coal or oil in a blast furnace. Hydrogen can be used with conventional vented burners as well as unvented burners. This would allow utilization of almost all of the 30 to 40% of the combustion energy of conventional burners that is lost as vented heat and combustion by-products.

ENERGY CARRIERS

Hydrogen is known as a secondary energy carrier, instead of a primary energy source. Energy is needed to extract the hydrogen from water, natural gas, or other compound that holds the hydrogen. This portrayal is not precise because it assumes solar, coal, oil or nuclear are primary energy sources, but energy is still expended to acquire them. Finding, extracting and delivering the so-called primary energy sources requires energy and major investments before they can be utilized. Coal and natural gas are closer to true primary energy sources since they can be burned directly with little or no refining, but energy is still needed to extract these resources and deliver them to where the energy is needed. Even when extensive drilling for oil is not required from shallow wells or pools, energy is still needed for pumping, refining and delivery.

Many environmental problems are the result of finding, transporting and burning fossil fuels. But, when hydrogen is used as a fuel, its by-product is essentially water vapor. When hydrogen is burned in the air, which contains nitrogen, nitrogen oxides can be formed as they are in gasoline engines. These oxides can almost be eliminated in hydrogen engines by lowering the combustion temperature of the engine. Some tests have shown that the air coming out of a hydrogen fueled engine is cleaner than the air entering the engine. Acid rain, ozone depletion and carbon dioxide accumulations could be greatly reduced by the use of hydrogen.

After it has been separated, hydrogen is an unusually clean-energy carrier and clean enough for the U.S. space shuttle program to use hydrogen-powered fuel cells to operate the shuttle’s electrical systems while the by-product of drinking water is used by the crew.

Hydrogen could be an alternative to hydrocarbon fuels such as gasoline with many potential uses, but it must be relatively safe to manufacture and use. Hydrogen fuel cells can be used to power cars, trucks, electrical plants, and buildings but the lack of an infrastructure for producing, transporting, and storing large quantities of hydrogen inhibit its growth and practicality. Although the technology for electrochemical power has been known since 1839, fuel cells are still not in widespread use. The electrochemical process allows fuel cells have few moving parts. Air compressors are often used to improve the efficiency although there are compressor-less designs.

Fuel cells operate like batteries expect that they combine a fuel, usually hydrogen, and an oxidant, usually oxygen from the air, without combustion.

HYDROGEN PRODUCTION

Hydrogen can be obtained from natural gas, gasoline, coal-gas, methanol, propane, landfill gas, biomass, anaerobic digester gas, other fuels containing hydrocarbons, and water. Obtaining hydrogen from water is an energy intensive process called electrolysis, while hydrocarbons require a more efficient reforming process.

Hydrogen may be produced by splitting water (H2O) into its component parts of hydrogen (H₂) and oxygen (O). Steam reforming of methane from natural gas is one way to do this. It converts the methane and other hydrocarbons in natural gas into hydrogen and carbon monoxide using the reaction of steam over a nickel catalyst. Another method is electrolysis which uses an electrical current to split water into hydrogen at the cathode (+ terminal) and oxygen at the anode (− terminal). Steam electrolysis adds heat to the process and this heat provides some of the energy needed to split water and makes the process more energy efficient. When hydrogen is generated from renewable sources, its production and use becomes part of a clean, natural cycle.

Thermochemical water splitting uses chemicals and heat in several steps to split water into hydrogen and oxygen. Photolysis is a photoelectrochemical process that uses sunlight and catalysts to split water. Biological and photobiological water splitting use sunlight and biological organisms. Thermal water splitting uses a high temperature of 1000°C. Biomass gasification uses microbes to break down different biomass feedstocks into hydrogen.

Some of the first life forms on Earth were photosynthetic algae that existed about 4 billion years ago. Hydrogenase is an enzyme that can be used in extracting hydrogen from carbon. Chlorophyll uses sunlight to extract hydrogen from water. In the future, developments in Microbiology, Molecular Biology and Nanotechnology are expected to allow biological hydrogen production systems to be fully realized.

Cost is one hurdle that is keeping hydrogen from being more widely as a fuel. Many changes in the energy infrastructure are needed to use hydrogen.

Electricity is required for many hydrogen production methods and the cost of this electricity tends to make hydrogen more expensive than the fuels it would replace.

Another matter is hydrogen’s flammability since it can ignite in low concentrations and can leak through seals. Leaks in transport and storage equipment could present public safety hazards. Gasoline transport and storage presents similar public safety hazards. Older gasoline storage tanks at filling stations have leaked and contaminated groundwater at many locations. A leaking pipeline contaminated the soil under a California coastal town and required demolition and rebuilding of the town in order to replace the soil.

STORAGE AND TRANSPORTATION

Hydrogen can be stored and transported as a compressed gas, a cryogenic liquid or in solids. Liquid hydrogen is closer to gasoline in the areas of volume and vehicular weight. In commercial aircraft, the t...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Chapter 1 The Energy Evolution
• Chapter 2 Energy and Changes in the Environment
• Chapter 3 Alternative Fuel Sources
• Chapter 4 Hydrogen Sources
• Chapter 5 Transportation Fuel Cells
• Chapter 6 Power Generation
• Chapter 7 Heating and Cooling Energy
• Chapter 8 The Power and Transportation Future
• Index