Biomass for Energy

Biomass is the oldest form of fuel utilized by humans. The discovery of fire is at the very beginning of civilizations and still today about 10 of the primary energy needs globally are covered by so-called traditional biomass, that is burning of fuel wood, dung and other agricultural residues, mainly for cooking and heating. Beyond the traditional use of biomass as a fuel, there has been increasing interest in using biomass as a resource in a sustainable energy system. Biomass has the advantage...

Conversion of Hydrogen to Energy

Hydrogen's primary use is likely to be as a fuel in the transport sector, as this is the area in Western economies with the highest fossil fuel dependence, but more generally, hydrogen may be used in three main modes to generate power. 1. By direct combustion with air in conventional engines, that is internal combustion, gas turbine or steam engines. 2. Reaction with pure oxygen in rocket type combustors. 3. Through electrochemical conversion of hydrogen and air mixtures to electrical energy in...

Fossil Fuels

Few commodities have had such a fundamental impact on modern society as fossil fuels. Before human beings learned to exploit the energy stored in the hydrocarbon bonds of fossil fuels, they relied solely on muscular effort, direct solar, wind and water energy and the energy stored in biomass. In the last two hundred years, the remarkable rise of the coal, oil and more recently the natural gas industries has led to radical changes in almost every aspect of life.

Future Trends

The International Energy Agency expects world energy demand to rise by more than 50 until 2030 5 . A substantial decoupling of energy and economic production has been observed in several studies, but energy and economic activity are still strongly connected in most industrialized and developing countries 4 . As economic development and population growth continue to push energy demand upward and concerns over the acceleration of global warming by combustion of fossil fuel are increasing, drastic...

Implementation ofthe Hydrogen Cycle Technical Issues Possible Scenarios

In Section 3.3.1, the key elements of the hydrogen cycle were identified as Production, Distribution Storage and Power Conversion. Overall, the chain involves the use of renewable electricity to electrolyze water for hydrogen, which is used as an energy carrier or energy vector to various conversion devices, where it is transformed back into useful electricity for the end-user applications. This sequence is shown schematically in Fig. 3.8. Fig. 3.8 The hydrogen cycle in practice. Fig. 3.8 The...

Other Cycles Active in the Global Environment

A central theme of the present volume is amelioration of global warming problems by the adoption of hydrogen as an alternative fuel. The dominant biosphere cycles underlying these problems are those associated with carbon and water. Other cycles operate in the biosphere but, whilst of importance, have a less marked influence on climate and the environment 37 . Sulfur Sulfur is an essential life element, being assimilated by living organisms and released as the end product of metabolism. Over...

Transmission Distribution and Storage of Hydrogen

Ofthe elements needed for successful exploitation ofthe hydrogen cycle, the downstream technologies needed to reach the end user, that is transmission, distribution and storage of hydrogen, are likely to be the least problematic. Western industrial economies have over 150 years of experience in the technology requirements for coal, or town gas, which was largely based on hydrogen. More recently, similar problems have been solved successfully for the exploitation and distribution of natural gas....

Two Centuries of Growth

The oldest evidence of the use of fossil fuels dates back to prehistoric times. Accumulations of oil and tar were occasionally found at the surface of the earth and used for lighting, heating and building purposes. However, systematic exploitation of fossil fuels did not occur until modern times. The invention ofthe coal-powered steam engine at the end ofthe eighteenth century was a landmark for the industrial revolution. A few decades later, high-pressure mobile steam engines were introduced...

Use of Biomass for Hydrogen Production or as a Renewable Carbon Resource

As biomass is per se a form of chemically stored renewable energy, there is no need to convert it to hydrogen for storage purposes, as is the case for solar energy, wind-or hydro-power, where hydrogen is expected to play an important role as a storage medium. Hydrogen can be produced from biomass in very much the same way as it is currently produced from fossil fuels, that is by steam reforming of the carbon compounds constituting the biomass material. As with fossil fuels, it only makes sense...

Replacing the Fossil Fuel Carbon Cycles with Hydrogen

Senebier's carbon cycle in its original and simplest form, described the absorption of atmospheric carbon dioxide by plants, which are subsequently eaten by animals, who in turn return the carbon dioxide to the atmosphere by respiration and Fossil fuel combustion Tropical deforestation Uptake by Northern Hemisphere reforestation excrement. This concept and a more extended form of the carbon cycle, including fossil fuel usage, is shown in Fig. 3.4. Carbon-rich fossil fuels, oil, coal and natural...

Advantages and Uses of Fossil Fuels

What enabled the fossil fuel industries to attain such a dominant position in the global energy market in such a short time The main reason is the fact that fossil fuels constitute excellent energy sources with a very high specific energy. One tonne of oil equivalent equals 42.7 gigajoules, one thousand cubic meters of natural gas approximately 37 gigajoules and one tonne of coal 25 gigajoules. One million tonnes of oil produces about 4.5 terawatt-hours of electricity in a modern power plant....

Formation and Composition of Fossil Fuels

Fossil fuels are complex mixtures of hydrocarbons formed in a process lasting millions ofyears by decomposition ofbiological matter. Carbon and hydrogen are the main components, but other elements such as sulfur, nitrogen, oxygen and metals are also present in small amounts. At normal temperatures and pressures, these compounds may be gaseous, liquid or solid, depending on the complexity of their molecules. All fossil fuels are derived from biological materials, either marine plankton or...

Thermodynamic Properties Surface Segregation

Although the H-metal bond is electronic in nature, a thermodynamic description of some adsorption properties is adequate. The relevant thermodynamics, with emphasis on surface problems, can be found, for example, in Ref. 62 . A weak van der Waals attraction is the origin of the physisorption of molecular H2 63, 64 . Accordingly, heats of physisorption are very small (> - 5 kJ (mol H)-1), and experimental physisorption studies have to be performed at low temperatures. The growing interest in...

Environmental Impact

Exploration, drilling and extraction activities are known as the upstream phase of the fossil fuels industry. Depending on the nature and location of the extracted fuel, these processes may affect the local environment in various ways. Coal extraction, particularly from surface mines, disrupts the natural landscape and produces large quantities ofwaste. The same holds true for surface mining ofnonconventional oil resources such as tar sands. Production of conventional oil and gas reserves...

Global Reserves and Production

Although reserves are finite, a shortage of fossil fuels is not to be expected in the foreseeable future. Accumulations ofhydrocarbons occur in almost every part of the world, from conveniently located, easily accessible sites, to very hostile and remote environments such as the Polar Regions or offshore locations in deep water. Fossil fuel resources are usually subdivided into several categories. The well-explored shares of total resources that can be extracted with available technology at...

Hydrogen in the Twenty First Century

During the twenty first century, the world pattern ofenergy usage has to be transformed. To continue our ever increasing dependence on fossil fuels is futile and will accelerate the onset of further extreme climatic events. Hydrogen has the potential to be a key factor in this transformation. This chapter has outlined the hydrogen cycle-based principles, by which the change from fossil fuel dominance to a sustainable global energy system can be achieved. The penetration and growth ofhydrogen...

The Carbon Cycle

Living systems are characterized by a continuous exchange ofmaterial and energy with their environment. The chemical energy responsible for maintaining life on the planet is produced by complex photochemical reactions involving the photochemical reduction of CO2 with water to organic forms of carbon and molecular oxygen. The process is referred to as photosynthesis. The photosynthetic conversion of CO2 and water to glucose and oxygen absorbs an energy equivalent of 2800 kJ mol-1 The reverse...

Hydrogen Isotopes

Hydrogen 1 hydrogenium, vhrnp the water, yevveiv to give birth is the first element in the periodic table of the elements having the atomic number 1 and the electron configuration 1s1. Hydrogen was prepared many years before it was recognized as a distinct substance by Cavendish in 1766 and it was named by Lavoisier. Hydrogen is the most abundant of all elements in the universe and it is thought that the heavier elements were, and still are, built from hydrogen and helium. It has been estimated...

Hydrogen Molecule

Proton Proton Potential Energy

The isotopes H, D and T form diatomic molecules. The interaction potential energy of two hydrogen atoms goes through a minimum at a certain interatomic distance when two electrons form a singlet state1 Eg , namely, the state with a total electron spin equal to zero the combination of two electrons with opposite spin . The energy of the triplet state 3Eu , having a total electron spin of unity, increases when two hydrogen atoms with parallel spin approach each other. Hydrogen atoms of opposite...

Carbon Reservoirs

Carbon Reservoirs Earth

Human beings developed on Earth on the basis of plants, that is biomass, as the only energy carrier. The average power consumed by a human body at rest is 0.1 kW and approximately 0.4 kW for a hard working body, delivering about 0.1 kW of work. The consumption of plants by humans and animals did not change the atmosphere because the carbon dioxide liberated by humans and animals was reabsorbed by the plants in the photosynthesis process. The only mechanical work available from nonliving systems...

The Theoretical Approach

Potential Energy Diagram For

When a H2 molecule approaches a metal surface, as indicated in Figure 4.14 it will first feel the van der Waals interaction. This is a weak interaction due to polarization effects, which typically amounts to only 10 kJ mol-1 for H2 and thus only leads to adsorption at very low temperatures or high pressures. When approaching even closer there may be an exchange between the hydrogen electrons and the electrons in the metal leading to associative chemisorption, that is the H2 molecule remians...

Biomass and Hydrogen

The chemical composition of biomass with respect to carbon, hydrogen and oxygen can be approximated by the formula C6H9O4, that is biomass contains a little less Fossil fuel consumption 5.3 Solar radiation hitting earth surface 4.67 1021 based on glucose as primary product of photosynthesis 2.33 1021 Ref. 27 oxygen than the primary product of photosynthesis, glucose C6Hi2O lt s , but much more than fossil fuels CH2 to CH4 . The oxidation state of carbon in biomass is close to zero while for...

Ignition and Detonation Performance

Flammability Limits

Hydrogen reacts, when the ignition energy thermal activation energy of 0.02 mJ is provided, violently with oxidizing agents such as oxygen air , fluorine or chlorine and N2O. Combustion, deflagration or detonation may occur, depending on the conditions. The ignition and detonation properties of hydrogen-air mixtures are particularly important from the safety aspect. The flammability limits i.e. the minimum and the maximum concentration of hydrogen in air are exceptionally wide for hydrogen....

Hydrogen in Transportation

Karl Kordesch

Cavendish, who called hydrogen inflammable air, was also the first to measure its density. He reported in his 1766 paper that hydrogen is 7 to 11 times lighter than air the correct value is 14.4 . Cavendish's results not only opened up a new chapter in the history of gases, but also attracted attention to hydrogen as an alternative to hot air as a buoyant gas. Jacques Alexandre Cesar Charles was the first to take advantage of this, soon after the first public demonstration by the Mongolfier...

Joule Thomson Effect Inversion Curve

Joule Thomson Koeffizient Co2

The differential coefficient was first investigated by James Joule and William Thomson in the 1850s 23 , before Thomson was elevated to the peerage, to become the first Lord Kelvin. So it is also referred to as the Joule-Kelvin coefficient. It is a measure of the effect of the throttling process on a gas, when it is forced through a porous plug, or a small aperture or nozzle. The drop in pressure, at constant enthalpy H, has an effect on temperature. The enthalpy of hydrogen as a Van der Waals...

Potential Hazards ofthe Hydrogen Economy

Effects on the Environment Until recently, it was assumed that migration to a hydrogen fuel economy would have no negative aspects for the environment. However, in mid-2002, it was proposed that the widespread use of hydrogen could lead to hitherto unknown environmental impacts due to hydrogen emissions 56 , the central claim being there will be substantial leakage of hydrogen associated with the production, transportation and storage of hydrogen. It is estimated that the total anthropogenic...

Preface For Hydrogen A For The Future

Thermodynamically speaking a human being, like any animal, is an engine combusting an energy carrier like food into work. In other words, the difference between living matter and dead matter is the ability to convert energy. Therefore, energy is essential for our existence and development. Natural processes led to a spontaneous accumulation of carbon- and hydrogen-based energy carriers - the so-called fossil fuels. A large amount of fossil fuels was given by nature, which allowed us to start...

The Hindenburg and Challenger Disasters

Rocket Lift Off Explosion

The LZ-129 Hindenburg and her sister-ship LZ-130 Graf Zeppelin II were the two largest aircrafts ever built. The Hindenburg was named after the President of Germany, Paul von Hindenburg. It was a brand new all-aluminum design 245 m long, 41 m in diameter, containing 211 890 m3 of gas in 16 bags or cells, with a Fig. 2.6 On May 6, 1937, at 19 25 the German zeppelin Hindenburg caught fire and was utterly destroyed within a minute while attempting to dock with its mooring mast at Lakehurst Naval...

Introduction

Global energy demand is forecast to double by 2050. By persisting in our use of current energy technologies most of this demand will be met by the increased use of our rapidly dwindling supplies of petrochemicals. In Europe alone, the oil import dependence is set to grow from 50 currently, to 70 or more, by 2025. Even more serious, the European Community is already dependent on oil for 90 of its transport needs. A central theme of this volume is that the Western economies must take the lead in...

Chemical Properties and Diffusion

Bond Dissociation Energy Table

Hydrogen is the element with the highest diffusion capacity because of its small size and small mass. Some diffusion coefficients 25 of hydrogen in gases and liquids are listed in Table 4.10 . In metals with a high hydrogen solubility a high hydrogen diffusion rate is also usually found. The diffusion coefficients are in the same range as for hydrogen ions in water 10-4 cm2 s-1 at 25 C . Table 4.10 Diffusion coefficients of hydrogen in gases p 101.3 kPa and liquids Table 4.10 Diffusion...

Timeline of the History of Hydrogen

Jacques Alexandre Sar Charles

Jan Baptista van Helmont 1577 to 1644 was one of the first to reject the basic elements ofAristoteles. He discovered that air is not an element and that another air with different properties exists. He called it, based on the Greek word chaos which means empty space, according to the Dutch spelling gas. In the Middle Ages Paracelsus 1493 to 1541 is reported to have noted that a gas is yielded when iron is dissolved in spirit of vitriole. Turquet De Mayerne 1573-1655 noted that this gas was...