03-03-2011, 10:07 AM
PRESENTED BY:
P.BABU RAO
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HYDROGEN - THE FUTURE FUEL
ABSTRACT
Fossil fuels were formed before and during the time of the dinosaurs - when plants and animals died. Their decomposed remains gradually changed over the years to form coal, oil and natural gas. Fossil fuels took millions of years to make. The fuels which are using now-a-days are formed more than 65 million years ago. They can't be renewed; they can't be made again. Save fossil fuels by conserving and finding ways to harness energy from seemingly "endless sources," like the sun and the wind.
The energy crisis, which began in 1973, caused petroleum supplies to decrease and prices to rise exorbitantly. This crisis forced developing countries to reduce or postpone important development programs, so they could purchase petroleum to keep their economies operating. It created urgent necessity to find and develop alternative energy sources, such as other fossil fuels (coal, gas), nuclear energy and renewable energy sources.
Future energy development faces great challenges due to an increasing world population, demands for higher standards of living, demand for less population and a much-discussed end to fossil fuels. Without energy, the world’s entire industrialized infrastructure would collapse; agriculture, transportation, waste collection, information technology, communications and much of the prerequisites that a developed nation takes for granted. The nuclear alternative is undesirable. The associated accident risks, waste disposal difficulties, nuclear terrorism, and nuclear weapon proliferation are dangerous in themselves, and make this form of energy excessively expensive. Acquiring nuclear energy from the industrialized world could, moreover result in greater technological and economical dependence on developed countries. A more feasible alternative to petroleum, coal, and nuclear reactors in developing countries is the direct and indirect use of solar energy, which is renewable, abundant, de-centralized and non-polluting.
Use of fossil fuels forever is not possible as they are a non-renewable and finite resource. Now a days use of hydrogen came into picture
1. INTRODUCTION
Hydrogen is a colorless, odorless gas that accounts for 75 percent of the entire universe's mass. Hydrogen is found on Earth only in combination with other elements such as oxygen, carbon and nitrogen. To use hydrogen, it must be separated from these other elements. Today, hydrogen is used primarily in ammonia manufacturing, petroleum refining and synthesis of methanol. It's also used in NASA's space program as fuel for the space shuttles, and in fuel cells that provide heat, electricity and drinking water for astronauts. Fuel cells are devices that directly convert hydrogen into electricity. In the future, hydrogen could be used to fuel vehicles and aircraft, and provide power for our homes and offices.
Hydrogen as a fuel is high in energy, yet a machine that burns pure hydrogen produces almost zero pollution. NASA has used liquid hydrogen since the 1970’s to propel rockets.
HYDROGEN ---“THE FUTURE FUEL”:-
Hydrogen is the simplest element known to man. Each atom of hydrogen has only one proton. It is also the most plentiful gas in the universe. Stars are made primarily of hydrogen. Hydrogen, first on the periodic table of the elements, is the least complex and most abundant element in the universe.
ATOMIC NUMBER: 1 ATOMIC RADIUS: 78 pm
ATOMIC SYMBOL: H MELTING POINT: -259.34°C
ATOMIC WEIGHT: 1.0079 BOILING POINTS: -252.87°C=
ELECTRONIC CONFIGURATION: 1S1 OXIDATION STATES: 1,-1
Hydrogen is the element that has existed in the world for a long time; however, its usefulness came across only few decades ago. After that, people that work in the field of science, have tried to work out different ways that would be more efficient for getting hydrogen out of the combined elements and use it as a fuel in other places. The sun is basically a giant ball of hydrogen and helium gases. In the sun's core, hydrogen atoms combine to form helium atoms. This process—called fusion—gives off radiant energy. This radiant energy sustains life on earth. It gives us light and makes plants grow. It makes the wind blow and rain fall. It is stored as chemical energy in fossil fuels.
2. PREPARATION
Since hydrogen doesn't exist on earth as a gas, it can be separated from other elements. Hydrogen can be separated from water, biomass, or natural gas molecules. The two most common methods for producing hydrogen are steam reforming and electrolysis (water splitting). Scientists have even discovered that some algae and bacteria give off hydrogen.
2.1 Steam Reformer:
Steam reforming is currently the least expensive method of producing hydrogen and accounts for about 95 percent of the hydrogen produced in the United States. It is used in industries to separate hydrogen atoms from carbon atoms in methane (CH4). Because methane is a fossil fuel, the process of steam reforming results in greenhouse gas emissions that are linked with global warming.
Flow Chart of a Steam Reformer:
1 Feed Pre-Treatment
2 Reforming & Steam Generation
3 High Temperature Conversion
4 Heat Exchanger Unit
5 Purification Unit * optional, depending on reformer design a either heat exchanger for low pressure reformer or compression to 1 bar for high pressure reformer Flow Chart of a Steam Reformer