Here is an essay on ‘Hydrogen Energy’ for class 8, 9, 10, 11 and 12. Find paragraphs, long and short essays on ‘Hydrogen Energy’ especially written for school and college students.

Essay on Hydrogen Energy

Essay Contents:

  1. Essay on the Introduction to Hydrogen Energy
  2. Essay on the Utilization of Hydrogen Energy
  3. Essay on Hydrogen Energy for Air and Surface Transport
  4. Essay on Power Generation Using Hydrogen Energy
  5. Essay on the Miscellaneous Applications of Hydrogen Energy
  6. Essay on Hydrogen Storage and Distribution
  7. Essay on Hydrogen Production
  8. Essay on the Limitations of Hydrogen Energy

Essay # 1. Introduction to Hydrogen Energy:

ADVERTISEMENTS:

Electrical energy is the most convenient form of energy because it can be easily controlled, transported and converted into heat and work at very high efficien­cies. The only shortcoming of electrical energy is that it cannot be stored in large quantities. Alternative energy of future is hydrogen energy which can also be easily stored in addition to other qualities of electrical energy.

But is highly inflammable and special handling precautions are needed during its production, transportation, storage and utilization. Hydrogen is a secondary fuel that is produced by utilizing energy from a primary source. Water and solar energy are freely and abundantly available in nature on earth. Hydrogen can be produced from water by using solar energy. All plants and hydrocarbons (fossil fuels) are sources of hydrogen.

Hydrogen can be stored as gas underground or in high pressure cylinders. Also it can be stored in liquid form at low temperatures. There are a number of metals and alloys which form solid hydrides with hydrogen. The hydrogen can be easily recovered by heating metal hydrides. Thus metal hydrides provide a possible means for hydrogen storage in solid form. Hydrogen can be similarly transported as gas through pipes or storage cylinders or as liquid hydrogen or as metal hydrides.

Hydrogen has the highest energy content per unit mass. Its burning process is non-polluting and it can be used in fuel cells to produce both electricity and useful heat. It can be used as a fuel directly in gas turbines or spark-ignition engines. It can be used as motor vehicle fuel in urban transportation where air pollution problems are critical.

ADVERTISEMENTS:

Its specific energy content is almost three times that of hydrocarbon fuels. Therefore it can be directly used as aircraft fuel for air transport. Hydrogen has been used as a fuel for space craft’s. A H2 – O2 fuel cell liberates energy and also water as sole material product for the use of space craft passengers.

The simplest practical way to obtain hydrogen from water is its electrolysis using electricity. The latter can be generated from removable energy sources like solar energy, wind energy, geothermal energy.

Hydrogen has huge market. However, enormous capital investment is re­quired for its production, distribution and storage. Special design precautions are needed for the safe operation of equipment and systems. This is presenting the essential obstacle in the quick introduction of hydrogen.

Essay # 2. Utilization of Hydrogen Energy:

ADVERTISEMENTS:

Hydrogen has the following properties which make it an attractive alternative energy source:

1. At room temperature and pressure, hydrogen is a light gas. Its density is only 1/14th of that of air and 1/9th that of natural gas.

2. At atmospheric pressure, hydrogen can be liquefied at – 253°C. The liquid hydrogen has a specific gravity of 0.07 which is 1/10th that of gasoline.

3. The standard heating value of hydrogen gas is 12.1 MJ/m3 compared with 38.3 MJ/m3 for natural gas.

ADVERTISEMENTS:

4. The heating value of liquid hydrogen is 120 MJ/kg or 8400 MJ/m3 as compared to 44MJ/kg or 32000 MJ/m3 of aviation petrol. The specific energy of hydrogen liquid is superior to gasoline on mass basis but inferior on volume basis.

5. The flame speed of hydrogen when burning in air is much greater than for natural gas.

6. The ignition energy to initiate combustion is less for hydrogen than for natural gas.

7. Detonation can occur between hydrogen-air mixture between 18 and 59 percent. The internal combustion engine on hydrogen fuel can work from very rich (excess fuel) to very lean (excess air) mixture. The adjustment of air fuel ratio is less critical than for gasoline engine.

ADVERTISEMENTS:

8. Mixture of hydrogen and air are combustible over a wide range of com­position. The flammability limits are from 4 to 74 percent by volume of hydrogen in air at ordinary temperatures.

9. The combustion of hydrogen with oxygen from air results in release of energy and water as by-product.

10. The burning process of hydrogen is pollution free.

The possible areas of use of hydrogen in the near future are as follows:

1. Production of Useful Heat:

(i) In a high-temperature combustion of hydrogen with oxygen or air.

(ii) In a low-temperature flameless catalytic combustion with extremely low NOx emission.

2. Power Generation:

(i) In reactors with direct steam generation.

(ii) In high-temperature and membrane fuel cells.

3. Cogeneration of Heat and Electricity:

(i) In internal combustion engine based cogeneration plants.

(ii) In combined-cycle power plants.

4. Automotive and Aircraft Fuel:

(i) Environmentally friendly fuel for motor vehicles.

(ii) Aircraft fuel.

5. Energy Storage:

(a) Compressed hydrogen gas storage under high pressure.

(ii) Metal hydrides.

6. Synthesis of Fuels:

(i) Raw material to produce methanol, ammonia or hydrocarbon using carbon dioxide or nitrogen from air.

(ii) Raw material for manufacture of gaseous fuels.

Essay # 3. Hydrogen Energy for Air and Surface Transport:

1. Jet Fuel:

The high energy density 33.3 kWh/kg of liquid hydrogen against 12.7 kWh/kg of conventional jet fuel is the main advantage in air transportation where hy­drogen energy can be used. Although volume of liquid hydrogen would be greater than regular fuel but this could be accommodated on a large aircraft.

The cold liquid hydrogen can also be used directly or indirectly for cooling engine and airframe surfaces of high speed aircrafts. Liquid hydrogen may be the only practical fuel for hypersonic aircraft when developed. Because of smaller total weight, it may be possible to achieve shorter take-off runs, steeper climbing path, smaller engine thrust and less noise production. `

The favorable diffusion properties and high thermal conductivity of hydrogen help to use shorter combustion chambers. Wide range of ignition for H2 – O2 mixtures (5% to 75%) by volume of hydrogen helps better control of engine operation especially under part load conditions and reduction in NOx emission.

The heat required to vaporize hydrogen for the engines can be obtained from certain outer skin of wings and fuselage. This helps to cool the boundary layer. The laminar boundary layer so developed helps to reduce drag and fuel con­sumption.

The main problems are economic production of hydrogen, infrastructure for fueling of aircrafts and sitting of bulky hydrogen tanks in the aircraft body.

2. Road Vehicles:

The use of hydrogen fuel in engines of automobiles, buses, trucks and farm machinery can help conserve petroleum products and reduce atmospheric pol­lution. A mixture of hydrogen gas and air of constant ratio is introduced into the manifold. The engine speed and power are controlled by varying the quality of mixture entering the cylinder with the help of a throttle valve.

In another design, hydrogen gas under pressure can be directly injected into the engine cylinder through a valve and air is admitted through another intake valve. The spark advance has to be retarded because of higher speed of flame of hydrogen in air. The engine emission will not contain carbon monoxide and hydrocarbon because the only product of combustion is H2O. In order to control NOx emis­sion, the cylinder exhaust containing H2O is injected to reduce combustion temperature.

Storage of hydrogen as compressed gas or metal hydrides for the vehicles is a dis-advance against hydrogen fuel because of lesser energy density per unit volume and the weight of metal hydrides is also excessive. The best way to use hydrogen as vehicle fuel is the use of fuel cells. The electricity generated in the fuel cells operating with hydrogen fuel can be uti­lized to operate electric motors for propelling the vehicle.

Essay # 4. Power Generation Using Hydro Energy:

1. Central Power Plants:

The plants working on natural gas can be changed to hydrogen-fired plants without significant technological changes. These plants may be combined-cycle power plants with gas and steam turbines or cogeneration plants with gas turbine and internal combustion engines. Hydrogen-fired plants compared to gas-fired plants have lower capital cost and higher efficiency.

Hydrogen fuel has higher combustion velocity and flame temperature as compared to natural gas. Higher combustion velocity results in unstable com­bustion and higher flame temperature leads to higher Nox emissions.

2. Autonomous Power Plants:

Hydrogen fuelled fuel cells can be used for domestic power generation as well as industrial power generation. Alkaline fuel cells can be used for produc­ing electricity from pure hydrogen and oxygen. Fuel cells with acid electrolytes can be operated with impure hydrogen and hydrocarbons. High temperature fuel cells with molten carbonate electrolytes operating at 600°C are advanced generation fuel cells for electricity and heat production in cogeneration plants.

Essay # 5. Miscellaneous Applications of Hydro Energy:

Hydrogen can be used for domestic cooking replacing LPG. The burner design has to be changed with bigger holes and air supply system to take care of greater flame speed and low specific energy per unit volume when hydrogen is used as fuel.

Hydrogen can be usefully used in radiant space heating with flameless combustion on a catalytic surface. In this case combustion temperature is low with negligible NOx formation.

Hydrogen has many advantages over industrial gases for production of heat and other uses.

Essay # 6. Hydrogen Storage and Distribution:

There are five principle methods that have been considered for hydrogen storage:

1. Compressed gas storage. Hydrogen is conveniently stored for many applications in higher pres­sure cylinders. The method is rather expensive and bulky.

2. Liquid storage as cryogenic storage in vacuum insulated or super in­sulted storage tanks. The liquid hydrogen fuel used as rocket propellant in the space programme is stored in large tanks.

3. Line packs system where it is allowed to vary the pressure in the trans­mission and distribution system.

4. Underground storage of hydrogen gas in depleted oil and gas fields or in aquifer systems. This is the cheapest way to store large amounts of hydrogen for subsequent distribution.

5. Storage as metal hydrides in chemically bound form. A number of metals and alloys form solid compounds by direct reaction with hydrogen gas. The metal hydrides can be transported in solid form. When the hydride is heated, hydrogen is released for use.

Hydrogen Transportation:

1. Long distance hydrogen gas transmission pipelines of lengths greater than 90 km must be supplied with booster compressors. Therefore, the cost of transmitting hydrogen by pipelines must include the cost of pip­ing, compressor and power consumption by compressors. Another prob­lem of hydrogen transmission is hydrogen embrittlement of the pipeline materials.

2. Hydrogen in bulk can be transported and distributed as the liquid in double-walled insulated tanks. Distribution of liquid hydrogen by pipe­lines, jacketed with liquid nitrogen can also be considered.

3. Hydrogen can also be transported as a solid metal hydride. The main drawback is the heavy weight of hydride relative to its hydrogen yield.

Safety Precautions:

Hydrogen is highly inflammable and explosive and can lead to fire and serious accidents. The production, storage and distribution of hydrogen require special precautions.

1. The system should be designed to withstand the explosion pressures.

2. The system should be designed to withstand pressure surges.

3. Proper exposition-relief system must be provided.

4. Flame traps, flame suppressors, explosion-relief devices and rapid-closing devices must be used.

5. The design, manufacture, storage should follow Petroleum Act.

Essay # 7. Hydrogen Production:

1. From Fossil Fuels:

The conventional hydrogen production processes are shown in Fig. 17.1.

Hydrogen Gas Production from Fossil Fuels

A. Natural Gas/Naptha:

1. The natural gas or naptha is reformed with steam at 900°C to produce a mixture of gases by the following reaction:

The gas produced has the following compositions:

2. The CO present is converted into CO2 by two-stage catalytic conversion process:

1st stage process at 300-500°C

2nd stage process at 200°C

CO + H2O (steam) = CO2 + H2

CH4 is converted into CO2 by the following reactions:

CH4 + H2O = CO + 3H2 – 205 kJ/mol

CH4 + 2H2O = CO2 + 4H2 – 164 kJ/mol

3. Finally CO2 is removed by scrubbing process. H2 is obtained as product gas.

4. The energy content of H2 product gas is 75-80% of natural gas. The cost of H2 is comparable with that of electricity on similar basis.

B. Coal and Heavy Oil:

a. The coal or heavy oil undergoes partial oxidation or gasification at 1400°C with oxygen as gasifying medium.

b. The CO present is converted into CO2 by two-stage catalytic conversion process.

c. CO2 is removed by scrubbing.

d. The energy content of H2 product gas is 55 to 60% of raw coal. The cost of H2 produced is higher than produced from natural gas if lignite or hard coal is used as feedstock.

2. By Water Electrolysis:

The principle of operation of an alkaline water electrolysis cell is shown in figure 17.2.

Alkaline Cell Water Electrolysis

Hydrogen is produced by electrolytic dissociation of water.

The following electrolysis processes are available:

i. Alkaline electrolysis.

ii. Membrane electrolysis.

iii. High temperature steam electrolysis.

3. Solar Energy Methods:

Hydrogen can be produced using solar radiation by the following pro­cesses:

I. Bio photolysis.

II. Photo electrolysis.

I. Biophotolysis:

Hydrogen can be produced very cheaply by using green algae’s ability to generate hydrogen gas from water and sunlight. The green algae are a simple plant. It should be kept in an anaerobic (oxygen-free) environment free from sulphur.

II. Photo Electrolysis:

Hydrogen and oxygen gases are liberated at the cathode and anode respec­tively by decomposition of water when both the electrodes are subject to sun­light. It is a very attractive method of producing hydrogen as the process is intermittent. There is no need for storage of gas.

The solar electricity can be produced by photo-electrically or thermo-chemically.

Essay # 8. Limitations of Hydrogen Energy:

Hydrogen has very attractive properties and can be a future source of energy:

i. Availability.

ii. Manufacture without harm to environment.

iii. Good storage properties.

iv. Readily convertible to other forms of energy.

It can easily replace electricity, natural gas, synthesis gas, etc. There is still a need for considerable research and development in the following areas of hydrogen technology.

i. Production of hydrogen of photo-electrolysis of water using solar energy.

ii. Production of hydrogen by blue green algae and by certain bacterial species.

iii. Storage of hydrogen through metal hydrides and non-metal hydrides (rice husk and misch-metal)

iv. Liquid hydrogen production, storage and utilization.

v. Development of suitable engines and burners to utilize hydrogen as a fuel.

Home››Essay››Hydrogen Energy››