The basic principle of gas power plant is to burn the gas and expand it with high pressure to the turbine blade. The turbine starts rotating and the generator also rotates with the turbine and generates electricity. This is the main principle of natural gas electricity production. The natural gas power plant is sometimes called a methane gas power plant. It is because 70% to 90% of methane is found in natural gas. Gas is a fossil fuel that is used for various purposes. Nowadays, natural gas is used extensively in the electricity generation center. Here bulk electricity is generated by some special process. This thing encourages us to know how natural gas power plants work. So, here we go.
What Is Natural Gas?
Gas is a natural energy but not a renewable energy source. Gas is a gaseous substance that is collected from a natural source. Natural gas is found in the gas mines where gas is mixed with hydrocarbons that are made up of methane (CH4).
Whenever this gas is collected from the source then various gases exist like butane, methane, ethane, propane, butane, and low levels of carbon dioxide, nitrogen, hydrogen, and other substances. In generating electricity from natural gas, methane is required for high efficiency and better combustion.
How Do Natural Gas Power Plants Work?
We know that gas power plants generate electricity by burning natural gas in a combustion turbine to produce mechanical energy. This mechanical energy is converted into electrical energy through a generator. This is a gas turbine power plant working process. If we want to reach from first to last (burning gas to generate electricity) then we must beyond a few crucial steps. So, take a look what are these steps of operation of gas power plant or working process.
Collecting Gas from The Source
After finding the gas mine, it is drilled with some special equipment to extract the natural gas from the reservoir. In most cases, the natural gas is trapped within rock-hole, such as sandstone or shale. To release the gas and flow freely some essential techniques are adopted, such as hydraulic fracturing (fracking) or directional drilling.
Once the gas is brought to the earth’s surface, it is collected and transported through special pipelines or tanker trucks to processing facilities. After that, the raw natural gas is sent to the processing to remove different impurities such as water, sulfur compounds, and other contaminants.
Useable or pure gas is separated by this inspection. Now the processed natural gas is transported to distribution centers. Users also get this gas through an extensive network of pipelines, Liquefied Natural Gas (LNG) tankers, or Compressed Natural Gas (CNG) trucks. It is noted that natural gas is delivered to the power plant through pipelines from gas storage.
Gas Power Plant Working Principle
The gas power plant working procedure follows the electromagnetic induction process. In the gas power plants, the main thing is that we have to burn the gas. Burning the gas requires three main things. We have to provide these three things into the combustion chamber to burn the gas.
- Fuel or gas
- Air or Oxygen
- Fire or heat
Using natural gas to generate electricity, gas is injected into the combustion chamber, high-pressure air is given from the compressor, and heat or fire is given from a spark plug. In this way gas is burned and extensive heat is generated. This heat reaches more than 2000 Degrees Fahrenheit or more than 1090 Degrees Celsius in the combustion chamber.
This generated high heat and heavy pressure runs through a pipe and heat to the gas turbine. Now gas turbine starts rotating with 3000 R.P.M. (Revolution Per Minute) and the frequency range is 50 Hz. It is good to say that this one portion of a turbine is coupled with the compressor. It means if the turbine runs then the compressor will run also. This is because extensive Oxygen is required in the combustion chamber for fire.
Another portion of the gas turbine is connected or coupled to the alternator or generator. This generator is used to convert the mechanical energy of turbine into the electrical energy. in the above figure, we see that some gases are exhausting. It is because, whenever a gas turbine runs then some gases pass into the atmosphere through the exhaust chimney. So, this is a closed-cycle gas turbine working principle.
This working process is applicable for booth cycle: open cycle or simple cycle gas turbine power plant and combined cycle gas power plant. Indeed, exhausted gas is re-used in the combined cycle power plant to reduce generation costs and save environmental pollution. In that case, the combined cycle requires some extra equipment and devices to be added.
So, this process proves how does natural gas become electricity in the open cycle or simple cycle power plant. It is noted that a gas cycle power plant is often referred to as a gas-fired power plant.
It is noted that the shaft is the main equipment in gas turbine power plants whereas the compressor, turbine, generator, and starting motor are connected to the continuous flow of the air. It is good to say that. The starting motor is used to rotate that shaft.
What Type of Gas Is Natural Gas?
Natural gas is an odorless gaseous substance that is found in nature. This gas is stored under the earth’s surface in the rock field. Methane is the main component, and a large number of amount around 70-90% of natural gas. It is noted that Methane is a major hydrocarbon that contains ethane, propane, butane, and pentane. There are four or five main types of natural gas that we collect from the underground:
- Methane (CH4)
- Ethane (C2H6)
- Propane (C3H8)
- Butane (C4H10)
- pentane (C5H12)
How Gas Turbines Produce Electricity?
The turbine consists of a series of blades mounted on a shaft. Gas turbines produce electricity through the thermoelectric generation process. Artificial combustion happens with Oxygen, gas, and fire in a combustion chamber in gas turbine power plant. This combustion generates very high-temperature (2000 F) and very high-pressure gas. This high-pressure gas rushes continuously through the pipe.
The heated gas flows over these blades and the turbine starts to spin at high speed (3000 R.P.M.) and produce mechanical energy. This turbine is connected to a generator. Generator input receives mechanical power from turbine output and the generator or alternator generates electricity. It is noted that this process happens through the principles of electromagnetic induction.
Closed Cycle Power Plant Working Principle
A closed-cycle power plant is an assembly of some extra equipment that is used to catch the exhausted gas or air of the gas turbine and use that again to rotate the turbine. In closed-cycle power plants, exhausted gases (those gases or air that come out to the atmosphere) are sent to the compressor again through the heat exchanger.
The heat exchanger is used to cool the high-heat exhaust gas or air to send again to the compressor. The compressor compresses that gas and sends it to the combustion chamber and comes to the turbine. This working process happens continuously. This entire process is called a closed-cycle power plant.
Major Components of Gas Turbine Power Plant
A power plant may have extensive equipment and devices. Gas power plants have different types of components. These components play a crucial role in any specific place. So, take a look at the main components of a gas turbine power plant. So, take a look at the components of gas turbine plant or gas turbine power plant parts.
- Air Intake System.
- Compressor.
- Combustion Chamber.
- Turbine.
- Generator.
- Exhaust System (chimney) for passing the exhausted gas from the turbine.
- Cooling arrangements that can cool the exhausted gas to feed them again.
- The Fuel System is responsible for delivering the appropriate fuel (natural gas) to the combustion chamber.
- Control System controls and measures temperature, pressure, and power output, making adjustments as necessary.
- Auxiliary Systems include systems for lubrication, filtration, and vibration monitoring.
Advantages and Disadvantages of Gas Power Plant
Every single thing has merits and demerits. Gas-fired power plants are well suited to meet the daily load demand for a base hour and peak hour. Indeed, this power plant has also some advantages of gas turbine power plant and disadvantages. So, take a look at what advantages and disadvantages of gas turbine power plants attract you to make suggestions to generate electricity.
- Gas power plants are highly efficient in converting fuel into electricity. Combined-cycle plant efficiency is over 60%.
- This power plant is highly reliable for generating electricity.
- It can be quickly started and stopped, which allows for rapid response to changes in load demand for providing baseload, intermediate, or peaking power.
- Gas power plants produce fewer greenhouse gas emissions (carbon dioxide (CO2) compared to coal-fired power plants.
- This power plant can be easily integrated with renewable energy sources like wind power plants and solar power plants.
Disadvantages
- Dependency on natural gas supply impacts the generation cost if fluctuate in natural gas prices.
- Open-cycle power plants release large amounts of CO2 that are highly harmful to the environment.
- Gas power plants require significant amounts of water for cooling purposes which can put pressure on local water resources.
- Methane is a potential greenhouse gas. If methane is emitted into the environment, then it may pollute the environment.
Final Thought
Natural gas power plants work by burning natural gas to generate electricity. This process happens by the electromagnetic induction process. I have shared here in detail about how natural gas power plants work, their merits, demerits, components, and many more things. Hopefully, this article may be enough to give you the best knowledge about gas turbine power plants. So, study, enjoy yourself, and boost your knowledge.
Frequently Asked Question
How Did Natural Gas Form?
Natural gas has been built naturally under the ground surface. Natural gas sources have been created millions of years ago through the decomposition of organic matter buried deep beneath the Earth’s surface. The process begins with the accumulation of organic material layers, such as dead plants and microscopic organisms, in areas like swamps, marshes, and sea beds.
Over time, more layers accumulate, and the weight of the overlying sediment and the heat from the Earth’s interior cause the organic material to undergo a transformation called diagenesis.
The organic material is subjected to increasing pressure and temperature through diagenesis. It initiates chemical reactions that break down complex organic molecules into simpler compounds. This decomposition process continues, and the organic material is converted into a mixture of hydrocarbons. These are molecules composed primarily of hydrogen and carbon atoms.
The hydrocarbons produced are in the waxy substance form called kerogen. The temperatures and pressures increase further with burial depth. In that case, the kerogen undergoes chemical transformations. Eventually, it leads to the hydrocarbons formation in the gaseous state, such as methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10).
After that these gases migrate upward through porous rock formations. These reservoirs can be found in various geological formations, including sandstone, shale, and limestone. This natural gas is extracted by drilling wells into these reservoirs.
Where Is Natural Gas Found?
Natural gas is found in nature. Natural gas is found in rock formations (sandstone, shale, and coal beds) on the underground surface of the earth. It can also be found in various geological formations, including conventional reservoirs, unconventional reservoirs, etc.
How Do We Find Natural Gas?
Natural gas is found using some crucial methods, such as seismic surveys, exploration drilling, and advanced geological analysis. Seismic surveys involve sending sound waves into the ground and measuring their reflections to identify potential gas reservoirs. Exploration drilling is conducted to confirm the presence of natural gas. Advanced geological analysis helps assess the size and viability of the reservoir for extraction.
What Happens When Natural Gas Is Found?
When natural gas is found under the ground surface, it marks the beginning of a series of carefully organized to harness this crucial resource. The geologists and engineers assess the discovery to determine its size, composition, and feasibility for extraction.
If the assessment proves the gas reservoir, then drilling is conducted to confirm the natural gas presence in the reservoir. If it becomes possible to pick up, then the infrastructure such as pipelines and processing facilities are established and natural gas is extracted from the reservoir.
Which Gas Is Used in Gas Power Plant?
Natural gas is used in a gas power plant to generate electricity. Power plants using gas contain methane. That’s why, this type of power plant is sometimes called a methane gas power plant. It is because natural gas is a versatile and efficient fuel for power generation. It is utilized in simple cycle power plants and combined cycle power plants.
On Which Cycle Does a Gas Power Plant Work?
A gas power plant operates on a Brayton cycle. It is sometimes called a gas turbine cycle. The Brayton cycle is a thermodynamic cycle. Carnot cycle is also a thermodynamic cycle. On the other hand, coal power plant works on the Rankine cycle. It is also a cycle of the thermodynamic cycle. Brayton cycle consists of four main processes.
- Compression.
- Combustion.
- Expansion.
- exhaust.
What Type of Energy Is Natural Gas?
Natural gas is primarily a form of chemical energy due to the mix of methane and small amounts of other hydrocarbons. Natural gas fuel is a fossil fuel that is made naturally over millions of years due to the action of heat and pressure on organic materials. On the other hand, gas is primarily considered a form of chemical energy.
It is composed of methane CH4 (one carbon atom and 4 hydrogen atoms) with smaller amounts of other hydrocarbons. When combusted, the chemical bonds in these hydrocarbons are broken and release heat energy.
Is a Gas Power Plant a Thermal Power Plant?
Yes, the gas power plant is considered a thermal power plant. This is because thermal power plants generate electricity by converting thermal energy (heat) into electrical energy. In a gas power plant thermal energy is produced by burning gas in the combustion chamber and creating high pressure by the special plan. This high heat and high-pressure gases hit the turbine and it helps to rotate the generator and generate electricity.
How Much Energy Does a Natural Gas Power Plant Produce Per Day?
The generation factor depends on some essential factors: load demand capacity, adequate of fuel, plant efficiency, operating cost, per unit cost, and others.
For example, if a 500-megawatt natural gas power plant operates at full capacity for 24 hours. It will produce 12,000 megawatt-hours (MWh) of energy per day. However, power plants do not always operate at full capacity.
However, natural gas power stations may have different capacities ranging from a few megawatts to several hundred megawatts. The energy output of a power plant is often measured in terms of its capacity multiplied by the number of hours it operates. These are expressed in kilowatt-hours (kWh) or megawatt-hours (MWh).