As everyone knows LPG(Liquefied petroleum gas) is used as a fuel in appliances cooking equipment and vehicles as well. LPG consists of methane propane, butane, and butylene in different ratios, other ways it is the mixture of hydrocarbons. LPG is a by-product of natural gas and petroleum.
Gases at normal temperatures and pressures are the main components. It is odorless in its natural state and this gas is basically the mixture of propane and butane. The composition of LPG gas is primarily of propane, butane, isobutane, and mixtures of these gases. LPG exists as liquid or gas [vapor], depending on pressure and temperature. LPG is stored in a steel container in the form of Liquid under pressure, it varies according to the type of LPG used and the outside temperature.
It is completely derived from fossil fuels, during the refining of petroleum or extracted from the natural gas stream as they emerge from the ground. It can cause air pollution but does not pose ground or water pollution hazards, as it is a gas. It is a common fact that LPG quickly evaporates at the normal temperature and pressure because it’s the boiling point is below room temperature.
To allow thermal expansion of the contained liquid, they are typically filled to 80-85% of their capacity. Depending on the composition, pressure, and temperature ratio between the volumes of the vaporized gas and the liquified gas varies. LPG easily burns in the air, which is similar to petrol and the energy content in LPG is twice as much as natural gas which makes LPG fuel for cooking, heating, and for auto. When transporting the gas it must be kept under modest pressure.
Only then it can be stored and transported in LPG cylinders. Do you know that you can check the level of gas in your LPG cylinder by carefully pouring hot water down the side of the cylinder and after a minute run your hand down the cylinder? At the level of the gas, It will feel cool to the touch.
Different Types of cylinders
LPG cylinders are available in four different sizes.
- Domestic cylinders are available in 5 kg and 14.2 kg
- Commercial cylinder is 19 kg and the Industrial cylinder is available at 35 kg.
- In a Domestic LPG cylinder of 14.2 kg the pressure is up to 16.9 kg/sqm.
- Regular LPG cylinder has pressure from 5.5 kg/sqm to 6.5 kg /sqm depending on the surrounding pressure.
A new sealed LPG cylinder has approximately 85% liquid and rests vapor. Typically the same propane and butane or a mixture of the two gases are the same combinations in both domestic and commercial LPG cylinders.
LPG is liquid under pressure but gaseous in ambient conditions. Depending on the propane content LPG boiling point is between -42 degree Celsius -0.4 degree celsius. The LPG gas is measured by weight in kilograms, pounds, tons, or metric tonnes as a gas measurement unit. When sold in gas bottles or cylinders LPG gas is measured by weight. It is measured in tonnes when stored or transported in bulk tankers or vessels and it is measured in liters when it is sold by volume. Gas is normally measured at Standard Temperature and Pressure [STP].
LPG has an explosive range of 1.85 to 9.55 volume of gas in the air. As compared to other common gaseous fuels it is considerably narrower.
Normally LPG will not catch fire on its own at the normal temperature, the temperature for auto-ignition is about 410-580 degrees.
Besides, the combustion reaction in LPG helps to increase the volume of the products. LPG requires up to 50 times its own volume of air for the complete combustion reaction. Also, adequate ventilation required when LPG is burnt in enclosed spaces.
LPG has only a very faint smell. It is odorless in nature. It is necessary to add some odorant to help people smell potentially dangerous gas leaks which might otherwise go undetected. An agent called Ethyl Mercaptan, which is also known as Ethanethiol which creates a smell when gas leaks. This substance is added to the gas in a quantity adequately in order to allow detection in the environment.
To reflect the gas inside sometimes the LPG cans are color-coded. Both liquid and vapor phase LPG are colorless. The vaporization of liquid cools the atmosphere and condenses the water vapor contained in them to form a whitish fog during the leakage which makes it possible to see an escape of LPG.
Some of the advantages of LPG are
- Easy to transport
- Higher heating value allows faster cooking.
- Burns is a lot cleaner than other fuels.
- More reliable than other forms of energy.
- More environmentally friendly than other sources of energy.
- Easy to handle
- LPG is economical. Stoves and burners require less maintenance.
- It is convenient and safe to use.
- It is cheap and easily available.
- It is non-toxic
- They do not give smoke when burnt.
What should be done if the LPG cylinder catches fire?
If a gas cylinder at your home or commercial uses catches fire the first initial thing to be done is to wrap the cylinder with a wet cloth or blanket. This will help to cool the metal body of the cylinder from overheating and allows the gas to cool off before it reaches the ignition temperature. If available a dry powder extinguisher should be used. Then close the knob of the regulator or take the cylinder to an open area away from your home or crowd to minimize the human casualty and collateral damage. After that cool with water.
Some of the safety precautions that should be followed while handling LPG cylinders are
- Do not put the cylinder in a hot water bath as chances of a gas cylinder explosion are always on the rise when they are exposed to heat and fire.
- When not in use remember to keep the regulator knob in off position.
- The handling of electrical appliances should be proper.
- The kitchen and cooking area should be properly ventilated.
- Rubber tubes and regulators used should be ISI approved.
- LPG cylinders should be only bought from authorized franchises.
It is mostly negligent and careless handling that leads to a cooking gas cylinder explosion. In case of leakage, avoid all kinds of activities that will start burning. Remove installations that may cause a spark. Do not electric switch buttons. If the leakage has been formed in closed areas like a kitchen or room, ensure air circulation by opening doors and windows and adequate proper ventilation.
In case of contact with eyes, it must be washed with a lot of cold water. In contact with skin, if the burn has formed dip the affected area into warm water. In case of contact through respiration, the contacted person must be taken out for fresh air and sent to the nearest health institution.
It is often referred to as Auto Gas when specifically used as a vehicle fuel. Since LPG is a clean fuel harmful emissions are reduced significantly. When used in automobiles its purity is maintained because it cannot tamper. When using LPG, vehicle performance will be always smooth and consistent.
LPG is easily available in numerous dispensing stations which makes it easy to procure.
In areas that do not have direct access to piped natural gas, LPG is most often used. It must be stored in pressure tanks or vessels in a refinery or gas plant. These containers are either cylindrical and horizontal or spherical in shape.
In European countries LPG water heaters are common. It is also used as a backup for generators and used to produce electrical energy by running turbines and popularly used refrigerant. Paper industries and the Food processing industry are the topmost industries that rely heavily on LPG. It is also used in agricultural purposes for drying purposes.
Because of its high heating or caloric value, The rate of heat from LPG is higher and It will burn cleaner, due to the virtual absence of sulfur. Usually stored in gas cylinders,
LPG is a convenient, portable energy source that is easy to transport and store. Although LPG contributes less than 2 percent of the total energy people use it is still one of the most important alternatives to gasoline.