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| CNG |
WHAT IS CNG?
CNG is compressed natural gas. It is produced simply by compressing standard natural gas to a fraction of its volume through a common technological process, usually at a pressure of around 200 bar (1 bar = 1 atm).
As a fuel, CNG is a far more cost effective solution than conventional fuels such as petrol and diesel. It is also considerably safer, even in the case of leakage, and far more environmentally friendly. Boasting a 70-90% reduction in Carbon Monoxide content, CNG can contribute significantly towards the reduction of emissions.
CNG can be used both as a fuel for power generation and in automotive applications. In terms of equipment, CNG provides a reduction in general operating wear and tear; examples of this include a lack of contamination or dilution of crank case oil and the elimination of the fouling of spark plugs. As an added advantage, vehicles powered by CNG retain the ability to also run on petrol.
CNG offers a fuel that is both cheaper and more environmentally friendly than petrol and diesel, and as such is an ideal fuel to drive growth while promoting environmental responsibility and sustainability in today’s world.
HOW SAFE IS NATURAL GAS?
• Natural gas at ambient temperature and pressure is in the gaseous phase.
• Natural gas is an environmentally friendly fuel. It is a cleaner burning fuel than both gasoline and diesel fuels. In fact, natural gas offers significant safety advantages as compared to both gasoline and diesel.
• Natural gas is non-toxic, and has no potential for ground or water contamination in the event of a fuel release.
• Being lighter than air, natural gas rapidly disperses upwards and to a state of low concentration when released into the environment, making it a far safer form of fuel in the event of a leak or accident.
• Liquid fuels such as gasoline and diesel, on the other hand, are heavier than air. As they evaporate, gasoline and diesel vapors tend to accumulate around the source and pose an explosion hazard. Liquefied petroleum gas (LPG) is another fuel less safe than natural gas, as it is heavier and will also tend to accumulate.
• Odourant is added to natural gas to create a recognizable smell in the case of leakage. Where necessary, gas detection equipment can be installed so that an immediate alarm is activated in the unlikely event of a leakage.
• Three conditions must be met before there is potential for a fire or an explosion:
1. Leakage
2. Mixing of fuel with air to create a mixture in the flammable range, which, given the nature of the fuel is highly unlikely.
3. A suitable source of ignition
LEAKAGE
• Natural gas is supplied through pipelines and there is normally no storage requirement. Diesel, on the other hand, is stored in large tanks which offer a very real threat of leakage, posing a fire hazard.
• Natural gas, unlike liquid fuels can not be siphoned, which is a strong risk of leakage / spillage, and is a frequent source of disaster in many locations across the world.
• Natural gas systems are “sealed” to prevent any spills.
CREATING A FLAMMABLE FUEL-AIR MIXTURE
1. Natural gas will ignite at a temperature of 1,200 degrees Fahrenheit and between 5.3% to 14% concentration in air.
The high ignition temperature and limited flammability range make any accidental ignition or combustion of natural gas highly unlikely.
2. Gasoline will ignite at a temperature of 450 - 900 degrees F and between 1.4% to 7.6% concentrations in air.
3. Diesel will ignite at a temperature of 400-500 degrees F and between 0.7% to 5.0 % concentrations in air.
Diesel is a potentially dangerous fuel, but, over time, we have learned to use it safely.
Like diesel, natural gas must be understood and respected to be used safely.
SAFETY RECORD
• There are two basic reasons for the excellent safety records of Natural gas:
1. The structural integrity of natural gas systems
2. The physical quantities of natural gas as a fuel handled in a power plant, such that there is a smaller volumetric energy density in a natural gas fuelled system than in an equivalent gasoline or diesel fuelled system.
