Compressed Natural Gas (CNG)

Natural Gas (NG)

Natural Gas (NG) is the most widely used gas in the world. In 2015 over 3550 billion cubic meters were consumed worldwide. NG can be used in most heating processes, such as in furnaces and kilns, and for applications like thermal cutting. We assist our customers in converting to NG for heating requirements with minimal disruption. Another popular and ever increasing use of NG is an alternative fuel for vehicles. There are over 25 million vehicles around the world using NG, and South Africa is quickly adopting this technology.

Tetra4 not only supplies the gas, but also converts vehicles to run on NG or a combination of NG and existing fuels.

What is Compressed Natural Gas (CNG)?

Compressed Natural Gas, commonly referred to as CNG, is natural gas that is compressed to high pressure, so that large volumes can be stored in compact containers.

Gas supplied by Tetra4 typically consists of 94% methane, with the balance comprising helium and nitrogen. This gas is compressed up to 300 bars and stored in high-pressure vessels that can be transported via trailers to customer sites. Once at the customer, the CNG pressure is reduced to the process requirements using a pressure reducing station (PRS) which can be supplied and installed by Tetra4.

Fuel characteristics and comparison

Safety advantages

  • NG is lighter than air, and any leaks tend to disperse upwards into the atmosphere whereas Liquefied petroleum gas (LPG), which is denser than air, will congregate at ground level.
  • LPG has a Lower Explosive Limit of 2% whereas NG is considerably higher at 5%
  • The auto-ignition temperature of LPG is 470C compared to 600C for NG

Benefits of CNG

  • Reduced CO2 emissions – up to 30% lower than oil and 50% less than coal
  • Cleaner burning – no sulphur components in the gas
  • Consistent quality – over 90% methane in the gas ensures perfect combustion every time, whereas the composition of LPG (mixture of Butane and Propane) can vary resulting in inconsistent combustion
  • No sooting issues – LPG frequently has residual ‘heavy ends’ that can cause “sooty” combustion. Tetra4’s NG is totally free from contaminants
  • Transport/logistics companies- substitution of diesel fuel with CNG
  • Industrial companies- substitution of electricity, diesel or power paraffin with CNG for heating applications in boilers and or burners