How CNG is Made in India – A Step-by-Step Guide

Compressed Natural Gas, commonly known as CNG, has gained popularity as a clean automotive fuel in India. With many cities plagued by air pollution, CNG provides a less-polluting alternative to petrol and diesel for vehicles. But have you ever wondered – how is CNG produced in India? What processes are involved in making this compressed fuel that now powers everything from public transport buses to private cars in the country?

In this blog, I will take you through a step-by-step guide on how CNG is manufactured in India – from extracting natural gas to compressing it for use in vehicles. Understanding the CNG production process can help us appreciate this smart fuel choice better. So let’s get started!

Overview of CNG Production

CNG is a fuel gas mainly composed of methane compressed to less than 1% of the volume it occupies at standard atmospheric pressure. CNG or Compressed Natural Gas is essentially methane stored at high pressure. Methane is the main component of natural gas – a fossil fuel formed underground in porous rock formations. The key steps involved in CNG production are:

  • Extraction – Getting natural gas out of underground deposits
  • Treatment – Removing impurities from natural gas
  • Compression – Squeezing natural gas at high pressure to turn it into CNG
  • Storage – Storing CNG in cylinders for distribution
  • Transportation – Distributing CNG to refueling stations

Now, let me explain these CNG production steps in a bit more detail:

Extraction of Natural Gas

The first step is extracting natural gas, which is composed mainly of methane and other light hydrocarbons. This happens through conventional methods like:

  • Vertical drilling – Drilling vertically down to tap natural gas pockets
  • Hydraulic fracturing – Pumping fluid at high pressure to fracture shale rock and release trapped gas
  • Horizontal drilling – Drilling sideways into a gas reservoir to increase extraction

India has both onshore and offshore natural gas reserves. Once extracted, raw natural gas contains some impurities that need to be removed before it can be compressed into CNG.

Treatment of Natural Gas

The treatment process cleans raw natural gas by separating impurities like:

  • Water vapor
  • Hydrogen sulfide
  • Carbon dioxide
  • Liquid hydrocarbons

Special filters, absorbers, and distillation columns help eliminate these impurities. This produces pipeline-quality natural gas that is about 90-95% pure methane.

Compression of Natural Gas

This is the most crucial step in CNG production. Pipeline gas is compressed to turn it into a vehicular fuel. Here’s how the compression process works:

  • Natural gas enters a multistage reciprocating compressor station.
  • It is compressed in successive stages up to a pressure of 3000 psi.
  • Cooling occurs between each compression stage to remove heat.
  • The highly compressed gas gets stored in strong cylinders at high pressure.
  • This high-pressure storage as CNG reduces the volume by 99% compared to natural gas.
  • Odorants are added to help detect gas leaks.

After compression, CNG is ready to be transported in cylinder cascades to dispensing stations for use as automotive fuel.

Storage and Transportation of CNG

CNG needs robust, specially designed cylinders for storage and transportation:

  • CNG is packed into strong, welded steel or composite cylinders.
  • Cylinders have safety valves and are rigorously tested.
  • Cylinder cascades are used to carry bulk quantities of CNG.
  • CNG trailers, rail cars, and pipelines help distribute CNG from production to storage facilities.
  • Compression stations can be located near consumption centers.
  • CNG is delivered to retail outlets through pipelines or in cylinder trucks.

CNG Distribution System in India

So how does CNG reach vehicles in Indian cities? Here is an overview of the CNG supply infrastructure:

  • Producers – State-owned oil companies like ONGC, GAIL, IOCL extract and process natural gas. Private companies also produce gas.
  • Suppliers – GAIL owns most of India’s natural gas pipeline network spreading over 11,000 km.
  • Distributors – City gas distribution (CGD) networks purchase natural gas to compress it into CNG for urban consumption.
  • Retail Outlets – CNG pumps operated by CGD entities sell CNG to vehicle owners through dispensing stations.

So from extraction to distribution, CNG passes through an elaborate supply chain before providing clean fuel to Indian vehicles!

Challenges in CNG Production and Supply in India

Though CNG has advantages, India faces some obstacles in production and supply:

  • High cost of setting up CNG stations and distribution infrastructure.
  • Limited domestic natural gas reserves – India depends on imports for over 50% of natural gas needs.
  • Gas fields are located far from demand centers, requiring long pipelines.
  • Competition from subsidized liquid fuels like petrol and diesel.
  • Lack of CNG dispensing stations and production facilities in many parts of India.
  • CNG production being concentrated mainly in western and northern regions.

Future of CNG in India

But the future looks promising for CNG to expand as a green automotive fuel in India:

  • Government plans to rapidly grow CGD infrastructure under the Sustainable Alternative Towards Affordable Transportation (SATAT) initiative.
  • Discovery of new gas fields expected to enhance domestic supply.
  • Increased adoption of CNG by public transport fleets, taxis, private cars.
  • Growing awareness of CNG benefits – efficiency, low emissions, cost savings.
  • More technological advancement in gas extraction techniques like coal bed methane production.
  • Foreign investment and private sector participation to boost infrastructure.

So while CNG production and supply logistics pose challenges, India is committed to expand this clean fuel option. With supportive policies and innovative solutions, the country can benefit enormously from embracing CNG on a larger scale.


I hope this guide gave you a good understanding of the key steps involved in producing CNG in India – from gas extraction to treatment, compression, storage and distribution. Though complex industrial processes are involved, they culminate in giving us CNG – a smart fuel choice that is efficient, relatively affordable, and environment-friendly.

As India tries to control air pollution and meet its energy needs sustainably, embracing CNG as a popular auto fuel can significantly help the country.

So the next time you see a CNG powered vehicle, you know the complex journey the compressed natural gas has undertaken right from underground deposits to reach your automobile!


How is CNG compressed at the refueling stations?

At CNG stations, a booster compressor compresses natural gas from the supplied pipeline network into on-site storage cascades at pressure up to 5000 psi. High-pressure nozzles then transfer CNG into vehicle cylinders up to the recommended filling pressure.

What are the benefits of CNG over petrol and diesel?

CNG emits up to 90% fewer polluting fumes compared to gasoline or diesel. It also gives 20-30% better fuel efficiency. CNG is safer with a narrow flammability range. It does not contaminate or spill like liquid fuels. For consumers, CNG offers 30-50% savings on fuel costs.

How is the quality of CNG ensured in India?

CNG quality is maintained as per Bureau of Indian Standards code IS 16087. Checks are conducted for composition, hydrogen sulfide limits, particulate matter, odour, and other parameters. Safety regulations also cover CNG cylinder testing, site distances, fire compliance, etc. to ensure high quality and standards.

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