The prospects of natural gas compressors

A compressed natural gas compressor(CNG compressor) is a type of fluid machinery that is specially designed for compressing natural gas.

Applications of Air Compressors in  Natural Gas (CNG).

Support multiple application scenarios

The role of natural gas compressors

The natural gas compressor is an important part of the natural gas transmission system and plays an important role in the transportation, storage, and use of natural gas.

It is a type of fluid machinery. Its function is to extract natural gas from the wellhead or gas storage, compress the volume of natural gas and increase its pressure to the required level, so that people can store as much natural gas and put them in proper places or send them to the users.

Because of the reduction in volume and increase in pressure, the compressed natural gas can also be transported by natural gas stations to urban gas pipelines or user terminals through special gas tanks and pipelines for people to use.

At the same time, natural gas compressors can also be used in the field of natural gas power generation, compressing natural gas to supply gas turbines or internal combustion engines for power generation.

Therefore, the role of natural gas compressors is mainly reflected in the following aspects:

  1. Increase the efficiency of transportation: In the process of transporting natural gas, due to the changes in pipeline length and terrain, natural gas needs to be compressed to obtain sufficient pressure before it can reach the target location. Natural gas compressors can improve the efficiency of natural gas transportation, compress natural gas into high-pressure gas through multi-stage compression, reduce energy loss during transportation, and ensure that natural gas is stably and efficiently transported to the user end.
  1. Improve storage efficiency: In the process of natural gas storage, high-pressure gas can occupy storage space more effectively, thereby increasing storage density and reducing storage costs. Natural gas compressors can compress natural gas into high-pressure gas, so that natural gas occupies a smaller space during storage and improve storage efficiency.CNG (Compressed Natural Gas) Compressor solutions
  1. Provide a stable gas source: Natural gas compressors play an important role in the process of natural gas extraction. They extract low-pressure wells by boosting pressure, and discharge natural gas into the main pipeline of natural gas after boosting pressure, ensuring a stable supply of gas source. At the same time, during the use of natural gas, the compressor can stably provide high-pressure gas to meet the demand for high-pressure gas in industrial production or residential gas use.
  1. Energy saving and environmental protection: Natural gas compressors help reduce energy waste and environmental pollution by increasing the pressure of natural gas. For example, in oil wells, the natural gas that was originally directly vented not only wasted resources but also polluted the environment. Now, the natural gas compressor is used to pressurize and recover it, which not only increases oil production but also is beneficial to environmental
  1. Support multiple application scenarios: Natural gas compressors are widely used in various natural gas pipeline transportation, natural gas storage, natural gas power generation and other fields, as well as pressure stabilization, compression and transportation in petrochemical processes, providing stable and reliable natural gas supply for different users.

The Difference Between Natural Gas Compressors and Air Compressors

Natural gas compressors are not the same as ordinary air compressors. There are many differences between them.

  1. Different compressed media
    Air compressors generally directly compress the air in our daily lives, and use the compressed air as a power source to supply other pneumatic tools, which is safe and pollution-free. The natural gas compressed by natural gas compressors is fossil gas/methane gas, which is toxic to the human body and can affect the climate. It cannot be obtained anywhere or discharged at will.
  1. Different usage scenarios
    Natural gas compressors are mainly used for natural gas storage, gas compression during transportation, and natural gas filling stations. Air compressors are suitable for a wide range of industrial fields, such as mining, construction, electronic manufacturing, pharmaceuticals, textiles, aircraft and other industries.
  1. Different pressure requirements
    Due to the limited reserves of natural gas and far away from cities, natural gas needs to be compressed to a high pressure state for storage and long-distance transportation. Therefore, natural gas compressors need to meet higher pressure requirements during operation. The exhaust pressure of natural gas compressors used for natural gas pipeline transportation is usually around 100-400 bar. The pressure requirements of ordinary air compressors are usually between 7-15 bar.
Kotech Gas Air Compressor

Are you looking for a reliable and efficient power source for your textile industry? Kotech dealers are experienced in finding the perfect air compressor for your needs.

Contact your local Kotech dealer today and discover how an air compressor can increase your productivity and safety.

Can an air compressor be used instead of a dedicated natural gas compressor?

compressing natural gas
Main components of compressing natural gas

No. Do not use ordinary air compressors to compress natural gas, because natural gas is mainly composed of methane (about 95%) and various small amounts of other higher alkane, and usually contains trace amounts of carbon dioxide, nitrogen, hydrogen sulfide and helium (data source: Wikipedia).

Methane is colorless and odorless like air, but it is a flammable and explosive substance, unlike air, which is a stable medium.

It is also toxic and will have a bad impact on the climate if not be treated. Ordinary air compressors, especially high-pressure air compressors, tend to generate a lot of heat when they are working.

If the heat cannot be dissipated in time to cool the machine, encountering natural gas may cause very serious consequences-explosion!

Natural gas compressors usually use special compressor oils, such as polyether oil or polyurethane oil, because some components in the gas can damage the lubricating oil. Air compressors are usually lubricated with mineral oil or synthetic oil.

Natural gas compressor and natural gas air compressor

It is worth noting that there is a type of air compressor that is easily confused with a natural gas compressor, and that is a natural gas air compressor. Unlike the common traditional air compressors that use electricity or fuel as energy, it uses natural gas. As a high-quality energy source, natural gas is not only cheap, but also has little impact on the environment.

It is now being used more and more widely. But it is not a natural gas compressor, and it cannot be used to compress natural gas, because it is just a type of ordinary air compressor, and its compression medium is still air.

How natural gas compressors work

How piston natural gas compressors work

Natural gas enters the compressor through the air inlet and enters the compression chamber. There is a piston inside the compression chamber, which is driven by an electric motor or a diesel engine. When the piston moves downward, the volume of the compression chamber increases, and the gas enters the chamber through the air inlet.

As the piston moves upward, the volume of the compression chamber decreases, the gas is compressed, and the pressure of the gas gradually increases. The piston natural gas compressor uses the up and down movement of the piston in the compression chamber to compress the gas into high-pressure gas. This type of compressor is usually widely used in natural gas filling stations, natural gas storage depots and other fields.

How rotary screw natural gas compressors work

The working principle of rotary screw gas compressor is based on the special shape and movement of the screw. When the two screws rotate, the working chamber sealed by their gears pushes the gas forward. As the two screws rotate around their axes, their gears push against the gas, compressing it. As the screws rotate, the gas is pushed into the closed space between the other screws.

When the gas is compressed to the required pressure, the valve opens and the compression is completed. Screw gas compressors are widely used in oil and gas exploration, production, pipeline transportation and other links.

How centrifugal natural gas compressors work

Centrifugal compression technology is a common compression technology. Its main features are simple structure, reliable performance and high efficiency. This technology is suitable for natural gas compression scenarios in the low and medium pressure range. The structure and working principle of the centrifugal compressor are very similar to those of the centrifugal blower.

However, its working principle is fundamentally different from that of the piston and screw compressors. It does not increase the pressure of the gas by reducing the cylinder volume, but relies on the change of kinetic energy to increase the gas pressure. In the centrifugal compressor, when the gas enters the unit, it is sucked in by the rotation of the centrifugal wheel and rotates in the gap between the wheel cover and the centrifugal wheel.

The air gains kinetic energy due to the centrifugal force, and at the same time, the gas in the wheel cover gains more kinetic energy due to the high-speed circular motion. Finally, part of the kinetic energy will be converted into gas pressure, and the gas is compressed.

Types of CNG compressors

CNG compressors for drainage and gas extraction

During the process of natural gas production, the gas reservoir will experience pressure depletion. In order to maintain the pressure of the gas reservoir and continue production, a CNG compressor is needed for pressurization.

The gas lift process is to inject high-pressure gas into the well with the help of CNG compressor, reduce the pressure gradient from the injection point to the wellhead, and then reduce the bottom hole back pressure, increase the production pressure difference, thereby increasing the fluid flow rate, increasing the liquid carrying capacity of natural gas, and then draining the bottom liquid, so that the flooded well can resume production and finally achieve continuous or intermittent production of drainage and gas production. CNG compressors play a vital role in this process.

CNG compressors for gas gathering and processing

As gas wells are continuously mined, the parallel port pressure will also decrease. When the pressure drops below the pressure of the gas gathering system, boosting equipment is needed to input the produced natural gas into the gas gathering pipeline network. The types of CNG compressors suitable for high-pressure gas gathering processes are mainly reciprocating compressors.

In the process of designing the unit, the important technical parameters are mainly outlet pressure, inlet pressure and exhaust volume. In the boosting scheme of the gas gathering station, the compressor outlet pressure must be greater than or equal to the operating pressure of the branch line and the trunk line to ensure that the boosted natural gas can smoothly enter the branch line and the trunk line.Natural Gas Boosting Stations

The inlet pressure is determined by the bottom hole pressure at the end of the gas field boosting stable production period. The compressor is installed in or near the gas gathering station, and the inlet pressure is required to be basically consistent with the natural gas inlet pressure from the gas well.

Finally, the single unit power is determined according to the total processing scale of the station and the number of compressors.

Generally, the number of compressors for each gas gathering station is preferably 3~5. The compressor used for gas gathering and processing does not have high pressure requirements, generally below 8MPa, and the power level is determined according to the natural gas processing volume requirements of the gas gathering station. The general single-unit power is within 3500kW.

CNG compressors for pipeline transportation

Long-distance natural gas pipelines need to build natural gas boosting stations along the way. Only by multiple multi-stage boosting by compressors can long-distance transportation of natural gas be achieved. CNG compressors are often likened to the “heart” of natural gas pipeline transportation. There are two types of natural gas compressors commonly used for pipeline transportation: reciprocating and centrifugal.

The specific type to be used needs to be determined based on the pipeline boosting conditions and the environmental conditions for installing the natural gas compressor. Generally speaking, the reciprocating type is suitable for unstable working conditions, high or ultra-high pressure and small flow rate; while the centrifugal type is suitable for large processing volume and small fluctuation range of processing volume (variation range between 70% and 120%).

According to the current development trend of newly built natural gas transmission pipelines at home and abroad (high pressure, large diameter and high flow), the use of centrifugal types will become more and more extensive.(data source:

CNG compressors for gas storage

The function of natural gas storage is to peak load. Gas is injected into the gas storage for storage when consumption is low, and natural gas is transported to the pipeline during peak hours.

During the injection process, a large natural gas compressor is required. There are two main types of natural gas compressors used in gas storage: reciprocating and centrifugal compressors.

Since the price of centrifugal compressors is much higher than that of reciprocating compressors and they have great working limitations, reciprocating compressors are generally used.

Other types

In addition to the above main types, compressors also have other uses in the natural gas industry. For example, a large number of compressors are needed in CNG filling stations. CNG filling stations are basically divided into three types: conventional stations, CNG mother stations, and CNG substations according to their location and functions. The equipment they use, especially the type of compressor, is also very different.

Conventional station: The filling station takes gas from the pipeline network and directly fills the vehicle with gas. The station usually has a ground high-pressure gas cylinder group (200~250kg), a compressor block, a control system and a gas dispenser.

CNG mother station: In addition to having the functions of a conventional station, it also fills the substation trailer with gas through the gas filling column set up in the station. The substation trailer can transport CNG to the substation and supply gas to the substation.

CNG substation: It is established in places where the central urban pipeline network cannot reach, and the substation trailer supplies gas to it, and then the compressor

Ground gas storage system, ground gas cylinder group, and gas dispenser are used to fill the vehicle with gas.

The main equipment of CNG filling stations include: gas dryer, compressor unit, gas storage device, filling priority control panel, gas column, gas vending machine, etc.

Benefits of CNG compressors compressing natural gas

  • After compressing the gas, the floor space occupied can be reduced, the storage density can be increased, and the storage can be safer and more reliable.
  • After compressing the gas, the gas can be directly transported to a farther place through a pipeline, reducing the transportation cost.
  • After compressing natural gas into high-pressure gas, it can be better used in gas water heaters, natural gas engines and other application fields.
  • By compressing natural gas to a certain pressure to increase its density and reduce its volume, it becomes a new type of fuel with high energy storage density and stability. Compared with ordinary natural gas, compressed natural gas can reduce 80% of nitrogen oxide emissions and 99% of particulate pollutant emissions, and is more environmentally friendly.
  • Compressed natural gas has a wide range of applications. Compared with traditional petroleum energy, it has higher storage density, emission reduction advantages and safety, and is one of the new fuels developed at home and abroad.

Benefits of CNG compressors

Application of natural gas compressor

The application fields of natural gas compressors are very wide, mainly including natural gas storage tanks, gas pipelines, CNG filling stations, LNG stations, etc. These fields all require the use of natural gas compressors to compress natural gas for storage and transportation. In addition, as a green energy source, natural gas has very high requirements for use, especially in terms of transportation process and safety of use.

The use of natural gas compressors has improved these problems to a certain extent. By increasing the pressure of the gas, the gas exists in liquid form, which is convenient for transportation and use. In addition, natural gas compressors can also be used in petrochemical, chemical, oxygen production, hydrogen production and other industrial fields.

The prospects of natural gas compressors

The prospects of natural gas compressors

The technology of natural gas compressors is now becoming more and more mature, and the manufacturing cost of natural gas compressors is not particularly expensive. However, natural gas compressors have high economic benefits, are pollution-free, safe and convenient, and according to this development trend, there is obviously a great prospect for application. Natural gas compressors are now generally used on a large scale in engineering equipment on the market.

Natural gas compressors are also a common application in urban gas industry. Now residents with certain economic strength are willing to use natural gas fuel. The use of natural gas is becoming more and more popular because natural gas is a green energy source and has little pollution to the environment.

As of 2009, the estimated remaining recoverable reserves of natural gas are 850,000 cubic kilometers (200,000 cubic miles), of which 66,000 cubic kilometers (16,000 cubic miles) have been mined (accounting for 8%). (Data source: Wikipedia) Modern society also strongly advocates the use of natural gas. In the foreseeable future, the use of natural gas compressors will become more and more important.