Vapours are released into the atmosphere every time an oil/gas storage tank is filled. These organic compounds (VOCs) react with nitrogen oxides in sunlight and form ground-level ozone, a substance that is highly toxic to humans, is a strong environmental pollutant and a factor in global warming. These toxic and explosive fumes can be eliminated through the use of a vapour recovery unit. Vapour recovery is also critical as storage containers are prone to leaks via the hatch and/or safety valve and internal vapour pressure builds up over time. Canada has created the Canadian Environmental Protection Act, establishing regulations and standards relating to the emission of volatile organic compounds. The use of systems that control emissions and recover vapours from storage tanks, processing units and transportation loading platforms (rails, marine, trucks) has also been mandated.

What is a VRU in the Oil and Gas

Vapour recovery is the process of removing harmful vapour and fluid contaminants from oil, gas, and other products to improve purity and prevent the release of toxic pollutants into the environment. Vapour recovery is an alternative to flaring or venting, where the negative pressure created by a vacuum pump works with the pressure of the storage tank to pull in the vapours. 

What is a Vapour Recovery Unit (VRU)

A Vapour Recovery Unit (VRU) is an engineered compression package, which lowers emissions levels coming from the vapours of oil and gas while recovering valuable hydrocarbons to be sold or reused. VRUs are designed to remove unwanted vapours (about 95%) present in crude oil or distillate tanks allowing operators to reduce emissions and meet current emission requirements.  These units are mechanically driven, and powered by an electric motor or gas engine. There are several variants of VRUs, employed in oil and gas installations/plants as well as in the chemical industry (gas-lift, wellhead compression, tank battery vapour, industrial tail gas recovery, etc.). A typical unit consists of four principal components:

  • Gas Compressor (rotary screw, rotary sliding vane or reciprocating piston)
  • Scrubber (removes fluid impurities)
  • Variable Frequency Drive (adjusts the speed of the compressor)
  • Switching device (detects changes in pressure and starts/stops unit)

How Does a Vapour Recovery Unit Work

When a VRU is used in the oil and gas industry the following steps are involved. 

  • The compressor sucks liquid molecules into the scrubber.
  • The scrubber removes the water vapour, debris, and unwanted fluids from the tank.
  • The recovered vapour is pumped into lines while the trapped liquids are channelled to pipelines.

The Benefits of Vapour Recovery Units:

There are a number of advantages to the use of VRUs.

  • Cost Savings and/or New Revenue Stream:  Recovered vapours, that would otherwise be vented, can be utilized, returning them to the production line for sale, helping maximize profits.
  • Reduces Back Pressure: VRUs solve back pressure by taking the gas from the casing, compressing it and putting it back into the production line.
  • Reduce Fire Hazard: VRUs minimize the risk of fire by collecting combustible vapours from tanks and ensuring the large majority remains in the system.
  • Easy to operate and maintain: This cutting-edge technology is relatively simple to operate and maintenance needs are low. 
  • Higher Btu: Recovered vapours have much higher BTU content than pipeline-quality natural gas.
  • Reduce regulatory & liability exposure by assisting companies with compliance with current regulations.

What is the Environmental Impact of Using VRUs?

Reduce Health, Safety and Environmental Risks: VRUs collect carcinogenic gasses that create serious health issues, help companies comply with regulations and enhance environmental protection. Research supports that vapour recovery devices can achieve high capture rates for not only VOCs but also methane. 

  • Enhance Social and Environmental Responsibility: Venting is eliminated and emissions of dangerous pollutants are reduced by up to 95%, demonstrating a commitment to social responsibility and environmental protection.

As the climate change discussion continues, capturing toxic vapours remains a focal point of the federal government as well as oil and gas producers. Environmental compliance requires operators to have vapour recovery units to remove harmful particles. VRUs help control air quality around processing plants and storage tanks, eliminating 95% of harmful vapour particles. VRUs are uniquely suited for vapour recovery.

Interested in a vapour recovery unit for your facility? Contact Gaspro Compression Corp. We have a focused team that takes pride in their work, striving to provide dependable products and prompt service to all clients. We’re continually improving and innovating our products to meet changing industry demands. Gaspro is a leading provider of compressor packages in Canada. Contact us to request a proposal. Call 403-443-8886 or email us at