Vapours are released into the atmosphere every time an oil/gas storage tank is filled. These organic compounds react with nitrogen oxides in sunlight and form ground-level ozone, a substance that is highly toxic to humans and a strong environmental pollutant. 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. 

What is vapour recovery?

Vapour recovery is the process of removing harmful vapour and fluid contaminants from oil, gas, and other products to improve the 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 Vapor 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. They’re designed to remove unwanted vapours (about 95%) present in crude oil or distillate tanks allowing operators to reduce emissions. These units are mechanically driven, powered by an electric motor or gas engine. There are several variants of VRUs, employed in a wide range of oil and gas installations/plants as well as in the chemical industry (gas-lift, wellhead compression, tank battery vapour, industrial tail gas recovery, etc.). The 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)

The vapour recovery procedure involves the following steps:

  • 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:

  • 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.
  • 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: Minimize the risk of fire by collecting combustible vapours from tanks and ensuring the large majority remains in the system.
  • Reduce Health, Safety and Environmental Risks: VRUs collect carcinogenic gasses that create serious health issues and they enhance environmental protection.
  • 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.

VRUs reduce air pollution emissions by recovering vent gas that would be emitted to the atmosphere or burned in a flare. They reduce current and future risks and liability associated with greenhouse gas (GHG) emissions. VRUs are an ideal vapour recovery solution for the petroleum and petrochemical industries. They enable companies to treat a wide range of vapours in hydrocarbon storage units, saving money, reducing emissions, decreasing fire hazards and safeguarding the health of people and the environment. 

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