A Vapor Recovery Unit (VRU) is an engineered compression package, which aims to lower emissions levels coming from the vapors of gasoline or other fuels while recovering valuable hydrocarbons to be sold or reused as fuel onsite. A package for vapor recovery is designed to capture about 95% of Btu-rich vapors, generating many benefits, guaranteeing less air pollution, and recovering gasoline vapors to be used as fuel.
Yes, there are two completely different pieces of engineered equipment for different applications that are both referred to as Vapor Recovery Units.
A mechanical VRU is a compression package that is often used to recover tank vapors- gas formed when liquid in a storage tank is heated by outdoor temperatures and collects in a space at the top of the tank. Tank vapor is routed to a mechanical VRU, where it is then compressed and sent to a pipeline that delivers the gas to another part of the facility or to a sales pipeline.
A carbon bed or adsorption type VRU is essentially a large filtration system. These are used to handle vapors that are offset during liquid loading of trucks, railcars, marine vessels, or tanks. Vapor is routed to the VRU, where it passes through a bed of activated carbon that adsorbs hydrocarbons and allows clean air to exit the system. When the carbon bed reaches its maximum capacity, a vacuum pump can then extract the hydrocarbon vapor, send it to an absorber tower, and return the vapor back to a liquid state, so it can be put back into the tanks.