VRU Systems for Oil Storage Tanks

VRU Systems for Oil Storage Tanks

In Canadian oil and gas operations, storage tanks are one of the most common sources of hydrocarbon emissions, following pneumatic controllers. As liquids are stored, transferred and exposed to temperature changes, vapours naturally build up inside the tank. Without proper control, these vapours are released into the atmosphere, resulting in product loss and increased emissions. 

VRU systems are specifically designed to address this issue. By capturing vapours directly from tank vents, these systems prevent gas from escaping while maintaining stable pressure conditions. This makes them an essential component for operators looking to meet regulatory requirements and improve efficiency. 

With federal limits on venting and strict expectations for gas conservation, installing VRU systems on storage tanks is no longer optional for many facilities. It is a practical solution that aligns with both compliance and operational goals. 

How Vapour Recovery Works on Oil Storage Tanks 

VRU systems for oil storage tanks work by drawing vapours from the tank’s headspace. These vapours are created as crude oil or condensate releases dissolved gases due to pressure changes and temperature fluctuations. 

The VRU uses a compressor to pull these vapours into the system, where they are processed and redirected. The recovered gas can then be used as fuel, injected back into the system or sent to a sales line, depending on the facility setup. 

Maintaining proper pressure is a key part of this process. The system must be carefully calibrated to avoid creating too much vacuum or backpressure, both of which can disrupt tank operations. A well-designed system ensures smooth and continuous vapour capture without interfering with production. 

Common Challenges with Tank Vapours 

Storage tank vapour recovery comes with its own set of challenges. Vapour generation is not constant, and systems must be able to handle fluctuations in both volume and composition. 

Temperature swings, particularly in Central Alberta and Canada in general, can significantly impact vapour production. Warmer temperatures increase vapour pressure, leading to higher emission rates. During colder periods, vapour generation may decrease, requiring the system to maintain optimal efficiency at lower flow rates. 

Another challenge is the presence of heavier hydrocarbons in the vapour stream. These components can condense within the system, potentially affecting performance if not properly managed. Selecting the right equipment and materials is essential to address these conditions. 

Working with an experienced vapour recovery unit manufacturer like Eagle Pump & Compressor helps ensure that these variables are accounted for during system design. Customization is often necessary to achieve consistent performance across different operating conditions. 

Why Install VRUs on Storage Tanks? 

The advantages of VRU systems extend beyond emissions reduction. One of the most immediate benefits is the recovery of valuable hydrocarbons that would otherwise be lost. 

Captured gas can be reused on-site, reducing fuel costs and improving energy efficiency. In some cases, it can also be sold, creating an additional revenue stream. This makes vapour recovery a financially attractive option for many operators. 

Improved safety is another important benefit. By controlling vapour buildup and maintaining stable pressure levels, VRU systems reduce the risk of overpressure events and other operational hazards. 

There is also a clear compliance advantage. Meeting regulatory requirements becomes more straightforward when emissions are actively managed through vapour recovery. This reduces the risk of penalties and helps ensure smooth operations.