Opsis AB

Ambient air quality monitoring solutions for benzene fence-line monitoring - Air and Climate - Air Monitoring and Testing

To monitor benzene emissions can be a challenge, but OPSIS makes it easy. Benzene is an aromatic hydrocarbon liquid that evaporates quickly if exposed to ambient air. It is one of the most commonly used substances in the chemical industry and it is known to cause cancer. For this reason, refineries in the United States must start monitoring fugitive emissions of benzene from January 30, 2018. This is part of the 2015 U.S. EPA Petroleum Refinery rule. In case a yearly rolling average of benzene concentrations exceeds 9 μg/m3, actions have to be taken to reduce the fugitive emissions.

Benzene emissions can be conveniently and accurately monitored in real time using OPSIS UV-DOASsystems. The UV-DOAS technology utilizes a beam of light to measure gas concentrations. By arranging the light paths along the fence-line of a refinery, the benzene emissions from within the fence can be isolated and detected. In combination with meteorological sensors, it is also possible to calculate the locations and strengths of the benzene emission sources.

The OPSIS UV-DOAS systems are made for long-term, continuous operation. The level of maintenance involved when operating a system is minimal. Calibration with reference gas has to be made only once every quarter according to the U.S. EPA protocol. 

OPSIS monitoring systems are internationally tested and approved by a number of authorities and test institutes such as U.S. EPA, MCERTS and TÜV.

System Overview