Emerson Provides IR Analyzers To Roplex To Monitor Vapor Recovery Units

Solon, OH - Emerson Process Management is providing Rosemount Analytical X-STREAM Process Gas analyzers to Roplex Engineering, one of the leading provider of Vapor Recovery Units (VRUs) and services to petroleum distribution terminals. The explosion proof, dual channel X-STREAM infrared analyzers are being used to measure carbon monoxide and butane, monitoring the effectiveness of the VRU in removing all the hydrocarbons and thereby adding additional levels of safety at terminals.

"A prime consideration for these applications is accuracy and reliability," said John Robson, managing director of Roplex Engineering. "We used to purchase cheaper analyzers with electrochemical sensors, but we find that the X-STREAM's proven infrared technology provides a superior solution, something our customers will readily acknowledge."

VRU's have long been installed on petroleum tanker loading terminals in response to legislation limiting the amount of hydrocarbon vapors being emitted to the atmosphere. When tankers arrive at the refuelling points they are empty of fuel but full of air saturated with vapor, up to 40% by volume. As the tanker is filled, the expelled vapor is collected and fed to a VRU where the hydrocarbons are removed before the air is vented to atmosphere.

A typical VRU has two scrubbers both containing activated carbon. Installed in parallel, the scrubbers are routinely switched. One adsorbs the hydrocarbons and then, once saturated, the beds switch and the hydrocarbons are removed and returned to liquid form. The X-STREAM analyzers detect carbon monoxide in the gas exiting the adsorber bed - a presence of the gas provides an early indication of an upset condition that has the potential to become a hazard. The second measurement, butane, is made on the final vent-to-atmosphere to ensure that the VRU is working effectively.

The X-STREAM analyzers utilize appropriate non-dispersive infrared (NDIR), ultraviolet (UV) spectroscopy as well as paramagnetic and thermal conductivity detectors to detect oxygen, carbon monoxide, carbon dioxide, hydrogen, or other gases. X-STREAM analyzers offer single or dual channel analysis and provide real-time control to help customers fine-tune their processes for increased productivity and profitability.

With EExd Flameproof or EExp ATEX certification the X-Stream Analyzer is rated to IP66/NEMA 4X for field mounting and is suitable for operating temperatures from -20 to +50 deg C. A 19" rack mounting version is also available.

SOURCE: Emerson Process Management