Gas analysis monitoring functions at the ExxonMobil Chemicals Olefins ethylene manufacturing plant in Fife, are now being carried out by two Servomex infrared gas analysers.
The new equipment has replaced Servomex PSA 402 analysers dating from when the plant was first commissioned in 1985. Both PSA 402 analysers still operate efficiently and have, in fact, been retained for spare parts.
When it was decided to replace the ageing PSA 402 gas analysers, the Exxon Mobil engineering team asked potential suppliers, including Servomex Group, to quote for two quite separate process monitoring applications. One of these, for which Servomex recommended a xendos 2510 infrared process analyser, is the constant sampling of the raw ethane feedstock into the process to check for the presence and percentage of carbon monoxide in the stream.
This requires an analyser operating in the range 0-1000ppm using the existing Servomex sampling system installed in 1985. The second application is the monitoring of the ethane stream from the distillation column for the presence of ethylene in the ethane being recycled to the furnace feedstock. For this, Servomex proposed a xendos 2500 infrared gas analyser.
The Servomex xendos 2500 is a single-beam, dual-wavelength infrared process analyser suitable for measuring a single infrared-absorbing component, or component group, in a gas or liquid sample stream. Each unit is designed, manufactured and tested in a configuration specific to the required measurement and background stream.
The 2500 is designed for continuous operation and is not normally switched off.
The xendos 2510 analyser, used to monitor the presence of carbon dioxide in the ethane feedstock is a single-beam gas filter correlation infrared analyser for measuring a single infrared absorbing component in a sample stream. Designed for aggressive industrial environments, the 2510 is ruggedly built and suitable for process plant applications.
It is operated using a simple control panel mounted on the analyser or in the optional separate 2010 controller, which can be mounted up to 500 metres from the analyser.
The engineering team at ExxonMobil Chemical Olefins installed the analysers themselves, backed by Servomex support.