Flare Gas Recirculation Reduces Product Losses and Emissions At Lyondellbasell Ethylene Plant

Hydrocarbon losses to an ethylene plant’s flare system, from such varied sources as relief valve leakage, vents from process vessels and clearing of equipment, represent both an economic loss and an emissions source.  One method for reducing these flare losses involves recirculating the flare gas back into the process.  This paper describes one such system, in operation in LyondellBasell’s ethylene plant in Berre, France for over 25 years.  Performance of the system in normal operation as well as response to process upsets will be described.  In addition, the potential for build-up of trace contaminants which otherwise would have left in the flare gas, and how these were addressed will be covered.