[en] Full text: The Gorgon project needs almost no introduction. Located off the north-west coast of Western Australia, it is one of the world's largest natural gas projects, set on the environmentally sensitive Barrow Island. To protect the island's unique habitats, stringent environmental conditions have been imposed in terms of air, noise and light emissions, making the emission control system critical to the project's viability. Luhr Filter, specialists in dust and fume control solutions, were chosen by KMH Environmental to supply an emission control system for a waste incinerator facility serving the LNG processing plant on Barrow Island. KMH's preference was for a 'one stop' supplier of the entire pollution control system. This included a heat exchanger which had the added benefit of a compact build to fit in the limited real estate. The solution put forward was tailored to the unique environmental requirements of the Gorgon project. It was very much about collaboration and innovation to achieve the requisite results. KMH were also keen to limit the number of sub-contractors they had to deal with, and Luhr offered them a turn-key plant for the gas cleaning, integrating design and supply of all the equipment. Among the environmental requirements was that all putrescible waste created on-site - from the accommodation camps during the construction and, eventually, production phases - had to be incinerated rather than sent to landfill. The flue gas from the incinerators had to be treated in order to meet world-class environmental standards for emission of particulate, acid gases, metals and dioxins. KMH designed an incinerator system with primary and secondary combustion chambers in modular units to minimise labour requirements on site. The dry absorption system integrates Luhr's unique technologies for heat exchangers, absorption reactors, utilisation of the absorbent and the baghouse style filters with reverse pulse bag cleaning. The first stage of the gas cleaning system is a compact Luhr flat tube gas-to-air heat exchanger. Flue gas from the incinerator stack passes on the outside of the flat heat exchanger tubes at low pressure loss, with cooling air being fan forced through the tubes. The absorbents - hydrated lime and pulverised activated carbon - are supplied pre-mixed in bulk bags and injected pneumatically into the gas stream upstream of the absorption reactor. The Luhr absorption reactor allows sufficient residence time for the first stage absorption of the gas pollutants. Coarse and agglomerated particles are milled or disintegrated when passing through a drum partly filled by grinding spheres, partly filled by grinding spheres, until the size in sufficiently reduced for the fines to be carried by the gas stream into the dust collector. The bag house filter collects the fly ash and completes the gas absorption in the filter cake on the bags. The filter is cleaned sequentially with pulses of compressed air reversing the gas flow through the bags. The main portion of the removed dust cake - ash and partly reacted absorbent - is recirculated by screw conveyors to the inlet of the absorption reactor, where the absorbent is reactivated in the milling drum. Several recirculation cycles ensure the absorbent capacity is fully exploited. Since a large amount of absorbent is held in circulation, a surplus is always available to cater for peaks in the stream of pollutants. This unique system of recirculating and discharging the reacted absorbent by mechanical means, combined with reduced heat losses through thermal insulation and trace heating, ensures reliable operation of the solids handling plant. The baghouse type dust collectors are supplied to site sub- assembled with the horizontally mounted Luhr flat bags installed. The compact build of these dust collectors has multiple benefits, facilitating transport to remote sites and reducing plant size. A fan downstream of the bag filter provides controlled draught for the incinerator and the gas treatment system and discharges the gas to the stack. Collected incinerator fly ash and spent absorbent is discharged from the bag filter hopper. Luhr Filter is currently supplying two similar pollution abatement systems for Exxon's LNG exploration and production facilities in Papua New Guinea, to go on stream by mid 2012. Expertise in customisation means that Luhr's dry absorption system is favoured by the chemical, oil and gas industries due to the special requirements such projects often have.