Clean coal technology company, Linc Energy has recently installed three Boge SL481 screw compressors at a coal tenement site in Queensland. Assisting Linc Energy in the extraction of syngas, the Boge compressors supply a constant stream of air which powers the underground coal gasification (UCG) process. Mariano Minotti, the project engineer at Linc Energy, comments: "Compressed air forms an integral part of the UCG process. When this new site was chosen for UCG it was agreed that investing in a new compressed air system would be more economical than hiring equipment."
Consequently, three Boge SL481 screw compressors were installed. The gasification is done in situ by injecting high pressure air as oxidant into the previously ignited coal seam. The screw compressors constantly supply air at 10 to 12 bar to keep the process running. The chemical reactions underground produce a syngas that is then collected on the surface through 'production' wells. This syngas is then cleaned up and used in a gas to liquids demo plant to produce liquid fuels (diesel) through the Fischer-Tropsch process. As a direct coupled compressor, with no belt drive or gears, the SL series virtually eliminates transmission losses. The resultant specific power characteristics of these large direct coupled units (kW consumed per cubic metre produced) assure Linc Energy of an economical energy-efficient installation.