Characteristic of low rank coal from Warukin Formation, South Kalimantan and their implication for coal liquefaction

Abstract

The research was conducted on petrology and geochemistry of coal at Warukin Formation, Barito Basin, in South Kalimantan. Research is focused on composition and behavior of low rank coal toward its liquefaction. The sampling location is in the coal mining of PT. Adaro Indonesia which involves some mining location such as Wara, Tutupan and Paringin area. The sampling was conducted in seam Wara 110, Wara 120, Wara 200, Tutupan 210 and Paringin 712 with ply by ply method. Sample analysis consists of proximate and ultimate properties, composition of maseral, reflectance vitrinite, as well as composition of mineral, major element and organic geochemistry. Experiment of coal liquefaction was conducted on the autoclave with temperature and pressure of 120° C and 14.17 psi. The problems are focusing on influence of maceral, mineralogy and geochemistry low rank coal of Warukin formation in Barito Basin on coal liquefaction, behavior of coal liquefaction to the change in variable of time to result of coal liquefaction yield. The physical and chemical characteristics of coal in Wara seam content are ash (< 7 %) adb, inherent moisture (< 31%) adb, volatile matter (< 5)%) adb and fixed carbon (< 33%) adb. Then in Tutupan and Paringin are ash < 3% adb, inherent moisture < 21% adb, volatile matter < 48% adb and fixed carbon < 40 % adb. Composition element in Wara coal are carbon < 64 % adb, hydrogen < 7 % adb, oxygen < 34% adb and nitrogen < 1% adb, then in Tutupan and Paringin seam consist of carbon (< 65 % adb), hydrogen (< 6 % adb), oxygen (< 32% adb) and nitrogen < 2% adb. The content of maseral in Wara seam coal consist of vitrinite, liptinite, inertinite maseral group which are 81%, 51% and 27% respectively. Result of coal liquefaction on Wara seam with time reaction of 30 minutes is 48.60 % and for 60 minutes is 51.27%. The result of liquefaction is decreasing on reaction time of 90 minutes and 120 minutes, which are 46.72%, 35.51% respectively. The liquefaction conversion obtained from Tutupan and Paringin seam within reaction time 30 minutes and 60 minutes are 8.22% and 15.46% respectively. The conversion is decreasing on reaction time 90 minutes and 120 minutes which of 6.23% and 5.54% respectively. The coal with more lignite is easier to be liquefied than sub-bituminous because the coal has higher hydroxyl group.