Solubilisation of Victorian brown coal in 'distillable' DIMCARB

Ying Qi, Tarun Tikkoo, Vince Verheyen, Vijay Ranganathan, Douglas MacFarlane, Alan L. Chaffee

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearch


Victorian (Australia) brown coal is an abundant and cheap energy resource. There is intense interest in identifying new opportunities for its efficient and clean use, for example by solubilisation to produce high quality fuel or chemicals. Ionic liquids (ILs) have been applied increasingly in recent years to solubilize and recover cellulose, lignin and other components from complex biomass mixtures. Conventional ILs are not distillable and it can be difficult to separate the soluble product from the solvent. However, there is a group of ILs, produced by the association of a secondary amine and CO2 that are 'distillable' in that they will dissociate back to the respective amine and CO2 at moderate temperature to facilitate recovery. They can then be re-associated (recycled) by condensation at lower temperature. The simplest form of such ILs, DIMCARB, consists of dimethylamine associated with CO2 at a molar ratio of 2:1. DIMCARB has previously been found to be superior (in terms of solubility) to other ILs in this group for the extraction of a Victorian brown coal. In this study the extractability of a woody coal sample was compared with a run-of-mine (ROM) sample, both without pretreatment. The wet coal was mixed with DIMCARB at a dry mass ratio of 1 to 20 for 24 hours at room temperature. The soluble product was recovered by centrifuge and acid washed to remove residual DIMCARB. An extraction yield of 25% was achieved for the ROM sample, while for the woody coal the yield was only 10%. The recovered products were characterized by a range of chemical techniques including FTIR and Pyrolysis GC-MS. The lower solubility of the woody coal seems to be associated with a high degree of oxygen containing aromatic components. The nature of this difference and the selectivity of the extraction are discussed.

Original languageEnglish
Title of host publication30th Annual International Pittsburgh Coal Conference 2013, PCC 2013
Subtitle of host publicationBeijing, China; 15-18 September 2013
Place of PublicationPittsburgh, Pennsylvania, USA
PublisherInternational Pittsburgh Coal Conference
Number of pages9
ISBN (Print)9781629934389
Publication statusPublished - 2013
EventInternational Pittsburgh Coal Conference 2013 - Beijing, China
Duration: 15 Sept 201318 Sept 2013
Conference number: 30th


ConferenceInternational Pittsburgh Coal Conference 2013
Abbreviated titlePCC 2013

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