BIOSOLUBIUZADON AND BIOGASIFICADON OF INDIGENOUS LOW RANK COAL FOR ITS APPUCATIONS

Abstract

Coal has been ensuring energy security and stabi lity for a long period of time in terms of increasing exploitation and excavation of high rank coals, thus, leaving behind huge unattended low rank coal reserves. Furthermore, thermal systems were designed on the basis of physico-chemical properties of high rank coals. However, temporarily, low rank coals were abandoned as these had been found to be associated with high moisture contents and low calorific values, which posed their unsuitability for application in conventional thermal systems. The present study was aimed at investigating and exploring the prospects of possible intervention of biotechnological approaches into conventional fuel sciences for the extraction of alternative fuel options like methane and value added products such as humic acids. In this regard, fungal degradation of coal can serve as a pretreatment step in order to make coal a suitable substrate for biological beneficiation. Thirty one (31) coal samples, originating from eight coal areas of Pakistan and majority from Thar coal field, were subjected to detailed chemical analyses including maceral analysis and these indicated that geological stage of Thar coal, which might be susceptible to biological modification. A fungal strain MW 1, identified as Penicillium chrysogenul11 on the basis of fungal ITS sequences, was isolated from a core sample of sub-bituminous coal and twelve (12) low rank coal samples were treated with this isolate for further studies. Liquid extracts were analyzed thTough Excitation-Emission Matrix Spectroscopy (EEMS) to obtain qualitative estimates of solubilized coal; these analyses exhibited the release of complex organic moieties. In addition, analysis of these extracts, based on Gas Chromatography-Mass Spectrometry (GC-MS), confirmed the presence of single ring aromatics, polyaromatic hydrocarbons (PAHs), aromatic nitrogen compounds and some aliphatics. Subsequently, the released organics were subjected to a bioassay WBC-2, based on mixed bacterial consortium, containing methanogenic and non-methanogenic types, for the generation of methane, which conferred the potential application of fungal degradation as pretreatment.