Tripathi, P.S.M. and Mishra, K.K. and roy, R.R.P. and Tewari, D.N. (2001) Gamma - Radiolytic desulphurisation of some high-sulphur Indian coals catalytically accelerated by MnO2. Fuel Processing Technology, 70 (2). pp. 77-96. ISSN 0378-3820

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Abstract

γ-Radiolysis of acidic aqueous coal slurries is a novel and effective method for the simultaneous oxidative desulphurisation and demineralisation of high-sulphur coals. This method is capable to selectively remove the inorganic and organic forms of sulphur simultaneously through the in situ-generated H2O2 and other radiolytic products. In effect, there is neither any appreciable degradation of coal matrix nor any loss in the caking property and volatile matter content of the coals after the removal of sulphur. However, significant removals of sulphur and mineral matter are effected at rather high γ -dose (175X104 Gy or so). Therefore, for the process to be economically viable and commercially adaptable, the applied γ -dose needs to be somehow substantially brought down, at which the same level of desulphurisation could be achieved. Catalytically, accelerating the radiolysis process is one such possibility to effect the desulphurization step at a low γ -dose. Reported in this paper are the results of investigations on the desulphurisation and demineralization of high-sulphur (sulphur content in the range 3–5.5%) Churphy, Chalang and Bapung coals of Meghalaya by γ -radiolytic process catalysed by MnO2. The maximum removal of total sulphur (15.6%, 30.0% and 29.8%) at 30 X 104 Gy in the presence of MnO2 and the simultaneous removal of mineral matter (20.0% and 18.5% from Churphy and Chalang coals at 30 X 104 Gy and 12.0% from Bapung coal at 45 X 104 Gy. are at par with removals at 175 X 104 Gy without MnO2, which has been attributed to MnO2 catalytically accelerating the radiolytic process via the formation of highly reactive MnO under the action of γ -rays. All the other features of non-catalysed radiolytic desulphurisation such as stabilisation of the slurry and coal not becoming radioactive during irradiation, increase in the heating value, improvement in the caking property,

Item Type:	Article
Uncontrolled Keywords:	High-sulphur coal; Desulphurisation; Demineralisation; MnO2-catalysed γ -radiolysis
Subjects:	Respiratory Protection Laboratory
Divisions:	UNSPECIFIED
Depositing User:	Dr. Satyendra Kumar Singh
Date Deposited:	24 Jan 2012 06:42
Last Modified:	24 Jan 2012 06:42
URI:	http://cimfr.csircentral.net/id/eprint/773

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