β Scribed by D. Borah; M.K. Baruah; I. Haque
No coin nor oath required. For personal study only.
A systematic study has been made on the desulphurisation of organic sulphur in both feed and mercury-treated coal for their unoxidised samples as well as their oxidised samples prepared at 50, 100 and 150ΠC in air under normal atmospheric pressure. A continuous increase of organic sulphur loss has been observed; the magnitude of which is substantial in mercury-treated samples. Formation of oxidised organic sulphur functionalities (SyO and -SO 2 ) are identified by infrared spectroscopy. The band in the region 1080-1020 cm Οͺ1 assignable to SyO stretch for all oxidised sulphur species (sulphoxide, sulphone, sulphonic acid, sulfenic acid and sulphinic acid) while the band in the region 1350-1320 cm Οͺ1 attributable to assymmetric and 1170-1120 cm Οͺ1 to symmetric for -SO 2 stretch for sulphones, sulphonic acid and sulphinic acid, increase in intensity up to 100ΠC which decline at 150ΠC. The absorbance of these bands are qualitatively correlated with those of aliphatic and aromatic C-H content. The aliphatic C-H content follows similar pattern as observed for the absorbance for SyO and -SO 2 strech; however, the trend is exactly similar with the mercury-treated sample. The difference of absorbance between SyO and -SO 2 gives an indication of the extent of sulphoxide and sulfenic acid formation. Mercury has a catalytic effect in both accelerating the oxidised species formation and their desulphurisation. This study further reveals that up to 50ΠC desulphurisation is primarily due to the release of free radicals of sulphur species while SyO species along with these radicals predominantly removed beyond 50ΠC. Knowledge gained from this study would be helpful for various coal conversion processes.
π SIMILAR VOLUMES
This paper describes a simple oxidative method of desulphurisation of coal organic sulphur carried out by using hydrogen peroxide as an oxidant. Desulphurisation achieved up to the extent of 3.70Β±6.25 wt% in 1Β±4 h whereas at 24 h, it increases to 9.24 wt%. When metal ions are externally added to the
01 Solid fuels (transport, storage) 02/01302 Microbial solubilization of Iignites
Hydropyrolysis (HyPy) of a high-sulphur (4.3 wt% mf) and high-calcite (7.3 wt% mf) subbituminous coal (Sulcis coal) has been studied in a semi-batch fixed-bed reactor under a pressure of 1 or 3 MPa from 580 to 850Β°C. The maximum temperature attained is not necessarily the temperature that the reacto
In this paper, experiments have been undertaken to understand the nature of organic sulphur compounds retained after oxidation at 50,100 and 150ΠC for both feed and Hg-treated coals as well as the extent of desulphurization by the electron transfer process. It has been observed that oxidation of coa