Organic sulfur containing structures coals

Distribution of Organic-Sulfur-Containing Structures in High Organic Sulfur Coals... 

Until recently, there have been only a few reports of aliphatic sulfur structures in coal (1,12). These results together with the experiments of Gorbaty et al. (11), give further support for the presence of labile (presumably aliphatic) sulfur moieties in high-organic sulfur-containing coals. In the previous sulfur study (1), one bituminous coal was analyzed for organic sulfur forms both by the... 

Generally, coal treated with bacteria shows an improvement in quality. Apart from the reduction of the sulfur content, the mineral matter content (measured as ash production) in bacteria-treated coals are substantially reduced. However, the removal of organic sulfur depends on the structure and type of the sulfur-containing organic compounds present in coal. 

The organic chemical structural types believed to be characteristic of coals include complex polycyclic aromatic ring systems with connecting bridges and varied oxygen-, sulfur-, and nitrogen-containing functionalities. 

Coal is a complex mixture of high molecular weight hydrocarbons that are about 85% carbon by mass. It usually contains a relatively small but variable amount of sulfur. The small amount of sulfur can be a significant factor when one considers its potential as a contributor to air pollution and acid precipitation, however. By way of contrast with petroleum, coal has more fused rings of carbon atoms, and the organic structure of coal is much more complicated. 

The chemical structure of coal is complex (Chapter 10), but there are strong indications (and little, or no, evidence to the contrary) that the nitrogen is entirely contained within the organic matrix. On the other hand, oxygen and sulfur occur in both organic and inorganic combinations. 

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