REACTIONS OF A BITUMINOUS COAL WITH SULFURIC ACID

Special Research Report SR-5 The chemical reactions of bituminous coals with sulfuric acid are being investigated for the purpose of learning more about the chemical properties and constitution of these coals, and if possible develop new chemical products for the growing organic chemicals market. Pittsburgh seam coal reacts with hot concentrated sulfuric acid, over a range of conditions, to give a product weighing about 115% of the original weight of coal. The increase in weight is the result of the introduction of sulfur and oxygen into the product. At the same time, about 13% of the carbon of the coal and over 50% of the hydrogen are removed. unchanged. The nitrogen content remains practically The chemical and physical properties of the product indicate a structure similar to that of many chars and carbons except for the presence of sulfur- and oxygen-containing groups introduced by the sulfuric acid treatment. This suggests that the type of structure present in the treated coal product is polycyclic aromatic (benzene series) or quinoid (benzoquinone series) in character. Many compounds having these structures are useful industrially; consequently, the main problem is to degrade the complex coal molecules into simpler ones. The components of the coal eliminated by the sulfuric acid treatment, on the other hand, are la:r-gely aliphatic. These are the structures in the coal which produce gas and tar when it is coked. Attempts are being made to find out the identity of the chemical products removed by the sulfuric acid.