Nitrogen and Sulphur in Coal

Abstract

As it was considered that the origin of nitrogen in coal was protein, cellulose and lignin were coalified with protein (egg albumin) in water medium at 300°C under corresponding pressure. The behaviors of nitrogen in the artificial coalification processes were observed and the properties of thus obtained coals were examined. Nitrogen in protein is chemically combined with cellulose and lignin, and the proper amount of protein accelerates the huminification of cellulose and the bituminization of lignin. When these nitrogen containing artificial coals are oxidized with alkaline KMnO₄, nitrogen is recovered as NH₃ and NO´₃ almost quantitatively, as same as in the case of natural coals. With this fact, it seems probable that nitrogen in artificial coal is in the same condition of that in natural coal. Cellulose and lignin were artificially coalified in aqueous solutions or suspension of sulfides or sulfates to discuss the origin of sulphur in coal. Water soluble sulfides supply sulphur into artificial coal as organic sulphur, but water insoluble sulfides or sulfates (even water sobluble) do not. It can be concluded that the origin of organic sulphur in coal is water soluble sulfides and that the hypothesis, which explaines that iron sulfates are reduced to pyrite in the coal forming process, seems scarecely probable.