Structural classification of hydrothermally soluble fraction from Shenshan coal by scaffold tree approach.

Shenshan sub-bituminous coal has been extracted with water at 200°C and 2 MPa. The resulting soluble mixture was separated into a deposit and a water-soluble fraction. The gas chromatography/mass spectrometry detectable species in both the deposit and the water-soluble fraction can be classified into linear molecules and cyclic molecules using the scaffold tree approach. The linear molecules consist of alkanes, acids, alkenes, alkanols, esters, ketones, aldehydes, ethers, nitrogen-containing organic compounds, and sulfur-containing organic compounds. The chemical structures of the cyclic molecules are more complicated and provide insight into the carbon skeleton structures and bridging linkages of the soluble molecules. [ABSTRACT FROM PUBLISHER]