Thermal Analysis and Pyrolysis Pathways of Coal-Related Ether Compounds

Abstract

The stability of the ether bond affects coal dissolution during direct coal liquefaction and aliphatic ethers are reportedly the most reactive of the oxygenate classes during liquefaction. Some ether compounds are also persistent to high temperature during coal pyrolysis. The thermolysis of ether compounds using high-pressure differential scanning calorimetry (HPDSC) were performed to study the thermal decomposition of aliphatic and aromatic ethers. These results showed that the melting point of each ether sample is quite accurate compared to the literature data, and the high temperature decomposition could be determined. GC-MS results indicated that the ether compounds decomposed to a number of smaller and larger organic molecules. The detailed reaction pathways of the model ether compounds on their own and in the presence of a hydrogen-donor solvent were studied. These results help us to understand the role of autothermolysis of ethers versus induced thermolysis of ethers during coal liquefaction.