Solvent extraction of coal: Influence of solvent chemical structure on extraction yield and product composition

Abstract

In recent years the need for new carbon sources to supplement crude oil for the production of fuels and chemicals, again focused on coal as suitable candidate. Old and new technologies are being developed to convert coal in valuable products. An old technology such as solvent extraction of coal is again attracting industry attention. Despite being a widely studied technology, several questions remain unanswered. The present work aims to set the basis for further understanding of the solvent role. Physical and chemical properties reported in the literature, each one related to the solvent functional group, were put to the test. At low temperature, chemical structure of the solvent and its polarity are the most important properties for obtaining high extraction yields. At high temperature, solvents with high hydrogen donor ability give the highest extraction yields. Further investigation is needed to establish the influence of the solvent functional group on product composition.