DEPOLIMERIZACIÓN DE CARBÓN DE GUASARE EN SISTEMAS EUTÉCTICOS: COMPARACIÓN CON LAS EXTRACCIONES SOXHLET

Abstract

The extent of depolimerization of Guasare coal (Paleocene) by treatment with some eutectic systems was examined, in the temperature interval 80 – 240ºC; these results were compared with those obtained under Soxhlet extraction with a suite of organic solvents, with the aim of establishing the advantages of the coal depolimerization assisted by molten salts. Organic solvents exhibited a wide interval of extraction-depolimerization yields, ranging between less than 3% in “conventional” solvents; 2 – 10% for oxygen-containing solvents, and 21 – 51% in nitrogen-containing solvents; the mixture NMP / CS2 gave an unusual yield of 71%. The basic nature of the solvent and not the temperature is determining its degradative skill in the coal. In contrast, eutectic molten salts systems assayed show yields not more than 30%. Identity of the metal in the salt and particularly the Lewis acid character, its catalitic strenght or both, are fundamental in the depolimerization extent. In spite of the advantages of the eutectic systems, they cannot compete with the depolimerización using solvents as NMP.