The use of an industrial mineral waste as catalyst in the hydroconversion of dibenzylether and a colombian subbituminous coal

Abstract

An industrial mineral waste produced in the aluminum sulphate industry was selected as a low cost catalyst precursor. This material has been active in dibenzylether hydroconversion, as a model compound of C-O linkages in coal. Besides, it was used in the hydroconversion of a colombian subbituminous coal. The mineral waste and a commercial iron oxide (as reference material) were sulfided in order to produce iron sulfide, pyrrhotite type (Fe1-xS), which is the active phase in hydroconversion reactions. The solids were characterized by X-ray fluorescence, X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Catalytic tests with the model compound and coal were carried out at 5 MPa of H2, temperatures between 240 °C and 400 °C and reaction times were 0.5 h or 1 h. The results showed a higher activity of the industrial mineral waste compared with the reference material in the dibenzylether C-O bond cleavage. These kind of bonds are responsible for asphalthenes and preasphalthenes assembly in the molecular coal structure. In addition, coal conversion in presence of catalysts was 83.9 %, this value was 1.8 times higher than conversion without catalyst. Results show the potential of the industrial mineral waste to be used as catalyst in the hydroconversion of coal due to its good activity and low cost.

Keywords

• Bauxite
• iron sulfides
• dibenzylether
• hydroconversion
• coal.