Photocatalytic Dissolution of Two Turkish Lignites in Tetralin: Effects of UV Irradiation, TiO2 and ZnO as Photocatalyst

Abstract

The effects of ultraviolet (UV) irradiation, photocatalyst, and reaction time on the dissolution of two Turkish lignites (Beypazarı and Tunçbilek lignites) in tetralin have been investigated under ambient conditions. Lignites samples were irradiated in the presence or absence of added photocatalysts (TiO 2 and ZnO) at varying reaction times (1–10 days), constant irradiation power (180 W), and constant solvent/lignite ratio (5/1). The solubility of lignites increased with reaction time under UV light. The liquefaction behaviors of the lignites are different from each other. As the maximum solubility (45%) with Tunçbilek lignite has been achieved at shorter reaction times, it has been reached at longer reaction times for Beypazarı lignite (32%). The solubility values obtained from noncatalytic liquefaction are higher than those obtained from liquefaction with TiO 2 and ZnO.