Preparation of Sulfonated SiO₂Catalyst from Geothermal Sludge Waste for Sago Flour Hydrolysis

Abstract

Catalyst is a substance that is widely used in chemical reactions to obtain certain products. This study has been focusing on preparing and employing solid catalyst derived from geothermal sludge (GS) as waste material from Dieng Geothermal Power Plant (PLTPB) activity. The methodology of catalyst preparation was extraction of silica from the sludge by alkali solution, followed by gelling formation and acidification with sulfuric acid solution. The prepared catalyst was then applied in hydrolysis reaction to convert sago flour into glucose.Catalyst properties were assessed in term of morphology, crystallinity, surface area, and activity (hydrolysis reaction). Sample analysis confirmed the produced catalyst was amorphous in general, having 127 m2/g of surface area. In addition, the prepared catalyst contained 78 - 79 % of silica, a significant increase - as a result of preparation - from that of raw material sludge which had 33 - 43 % silica. From the catalyst activity test conducted at 120 - 185°C hydrolysis reaction, as much as 50 % of glucose yield could be obtained from sago starch conversion, indicating prospective catalyst performance.Keyword: Sulfonated SiO2, Catalyst, Geothermal Sludge Waste, Sago, Hydrolysis