Development of Geothermal Sludge Derived - Silica Catalyst for Sago Starch Hydrolysis

Silica based catalyst was prepared from geothermal sludge – solid waste from geothermal exploration - of Dieng Power Station, Central Java, Indonesia. The catalyst was prepared by extracting silica compound from the sludge matrix, followed by sulfonation to obtain sulfonated – solid catalyst. Catalyst sample analysis informed the catalyst was generally amorphous in structures, possessed surface area between 76 – 81 m 2 /g, with acidity approximately 5-6 mmol/g. Evaluation on catalyst activity was performed by applying it on sago starch hydrolysis - atmospheric pressure and 100 – 150°C (373 – 423 K) - in which more than 90 % conversion could be achieved.