Silica catalyst from geothermal sludge waste for palm empty fruit bunches hydrolysis reaction

The need to utilize renewable natural resources is critical for addressing global energy and environmental sustainability challenges. Geothermal Power Plants (GPP) in Indonesia, while environmentally friendly, produce significant quantities of geothermal sludge rich in silica. This study explores the use of this silica in producing solid catalysts for the hydrolysis of Empty Fruit Bunches (EFB) from the palm oil industry, to produce glucose. The research examined variables such as temperature, catalyst ratio, and reaction time. The silica catalyst from geothermal sludge was characterized and used to investigate its impact on glucose yield from EFB hydrolysis. The production process involved forming sodium silicate, converting it to silica gel, and sulfonating the gel, verified through SEM-EDX analysis. The EFB hydrolysis, facilitated by geothermal solid catalysts, showed cellulose conversion up to 57%. The highest glucose yield of 4.71% was achieved at 150°C or 423 K (5% catalyst loading, 90-min reaction). The hydrolysis reaction followed first-order kinetics with an activation energy of 35,677.04 J/mol and a reaction rate constant of 0.0071 min1.