Determining the Optimum Total Solid Yield of Hydrothermal Waste Processing Products Through Mechanical Drying

In the application of hydrothermal technology, it is necessary to optimize mechanical water drying to increase the calorific value of hydrothermal waste products. This study was conducted to find the total optimum solids, optimum drying time, and characteristics of hydrothermal waste processing products that occur after optimal mechanical drying. The mechanical drying design was carried out 4, 6, and 8 bars of pressure. At pressure bars 4, 6, and 8, the total optimum solid yields were 50.11%, 51.56%, and 54.56%, with 6.56, 6.82, and 5.11 minutes of drying time, respectively. Optimum mechanical drying yielded a calorific value of 5154 kcal/kg, which is the equivalent of sub-bituminous coal. An increase of the C/N (Carbon to Nitrogen) ratio to 32.185 resulted in hydrothermal waste processing products that did not comply with the Indonesia compost quality standard.