Heat Transfer Analysis of Thermal Hydrolysis Process of Perishable Organic Wastes

The thermal hydrolysis (TH) process is widely used in the pretreatment of perishable organic waste (POW) to improve the dissolution of organic matter. However, energy consumption calculation and precise temperature control during the hydrothermal hydrolysis process have not yet been effectively analyzed and resolved. In this study, the thermodynamic process of the heating process in laboratory-scale TH equipment was analyzed in detail. The results showed that from 20 to 160 °C, 300 g of POW liquid (TS, 11.35%) absorbed approximately 159.70 kJ. When the temperature of the heating element of the equipment is accurately controlled at 162.71 °C, the temperature of the POW liquid can be accurately controlled at 160 °C. A calculation method for POW heat consumption in the TH process was proposed from both physical and mathematical perspectives, and its heat transfer process was analyzed in detail. These methods contribute to precise temperature control and energy consumption calculation in the TH process. At the same time, in order to improve the heating efficiency of TH equipment, a method of prepressurizing and then heating was proposed. This study contributes to the practical application of conduction heating thermal hydrolysis equipment in the treatment of perishable organic waste.