• Journal of the Korea Organic Resources Recycling Association
• /
• v.23 no.4
• /
• pp.95-103
• /
• 2015

The purpose of this study was performed to quantitatively measure the thermal conductivity of poultry slaughter waste with variation of reaction temperature for optimal design of thermal hydrolysis reactor. We continuously quantified the thermal conductivity of dehydrated sludge related to the reaction temperature. As the reaction temperature increased, the dehydrated sludge is thermally liquefied under high temperature and pressure by the thermal hydrolysis reaction. Therefore, the bond water in the sludge cells comes out as free water, which changes the dehydrated sludge from a solid phase to slurry of a liquid phase. As a result, the thermal conductivity of the its sludge was more than 2.11 times lower than that of the water at $20^{\circ}C$. However, the thermal conductivity of the sludge approached to $0.677W/m{\cdot}^{\circ}C$ of water at $200^{\circ}C$, experimentally substantiating liquefaction of the dehydrated sludge. Therefore, we confirmed that the change in physical properties due to thermal hydrolysis appears to be an important factor for heat transfer efficiency. And the thermal conductivity function related to reaction temperature was derived to give the boundary condition for the optimal design of the thermal hydrolysis reactor. The consistency of the calculated function was 99.69%.