Influence of moisture content and temperature on thermal properties of cocoa pods

S. O. Jekayinfa; J. A. Olaniran; C. T. Oloyede; K. F. Aiyeoba; C. A Ogunlade

S. O. Jekayinfa Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
J. A. Olaniran Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
C. T. Oloyede Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
K. F. Aiyeoba Adeleke University, Ede
C. A Ogunlade Adeleke University, Ede

Keywords: cocoa pods, specific heat capacity, thermal conductivity, thermal diffusivity

Abstract

Knowledge of thermal properties is essential for equipment design, study and prediction of heat transfer operations such as heating, drying and cooling processes. The availability of relevant data on the thermal properties of the crop residue will aid design and manufacture of processing equipment. The objective of this study was to determine the effect of moisture content and temperature on the specific heat capacity, thermal conductivity and thermal diffusivity of cocoa pods. The specific heat capacity of cocoa pods was determined using the method of mixture; thermal conductivity was determined using method of poor conductors and the thermal diffusivity was calculated using the experimental data of thermal conductivity, specific heat capacity and bulk densities of the samples. The specific heat capacity of cocoa pods increased with both moisture content and temperature from 7.37 and 8.78 kJkg-1K-1 and 0.064 to 0.083 kJkg-1K-1; the results showed that there is a strong linear relationship between the specific heat capacity, moisture content and temperature. Also, the thermal conductivity of cocoa pods increased with both moisture content and temperature, values obtained lies between 0.229 to 0.308 Jm-1s-1 0C. The relationship was found to be linear between thermal conductivity, moisture content and temperature. An increasing trends in the thermal diffusivity of the pods were observed with increase in temperature and moisture content from 0.063 to 0.087m2s-1 which implies that there is a strong linear correlation between temperature, moisture content and thermal diffusivity of the pods.