MEASUREMENT AND MODEL VALIDATION OF SPECIFIC HEAT OF XANTHAN GUM USING JOULES CALORIMETER METHOD

Abstract

The purpose of this paper is to examine the concent ration and temperature influence on the specific he at of xanthan gum and to propose a model equation for estimating the specifi c heat of xanthan gum at different concentration an d temperature usingthe Joules calorimeter method. Joules calorimeter method was t ested with distilled water for accuracy and reliabi lity before applying to xanthan gum samples which varied in concentration. The spec ific heat of xanthan gum needs to be known for eval uating the design and modeling aspects of heat transfer processes of refr igeration, freezing, heating, pasteurization and dr ying. The specific heat of xanthan gum increases with an increase in temperature (293. 15 - 333.15K) and concentration (0.1 - 0.6 %w/w). T he minimum value of specific heat of xanthan gum was 4.133 KJ/kg K at 300.25K wi th a concentration of 0.2 %w/w, whereas the maximum value of specific heat of xanthan gum was 7.459 KJ/kg K at 333.95K with a con centration of 0.5 %w/w. The specific heat capacity of xanthan gum is compared with that of pure water at 308.15, 318.15 and 328.1 5 K and literature available model at 293.15 - 333. 15 K for 0.1 - 0.6 %w/w concentration of xanthan gum. The influence of oper ating parameters on the specific heat of xanthan gu m was determined by employing a central composite rotatable design in r esponse surface methodology (CCRD-RSM). The new mod el equation obtained for estimating the specific heat using RSM possesses go od agreement with experimental data with a regressi on coefficient of 0.9774. Index Terms: Specific heat, Xanthan gum, Pseudo plastic fluid an d Response surface methodology etc.…