5. EXPERIMENT Material: Instrument Experiment condition: DL-Mandelic Acid (+)-S-Mandelic Acid Water Instrument Experiment condition: Concentration: 20-70% Heating rates: 0.2-1.5 K/m Temperature range: 5-70oC Differential Reaction Calorimeter SETARAM

6.1.Influence of different parameters on solubility results 6. RESULTS & DISCUSSION 6.1.Influence of different parameters on solubility results Heating rate: samples with slower heating rates usually produce better solubilities due to better equilibrium. DL-Mandelic Acid 30%wt

6.1.Influence of different parameters on solubility results 6. RESULTS & DISCUSSION 6.1.Influence of different parameters on solubility results Concentration: samples with low concentration normally produce better solubilities. Higher concentration is difficult for stirring => heat exchange is worse. DL-Mandelic Acid 30%wt DL-Mandelic Acid 50%wt

6.1.Influence of different parameters on solubility results 6. RESULTS & DISCUSSION 6.1.Influence of different parameters on solubility results Baseline construction - Direct from initial point to end point - From end point draw a parallel line to the x-axis to determine initial point

6. RESULTS & DISCUSSION 6.3. Comparison between experimental heat flow and simulated heat flow Experimental curve is not as sharp as simulated curve due to: slow heat exchange between heating surface reactor and bulk liquid time lag of the calorimeter. Experimental curve Simulated curve

CONCLUSION ADVANTAGES Calorimetric method proves to be a useful method. Some promising results have been achieved in this work. Determination of the integration range can be chosen between different baseline. Simulation of heat flow helps to understand the experiment and heat capacity term can be observed FUTURE WORK A more complete model which describes heat capacity changes with respect to temperature and concentration of the solution should be developed to reflect all factors in the calculation Consider time lag to have a sharp curve