Two experimental systems were designed and tested to measure the CO2 solubility in sodium dibasic phosphate solutions (0.276, 2.76 and 5.52 g/100 g water) at different pressures (7.5 and 15.0 MPa) and temperatures (35, 40 and 50°C). The results were compared with those for pure water. Three thermodynamic solubility models were tested using the Aspen Simulation PlusTM software: 1) Peng-Robinson equation of state (EOS), where the a and b parameters were evaluated with the Wong and Sandler mixing rules (PRWS) and the activity coefficients were defined using the functional groups with the modified UNIFAC method 2) Electrolytic non-random two liquids (ELECNRTL) with the Redlich-Kwong equation of state for aqueous and mixed solvent applications 3) The completely predictive Soave-Redlich-Kwong (PSRK) equation of state. CO2 solubility was a strong function of sodium dibasic phosphate concentrations. The predictions of the PRWS EOS agreed well with the experimental data in the pressure and temperature ranges tested. A higher difference between the experimental and predicted results was observed for conditions close to the CO2 critical point and for low sodium dibasic phosphate concentrations. Thermodynamic models 2 and 3 predictions had a much higher deviations from experimental data.
Measurement and prediction of CO2 solubility in sodium phosphate monobasic solutions for food treatment with high pressure carbon dioxide
FERRENTINO, GIOVANNA;BARLETTA, Diego;FERRARI, Giovanna;POLETTO, Massimo
2010-01-01
Abstract
Two experimental systems were designed and tested to measure the CO2 solubility in sodium dibasic phosphate solutions (0.276, 2.76 and 5.52 g/100 g water) at different pressures (7.5 and 15.0 MPa) and temperatures (35, 40 and 50°C). The results were compared with those for pure water. Three thermodynamic solubility models were tested using the Aspen Simulation PlusTM software: 1) Peng-Robinson equation of state (EOS), where the a and b parameters were evaluated with the Wong and Sandler mixing rules (PRWS) and the activity coefficients were defined using the functional groups with the modified UNIFAC method 2) Electrolytic non-random two liquids (ELECNRTL) with the Redlich-Kwong equation of state for aqueous and mixed solvent applications 3) The completely predictive Soave-Redlich-Kwong (PSRK) equation of state. CO2 solubility was a strong function of sodium dibasic phosphate concentrations. The predictions of the PRWS EOS agreed well with the experimental data in the pressure and temperature ranges tested. A higher difference between the experimental and predicted results was observed for conditions close to the CO2 critical point and for low sodium dibasic phosphate concentrations. Thermodynamic models 2 and 3 predictions had a much higher deviations from experimental data.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
