| Abstract: | 本研究採用半流動式相平衡實驗裝置進行超臨界二氧化碳萃取實驗，在溫度308.15~328.15 K，與壓力89~300 bar之間的條件下量測單一蒽醌(9,10-Anthraquinone)，及同時含乙醇為共溶劑情況下，在超臨界二氧化碳流體中之平衡溶解度；此外並以Peng-Robinson狀態方程式(P-R EOS)配合凡德瓦爾混合律(van der Waal’s one-fluid, vdW-2)，以及Huron-Vidal混合律，並使用四種半經驗式包含Chrastil，Schmitt-Reid，Giddings和Santiago-Tega等進行數據關聯，其中且包括文獻中蒽醌於超臨界二氧化碳中之相平衡數據，希冀可由數種理論模式得到最佳的溶解度預測結果。
實驗結果顯示，蒽醌於超臨界二氧化碳中之平衡溶解度範圍在6.97 10-7~9.88 10-5間，而蒽醌於乙醇(EtOH)為共溶劑之超臨界二氧化碳系統中平衡溶解度則為3.88 10-6~1.25 10-4(xEtOH=0.03)與5.70 10-6~1.86 10-4(xEtOH=0.07)之間。實驗結果並顯示在蒽醌-二氧化碳二成份系統中交錯壓力發生在160~200 bar之間，而在蒽醌-二氧化碳-乙醇三成份系統中，則發生在140~150 bar之間。
本研究關聯結果顯示，針對蒽醌-二氧化碳系統關聯結果最佳者為Giddings半經驗式，及P-R EOS配合vdW-2混合律，其平均相對誤差分別為11.43%及12.46%；在蒽醌-二氧化碳-乙醇三成份系統中關聯最佳之模式為P-R EOS配合vdW-2混合律，以及Giddings半經驗式，其相對偏差分別為2.64%以及4.03%。
Solubility of 9, 10-Anthraquinone in supercritical CO2, both pure and modified, were measured at temperatures from 308.15 to 328.15 K and pressures from 89 up to 300 bar using a semi-flow apparatus. The solubility data measured in pure CO2 and in CO2 containing ethanol as modifier were both correlated using the Peng-Robinsin equation of state (P-R EOS) with van der Waal’s (vdW-2) and Huron-Vidal mixing rules, together with the density-based equations proposed by Chrastill, Schmitt and Reid, Giddings, and Santiago and Teja. The existing literature solubility data of 9, 10-Anthraquinone in pure CO2 were also incorporated into the data base to be correlated. The experimental results showed that observed solubilities of 9, 10-Antraquinone of the modified system were higher than those in pure CO2. Specifically, the solubility of 9, 10-Anthraquinone was in the range of 6.97 10-7~9.88 10-5 in terms of more fraction, while that of the modified system was between 3.88 10-6 and 1.25 10-4 (for xEtOH=0.03) and between 5.70 10-6~1.86 10-4(for xEtOH=0.07). For the pure CO2 system, the crossover pressures appeared in the 160-200 bar region over the measured temperature range, On the other hand, the crossover region for the modified system at the same temperatures was in the range of 140-150 bar.In the 9,10-Anthraquinone-CO2 system, the Giddings model and P-R EOS with vdW-2 mixing rules resulted in smallest deviations of 11.43% and 12.46%. Furthermore, the solubility data of 9,10-Anthraquinone in the modified system correlated using the P-R EOS with vdW-2 mixing rule and Giddings model also showed the smallest deviations of 2.63% and 4.03%. |
