- 學位論文
混合溶劑除濕劑(MgCl2/Glycol/H2O)及緩衝溶液(Buffer/Glycol/H2O)之比熱量測研究
Measurements of Heat Capacity of Mixed-Solvent Desiccant (MgCl2/Glycol/H2O) and Aqueous Buffer Solutions (Buffer/Glycol/H2O)
摘要
本研究主要量測(鹽類 + 二醇類 + 水)和(緩衝劑 + 二醇類 +水)的比熱，量測溫度範圍為30-80℃，其三成份系統之鹽類和緩衝劑濃度為(4.0, 9.0, 16.0 wt %)，二醇類濃度為(40 wt %)，利用示差掃描熱量計(differential scanning calorimeter, DSC)量測比熱，本研究使用無機鹽類為氯化鎂(MgCl2．6H2O)，緩衝劑為N-[tris(hydroxymethyl)methyl]-3-aminopropanesulfonic acid (TAPS) 和tris(hydroxymethyl)aminomethane (TRIS)，二醇類為diethylene glycol (DEG)、triethylene glycol (TEG)、tetraethylene glycol (T4EG)、propylene glycol (PG)、tripropylene glycol (TPG)、dipropylene glycol (DPG)。 實驗所量測之比熱值，以溫度與濃度為變數做迴歸計算，純物質以二次方經驗式，雙成份系統(TPG + H2O)則利用過剩比熱代入Redlich-Kister type equation；三成份系統則是利用Söhnel and Novotñy迴歸計算。比較迴歸結果加以討論，迴歸計算值與實驗值亦有良好之符合性，本研究之結果可作為熱力學之基礎數據的計算依據。
並列摘要
In this study, the heat capacities of ternary systems of salt/glycol/H2O and buffer/glycol/H2O were measured over the temperature range 30 to 80℃ and different solute concentrations: salt/buffer (4.0, 9.0, 16.0 wt %) + glycol (40 wt %) using a heat flow differential scanning calorimeter (DSC). The salt was magnesium chloride (MgCl2．6H2O) ; the buffers were N-[tris(hydroxymethyl)methyl] -3-aminopropanesulfonic acid (TAPS) and tris (hydroxymethyl) amionmethane (TRIS); and the glycols were diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (T4EG), propylene glycol (PG), tripropylene glycol (TPG), dipropylene glycol (DPG). For the pure system, the dependence of the molar heat capacity with temperature was correlated by a second order equation. The binary system of TPG + H2O for molar heat capacities and excess molar heat capacities were using a Redlich-Kister-type equation. The data were then reported as functions of temperature and composition. For the ternary systems, an equation proposed by Söhnel and Novotñy was used to represent the measured heat capacity data. Results showed that the measured heat capacity data were satisfactorily correlated using the applied correlations. Therefore, results presented in this are, in general, of sufficient accuracy for most engineering-design calculations