- 學位論文
五種多胺類水溶液之摩爾比熱量測研究
Molar Heat Capacities of Aqueous Polyamines Solutions Containing 1,3-Diaminopropane, 1,4-Diaminobutane, N,N-Dimethylethylenediamine, N,N,N’-Trimethylethylenediamine, and 1-(2-Aminoethyl)piperazine
摘要
本研究是以示差掃描熱量計 (Differential Scanning Calorimeter, DSC) 量測多胺類水溶液之摩爾比熱，其主要分為純物質系統(Polyamines) 、雙成分系統(Polyamines/H2O) 及三成分系統(Polyamines/Piperazine/H2O)，量測溫度範圍為30-80oC。本研究主要使用之多胺類為1,3-diaminopropane (DAP)、1,4-diaminobutane (DAB)、N,N-dimethylethylenediamine (N,N-diMEDA) 、N,N,N’-trimethylethylenediamine (N,N,N’-triMEDA)與1-(2-aminoethyl)piperazine (AEP)，以及促進劑Piperazine (PZ)。雙成分之濃度範圍為xpolyamines=0.1-0.9；三成分則固定水濃度為70 wt%，多胺類濃度為 (27, 24, 21, 18 wt%)，PZ濃度為 (3, 6, 9, 12 wt%)。 實驗所量測之比熱值，以溫度與濃度的函數做迴歸計算，純物質以溫度的二次方經驗式計算；雙成分系統以Redlich-Kister-type equation關係式來表示過剩比熱代入；三成分系統則是使用Söhnel and Novotný關係式。關係式能正確表示實驗數據，比較實驗值與迴歸結果並且加以討論，此實驗值和迴歸計算值有良好的符合性。 本研究結果可作為程序設計流體能量的計算依據，以及工廠設計汽提塔、熱交換器時，吸收劑的比熱將會是重要的設計數據。
並列摘要
Heat capacity is one of the basic thermodynamic properties essential in the design of CO2 absorption-stripping systems. In this work we presented new experimental data on the molar heat capacity, CP, of 1,3-diaminopropane (DAP), 1,4-diaminobutane (DAB), N,N-dimethylethylenediamine (N,N-diMEDA), N,N,N’-trimethylethylenediamine (N,N,N’-triMEDA), 1-(2-aminoethyl)piperazine (AEP). The heat capacities of binary aqueous solutions of these polyamines over the entire range of compositions (10 to 90 mol%) were determined. In addition, Cp of ternary aqueous polyamines/PZ blended solutions at 30 wt% total amine concentration and different polyamine/PZ ratios (18/12, 21/9, 24/6, 27/3 wt%). Measurements were performed at temperatures ranging from 303 K–353 K by differential scanning calorimetry, and the estimated overall uncertainty of the measured Cp was 2%. A second order equation was used to represent the temperature dependence of the molar heat capacity of the pure systems. The obtained CP data were represented as function temperature and composition using a RedlichKister expansion and a modified Sohnel and Novotny equation for the binary aqueous polyamines solutions and ternary aqueous polyamines/PZ, respectively. Such correlations gave average absolute deviations (AAD) between the experimental and the calculated data of 0.5% and 5.0% for molar heat capacity and excess molar heat capacity, respectively. Also, a modified Söhnel and Novotný equation suitably represented the temperature and concentration dependence of the CP of the ternary systems at an AAD of less than 0.1%. Thus, it can be said the proposed correlations in this study can be utilized to yield reliable estimates of the heat capacities of the studied systems.