添加2-呋喃甲胺對於甲烷水合物分解狀態與動力學數據之實驗量測

Measurements for the Dissociation Condition and Kinetic Data of Methane Hydrate in the Presence of 1-(2-furyl)methylamine

吳宗澤(Tsung-Tse Wu)

指導教授 ： 陳延平

國立臺灣大學/工學院/化學工程學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.00393

摘要

本研究之主要目的為建立一套高壓設備並利用等容溫度搜尋法量測甲烷+添加劑系統之相平衡點以及動力學數據。本實驗所選的添加劑為環醚類的2,3-二氫呋喃、2-環氧丁烷，胺類的N,N-二甲基乙胺、二乙基胺，以及兼具兩者官能基的2-呋喃甲胺。
本研究發現添加胺類的 N,N-二甲基乙胺以及二乙基胺對於水合物的生成皆為抑制效果，使水合物可穩定形成的區域變小，添加10wt%N,N-二甲基乙胺可降低平衡溫度約1.3~1.5K，添加10wt%的二乙基胺可降低平衡溫度約2.3K。添加5wt%環醚類的2-環氧丁烷則是可擴大水合物生成的區域，使水合物的相平衡邊界向高溫低壓方向移動，為促進劑，可促進約2.2~2.6K。添加10wt%環醚類的2,3-二氫呋喃則是抑制效果，可降低水合物平衡溫度約1.2K。添加2-呋喃甲胺也是抑制效果，最好的抑制效果為添加30wt%的2-呋喃甲胺，可降低水合物平衡溫度約2.2K。另外為了模擬海水的環境，本實驗以3.5wt%的鹽水作為系統中之液相來進行相平衡點之測量，實驗發現添加30wt%的2-呋喃甲胺於鹽水系統中時，水合物平衡溫度下降量會從2.2K 增加至4.5K，顯示鹽類具有一定的抑制效果實驗中同時發現 2-呋喃甲胺可能具有動力學的抑制效果可延長水合物生成的時間，因此使用2-呋喃甲胺作為添加劑進行動力學實驗中，發現2-呋喃甲胺確實具有延長水合物生成時間的效果，依照添加的濃度不同，最多可延長13 小時。然而對於水合物生成的速率以及生成量並沒有影響。本實驗同時也對結構的部分進行了推估，推測2-環氧丁烷為sII 型結構，2,3-二氫呋喃以及2-呋喃甲胺則為sI 型結構。

關鍵字

甲烷水合物 ； 等容溫度搜尋法 ； 2,3-二氫呋喃 ； 2-環氧丁烷 ； N,N-二甲基乙胺 ； 二乙基胺 ； 2-呋喃甲胺 ； 水合物動力學研究

並列摘要

This study demonstrated the equilibrium conditions for the formation of methane hydrates in the presence of cyclic ethers and alkyl amine, i.e. 2,3-dihydrofuran, 2-ethyloxirane, N-ethylethanamine and N,N-dimethylethanamine. Also we selected the compound which has these two functional group: 1-(2-furyl)methylamine. The three-phase (H-Lw-V) and the four-phase (H-Lw-La-V) equilibrium data in methane +
water + additives systems were measured by using isochoric method in the range of pressures from 8 to 13 MPa and temperature up to 301K. When 10wt% 2,3-dihydrofuran, N-ethylethanamine, N,N-dimethylethanamine and 1-(2-furyl)methylamine were added into methane hydrates systems respectively, the hydrate equilibrium temperatures showed a little decrease approximately 1.2 K for 2,3-dihydrofuran, 1.3~1.5 K for N,N-dimethylethanamine, 2.3 K for N-ethylethanamine and 2.2K for 30wt% 1-(2-furyl)methylamine at a specific pressure. On the other hand, adding 5wt% 2-ethyloxirane can increase the hydrate equilibrium temperatures by 2.2~2.6K. Moreover, in order to simulate the sea-water environment, the methane + 3.5wt% NaCl+ 30wt% 1-(2-furyl)methylamine systems were measured to acquire the equilibrium data of methane hydrate dissociation. With the existence of 3.5 wt% NaClin this system, the equilibrium temperature of the brine system reduced 2K compared to the original system. While measureing the equilibrium point of 1-(2-furyl)methylamine, we found that it has a kinetic inhibition effect, i.e. it can extend the time for hydrate formation. The experiment showed that the best effect is adding 30wt% 1-(2-furyl)methylamine which can increase the induction time from about 3hrs to 13hrs. But it didn’t affect the formation rate and the total consumed moles of methane. In the structure prediction by Clausius-Clapeyron Equation, we found that when adding 2,3-dihydrofuran and 1-(2-furyl)methylamine, the hydrates will form structure I, and form structure II while adding 2-ethyloxirane.

並列關鍵字

methane hydrate ； isochoric method ； 2,3-dihydrofuran ； 1-(2-furyl)methylamine ； 2-ethyloxirane ； N,N-dimethylethanamine ； N-ethylethanamine ； kinetic experiment

參考文獻

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