The equilibrium conditions, hydrate formation and dissociation rate and storage capacity of ethylene hydrate in presence of 1,4-dioxane

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• 作者：Mehrdad Manteghian ; ^{manteghi@modares.ac.ir} ; Seyed Mahmoud Mousavi Safavi¹ ; ^{sm.mousavisafavi@gmail.com} ; Abolfazl Mohammadi¹ ; ^{a.mohammadi.che@gmail.com}
• 关键词：Ethylene hydrate ; 1 ; 4-Dioxane ; Step heating method ; Formation ; Dissociation
• 刊名：Chemical Engineering Journal
• 出版年：2013
• 出版时间：1 February, 2013
• 年：2013
• 卷：217
• 期：Complete
• 页码：379-384
• 全文大小：1200 K

文摘

The effect of 1,4-dioxane on ethylene hydrate was investigated at three additive molar concentrations of 2.78 % , 5.56 % and 8.34 % . The equilibrium conditions for hydrate dissociation were obtained by step heating method. The results showed that addition of 1,4-dioxane concentration increases the pressure of hydrate dissociation. Diagram of Ln(P_eq) vs. T_eq demonstrated that system of 1,4-dioxane + ethylene + water form ethylene hydrate with structure I. In fact 1,4-dioxane cannot participate in hydrate structure because ethylene molecules are not a good help gas for occupation of S-cages in structure II. So, in this condition only ethylene hydrate with structure I could be formed. The experimental results on hydrate formation indicted that 1,4-dioxane accelerates the hydrate growth rate by increasing the solubility of ethylene in water and a maximum storage capacity of (V_STP/V_H) = 146 is obtained in a critical dioxane concentration of 5.56 % by mole. Also hydrate dissociation experiments revealed that maximum dissociation percentage is related to pure water (48 % ) and 1,4-dioxane decreases dissociation percentage of ethylene hydrate.