Equilibria in the Ammonium Carbamate-Urea-Water System
Equilibria in the Ammonium Carbamate-Urea-Water System
复制标题
氨基甲酸铵-尿素-水系统的平衡
DOI：
10.1021/ie50286a008
复制
发表时间：
1933
影响因子：
--
通讯作者：
C. E. Rist
中科院分区：
文献类型：
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作者：
K. Clark;V. L. Gaddy;C. E. Rist
Bassarov（1）在1870年发现，当氨基甲酸铵在密封的玻璃管中在130至140 ℃下加热时，会产生尿素。1897年，布尔乔亚（3）证明，尿素不仅可以由碳酸铵生产，也可以由氨的其他二氧化碳化合物生产。他将氨基甲酸盐、碳酸盐、倍半碳酸盐和碳酸氢盐加热到130 ℃，得到了1.5%~ 9.52%的尿素产率。在一个钢制反应堆里他注意到，在他的实验条件下，钢受到了相当强烈的攻击。根据Briner（3）和Isambert（7）的数据，氨基甲酸铵在60、130和197 ℃下的离解压力约为1、38和260个大气压，分别自Bassarov和Bourgeois以来，许多研究人员研究了该系统的平衡，报告了以尿素产率百分比表示的氨基甲酸酯转化率百分比的结果。1911年Fichter和Becker（5）以及1917年Fichter、Steiger和Stanisch（6）研究了在100 - 140 ℃的温度范围内，在镀锡反应器中由氨基甲酸铵生成尿素。Fichter和Becker报道了随着系统的重量-体积比的增加和约135 ℃的最佳转化温度的增加，尿素的产率增加。Fichter、Steiger和Stanisch在氨适度过量的情况下获得了尿素产量的增加。刘易斯和伯罗斯（11）在1912年测定了77 - 132 ℃之间水溶液的平衡。马蒂尼翁和Fre-jacques（13）在1920年观察到该体系由一个汽相和一个单一的均相液相组成，得出该体系是双变的结论。他们进一步指出，正如Fichter和Becker在实验中所确定的那样，随着气相体积的减少或重量体积比的增加，尿素的产率有望增加。马蒂尼翁和弗雷雅克的工作是在130 - 150 ℃的密封玻璃管中进行的.重量-体积比约为0.5克/cc，比以前使用的值稍高的值显示出相应较高的尿素产率。该实验室的各种研究人员已经研究了该系统在由氨和二氧化碳合成尿素的工业应用方面的情况。许多实验已经在锡衬里和Rezistal 4号反应器以及玻璃管中进行，温度高达150 ℃。这项工作的大部分结果已经由H. J.和NW Krase和V.L. Gaddy（9，10）.这些工作人员注意到，随着温度的升高、重量体积比的增加和氨过量的增加，尿素的产率增加。他们还表明，过量的二氧化碳对平衡的影响很小，而过量的水肯定会降低尿素的产率。Yakovkin（17）是第一个在150 ℃以上的温度下对该系统进行研究的人。他的工作是在铅衬里的反应器中进行的，并且在相对较高的重量体积比下进行。然而，他的方法不允许精确的温度测量或确保测量的平衡对应于观察到的温度范围。Neumann和Sonntag（15）在1931年报道了通过在镀锡反应器中加热氨基甲酸铵不同时间获得的尿素产率。这些作者1使用的重量体积比为0.75至0.90克/cc。在135至155 ℃的温度下。
Bassarov (1) discovered in 1870 that urea\vas produced when ammonium carbamate was heated in sealed glass tubes at 130 to 140 C. Bourgeois (3) demonstrated in 1897 that urea could be produced not only from ammonium carbonate but also from other carbon dioxide compounds of ammonia when he obtained yields of 1.5 to 9.52 per cent urea by heating the carbamate, the carbonate, the sesquicarbonate, and the bicarbonate to 130 C. in a steel reactor. He noted that the steel was rather strongly attacked under the conditions of his experiments. According to the data of Briner (3) and of Isambert (7) ammonium carbamate exerts a dissociation pressure of approximately 1, 38, and 260 atmospheres at 60, 130, and 197 C., respectively. Since Bassarov and Bourgeois numerous investigators have studied the equilibria in this system, reporting their results in terms of the percentage conversion of the carbamate ex-pressed as percentage yield of urea. Fichter and Becker (5) in 1911 and Fichter, Steiger, and Stanisch (6) in 1917 studied the formation of urea from ammonium carbamate in a tin-lined reactor over the temperature range100 to 140 C. Fichter and Becker reported increased yields of urea with an increase in the weight-volume ratio of the system and an optimum conversion temperature of approximately 135 C. Fichter, Steiger, and Stanisch obtained increased yields of urea with moderate excesses of ammonia. Lewis and Burrows (11) in 1912 determined the equilibrium in aqueous solutions between 77 and 132 C. Matignon and Fre-jacques (13) in 1920, observing the system to consist of a vapor phase with a single homogeneous liquid phase, con-cluded that the system was bivariant. They further pointed out that increasing yields of urea were to be expected with decreasing vapor-phase volumes or increasing weight-volume ratios as Fichter and Becker had determined experimentally. The work of Matignon and Frejacques carried out in sealed glass tubes at temperatures from 130 to 150 C. with a weight-volume ratio of approxi-mately 0.5 gram per cc., a value somewhat higher than had previously been used, showed correspondingly higher yields of urea. Various investigators at this laboratory have studied this system with regard to its industrial application for the synthesis of urea from ammonia and carbon dioxide. Many experiments have been carried out in tin-lined and in Rezistal No. 4 reactors, as well as in glass tubes, up to temperatures of 150 C. The results of much of this work have already been reported by H. J. and NW Krase and V. L. Gaddy (9, 10). These workers have noted increased yields of urea with increasing temperatures, with increasing weight-volume ratios and with increasing excesses of ammonia. They have also shown that an excess of carbon dioxide exerts little effect on the equilibrium, while an excess of waterdefinitely reduces the yield of urea. Yakovkin (17) was the first to report studies on this system at temperatures above 150 C. Hiswork was carried out in lead-lined reactors and at relatively high weight-volume ratios. However, his procedure did not permit an accurate temperature measurement or insure that the equilibrium measured corresponded to the observed temperature range. Neumann and Sonntag (15) in 1931 reported yields of urea obtained by heating ammonium carbamate in a tin-lined reactor for varying periods of time. These authors1 used a weight-volume ratio of 0.75 to 0.90 gram per cc. at temperatures from 135 to 155 C.