Analysis of the reasons for high and low methanol cooling temperatures in the carbon dioxide stripping process
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When the ammonia-to-carbon ratio is high, the temperature of the high-methane cold output fluid decreases； Conversely, the high-pressure refrigerant outlet temperature increases. Could some expert explain why? As I understand it, when the ammonia-to-carbon ratio is high, the process should proceed in the direction of forming methylamine; in that case, the temperature should rise. This post was last edited by lxq700918 on 2009-3-12 13:29.]
The poster is right – \"when the ammonia-to-carbon ratio is high, the reaction should proceed in the direction of forming methylamine.\" However, during the reaction process ammonia is always in excess; not all of it can be converted into methylamine, and some remains in a free state. Excess ammonia affects the thermal balance of the reaction; since the temperature of the liquid ammonia feed is not high, \"an elevated ammonia-to-carbon ratio results in a lower temperature of the high-methane cold stream\" ； Conversely, the high-temperature coolant outlet temperature increases.” This post was last edited by Fan Zhou Wu Hu on 2009-3-11 19:09.]
A look at the ternary system diagram for urea synthesis will make this clear: at an ammonia-to-carbon ratio of around 2.89, when the ammonia-to-carbon ratio is high, the temperature of the high-methane liquid stream decreases； Conversely, the high-pressure refrigerant outlet temperature increases. If the ammonia-to-carbon ratio is significantly too low, the high-pressure methanol refrigerant outlet temperature will also decrease.