脱氨塔碳铵结晶对酚回收装置的影响分析

Analysis of the influence of ammonium bicarbonate crystallization in deamination tower on phenol recovery device

在煤化工装置酚回收过程中,因脱氨塔顶部气相管线中同时存在二氧化碳和氨气,当其操作温度低于60 ℃时,容易形成碳铵结晶堵塞管道,造成脱氨塔压力升高,氨气净化塔压力下降,影响脱酸塔的安全稳定运行.当脱酸塔压力升高后,导致脱氨塔再沸器管壳程压差变小,温差降低,塔内的部分氨气不能很好的进行脱除,脱氨塔底部出来的脱氨水中含有大量的氨,使其pH值升高,pH值升高后在萃取过程中酚的分配系数降低,稀酚水中酚含量超标.为此通过增加蒸汽吹扫,降低脱酸塔顶产生碳铵结晶的风险,同时减少原料酚水中油含量,减少油品在装置内的累积,提高了装置运行的稳定性.

In the phenol recovery process of coal chemical device,due to the simultaneous presence of carbon dioxide and ammonia in the gas phase pipeline at the top of the deamination tower,when the operating temperature is below 60 C,it is easy to form ammonium bicarbonate crystals to block the pipeline,causing an increase in the pressure of the deamination tower and a decrease in the pressure of the ammonia purification tower,which affects the safe and stable operation of deacidification tower.When the pressure of the deacidification tower increases,it leads to a decrease in the pressure and temperature difference between the reboiler tube and shell of the deamination tower,and some of the ammonia in the tower cannot be effectively removed.The deamination water coming out of the bottom of the deamination tower contains a large amount of ammonia,which increases its pH value.After the pH value increases,the distribution coefficient of phenol decreases during the extraction process,and the phenol content in the dilute phenol water exceeds the standard.By increasing steam blowing,the risk of ammonium bicarbonate crystallization at the top of the deacidification tower is reduced,and the oil content in the raw phenolic water is also reduced,reducing the accumulation of oil in the device and improving the stability of the device operation.