尿素生产装置回收工艺的改进

Recovering process modification of urea production unit

中原大化集团公司52万t/a尿素生产装置存在解析塔处理能力不足,碳铵液储存容积小,中压放空尾气中氨含量高,装置开停车时废水、废气排放量大等问题。通过拆除解析塔塔板并在塔内填充不锈钢规整填料,增设碳铵液储罐及吸收塔,改进操作方法等措施,解决了上述问题。中压放空尾气中氨质量分数由改造前的20%降至5%以下,尿素氨耗降低约1.4kg/t,并使废水、废气的排放得到了彻底改善。

The urea production unit with its capability of 0.52 Mt/a in Zhong Yuan Dahua Group Ltd. of Henan Province had such problems as low capability of the desorbers, limited volume of depositing ammonium carbonate, high content of ammonium in blow-down tail gas of the medium pressure system, and large quantity of waste water and waste gas discharged when the unit was opened and closed, which were resolved by removing the column plate installed in the desorbers and filling regular packing made of stainless steel, besides, an ammonium carbonate liquid storing cistern and a absorber were added and operating steps improved. The mass fraction of ammonium in blow-down tail gas of the medium pressure system was decreased from 20% to 5% , ammonium consumption was decreased by 1.4 kg per ton of urea, and the discharge phenomena of waste water and waste gas were completely made better.