化工学报 ›› 2010, Vol. 61 ›› Issue (7): 1821-1828.

• 分离工程 • 上一篇    下一篇

煤气化废水酚氨分离回收系统的流程改造和工业实施

钱宇;周志远;陈赟;余振江   

  1. 华南理工大学化学与化工学院;中煤集团哈尔滨煤化工公司
  • 出版日期:2010-07-05 发布日期:2010-07-05

Process retrofit and industrial implementation of phenol and ammonia recovery from coal-gasification wastewater

QIAN Yu;ZHOU Zhiyuan;CHEN Yun;YU Zhenjiang   

  • Online:2010-07-05 Published:2010-07-05

摘要:

煤气化工艺中产生的洗气废水含有酚氨等高浓度难降解有机污染物。工业上采用化工分离和生化处理两段法来依次实现回收酚氨和净化排放。现有工艺中酚回收效率较低,难以保证进入生化工艺段的水质,影响最终排放。本文研究发现:萃取剂的选择和分离序列对萃取过程的pH值及随之对脱酚效率的影响极大。本文将脱氨装置单元前置,提出了精馏汽提塔侧线脱氨技术,将废水的pH值从10.5降到6.5,使萃取在偏酸条件下进行。采用甲基异丁基甲酮(MIBK)替代原有的二异丙醚(DIPE)萃取剂,显著提高了对多元酚的分配系数,总酚萃取效率从76% 提升到93%。以上新流程已在某大型煤化工企业3200 t·d-1煤气化污水化工分离系统中得以成功改造实施。新流程的实施提高了有机污染物的脱除率,为后续的生化处理工艺的达标排放奠定了基础。

关键词:

分离, 萃取, 煤气化废水, 甲基异丁基甲酮, 苯酚回收

Abstract:

A novel treatment process of the coal-gasification wastewater produced from Lurqi gasification was proposed in this paper. The new and old treatment processes were compared. The ammonia and acidic gas in coal-gasification wastewater were removed through a sour water stripping tower in the new process. The pH value of the treated wastewater removed ammonia was decreased from 10.5 to 6.5, which is beneficial to subsequent solvent extraction of phenols. The distribution coefficients of MIBK to phenol and polyhydric phenols were greater than DIPE. The application of MIBK as extraction solvent recovers more phenolic substances from wastewater. The COD value is further reduced before the coal-gasification wastewater fed into the following biochemical treatment section.

Key words:

分离, 萃取, 煤气化废水, 甲基异丁基甲酮, 苯酚回收