摘要
二硝基甲苯(DNT)生产过程中,合成的DNT中含有少量酚盐,酚盐杂质能否去除直接决定了DNT的纯度。为了进一步提高DNT产品品质,降低酚盐的含量,迫切需要进一步提高水洗工艺的脱除效率。通过两次实验,证明经过原水洗塔水洗的DNT原料,可通过进一步水洗不同程度地降低其酚盐含量,说明原水洗塔尚有改造空间;通过多级逆流萃取和多级错流萃取,酚盐含量都能够达到分离要求;多级错流萃取需要的理论板数更少,成本更低,确定了错流萃取的理论级数为4。基于实验结果,进行流程模拟、物料平衡分析,最终塔底酚盐质量流量降至1.13×10-5 kg/h。针对现有水洗塔,改造方案为塔径1100 mm,和原塔保持一致,塔板间距选择450 mm,法兰等预留空间500 mm,最终需要增加5000 mm的塔节。
During the production of dinitrotoluene(DNT),the synthesized DNT contains a small amount of phenolic salt,and the removal of phenolic salt impurities directly determines the purity of DNT.In order to further improve the quality of DNT products and reduce the phenolic salt content,it is urgent to further improve the removal efficiency of the washing process.Through two experiments,it is proved that the DNT raw material washed by raw washing tower could reduce its phenolic salt content to different degrees by further washing,indicating that there was still room for transformation of the raw washing tower.Through multistage countercurrent extraction and multistage cross-flow extraction,the phenolic salt content met the separation requirements.Multistage cross-flow extraction required fewer theoretical boards and lower cost,and the theoretical series of cross-flow extraction was determined to be four.Based on the experimental results,through flow simulation and material balance analysis,the final phenol salt content was reduced to 1.13×10-5.For the existing water washing tower,the improvement scheme was that the tower diameter and the original tower of 1100 mm,the tower spacing of 450 mm,the reserved space for flange of 500 mm,and the final tower section of 5000 mm was needed.
作者
谢华生
杜小岭
周镔
王红星
XIE Huasheng;DU Xiaoling;ZHOU Bin;WANG Hongxing(Cangzhou Dahua Co.,Ltd.,Technology Innovation Center of Modified Isocyanate of Hebei Province,Cangzhou 061000,China;School of Bioengineering,Tianjin University of Science&Technology,Tianjin 300457,China;College of Chemical Engineering and Materials Science,Tianjin University of Science&Technology,Tianjin 300457,China)
出处
《精细石油化工进展》
CAS
2024年第1期47-51,共5页
Advances in Fine Petrochemicals
基金
天津市研究生科研创新项目(2022SKYZ099)。
关键词
二硝基甲苯
水洗塔
多级错流萃取
多级逆流萃取
酚盐
dinitrotoluene
water scrubber
multistage cross-flow extraction
multistage countercurrent ex-traction
phenolate
