摘要
用Aspen Plus软件对乙二胺(EDA)合成三乙烯二胺(TEDA)体系中涉及到的主要化合物的热力学参数进行估算,并对涉及到的主、副反应的焓变、吉布斯自由能变和平衡常数随温度的变化进行了计算。以氯化钾为前驱体,用离子交换法改性HZSM-5制备KZSM-5催化剂,通过XRD,吡啶吸附红外光谱(Py-IR)表征,KZSM-5没有氯化钾晶体生成,骨架B酸位消失,L酸位变丰富。在温度340℃常压下,进料浓度5.90mol/L,停留时间88.06min下,原料转化率和三乙烯二胺的选择性分别为85%和51%。对催化机理进行分析,气相主体的乙二胺分子进入KZSM-5孔道,被K+活化生成二乙烯三胺,经分子内环合生成哌嗪。哌嗪从分子筛孔道中脱附进入气相主体在瓷环层与乙二胺反应生成三乙烯二胺。
Thermodynamic analysis of ethylenediamine to triethylenediamine reaction system was carried out.By using the Aspen Plus software,unknown parameters of thermodynamics were estimated,the enthalpy changes,Gibbs free energy changes and equilibrium constant of each reaction were calculated in detail as a function of temperature.The catalysts were prepared through modifying HZSM-5 zeolite by KCl ion exchange method and the structure and acidity of the catalysts were investigated with XRD,Py-IRtechnologies.The results showed that the KZSM-5 had no crystal formation of potassium chloride,the B acid bit disappeared,the L acid bit became enriched.The catalytic performance of KZSM-5 in synthesis of triethylenediamine(TEDA)from ethylenediamine(EDA)were investigated.The conversion rate of raw materials(EDA)and the selectivity of TEDA are 85%and 51%respectively,under the normal pressure,340℃,and the concentration of the raw material is 5.90 mol/L,and the stay time is 88.06 min.Catalytic mechanism explored,the gas phase of EDA molecule into KZSM-5 channel,combined with K+by activation and the other EDA molecules to form diethylenetriamine(DETA).The DETA was combined with K+to form PA in the elliptical channel,and the PA was removed from the molecular sieve pore to enter the main body of the gas phase to synthesize TEDA directly in the ceramic ring layer.
作者
王君
杨友得
郝红
王晨
孙瑞鸿
杜鲜萍
WANG Jun;YANG You-de;HAO Hong;WANG Chen;SUN Rui-hong;DU Xian-ping(College of Chemical Engineering,Northwest University,Xi′an 710069,Shaanxi Province,China;Shandong NHU Amino Acid Co.,Ltd.,Weifang 261108,Shandong Province,China)
出处
《化学工程》
CAS
CSCD
北大核心
2019年第6期64-68,共5页
Chemical Engineering(China)
基金
陕西省工业攻关项目(2014K10-03)
