清洁生产异氰酸酯安全反应过程构建及关键基础问题研究

Based on the idea and method of solving the problem of chemical process safety at the source, a safe reaction process for the production of 4,4'-diphenylmethane diisocyanate (MDI) was constructed in this project. Fundamental science problems associated with this process such as catalyst preparation, new catalytic reaction, multiple reaction integration in nano/micro scale and high-efficient conversion processes will be investigated. Firstly, an integrated reaction for the synthesis of aniline from ammonia, hydrogen peroxide and benzene will be realized, i.e. ammonia reacts with hydrogen peroxide to form hydroxylamine, and then the obtained hydroxylamine reacts with benzene to produce aniline. The integrated reaction will be controlled by designing a new combinatorial catalyst and a functionalized ionic liquid for stabilizing hydroxylamine. Secondly, acid ionic liquids will be designed and synthesized for improving 4,4'-methylenedianiline (MDA) selectivity and reducing reaction temperature. Thus, a green and safe process will be achieved for the preparation of MDA by the condensation of aldehyde with aniline. Thirdly, a new catalytic route will be developed for simultaneous synthesis of organic compounds and inorganic nano-materials, namely in-situ preparation of nano-ZnO and its composite materials can be achieved by using dynamic operation during the process for the synthesis of 4,4'-methylene diphenyl dimethylcarbamate (MDC). Lastly, using the obtained nano-ZnO composite materials as catalyst and an ionic liquid in place of organic medium, the reaction of MDC decomposition to MDI can be realized efficiently at lower reaction temperature by means of both variable temperature operation and dynamic feed mode.

基于从"源头"上解决化工过程安全问题的理念和方法，构建合成二苯甲烷二异氰酸酯（MDI）安全反应过程；并就催化剂制备、新催化反应过程、纳微尺度上多反应集成及高能效转化过程等关键基础问题进行研究。建立由氨和双氧水合成羟胺、羟胺进一步和苯合成苯胺构成的反应集成；设计制备可稳定羟胺的功能化离子液体和组合型催化剂，对集成反应进行调控，实现由氨、双氧水和苯为原料直接合成苯胺的安全反应过程。研制用于催化苯胺与甲醛缩合反应的酸性离子液体催化剂，提高MDA选择性并降低反应温度，实现二苯甲烷二胺（MDA）的绿色与安全合成过程。提出联合制备有机物和无机纳米材料的新催化反应过程，通过基于反应机制的动态操作方法，在催化合成二苯甲烷二氨基甲酸甲酯（MDC）的同时，制备纳米ZnO及其复合材料。采用原位反应法制备的ZnO基复合物催化剂，以离子液取代有机溶剂，通过变温和溶剂动态进料方法，实现MDC低温催化分解的高能效转化。

本项目基于从“源头”上解决化工过程安全问题的理念和方法，构建了合成异氰酸酯MDI、TDI安全反应过程。开展了功能化离子液体-“离子液体型羟胺”调控的直接合成含氮化合物反应集成，合成苯胺不锈钢基金属催化剂，用于缩合反应的境友好酸催化剂，联合制备有机物及无机纳米材料，以及MDC、TDC分解的简单化工艺等研究。.制备出一类新绿色化学品—“离子液体型羟胺盐”，建立了以氯化铵为原料直接制环己酮肟及其水解制备无机酸羟胺盐、离子液体型羟胺盐的合成方法，并成功地用于苯胺、苯酚、己内酰胺及苯甲腈等的直接、清洁、安全合成；创制出一类金属原子嵌入不锈钢表面空位构成的嵌入型不锈钢构件金属催化剂，提出“极稀液相还原制备铂原子—含铂原子流体撞击嵌入空位”制备方法，该催化剂在硝基苯液相加氢制苯胺反应过程中表现出非常优异的活性和稳定性；建立了均相乙酸锌催化合成TDC过程中联产用于其分解反应的纳米氧化锌催化剂的方法，异氰酸酯总收率达到98%；基于动态操作方法，以苯胺、DMC、甲醛为原料，在同一反应器中实现了MDC的“一锅法”合成，MDC的收率为73.9%；制备了化学键合负载型酸性离子液体、金属-有机骨架结合的杂多酸等为催化剂，催化苯胺与甲醛缩合生成MDA的反应，获得了较高的产率。.基于化学原理和化学工程理论，归纳总结出实现本质安全的七种方法（原理）；制备出一类新绿色化学品；创制出一类金属原子嵌入不锈钢表面空位构成的无内扩散金属催化剂，并提出了新颖的制备方法。这在化工本质安全理论建立、绿色化学品丰富、新型高效催化剂创制等方面具有重要的科学意义。