| 题名 | 氨基甲酸酯热解制备异氰酸酯新工艺研究 |
| 作者 | 朱干宇 |
| 学位类别 | 硕士 |
| 答辩日期 | 2012-05-23 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 唐清 ; 李会泉 ; 柳海涛 |
| 关键词 | 异氰酸酯 热分解 动力学 热分析 工艺条件 |
| 其他题名 | Preparation of Isocyanate by Thermal Decomposition of Carbamate |
| 学位专业 | 化学工程 |
| 中文摘要 | 异氰酸酯是一种重要的有机化工原料，工业上主要采用光气法生产，该方法使用剧毒光气原料同时副产盐酸，因此随着环保要求的日益强烈，发展非光气清洁路线制备异氰酸酯正在成为绿色化学化工的前沿。本文针对苯氨基甲酸酯(MPC)及二苯甲烷二氨基甲酸酯(MDC) 热分解制备异氰酸酯过程，提出低沸点溶剂加压热解新工艺，系统开展了热分解反应历程、反应本征、表观动力学及热解工艺条件优化研究，研究结果将为工业应用反应条件确定、大型工业反应器设计等提供理论依据。主要研究内容与进展如下： (1) 采用TG-IR联用技术对MPC热解历程进行分析研究，结果表明MPC一步热解得到苯基异氰酸酯(PI)；采用Flynn-Wall-Ozawa法计算得到热解反应的活化能E，并进一步采用5种非等温动力学计算方法研究该反应的本征动力学模型，计算动力学参数，结果表明热解机理为相边界反应模型，机理函数G(α)=α1/3，反应活化能E=20.52kJ/mol、指前因子A=169.82min-1。 (2) 以沸点低、易分离、热稳定性好的氯苯作为反应溶剂，开发了加压条件下非催化热解MPC制备PI新工艺，考察了反应时间、温度的影响规律；并对MPC热解表观动力学进行研究。最优条件下MPC转化率为88.18%，PI选择性约100%；动力学结果表明该体系中MPC热解为一级反应，反应活化能E=71.28kJ/mol，指前因子A=2.74×105min-1。 (3) 研究了MDC热解制备二苯甲烷二异氰酸酯(MDI)反应历程，研究表明该反应为两步连串反应；以氯苯为溶剂，考察了加压条件下反应温度、时间及反应物浓度的影响规律，结果表明经过工艺优化，可以实现MDC转化率>95%, MDI相对选择性>70%；进一步研究锌系催化剂条件下，反应温度和反应物浓度的影响规律，经过工艺优化，可以实现MDC转化率≥99%，MDI相对选择性>90%。 |
| 英文摘要 | Isocyanate, which is a kind of major organic raw material, is mainly synthesized through phosgene route in the industrial production. For the extreme toxicity of phosgene and serious pollution caused by the co-product HCl in the phosgene method, significant attempts have been made to develop non-phosgene routes. In this paper, Methyl N-Phenyl Carbamate (MPC) and Methylene Diphenyl Dicarbamate (MDC) were used to prepare isocyanate through the decomposition process. The intrinsic/apparent kinetics and technological conditions were studied. The achievements and progresses were exhibited as follows: (1) The thermal behavior and decomposition kinetics of MPC were investigated by differential scanning calorimetry (DSC)/thermogravimetry (TG)/derivative thermogravimetry (DTG) and infrared spectroscopy (IR) in nitrogen gas flow. The result indicated that the decomposition of MPC to Phenyl Isocyanate (PI) was one-step reaction. The activation energy value, pre-exponential factor and the possible conversion function were 20.52kJ/mol, 169.82min-1 and G(α)=α1/3 respectively, which were estimated through the Flynn-Wall-Ozawa, general equation, Satava-Sestak, Coats-Redfern, Madhusudanan-Krishnan-Ninan, and MacCallum-Tanner methods. (2) Under pressure, the impacts of reaction temperature and time on the decomposition of MPC were studied in the low-boiling-point solvent of chlorobenzene, which is easy to be separated and has good-thermal-stability. The results showed that increasement of reaction temperature and time could improve the conversion of MPC. The apparent kinetics was further studied that the reaction was confirmed to be the first-order. The activation energy and pre-exponential factor were 71.28 kJ/mol and 2.74×105min-1 respectively. (3) The decomposition of MDC was confirmed to be two-step reaction by high performance liquid chromatography (HPLC). The reaction conditions including temperature, time and concentration were studied at pressure in the solvent of chlorobenzene. The results indicated that after process optimization, the conversion of MDC is greater than 95% and the relative selectivity of Methylene Diphenyl Diisocyanate (MDI) is greater than 70%. Meanwhile, the effect of the ZnO/Zn catalysts was studied. After process optimization, the conversion of MDC is equal to or greater than 99% and the relative selectivity of MDI is greater than 90%. |
| 语种 | 中文 |
| 公开日期 | 2013-09-25 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1840]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 朱干宇. 氨基甲酸酯热解制备异氰酸酯新工艺研究[D]. 中国科学院研究生院. 2012. |
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