| 摘要 |
The recovery of toluene diamine from tar waste residues discharged from the synthesis process of toluene diisocyanate comprising steps of: a) grinding the tar waste residues into particles; b) dispersing the particles of tar waste residues into a phase transfer catalyst, alkali and water to obtain a slurry, said phase transfer catalyst being selected from the group consisting of higher alcohols, polyols, polyether compounds and combinations thereof having a boiling point ranging from 120 to 280°C; c) under the protection of a protective gas, subjecting the slurry to a hydrolysis reaction at a temperature of 120-180 °C under a meter-measured pressure of 0-0.95 MPa to produce toluene diamine; and d) recovering toluene diamine from the hydrolysis reaction solution. The present invention achieves highly efficient recovery of toluene diamine (the recovery rate of TDA is up to 60 %) under mild conditions such as 120-180°C and 0-0.95MPa (meter-measured pressure), and has a significant economic benefit and friendliness to the environment by recycling the phase transfer catalyst (its recovery rate is up to 99.6 %) and water. |
