| abstract |
The invention discloses a waste gas treatment process in the production of doxycycline hydrochloride. The process comprises the following steps: adopting a multi-spray tower in series countercurrent absorption mode to treat the waste gas, the first stage is 5-10% liquid caustic soda, the second stage is It is 1-5% sulfuric acid and the tertiary is water. After working for a period of time, the residual liquid after pre-distillation of the primary and secondary absorbing liquids to collect methanol and ethanol is subjected to post-treatment, and the tertiary absorbing liquid is pre-distilled to recover methanol and ethanol. The first stage and the second stage are used with absorbing liquid, and the methanol and ethanol obtained by pre-distillation are recycled into the second stage rectifying tower to obtain methanol, ethanol and water. In the present invention, the methanol and ethanol recovered after rectification are continued to be used in production, and water can be continuously used as the absorbing liquid, which not only saves the production cost, but also reduces the pollution to the environment. Method for waste gas in the production of cyclosporine. |