کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
207262 | 461211 | 2008 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Use of methanol and oxygen in promoting the destruction of deca-chlorobiphenyl in supercritical water Use of methanol and oxygen in promoting the destruction of deca-chlorobiphenyl in supercritical water](/preview/png/207262.png)
The destruction of the well-known PCB, deca-chlorobiphenyl (10-CB), by oxidation and methanolysis in supercritical water (SCW), has been studied in a micro-reactor hydrothermal diamond-anvil cell (DAC, 50 nL) and in larger batch reactors (6 mL). The DAC was coupled to optical and infrared microscopes. In the DAC experiments, 10-CB proved to be stable under pyrolytic conditions, whereas in water, it was hydrolyzed and actually dissolved at temperatures above 475 °C. When partial oxygen was added to the 10-CB/water system, the solubility of 10-CB increased slightly as compared to the pure water experiments, and 10-CB was further decomposed by oxidation. The addition of methanol resulted in further decomposition by methanolysis, as confirmed by FT–IR spectroscopy, and lowered the dissolution temperature to 419 °C. Both oxygen and methanol (25 vol.%) were then used to destroy 10-CB in batch reactors, in which the supercritical water experiments permitted a detailed study of the reaction products of the 10-CB destruction. In the absence of methanol, more than 12 intermediate products were detected by GC–MS, and 99.2% of the 10-CB was destroyed in the presence of 225% excess oxygen at 450 °C within 20 min. When methanol was used in the absence of any excess oxygen, a destruction rate of 100% was achieved at 450 °C within 10 min and only three intermediate products were detected. The enhanced destruction of 10-CB in the presence of methanol is attributed to the homogenous reaction conditions employed and the generation of free radicals.
Journal: Fuel - Volume 87, Issue 3, March 2008, Pages 353–358