Study On The Hydrolysis Of Carbon Tetrachloride In Subcritical Water In Silic Capillary With In Situ Raman Spectroscopy

A microscope with a recorder system and Raman spectroscopy wereused for the hydrolysis of CCl₄in a FSCR. The phase behavior duringheating to260℃was recorded by the microscope, while the Ramansignals variation of reactants and products in vapor and aqueous weredetected by Raman spectroscopy. The effects of the CCl₄: Vapor volumeratio （1:10,1:15,1:20）, CCl₄: H₂O liquid volume ratio （1:2,1:6,1:10）,and the reaction temperatures （240³00°C） on the hydrolysis rate wereinvestigated. The results showed that the CCl₄hydrolysis in the FSCRwas mainly a vapor phase reaction. The quenched liquid products wereanalyzed by gas chromatography-mass spectrometry （GC–MS） and ionchromatography （IC）, and the results indicated that the hydrolysisproducts were HCl and CO₂. Temperature was the prime determiningfactor for the hydrolysis rate，the CCl₄hydrolysis rate was also dependenton the initial concentration of vapor-phase CCl₄and the initial CCl₄: H₂Oliquid volume ratio. The kinetics of hydrolysis of CCl₄was analyzed, theresults showed the reaction followed a first order and an activationenergy of95.06±6.71kJ/mol was found.The magnified experiment was carried out in a FQTR with the tubalfurnace being used as the heating equipment and the results werecompared with the experiment conducted in the FSCR. Reactiontemperature and time were investigated and the hydrolysis products were analyzed by Raman、GC、GC-MS and IC. The results indicated that theuptrend of hydrolysis yield was consistent with the results in the FSCR;the hydrolysis yield increased with elevated reaction temperatures andincreased reaction time.The Raman properties of pure liquid or vapor H₂O and compressedCO₂gas in the FSCR at elevated temperatures ranging from100³50℃and50³50℃were also investigated, respectively. The results showedthat with increased temperature the Raman frequency of H₂O wasincreased, the fitted HBS became weaker but the HBW became stronger,and both the HBS and HBW FWHM widths became narrow in liquidH₂O. The Raman intensity of H₂O was increased while the frequency ofH₂O was decreased, and the FWHM of fitted HBW became wider invapor H₂O. The Fermi resonance bonds of CO₂became weaker and thehot bands became stronger with increased temperature.In addition, this new method could be applied to the study of thedegradation of other chlorinated organic compounds in sub-critical water.