Studyon Deavtivation Of The Mercuric Chloride Catalyst

In this paper, fresh, deactivate catalysts and recovery active carbon as theresearch objects，using thermo gravimetric, inductively coupled plasma atomicemission spectrometry (ICP-AES), specific surface area measurements and X-raydiffraction (XRD) and other characterization methods to study the reasons forcatalyst deactivation, the recycle of deactivated mercuric chloride catalyst on thisbasis, and activity detection of residual mercury by situ FT-IR.1．Comparing fresh and deactivated catalysts characterization results, mercuricchloride, the main active ingredient in catalysts, has a large loss as the reactionproceeding during the production of vinyl chloride, and specific surface area and porestructure of the deactivated catalyst have a severe loss. According to XRD detection,the peak of divalent mercury is not found, but the peak of monovalent mercury isappeared in fresh and deactivated mercuric chloride catalysts. There is a large amountof monovalent and divalent mercury according to XPS detection. The reason of thepresence of monovalent mercury is that Mercuric chloride formed multilayeradsorption in the support surface.2. After ICP-AES and TGAcharacterization, the mercury mass fraction in recycleactivated carbon is less than0.1%. Furthermore, the specific surface area of the carrieralso returned to a level close to the fresh catalyst. The mercury loss experiment onfresh catalyst shows that a small amount of mercury loses after280℃heat treatment,and there is almost no change in specific surface area. While the mercury lossexperiment on deactivated catalyst shows that there is a huge loss of active substance,and specific surface area has a certain recovery.3. According to situ infrared active test on fresh, deactivated catalysts, fresh anddeactivated catalysts have a certain catalytic effect on the reaction of acetylene and hydrogen chloride. Fresh catalyst activity was significantly better than the deactivatedcatalyst. According to situ infrared active test on mercuric chloride catalyst aftermercury loss experiment, there is substantially no activity difference between beforeand after mercury loss experiment, although the loss of mercury were in differentdegrees. This phenomenon indicates that the catalysts have a certain catalytic effecton the reaction, while pulse injection method of situ infrared test cannot test out theiractivity differences. Further activity research needs continuous injection activity tests.