Study On Catalytic Dehydrogenation Performance Of Iron Catalyst And Iron Oxide Catalyst In The Tail Chloride At Low Temperature

Chlor-alkali industry is known to occupy a very key position in Chinese industrial.Chlor-alkali production has been stable among the front-runners in the world.The ingredient from traditional electrolysis production method of tail chlorine is complicated because of Hydrogen generation,which makes subsequent processing and use of tail chlorine gas are a security risk.The explosion will happen when the hydrogen concentration exceeding 4 %,so it is a key to remove hydrogen in Tail chlorine gas safely in chlor-alkali industry.This experiment prepared reaction gas according to industrial tail chlorine components: chlorine（65 %⁸0 %）,oxygen（8 %¹0 %）,hydrogen（1.5 %⁴ %）.To remove hydrogen securely,we reacted in fixed bed reactor and used cheap metal iron and iron oxide as catalyst to catalytic hydrogen reacted with oxygen and chlorine of gas mixture.Owing to active,iron and iron oxide will chlorate,When catalyticing dehydrogenation of tail chlorine gas,we also explored the formation content of ferric chloride.according to the experimental results have the following conclusions :First,as catalysts for catalytic dehydrogenation of tail chlorine gas,iron powder and 80-100 mesh iron catalyst behaved good catalytic performance.They had similar catalytic dehydrogenation performance of tail chlorine gas.When catalyticing dehydrogenation,catalytic effect was good at beginning,Hydrogen conversion rate can reach 99 % at the temperature of110 ℃.However,hydrogen conversion rate decreased rapidly,it reduced to67 % after 240 min.the selectivity of hydrogen-chlorine reaction is higher than hydrogen-oxygen reaction’s at low temperature,on the contrary,the selectivity of hydrogen-chlorine reaction is higher at high temperature.Second,based on iron,zeolite,activated carbon,SAP was mixed with iron mechanically for catalytic dehydrogenation of tail chlorine gas.As the result showed,when mixing with iron powder mechanically,Molecular sieve catalyst at 50 % reached best catalytic effect,it was 74.61 %.Activated carbon at 100 % reached maximum of 90.61 %,SAP at 100 % reached maximum of 85.38 %.When mixed with 80-100 mesh iron mechanically,Molecular sieve catalyst at 50 % reached best catalytic effect,it was 84.02 %.Activated carbon at 100% reached maximum of 85.63 %,SAP at 150 %reached maximum of 82.35 %.Overall,the catalyst effect of three kinds of material mixed with iron powder is carbon > SAP > zeolite.For 80-100 mesh iron,When the content of three kinds of material was less than 100%,mixing with zeolite had better catalytic effect,the content of three kinds of material was more than 100%,mixing with activated carbon had better catalytic effect.Third,iron oxide was explored from the two aspects of non-Load and load.It showed that Fe₂O₃/Al₂O₃ had better performance in catalytic effect and catalytic stability than Fe₂O₃.They both presented the Selectivity of and hydrogen-chlorine was higher than hydrogen-oxygen reaction’s.The best conditions Fe₂O₃/Al₂O₃ of catalytic dehydrogenation reaction was 3% loading,calcination temperature 500 ℃,reaction temperature 70 ℃,Hydrogen conversion rate could reach 84.11 %.According to XRD,XPS,SEM,N₂ adsorption and desorption characteristics,iron oxide had a good dispersibility on the surface of the carrier.The carrier’s structure didn’t changed generally.The surface of catalyst after reaction became rough.Four,When catalyticing dehydrogenation,iron catalyst generated ferric chloride and ferrous chloride,after 240 min for iron reaction,Ferric chloride production was 35 %-45 %,ferrous chloride was 8 %-10 %,for 80-100 mesh iron,ferric chloride production was 23 %-32 %,ferrous chloride was 7 %-10 %,ferric oxide only chlorinated few amount of ferric chloride after catalyzing dehydrogenation of tail chlorine,about 11 %.