The Study Of Modified Carbon Materials For The Acetylene Hydrochlorination Reaction

Vinyl chloride referred to as VCM, it is mainly used to produce polyvinyl chloride （PVC）. PVC is oneof the five general-purpose resin （PVC, PE, PP, PS and ABS）, it is a kind of important plastic product withits fire resistance, insulation, corrosion resistance and advantages of mechanical strength, it is widely usedin many fields of industry, agriculture, construction, daily necessities, packaging and power. Currently, theproduction process of PVC are ethylene oxychlorination and calcium carbide acetylene. In our country, thespecial energy structure of coal-rich, oil-poor, short of ethylene, but the abundant coal resources providesufficient raw materials for acetylene hydrochlorination which decided the acetylene hydrochlorinationsynthesis of vinyl chloride process still occupy a dominant position in China. However, the traditionalHgCl₂/AC has been used as the catalyst in the acetylene hydrochlorination production process, which ishighly toxic, easy to lose and cause harm to human health and the environment. Therefore, many researchworkers of Chemistry and Chemical direction currently need to solve an urgent problem on how toeliminate Hg pollution, to achieve a clean and low consumption production process of the acetylenehydrochlorination synthesis of vinyl chloride. Recently, the development of non-mercury catalyst is the bestsolution to solve this problem, many scholars also conduct a lot of research, but the effect is poor.The improvement of non-mercuric catalyst has two aspects: on the one hand, adding additives toreduce metal catalyst content; on the other hand, choosing appropriate carrier to increase the interaction ofthe metal and carrier, and then improve its activity and stability. Most of the experimental reported thescreening of precious metals, but the carrier is relatively less, so there is a big space to choose a rightcarrier for the acetylene hydrochlorination reaction. In this works, screening suitable carrier for theacetylene hydrochlorination reaction as the starting point to carry out our woks.Preparation of activated carbon modified with urea, melamine, respectively, the activity test wasstudied. The results show that the catalytic activity of the activated carbon modified with melamine werevery high. Further to determine the optimum conditions for modified activated carbon with melamine. Themodified activated carbon as a carrier for Au/MOMC （Au loading1wt%） catalyst, the activity test ofAu/MOMC catalyst show the conversion of acetylene reached89%in24h, the conversion of acetyleneincreased30percentage points than unmodified activated carbon, the selectivity was up to98%Coconut shell activated carbon is modified with urea and melamine, respectively. The results showthat the activity of melamine modified activated carbon is better. The effect of calcination temperature andmelamine impregnation rate on the activity of activated carbon was studied. The activity test give theoptimum calcination temperature for the modified activated carbon is650°C, the optimum impregnationratio is0.8. Further investigated the activity of Au/MAC-0.8-650catalytic, the reaction temperature was150°C, C₂H₂（GHSV）=360h^-1, V （HCl）/V （C₂H₂）=1.15, the Au loading0.2%, the conversion ofacetylene of modified Au/MAC-0.8-650catalyst is higher7percentage points than the unmodified Au/ACcatalytic. The conversion of acetylene of Au/MAC-0.8-650was95%, the selectivity was up to99.91%.Finally, Coconut shell activated carbon is modified with NH₃, H₂reduction, KOH, NaOH and two-step （KOH+NH₃）, the results show that the conversion of C₂H₂was reached about45%when theNH₃was100ml/min.35%the activity of modified activated carbon have some extent improved, except forthe modified activated carbon AC-H₂. The conversion of C₂H₂reached35%. The conversion of acetylene ofthe two-step （KOH+NH₃） modified activated carbon ammonia can reach about45%.The conversion ofacetylene of Au/AC-NH₃and Au/AC-KOH-NH₃（Au loading0.2%） was91%and93%, the selectivity was99.94%and99.99%。...