Study Of Cyclopentadiene Separation From Ethylene Cracking C9By-products

Cyclopentadiene is a kind of alicyclic olefins which has very high chemicalactivity. Usually, the raw materials of producing cyclopentadiene are complexmixtures. And the cumbersome process producing high purity cyclopentadieneproducts is tedious. Thus the purity of most of cyclopentadiene in market is as lowas80%. As cyclopentadiene have been used more and more widely, high-puritycyclopentadiene is needed greatly. And it is an urgent need to find new methods forproducing high-purity cyclopentadiene.The preparation of high-purity cyclopentadiene from C9fraction mixture isstudied in this paper. The main contents are as follows:1) At the beginning of the research, the method of producing cyclopentadienefrom C9mixture is explored with traditional operation mode. With specificexperiment way of discussing the pyrolysis experiment of the specifications of eachdevice, pyrolysis heating mode, and the effect of polymerization inhibitor. Accordingto the aboveconclusion, the effect of polymerization inhibitor is tested firstly.The optimumtemperature and species were obtained secondly. The experiment equipmentspecifications was caculated according to the former conclusion. And then the devicewas improved.2) Cyclopentadiene was produced from the mixture of C9fraction. The effect oftemperature on the yield and purity of cyclopentadiene was studied. The bestoperating conditions was280~330?. The cyclopentadiene yield was92.5%.Methyl cyclopentadiene content in the product is0.17%. Double loop pentadiene is5.47%. The higher the experimental process analysis showed that pyrolysistemperature, pyrolysis generated when the polymer is less.3) with the results of the experiment as the foundation, gradually completed thedouble pentadiene experiment with complete design. Cyclopentadiene yield wassignificantly affected by pyrolysis retention time of raw material. Sufficient retentiontime was needed in this process. The residence time of the raw material in the axeis5~20s by calculation. The pyrolysis temperature is below280?. Thecyclopentadiene obtained at this condition is colorless, otherwise its color will be lightyellow. High temperature pyrolysis temperature is220~380?. Less than10%(Wt%) tar was produced during this thermal cracking process.The recovery ratio ofcyclopentadiene and methyl cyclopentadiene are more than90%.The purity ofcyclopentadiene is larger than95%.The purity of methyl cyclopentadiene is largerthan85%.