Method of preparing cyclopentane by continuous hydrogenation of cyclo pentadiene

Abstract

The continuous cyclopentadiene hydrogenating process to prepare cyclopentane is one continuous catalytic hydrogenation reaction of the mixture of cyclopentadiene, solvent and hydrogen in a fixed bed catalyst bed. The catalyst includes gamma-Al2O3 as carrier and Pa as active component. The solvent is any one of cyclopentane, n-hexane, benzene, toluene, cyclohexane, ethanol, methanol, etc. The molar ratio between cyclopentadiene and hydrogen is 1 to (3-4), and the reaction system has pressure of 0.9-1.8MPa and temperature of 44-72 deg.c. The reacted liquid is discharged partially and externally circulated partially with the weight ratio being 1 to 6-12, and the externally circulated liquid after being cooled is mixed with cyclopentadiene material and solvent before being mixed with hydrogen in venturi ejector, atomized into gas-liquid mixture and reacted in the catalyst bed. The catalyst load is 2-4 / hr accounted in liquid phase material, and the reacted heat is transferred via external circulation.

Description

technical field [0001] The invention relates to a method for preparing cyclopentane by hydrogenating cyclopentadiene. Background technique [0002] Cyclopentane is a new type of foaming agent that has no side effects on the atmospheric ozone layer. It has been widely used in polyurethane foam materials, especially as a foaming agent for refrigerator insulation materials. In the prior art, cyclopentane can be obtained by various methods, but the method of hydrogenation of cyclopentadiene has the most industrial application prospect. However, since the hydrogenation reaction of cyclopentadiene is a strong exothermic reaction, the catalyst bed is prone to overheating during the catalytic hydrogenation process, resulting in catalyst deactivation. method to remove the large amount of reaction heat generated. For example, Chinese patent ZL00107230.7 provides a method for producing cyclopentane by continuous depolymerization and hydrogenation of dicyclopentadiene. The hydrogenati...

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Problems solved by technology

The method of installing a heat exchange device in the hydrogenation reactor is used to remove the reaction heat generated during the hydrogenation of cyclopentadiene. The disadvantage is that the uniformity of cooling in the reactor is limited to a certain extent.

It is speculated that there is still a local excessive temperature rise in the catalyst bed, which causes partial catalyst deactivation, and cyclopentadiene is easily dimerized to form dicyclopentadiene in this high-temperature region, which will reduce the concentration of cyclopentane. yield

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