Process for cyclic dodecatriene selecting hydrogenated cyclic dode cene

A technology of cyclododecatriene and cyclododecene, which is applied in the field of selective hydrogenation of cyclododecatriene to cyclododecene, which can solve the problem of inhomogeneous active metal substances and unsuitability for the gas phase of cyclododecatriene Hydrogenation reaction, expensive catalyst production and other problems, to achieve high selectivity effect

Active Publication Date: 2004-09-08
EVONIK OPERATIONS GMBH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0017] Another disadvantage of this reaction system is that the production of the catalysts used is rather expensive, so such a system is not suitable for the production of cyclododecene on an industrial scale
[0018] Furthermore, it is stated in this article that commercial catalysts consisting of support materials containing finely divided noble metals are not suitable for the gas-phase hydrogenation of cyclododecatriene
The reason is that due to the uneven distribution of pores on the surface of this traditional support, the active metal species on the surface is also uneven, so the problem found in this article will directly cause the degradation of the catalyst activity, and will follow the material transfer. The increasing importance of the effect of the catalyst has led the authors Wieβmeier et al. to rule out the possibility of commercial catalysts being used in industry

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Embodiment 1 (not the present invention):

[0043] This example is from a paper by Chartered Engineer Georg F.L. Wieβmeier entitled: "Integral Microstructured Reactors with Microfluidic Channels and Regular Mesopore System for Selective Heterogeneously Catalyzed Gas-Phase Reactions", Shaker Press 1997, ISBN 3-8265-2183-8.

[0044] 0.16 g of catalyst Heraeus K-0204 (0.5% Pd on alumina) ground to an average particle size of 400 μm was filled into a tubular reactor having a diameter of 8.5 mm. The resulting bulk density is about 1g / cm 3 , while the pile height is 2.8mm. The volume flow was adjusted to 8.6 l / h, resulting in a flow velocity of 0.04 m / s. The total pressure is 110 kPa, the pressure of cyclododecatriene (CDT) is 110 Pa, the hydrogen pressure is 330 Pa (the rest is nitrogen) and the reaction temperature is 120°C. From these data, the Reynolds number Re related to the particle can be obtained by calculation p = 0.7, using the Picritic number Pe ax,p =2 calc...

Embodiment 2

[0045] Embodiment 2 (the present invention):

[0046] A shell catalyst with 0.5% Pd on alumina and an average particle size of 2.5 mm was filled into a tubular reactor with a pile height of 2 m and a cross-sectional area of ​​the reactor of 1.46 m 2 . When the flow velocity is 1.58m / s, the Reynolds number Re of the relevant particles is obtained p =247, when the axial Picritic number Pe ax,p = 2 results in a plate number Bo = 1600. Thus, the reaction was carried out at 120° C. under the same pressure and concentration conditions as in Example 1, and a CDEN selectivity of 90% was obtained, while the CDT conversion rate was 100%. The amount of residual CDD was kept at 0.2%. Thus, the overall conversion (CDT+CDD) was 99.8%.

[0047] This shows that with a very high number of plates, ie, backmixing, it is possible to obtain significantly increased selectivities in the selective hydrogenation of cyclododecatriene to cyclododecene.

Embodiment 3

[0048] Embodiment 3 (the present invention):

[0049] The operation was carried out similarly to Example 2, except that 3000 ppm of carbon monoxide was mixed into the reaction gas. The resulting CDEN selectivity was 94%, while the CDT conversion was 100%. The residual CDD amount remained at 0.2%. Thus, the overall conversion (CDT+CDD) was 99.8%.

[0050] The examples show that the selectivity can again be increased by adding carbon monoxide to the reaction gas.

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Abstract

A process for preparing cyclododecene by selective gas-phase hydrogenation of at least one starting material selected from cyclododecatriene, cyclododecadiene and mixtures thereof, wherein the starting material present in the gas phase is hydrogenated in the presence of a catalyst in a fixed-bed reactor and the Bodenstein number for the process is greater than 100.

Description

technical field [0001] The present invention relates to a method for the selective vapor-phase hydrogenation of cyclododecatriene and / or cyclododecadiene to cyclododecene over a solid-state catalyst containing a catalytically active metal of Group VIII of the Periodic Table of the Elements. Background technique [0002] The selective hydrogenation of cyclododecatriene to cyclododecene has been documented many times in many literatures, and a large number of experiments have been carried out to carry out selective hydrogenation reactions with high conversion and high selectivity. [0003] According to a general view, the hydrogenation of cyclododecatriene (hereinafter referred to as CDT), mainly in the form of cis, trans, trans-1,5,9-cyclododecatriene, is carried out by dienes, mainly trans , trans-1,5-cyclododecadiene and cis, trans-1,5-cyclododecadiene (both hereinafter denoted as CDD), and the almost corresponding equilibrium isomer mixture trans- and cis-cyclo Dodecene (...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C5/09C07B61/00C07C5/05C07C13/275
CPCC07C5/05C07C2523/44C07C2521/04C07C13/275
Inventor J·赫威格N·威尔佐克M·鲁斯R·布格哈德特G·奥恩布林克B·格恩泽尔
Owner EVONIK OPERATIONS GMBH
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