(19) TZZ _¥_T (11) EP 2 821 384 A1 (12) EUROPEAN PATENT APPLICATION published in accordance with Art. 153(4) EPC (43) Date of publication: (51) Int Cl.: 07.01.2015 Bulletin 2015/02 C07C 27/04 (2006.01) C07C 49/403 (2006.01) C07C 45/53 (2006.01) C07C 35/08 (2006.01) (2006.01) (21) Application number: 12873136.1 C07C 29/16 (22) Date of filing: 17.05.2012 (86) International application number: PCT/CN2012/075632 (87) International publication number: WO 2013/143211 (03.10.2013 Gazette 2013/40) (84) Designated Contracting States: (71) Applicant: Xiao, Zaosheng AL AT BE BG CH CY CZ DE DK EE ES FI FR GB Jiangsu 215123 (CN) GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (72) Inventor: Xiao, Zaosheng Designated Extension States: Jiangsu 215123 (CN) BA ME (74) Representative: Sun, Yiming (30) Priority: 31.03.2012 CN 201210091366 HUASUN Patent- und Rechtsanwälte Friedrichstraße 33 80801 München (DE) (54) PRODUCTION PROCESS FOR PREPARING CYCLOHEXANOL AND CYCLOHEXANONE BY CYCLOHEXANE OXIDATION (57) A process for preparing cyclohexanol and cy- process of bis (tert-butyl) chromate with a heterogeneous clohexanone by cyclohexane oxidation, includes steps catalytic decomposition process of sodium hydroxide al- of: firstly processing uncatalyzed oxidation on cyclohex- kaline aqueous solution, including steps of: (1) perform- ane by molecular oxygen, in such a manner that an ox- ing the homogeneous catalytic decomposition by utilizing idized mixture with cyclohexyl hydrogen peroxide serving the bis(tert-butyl) chromate as a catalyst; (2) performing as a primary product is generated; then decomposing theheterogeneous catalytic decompositionin the sodium the cyclohexyl hydrogen peroxide to produce cyclohex- hydroxide alkaline aqueous solution under low alkalinity; anol and cyclohexanone; and then distilling to obtain a and (3) performing the heterogeneous catalytic decom- cyclohexanol product and a cyclohexanone product, position in the sodium hydroxide alkaline aqueous solu- wherein the step decomposing the cyclohexyl hydrogen tion under high alkalinity. The process has a high total peroxide utilizes a three-step decomposition process yield, a long continuous production cycle, a low consump- combining a homogeneous catalytic decomposition tion and a low production cost. EP 2 821 384 A1 Printed by Jouve, 75001 PARIS (FR) 1 EP 2 821 384 A1 2 Description the domestic and foreign devices thereof is only around 80%. FIELD OF INVENTION [0004] The non-homogeneous catalytic decomposi- tion by cobalt acetate in the alkaline aqueous solution of [0001] The present invention relates to a process for 5 sodium hydroxide also has three defects. Firstly, the de- preparing cyclohexanol and cyclohexanone by cyclohex- composition causes the big secondary reaction, and has ane oxidation, and more particularly to a process for pre- a low molar yield of only 84%. Secondly, it is difficult to paring cyclohexanol and cyclohexanone by cyclohexane completely separate the cyclohexane oil phase contain- oxidation comprising a three-step decomposition proc- ing cyclohexanol and cyclohexanone from the alkaline ess for decomposing the cyclohexyl hydrogen peroxide. 10 aqueous phase containing the alkaline waste. The oil phase always contains a certain amount of the waste BACKGROUND ARTS alkaline aqueous phase, in such a manner that the scales of the waste alkaline are always formed in the rectification [0002] The conventional process for the preparation of columns subsequently, which blocks the rectification col- cyclohexanol and cyclohexanone comprises: non-cata- 15 umns and the reboilers thereof, and results in the con- lyticly oxidizing cyclohexane with molecular oxygen to tinuous production cycle of only six months. Thirdly, the obtain an oxidized mixture containing cyclohexyl hy- decomposition has a high alkali consumption and a large droperoxide (CHHP) as a main product; decomposing discharge capacity of alkali waste. A concentration of the CHHP to obtain cyclohexanol and cyclohexanone; OH-ion in the alkali waste must be controlled around I and rectifying to obtain products of the cyclohexanol and 20 mol/L. If the concentration of OH-ion is over Imol/L, dif- the cyclohexanone. Internationally, the art of decompos- ficulty of combustion of alkaline waste is increased; if ing the CHHP to obtain the cyclohexanol and the cy- below Imol/L, decomposition conversion rate is low, and clohexanone comprisestwo manners: the homogeneous part of the cyclohexyl hydrogen peroxide is decomposed catalytic decomposition by bis(tert-butyl) chromate, dis- continuously in an cyclohexane recycling column and a closed by French Rhodia Company; and, the non-homo- 25 cyclohexane and cyclohexanone product column in the geneous catalytic decomposition by cobalt acetate in the subsequent process, and caprolactone and organic ac- alkaline aqueous solution of sodium hydroxide, disclosed ids are mainly generated, which decreases the total yield by Dutch DSM. Both of the two manners are improved of the device and influences quality of cyclohexanone low-temperaturedecomposition techniquesbased on the products. Currently, the conventional industrial devices conventional homogeneous catalytic homogeneous cat- 30 adopting the process have the molar yield of only about alytic oxidation process and the conventional saponifica- 80%. tion decomposition process by sodium hydroxide aque- [0005] Conventionally, the worldwide companies re- ous solution developed in the 1950s to 1970s. spectively adopt one of the above two manners to ac- [0003] Though having a molar yield up to 94% in the complish decomposing the CHHP at one step. The Chi- decomposition process, the homogeneous catalytic de- 35 nese patents ZL9411039.9 and ZL98112730.4, filed by composition of CHHP by the bis(tert-butyl) chromate has the inventor of this application, disclose the two-step de- two serious defects. Firstly, during decomposing, the composition art. At the first step thereof, the alkalinity is scale formation, mainly the chromium adipate, blocks lowered; the recycling amount of the alkaline aqueous equipments and pipelines. Disclosed by Rhodia, the phase is increased; the static mixer is used. Industrial phosphoric acid octyl ester is used as the scale inhibitor, 40 application results indicate that, the total molar yield of which fails to completely solve the scale formation. The the device thereof really increases, but the separation of continuous production cycle only lasts for four months; the cyclohexane oil phase from the waste alkaline aque- washing and descaling after stalling the production de- ous phase becomes more difficult. The several sets of vice are executed three times per year. Secondly, the industrial production devices of the whole two-step de- conversion rate is low, wherein the molar conversion rate 45 composition art have a molar total yield of around 82%. is only around 92%; and around 5% of the CHHP still remains in the decomposed materials. The remaining SUMMARY OF THE PRESENT INVENTION CHHP is decomposed under the conditions of a high con- centration of cyclohexanol and cyclohexanone, high [0006] An object of the present invention is to provide acidity and a high temperature inside the cyclohexane 50 a processfor preparingcyclohexanol and cyclohexanone recycling columns and the cyclohexanol and cyclohex- by cyclohexane oxidation, which has a high total yield, a anone product columns, so as to mainly produce acid long continuous production cycle, a low consumption and compounds, like adipic acid, and ester compounds, cost. mainly caprolactone; to speed up the condensation re- [0007] In order to solve the technical problems men- action of free radicals of the cyclohexanol and the cy- 55 tioned above, the present invention provides a process clohexanone, and the esterification reaction of cyclohex- for preparing cyclohexanol and cyclohexanone by cy- anol; and to generate the high-boiling-point substances, clohexane oxidation, comprising steps of: and reduce the yield. Conventionally, the molar yield of 2 3 EP 2 821 384 A1 4 firstly processinguncatalyzed oxidation on cyclohex- decomposition by utilizing the bis(tert-butyl) chromate as ane by molecular oxygen, in such a manner that an the catalyst further comprises adding 1-hydroxy oxidized mixture with cyclohexyl hydrogen peroxide ethidene-1, 1-diphosphonic acid (di)octyl ester for serv- serving as a primary product is generated; ing as a scale inhibitor, wherein adding amount of the 1- 5 hydroxy ethidene-1, 1-diphosphonic acid (di)octyl ester then decomposing the cyclohexyl hydrogen perox- is equivalent to adding amount of Chromium which is an ide to produce cyclohexanol and cyclohexanone; active component of the catalyst. and [0012] Further, in the step (2) of decomposing the cy- clohexyl hydrogen peroxide under low alkalinity, a mo- then rectifying to obtain a cyclohexanol product and 10 larity of OH- in sodium hydroxide aqueous solution is at a cyclohexanone product; a range of 0.560.2mol/L, and a reactor residence time is at a range of 5∼7 minutes, and preferably 6 minutes. wherein the step of decomposing the cyclohexyl hy- [0013] Further, in the step (3) for decomposing the cy- drogen peroxide utilizes a three-step decomposition clohexyl hydrogen peroxide under high alkalinity, the mo- process combining a homogeneous catalytic de-15 larity of OH- in sodium hydroxide aqueous solution is at composition process of bis(tert-butyl) chromate with a range of 1.560.5mol/L, and a reactor residence time a heterogeneous catalytic decomposition process of is at a range of 7~9 minutes, and preferably 8 minutes. sodium hydroxide alkaline aqueous solution, com- [0014] In the step (1) for decomposing the cyclohexyl prising steps of: hydrogen peroxide, the bis(tert-butyl) chromate is adopt- 20 ed as the catalyst for performing the homogeneous cat- (1) performing the homogeneous catalytic de- alytic decomposition. Though a conversion rate of the composition by utilizing the bis(tert-butyl) chro- decomposition is only at a range of 80∼92%, a molar mate as a catalyst; yield of the cyclohexanol and the cyclohexanone gener- ated by the decomposition is capable of reaching 94%.