(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

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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%. (2) performing the heterogeneous catalytic de- 25 [0015] The process of the present invention adopts the composition in the sodium hydroxide alkaline 1-hydroxyethidene-1, 1-diphosphonic acid (di)octyl ester aqueous solution under low alkalinity, wherein to replace phosphoric ester for serving as a scale inhib- the low alkalinity means that a molar concentra- itor, which completely solves the problem of scale forma- tion of OH- is at a range of 0.2~0.8mol/L ; and tion in cyclohexyl hydrogen peroxide homogeneous cat- 30 alytic decomposition by bis(tert-butyl) chromate, in such (3) performing the heterogeneous catalytic de- a manner that a production cycle of the homogeneous composition in the sodium hydroxide alkaline catalytic decomposition reaches more than a year. aqueous solution under high alkalinity, wherein [0016] In the step (2) of performing the heterogeneous the high alkalinity means that a molar concen- catalytic decomposition in the sodium hydroxide alkaline tration of OH- is at a range of 0.9∼ 2.2mol/L. 35 aqueous solution under low alkalinity, most of the cy- clohexyl hydrogen peroxide which is not decomposed [0008] Further, in the step (1) of decomposing the cy- yet in the step (1) is processed with decomposition again clohexyl hydrogen peroxide, while performing the homo- to generate the cyclohexanol and the cyclohexanone, in geneous catalytic decomposition by utilizing the bis(tert- such a manner that a conversion rate of the decomposi- butyl) chromate as the catalyst, adding amount of the 40 tion of the cyclohexyl hydrogen peroxide reaches 95%. catalyst is equivalent to that a mass fraction of Chromium Particularly, a concentration of sodium hydroxide of alkali in cyclohexane oxidation liquid is at a range of 12 68ppm, waste separated in the step (2) of the decomposition is preferably 10ppm. low. A molarity of OH- in the alkali waste may be control- [0009] Further, while performing the homogeneous led to be at a range of 0.5 60.2mol/L. Therefore, a portion catalytic decomposition by utilizing the bis(tert-butyl)45 of alkali water is discharged as alkali waste, so as to chromate as the catalyst, a decomposition temperature decrease discharge amount of the alkali waste, reduce is at a range of 60oC~160 oC, a decomposition pressure a consumption of sodium hydroxide, and facilitate burn- is at a range of 0.05MPa~1.3MPa, and a reactor resi- ing the alkali waste to reduce environmental pollution. dence time is at a range of 20~40 minutes, wherein the [0017] According to rules of Brown Lancaster, the re- decomposition pressure is an absolute pressure. 50 action rate is directly proportional to the concentration of [0010] Preferably, while performing the homogeneous OH- , in the step (3) of performing the heterogeneous catalytic decomposition by utilizing bis(tert-butyl) chro- catalytic decomposition in the sodium hydroxide alkaline mate as the catalyst, the decomposition temperature is aqueous solution under the high alkalinity, the molarity at a range of 90610oC, the decomposition pressure is of OH- in the sodium hydroxide solution is controlled at at an atmospheric pressure, and the reactor residence 55 a range of 1.560.5mol/L, in such a manner that decom- time is at a range of 24~26 minutes, and preferably 25 position reaction is carried out fully and completely, de- minutes. composition conversion of the cyclohexyl hydrogen per- [0011] Further, performing the homogeneous catalytic oxide is completed, and the decomposition conversion

3 5 EP 2 821 384 A1 6 is approximately 100%. Thus, the cyclohexyl hydrogen [0019] These and other objectives, features, and ad- peroxide is prevented from decomposing into acids and vantages of the present invention will become apparent esters in subsequent rectifying columns, and the cy- from the following detailed description, the accompany- clohexyl hydrogen peroxide is prevented from catalyzing ing drawings, and the appended claims. a condensation reaction of free radicals of cyclohexanol 5 and cyclohexanone in the rectifying columns with a high BRIEF DESCRIPTION OF THE DRAWINGS content of the cyclohexanol and the cyclohexanone, which affects a quality of cyclohexanone products and [0020] The Figure is a flow chart of a process for de- decreases a total yield of the device. In the step (3), the composing the cyclohexyl hydrogen peroxide according high alkalinity water phase of alkali is easy to perform 10 to a preferred embodiment of the present invention. settling separation from oil phase of cyclohexane, in such [0021] In the Figure, 1-pipeline I; 2-heat exchanger; 3- a manner that an amount of alkalinity water phase mixed pipeline II; 4-pipeline III; 5-pipeline IV; 6-homogeneous in the oil phase of cyclohexane is decreased, which is in catalytic decomposition reactor; 7-pipeline V; 8-pipeline favor of prolonging a production cycle. Since the addition VI; 9-pipeline VII; 10-pipeline VIII; 11- low-alkalinity het- of the 1-hydroxy ethidene-1, 1-diphosphonic acid (di)oc- 15 erogeneous catalytic decomposition reactor for step (2); tyl ester completely solves the problems of blocking by 12-pipeline IX; 13-pipeline X; 14-pipeline XI; 15-high-al- scale formation, the liquid of cyclohexane oxidation may kalinity heterogeneous catalytic decomposition reactor be performed with the cyclohexyl hydrogen peroxide ho- for step (3); 16-pipeline XII; 17-pipeline XIII; 18- water mogeneous catalytic decomposition by the bis(tert-butyl) washing device; 19-pipeline XIV; 20-pipeline XV. chromate after concentration and water washing, or oth- 20 erwise be directly performed with the cyclohexyl hydro- DETAILED DESCRIPTION OF THE PREFERRED EM- gen peroxide homogeneous catalytic decomposition by BODIMENT the bis(tert-butyl) chromate without the concentration and the water washing. During a process of the cy- [0022] Further description of the present invention is clohexyl hydrogen peroxide homogeneous catalytic de- 25 illustrated combining with preferred embodiments of the composition by the bis(tert-butyl) chromate, a large present invention. amount of heat is released and water is produced. The [0023] The Figure is a flow chart of a process for de- heat may be removed by evaporating the cyclohexane composing the cyclohexyl hydrogen peroxide according and the water. The evaporated cyclohexane and the wa- to a preferred embodiment of the present invention. From ter are introduced into a rectifying and dehydrating col- 30 a cyclohexane oxidation reactor, a cyclohexane oxidized umn. A first part of the cyclohexane by distillation flows mixture passes through a pipeline I 1, a heat exchanger back, and a second part thereof returns back to a cy- 2 and a pipeline pipeline IV 5 and enters a homogeneous clohexane oxidation reactor. The water is settled and catalytic decomposition reactor 6; separated in a backflow slot, and then discharged into a wherein a weight flow rate of the cyclohexane oxidized wastewater recollection slot. Flow rate of the cyclohex- 35 mixture is 381.788 tons/hour; wherein the cyclohexane ane oxidation and decomposition liquid is decreased af- oxidized mixture passes through the heat exchanger 2 ter the homogeneous decomposition, which is beneficial comprises components with weight percentages of: to separation of the oil phase and the alkaline water 95.27% cyclohexane, 3.4% cyclohexyl hydrogen perox- phase in the subsequent heterogeneous catalytic de- ide, 0.37% cyclohexanol, 0.26% cyclohexanone, 0.28% composition in the sodium hydroxide alkaline aqueous 40 acids, 0.28% esters, and 0.12% other components with solution. In addition, during the process of the cyclohexyl a light weight; hydrogen peroxide homogeneous catalytic decomposi- wherein a temperature thereof drops from 166oC to tion by the bis(tert-butyl) chromate, an external circulat- 114oC; ing pump and a heater are provided to replace a stirrer wherein a weight ratio of bis(tert-butyl) chromate serving in the conventional decomposition reaction, so as to in- 45 as a catalyst which is fed into the homogeneous catalytic crease evaporation amount of the cyclohexane and the decomposition reactor 6 from a pipeline VI 8 is 100kg/h, water and stir by steam of the cyclohexane. Since the a weight percentage of Chromium of the bis(tert-butyl) water is removed to a greatest extent by azeotropy, the chromate is 3wt%, in such a manner that a mass fraction impact of activity decline of the homogeneous catalyst of Chromium of the bis(tert-butyl) chromate serving as caused by water is decreased, activity of the bis(tert-50 the catalyst in decomposition liquid is 10ppm by weight; butyl) chromate is significantly increased, the decompo- then a scale inhibitor of 1-hydroxy ethidene-1, 1-diphos- sition conversion rate is improved, a ratio of cyclohex- phonic acid (di)octyl ester are fed into a pipeline VII 9 anone to cyclohexanol is significantly increased and with a flow rate of 3kg/h at a temperature range of scale formation rate is slowed sharply. 9062oC, in such a manner that a step (1) of the homo- [0018] The process for preparing cyclohexanol and cy- 55 geneous catalytic decomposition for decomposing the clohexanone by cyclohexane oxidation according to the cyclohexyl hydrogen peroxide is performed under an at- present invention is capable of reaching a total molar mospheric pressure, and a reactor residence time is 25 yield of 85%. minutes. A conversion rate of decomposition of the cy-

4 7 EP 2 821 384 A1 8 clohexyl hydrogen peroxide is 90%, and a molar yield of cyclohexane, 0.23% cyclohexyl hydrogen peroxide, the cyclohexanol and the cyclohexanone generated by 1.85% cyclohexanol, 2.77% cyclohexanone, 0.01% ac- the decomposition is 94%. ids, 0.2% esters, and 0.2% other components with a light [0024] Decomposition heat and sensible heat of ma- weight. terials at an inlet causes a result that a large amount of 5 [0030] The oil phase of organic decomposition reac- cyclohexane is evaporated, which takes away water gen- tants of the low-alkalinity heterogeneous catalytic de- erated thereby, in such a manner that the cyclohexanol composition reaction of the step (2) enters a high-alka- and the cyclohexanone in decomposition materials are linity heterogeneous catalytic decomposition reactor 15 concentrated. for a step (3) via a pipeline XI14. A heterogeneous cat- [0025] In addition, a reboiler is provided in the homo- 10 alytic decomposition under a high alkalinity in the step geneous catalytic decomposition reactor 6, in such a (3) also adopts the piston flow reactor, i.e. the packed manner that cyclohexane is steamed out at a rate of 100 tower reactor. A residence time of materials is 8 minutes, tons/h in the homogeneous catalytic step. The steamed and a weight flow rate is 278.5t/h. cyclohexane returns back to the cyclohexane oxidation [0031] An alkaline solution with a mass concentration reactor 6 through a pipeline V 7, so as to obtain a homo- 15 of 32% NaOH and a weight flow rate of 4400Kg/h from geneous catalytic decomposition reaction liquid around a pipeline XII 16 and wash water with a weight flow rate 281 tons/h, wherein components and mass percentages of 10000Kg/h from a pipeline 20 are mixed to enter the thereof are as follows: 94.15% cyclohexane, 0.46% cy- high-alkalinity heterogeneous catalytic decomposition clohexyl hydrogen peroxide, 1.49% cyclohexanol, 2.66% reactor 15 for the step (3) for processing the high-alka- cyclohexanone, 0.46% acids, 0.59% esters, and 0.19% 20 linity heterogeneous catalytic decomposition therein. other components with a light weight. [0032] Since the scale inhibitor 1-hydroxy ethidene-1, [0026] Reaction mixtures after the homogeneous cat- 1-diphosphonic acid (di)octyl ester is capable of dissolv- alytic oxidation pass through a pipeline VIII 10 and enter ing a part of the catalyst of the bis(tert-butyl) chromate a low-alkalinity heterogeneous catalytic decomposition into the oil phase, addition of the catalyst of the bis(tert- reactor 11 for a step (2) of decomposing the cyclohexyl 25 butyl) chromate in the step (3) for decomposition is not hydrogen peroxide. Since the reaction mixtures after the required. homogeneous catalytic oxidation contain 10ppm of [0033] In decomposition liquid of the step (3), a decom- bis(tert-butyl) chromate serving as the catalyst already, position conversion of the cyclohexyl hydrogen peroxide addition of a transition metal ion catalyst is not required. is complete, and the esters are saponified completely. In [0027] Low-alkalinity alkaline aqueous solution in the 30 the step (3), the decomposition liquid is separated in a step (2) flows into a pipeline X 13, a molarity of NaOH in settling separator. A low layer is a alkaline water phase the alkaline aqueous solution is 1.5mol/L, and a flow rate containing 1.5mol/L of OH-, wherein a first part thereof thereof is 18 tons/h. After mixed with circulating alkali, is circulated at a weight flow rate of 18 tons /h, a second the molarityof NaOHdrops to 0.6mol/L.A heterogeneous part thereof passes through the pipeline X 13 and returns catalytic decomposition under a low alkalinity in the step 35 back to the low-alkalinity heterogeneous catalytic de- (2) adopts a piston flow reactor, i.e. a packed tower re- composition reactor 11 for the step (2). actor. A residence time is 6 minutes. A conversion rate [0034] An organic oil phase in an up layer of the high- of the cyclohexyl hydrogen peroxide accounts for 5% of alkalinity heterogeneous catalytic decomposition reactor the total decomposition reaction. Main objects of the de- 15 for the step (3) enters a water washing device 18 via composition in the step (2) are to neutralize acids gen- 40 a pipeline XIII 17. Fresh wash water passes through a erated in the cyclohexane oxidation process and the de- pipeline XIV 19 and enters the pipeline XIII 17 to be mixed composition process in the step (1), and to saponify ester with the organic oil phase on the up layer of the high- contained in the materials. alkalinity heterogeneous catalytic decomposition reactor [0028] After the low-alkalinity heterogeneous decom- 15 for the step (3), and then enters the water washing position in the step (2), the materials are settled and sep- 45 device 18 to wash off a small amount of alkaline liquid arated, a first part of low concentration alkaline water contained in the organic oil. A lower layer of water in a phase in a low layer is circulated at 110 tons/h, and a water washing separator of the water washing device 18 rest part thereof is discharged from a pipeline IX 12 as is discharged from a pipeline XV 20 at a weight flow rate alkali waste. A discharge rate of the alkali waste is 18 of 10 tons/h for diluting fresh alkaline liquid. tons/h. Liquid of the alkali waste comprises 19wt% by 50 [0035] An upper layer of organic oil in the water wash- weight ratio of organic acids sodium, 0.5wt% sodium hy- ing separator returns back to a heat exchanger 2 via the droxide, 2.5wt% sodium carbonate, and 78wt% water. pipeline II 3 to perform heat exchanging with the cy- [0029] In the step (2), an up layer of a separator after clohexane oxidation liquid. A flow rate of the organic oil the low-alkalinity heterogeneous catalytic decomposition phase is 278.4t/h, components and mass percentages reactor 11 obtains an oil phase of organic decomposition 55 thereof are as follows: 94.97% cyclohexane, <0.01% cy- reactants of the low-alkalinity heterogeneous catalytic clohexyl hydrogen peroxide, 1.97% cyclohexanol, 2.86% decomposition reaction of the step (2), and components cyclohexanone, 0% acids, <0.01 % esters, and 0.2% oth- and mass percentages thereof are as follows: 94.74% er components with a light weight.

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[0036] After the high-alkalinity heterogeneous decom- kaline aqueous solution, comprising steps of: position in the step (3) and the heat exchanging in the heat exchanger 2, the organic oil phase decomposition (1) performing the homogeneous catalytic liquid is sent to a set of cyclohexane columns via a pipe- decomposition by utilizing the bis(tert-butyl) line III 4 to steam out cyclohexane. Oxidized decompo- 5 chromate as a catalyst; sition products pass through a light column, a cyclohex- (2) performing the heterogeneous catalytic anone column and a cyclohexanol column and a dehy- decomposition in the sodium hydroxide al- drogenation system for processing. Finally, a cyclohex- kalineaqueous solution under low alkalinity, anone product with a weight flow rate of 13175Kg/h is wherein the low alkalinity means that a mo- obtained, which contains 99.95% of cyclohexanone by 10 lar concentration of OH- is at a range of weight. Furthermore, heavy-component X oil with a 0.2∼0.8mol/L ; and weight flow rate of 400Kg/h and light-component light oil (3) performing the heterogeneous catalytic with a weight flow rate of 160Kg/h are obtained. decomposition in the sodium hydroxide al- [0037] In the preferred embodiment of the present in- kaline aqueous solution under high alkalin- vention, a total yield from benzene hydrogenation for pro- 15 ity, wherein the high alkalinity means that a ducing cyclohexane to cyclohexane oxidation for produc- molar concentration of OH- is at a range of ing cyclohexanone is 85%, i.e., a total consumption of 0.9∼2.2mol/L. thedevice is (13.192tons /h ofcyclohexane) /(13175Kg/h of cyclohexanone) =1001.3Kg cyclohexane /ton cy- 2. The process for preparing cyclohexanol and cy- clohexanone =930Kg benzene / ton cyclohexanone.20 clohexanone by cyclohexane oxidation, as recited in Consumption of alkali 4400/13.175=334Kg (32wt%) claim 1, wherein in the step (1) of decomposing the NaOH/ton cyclohexanone. cyclohexyl hydrogen peroxide, while performing the [0038] One skilled in the art will understand that the homogeneous catalytic decomposition by utilizing embodiment of the present invention as shown in the the bis(tert-butyl) chromate as the catalyst, adding drawings and described above is exemplary only and not 25 amount of the catalyst is vequivalent to that a mass intended to be limiting. fraction of Chromium in cyclohexane oxidation liquid [0039] It will thus be seen that the objects of the present is at a range of 1268ppm. invention have been fully and effectively accomplished. Its embodiments have been shown and described for the 3. The process for preparing cyclohexanol and cy- purposes of illustrating the functional and structural prin- 30 clohexanone by cyclohexane oxidation, as recited in ciples of the present invention and is subject to change claim 2, wherein while performing the homogeneous without departure from such principles. Therefore, this catalytic decomposition by utilizing the bis(tert-butyl) invention includes all modifications encompassed within chromate as the catalyst, a decomposition temper- the spirit and scope of the following claims. ature is at a range of 60oC ∼160 oC, a decomposition 35 pressure is at a range of 0.05MPa∼1.3MPa, and a reactor residence time is at a range of 20~40 min- Claims utes, wherein the decomposition pressure is an ab- solute pressure. 1. A process for preparing cyclohexanol and cyclohex- anone by cyclohexane oxidation, comprising steps 40 4. The process for preparing cyclohexanol and cy- of: clohexanone by cyclohexane oxidation, as recited in claim 3, wherein while performing the homogeneous firstly processing uncatalyzed oxidation on cy- catalytic decomposition by utilizing the bis(tert-butyl) clohexane by molecular oxygen, in such a man- chromate as the catalyst, the decomposition temper- ner that an oxidized mixture with cyclohexyl hy- 45 ature is at a range of 90610oC, the decomposition drogen peroxide serving as a primary product is pressure is at an atmospheric pressure, and the re- generated; actor residence time is at a range of 24 ∼26 minutes. then decomposing the cyclohexyl hydrogen per- oxide to produce cyclohexanol and cyclohex- 5. The process for preparing cyclohexanol and cy- anone; and 50 clohexanone by cyclohexane oxidation, as recited in then rectifying to obtain a cyclohexanol product claim 4, wherein the reactor residence time is 25 and a cyclohexanone product; minutes. wherein the step of decomposing the cyclohexyl hydrogen peroxide utilizes a three-step decom- 6. The process for preparing cyclohexanol and cy- position process combining a homogeneous55 clohexanone by cyclohexane oxidation, as recited in catalytic decomposition process of bis(tert- anyone of the claims 1∼5, wherein the step of per- butyl) chromate with a heterogeneous catalytic forming the homogeneous catalytic decomposition decomposition process of sodium hydroxide al- by utilizing the bis(tert-butyl) chromate as the cata-

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lyst further comprises: adding 1-hydroxy ethidene- 1, 1-diphosphonic acid (di)octyl ester for serving as a scale inhibitor, wherein adding amount of the 1- hydroxy ethidene-1, 1-diphosphonic acid (di)octyl ester is equivalent to adding amount of Chromium 5 which is an active component of the catalyst.

7. The process for preparing cyclohexanol and cy- clohexanone by cyclohexane oxidation, as recited in anyone of the claims 1∼ 5, wherein in the step (2) for 10 decomposing the cyclohexyl hydrogen peroxide un- der low alkalinity, a molarity of OH- in sodium hy- droxide aqueous solution is at a range of 0.560.2mol/L, and a reactor residence time is at a range of 5∼7 minutes. 15

8. The process for preparing cyclohexanol and cy- clohexanone by cyclohexane oxidation, as recited in claim 7, wherein the reactor residence time is 6 min- utes. 20

9. The process for preparing cyclohexanol and cy- clohexanone by cyclohexane oxidation, as recited in anyone of the claims 1∼ 5, wherein in the step (3) for decomposing the cyclohexyl hydrogen peroxide un- 25 der high alkalinity, a molarity of OH- in sodium hy- droxide aqueous solution is at a range of 1.560.5mol/L, and a reactor residence time is at a range of 7~9 minutes. 30 10. The process for preparing cyclohexanol and cy- clohexanone by cyclohexane oxidation, as recited in claim 9, wherein the reactor residence time is 8 min- utes. 35

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