CN1087972C

CN1087972C - Cyclohexanol dehydrogenation catalyst

Info

Publication number: CN1087972C
Application number: CN99107095A
Authority: CN
Inventors: 张明慧; 李伟; 陶克毅
Original assignee: Nankai University
Current assignee: Nankai University
Priority date: 1999-05-27
Filing date: 1999-05-27
Publication date: 2002-07-24
Anticipated expiration: 2019-05-27
Also published as: CN1235870A

Abstract

The present invention belongs to a catalyst composed of basic oxide carriers for loading with metal active components and metal auxiliary agents, and a preparation method thereof. The catalyst adopts MgO as carriers for loading with an effective quantity of Cu, and is added with an effective quantity of Pd, La or transition group metal, wherein the loading quantity of Cu is from 10 to 40% of MgO carriers; the loading quantity of Pd is from 0.1 to 0.5% of MgO carriers; the loading quantity of La is from 0.1 to 2% of MgO carriers; the loading quantity of transition group metal is from 1 to 5% of MgO carriers. The present invention has high stability, the selectivity of cyclohexanone is larger than 99.7%, and the conversion rate reaches more than 83%. Therefore, the catalyst has high production intensity, and can well adapt to the requirements of industrial production.

Description

A kind of cyclohexanol dehydrogenation catalyst

The invention belongs to the Catalysts and its preparation method that basic anhydride carrier to load metal active component and metal promoter are formed.

Since nineteen thirty-nine, nylon came out, produced two the important raw and processed materials caprolactams of Fypro and the production of adipic acid and just more and more paid attention to by people.And as main intermediate---the preparation of cyclohexanone is each production R﹠D institution broad research more.The benzene of nineteen fifty du pont company employing wide material sources carries out hydrogenation as raw material and makes the high-purity cyclohexane, the technology that oxidation obtains cyclohexanol, cyclohexanone in the presence of the solubility cobalt salt is applied again, and cyclohexane oxidation explained hereafter caprolactam intermediate---cyclohexanone becomes one of main production methods thereby make.Because generate a large amount of cyclohexanol behind the cyclohexane oxidation, so preparing cyclohexanone by cyclohexanol dehydrogenation also is an important step in the caprolactam industrial production, it is directly connected to the quality and the production cost of product.

Cyclohexanol is produced cyclohexanone and is mainly contained two kinds of methods, and the one, oxidizing process is about to cyclohexanol chromic acid oxidation, is catalyst with metallic nickel or copper, obtains cyclohexanone 250～300 ℃ of following blowing air oxidations; The 2nd, dehydriding is about to cyclohexanol dehydrogenation in the presence of catalyst and generates cyclohexanone.Both compare, and the side reaction of dehydriding technical process is few, processing ease, yield height, and safety relatively.Therefore, generally adopt dehydriding by the cyclohexanol preparing cyclohexanone in the industrial production.

RUSSP (SU 697,179 SU 1,524,916) has reported that MgO is a carrier, loaded Cu, or be used for cyclohexanol dehydrogenation with the boron modification and produce the employed catalyst of cyclohexanone, but its stability is not high.

At present producing the employed catalyst of cyclohexanone in industrial cyclohexanol dehydrogenation mainly is that (the code name ICY) of the import U.S. is carrier with ZnO, with Al ₂O ₃Be adhesive, loaded copper oxide.The main feature of this catalyst is that reaction temperature is lower, is initial temperature at 250 ℃ generally, and conversion ratio is near equilibrium valve, and selectivity reaches 99%.Its major defect is to use high-speed, and mechanical strength poor (about 40N/cm).The domestic development work that also has this catalyst of imitation to carry out, no matter it all has some gaps at active and aspects such as mechanical strength and stability.In addition, Cu/ZnO/Al ₂O ₃Catalyst is to adopt the coprecipitation preparation.This method affect factor is many, is not easy to repeat to make in a large amount of production.Current subject matter is the high performance catalyst of developing low reaction temperatures, high activity, high selectivity, high stability, high mechanical properties, being convenient to the commercial scale manufacturing.

The object of the invention provides a kind of cyclohexanol dehydrogenation catalyst that is used for, its feature is to be easy to accomplish repeatability on the preparation method, be convenient to the commercial scale preparation, catalyst has the selectivity of very high low temperature active and nearly 100%, industry formulation catalyst side pressure degree reaches 70N/cm, and has fabulous stability.

The present invention is that to adopt MgO be carrier, with infusion process, and the Cu of load effective dose (accounting for the 10-40% of vehicle weight), and add effective dose Pd, La or magnesium-yttrium-transition metal is a structural promotor.

The present invention is with MgO carrier roasting preliminary treatment 4 hours, impregnated in the Cu (NO that contains Pd, La or magnesium-yttrium-transition metal then ₃) ₂In the solution, stirred 24 hours, filter, the washing back was in 110-120 ℃ of oven dry 4 hours, and 400 ℃ of roastings are after 4 hours again, and compression molding gets final product.

The purpose that the present invention adds co-catalyst is to improve the stability of catalyst.As not adding above-mentioned cocatalyst component, then the catalyst ratio is easier to inactivation.

Catalyst of the present invention has good stability.With the catalyst that contains 2% (wt) Pd is example, with liquid air speed 1.5h ^-1, 250 ℃ of reaction temperatures are initial, and more than 60%, the cyclohexanone selectivity is all greater than 99.7% at 1500h inner retaining ring hexanol conversion ratio.Be total to 18 ℃ of temperature raisings during temperature 600h, after this, keep 268 ℃ to no longer temperature raising of 1500h always, activity remains constant.

Catalyst of the present invention can adapt to very high air speed.With above-mentioned catalyst is example, and in the time of 300 ℃, the liquid air speed is at 2.0h ^-1The time, the cyclohexanol conversion ratio is 83.8%.Even air speed reaches 8h ^-1, conversion ratio still can reach more than 83%.Therefore, this catalyst has very high production intensity, can very well adapt to industrial needs.

The present invention is described in detail as follows with reference to embodiment:

Embodiment 1

Measure 0.5M Cu (NO ₃) ₂Solution 67.5ml and 0.02M H ₂PdCl ₄Solution 3.35ml-16.75ml solution is 0.1%, 0.2%, 0.3%, 0.4%, 0.5% ratio in Pd weight percentage in the catalyst, mixes; Take by weighing 5g at 4 hours MgO of 400 ℃ of roasting preliminary treatment, under agitation slowly add in the above-mentioned mixed solution, stirred 24 hours; Filter, the washing back is in 110-120 ℃ of oven dry 4 hours, in 400 ℃ of roastings after 4 hours, and compression molding.

Take by weighing above-mentioned catalyst 2.1ml in continuous flow reactor of fixed bed, in 220-300 ℃ of reduction 3 hours, reaction temperature was 250 ℃ under hydrogen stream, and the liquid volume air speed is 1.5h ^-1, product adopts gas chromatographic analysis, the yield of ring hexanone and selectivity after condenser is collected.The results are shown in Table 1.

Embodiment 2

With the H among the embodiment 1 ₂PdCl ₄Solution changes Pd (NH into ₃) ₂Cl ₂Solution, other is all with embodiment 1.The yield and the selectivity of cyclohexanone see Table 1.

Embodiment 3

With H in 1 among the embodiment ₂PdCl ₄Solution changes 0.5M Fe into ₂(NO ₃) ₃Solution is by containing Fe in the catalyst ₂O ₃Weight percentage be 1%, 2% and 5% ratio, with Cu (NO ₃) ₂Solution mixes, and all the other are all with embodiment 1, and the yield and the selectivity of cyclohexanone see Table 2.

Embodiment 4

With Fe among the embodiment 3 ₂(NO ₃) ₃Solution changes Co (NO into ₃) ₂Solution, all the other are all with embodiment 3, and the yield and the selectivity of cyclohexanone see Table 2.

Embodiment 5

With Fe among the embodiment 3 ₂(NO ₃) ₃Solution changes Ni (NO into ₃) ₂Solution, all the other are all with embodiment 3, and the yield and the selectivity of cyclohexanone see Table 2.

Embodiment 6

With Fe among the embodiment 3 ₂(NO ₃) ₃Solution changes La (NO into ₃) ₃Solution is by containing La in the catalyst ₂O ₃Weight percentage be 0.5%, 1% and 2% ratio and Cu (NO ₃) ₂Solution mixes.The yield and the selectivity of cyclohexanone see Table 2.

Embodiment 7

Changing the MgO carrier among the embodiment 4 into MgO/ diatomite weight ratio is 4/1 mixed carrier, and all the other are operated with embodiment 4.The yield and the selectivity of cyclohexanone see Table 2.

The comparative example:

Only use the MgO Supported CuO, do not add any co-catalyst.With best copper nitrate concentration 30% (wt) dipping MgO through experiment screening, all the other preparation conditions are with embodiment 1, experiment condition is with embodiment 1, experimental result is: cyclohexanol conversion ratio 57.5%, show through accelerating senile experiment, the catalyst of more above-mentioned each adding assistant of its deactivation rate want fast again more than.

The cyclohexanone yield and the cyclohexanol selectivity of the different Pd content of table 1. catalyst

Pd content (%)		0.1	0.2	0.3	0.4	0.5
Pd content (%)		0.1	0.2	0.3	0.4	0.5	Embodiment 1	Cyclohexanone yield (%)	63.9	64.6	64.4	64.1	62.8
Cyclohexanol selectivity (%)	100	99.6	99.6	100	100			Cyclohexanone yield (%)	63.9	64.6	64.4	64.1	62.8
Cyclohexanol selectivity (%)	100	99.6	99.6	100	100	Embodiment 2		Cyclohexanone yield (%)	61.9	61.7	63.6	67.0	65.6
Cyclohexanol selectivity (%)	100	99.7	100	100	100			Cyclohexanone yield (%)	61.9	61.7	63.6	67.0	65.6

The cyclohexanone yield of the different levels of transition metals catalyst of table 2. and cyclohexanol selectivity

	Transition metal oxide content (%)	Cyclohexanone yield (%)	Cyclohexanol selectivity (%)
	Transition metal oxide content (%)	Cyclohexanone yield (%)	Cyclohexanol selectivity (%)	Embodiment 3	1	65.0	100
2	64.2	100			1	65.0	100
2	64.2	100	5		68.1	100
Embodiment 4	1	64.6	5		68.1	100	99.8
	1	64.6	2	65.0	100		99.8
	5	65.9	2	65.0	100	100
	5	65.9	Embodiment 5	1	64.4	100	99.5
2	65.3	100		1	64.4		99.5
2	65.3	100		5	65.9	100
Embodiment 6	0.5	65.3		5	65.9	100	100
	0.5	65.3	1	65.6	100		100
	2	64.9	1	65.6	100	100
	2	64.9	Embodiment 7	5	65.6	100	99.5

Claims

1. a cyclohexanol dehydrogenation catalyst is characterized in that it is that employing MgO is a carrier, loaded Cu, and the catalyst of adding Pd, La or magnesium-yttrium-transition metal formation; The load capacity of described Cu is MgO carrier 10-40%; Described Pd load capacity is the 0.1-0.5% of MgO carrier; The La load capacity is the 0.1-2% of MgO carrier; The magnesium-yttrium-transition metal load capacity is the 1-5% of MgO carrier.

2. the preparation method of the described cyclohexanol dehydrogenation catalyst of claim 1 is characterized in that it is through following step:

With MgO carrier roasting preliminary treatment 4 hours, impregnated in the Cu (NO that contains Pd, La or magnesium-yttrium-transition metal then ₃) ₂In the solution, stirred 24 hours, filter, the washing back was in 110-120 ℃ of oven dry 4 hours, and after 4 hours, compression molding gets final product in 400 ℃ of roastings.