SU1524916A1 - Catalyst for dehydration and method of producing same - Google Patents

Abstract

This invention relates to catalytic chemistry, in particular to the preparation of a catalyst for the dehydrogenation of cyclohexanol. To increase the thermal stability of the catalyst, a composition containing, in wt.%, Is used: boron oxide 0.6-9.0, magnesium hydroxide in terms of oxide 31-34, copper hydroxide in terms of oxide the rest. The catalyst is obtained by precipitating copper and magnesium hydroxides from solutions of magnesium and copper nitrate salts with sodium hydroxide, followed by drying and shaping the mixture, impregnating with a solution of boric acid with a concentration of 5-100 g / l (2-100 h). The thermal stability of the catalyst (by mechanical strength after high-temperature treatment at 500 ° C) increases 2.5-6 times (from 0.4 to 1-3 kg / pellet) while maintaining activity and selectivity. 2 sec. f-ly, 1 tab.

Description

The invention relates to the manufacture of catalysts for the dehydrogenation of alcohols, in particular to the production of copper-magnesium catalysts for the dehydrogenation of cyclohexanol to cyclohexanone.

The aim of the invention is to increase the thermal stability of the catalyst due to the additional content of boron oxide in its composition at a certain ratio of components, while boron is introduced to catalyst B by impregnating it with boric acid of the required concentration.

Example 1. 1073 kg of demineralized water are fed to the reactor.

At the same time, 80 kg of magnesium nitrate Mg (LY3) -1-6HiO and 141 kg of a 50% solution of copper nitrate Cu (NOj), followed by stirring for 15 minutes. The precipitation of copper and magnesium hydroxides is carried out at a pH of 8–12 with a 12% solution of MaO, taken in an amount of 459 kg. Convicted copper and magnesium hydrates are washed in a centrifugal separator from an excess of alkali and sodium nitrate to a content of the latter of no more than 0.6 wt.% (In terms of the calcined substance). The catalyst mass is dried in air at 110–12 U C. The obtained pieces are ground in a hammer core.

fen yu

four:

WITH

O5

Bilke before granulation of 1 mm, followed by moistening the mass with demineralized water to 40% moisture, forming granules of 3 mm in size and drying them at 110-12U ° C.

1 g of boric acid is dissolved in 200 ml, the concentration of the solution is 5 g / l, 40 g of granules prepared as described above are added and kept under gentle stirring for 2 hours, then dried in air at 110-130 ° C.

A catalyst is obtained containing (in terms of oxides), wt.%: 0.6, CuO 6b, 7 and MgO 33.7.

The thermal stability of the catalyst is judged by the magnitude of the mechanical strength of the granules after high temperature treatment.

The splitting strength of the obtained catalyst granules directly after drying is 2 kg / granule, and the strength after heating to 51 ° C is 1 kg / granule.

The catalyst is tested in a cyclohexanol dehydrogenation reaction to cyclohexanone.

For this, a reactor loaded with 5 cm of catalyst is purged with nitrogen, then with a nitric mixture. Catalyst reduction is carried out with a nitric mixture with a 50% hydrogen content at 280 ° C. Then, in a stream of nitrogen, cyclohexanol is supplied with a volume rate of 1 h.

Data on the activity and selectivity of the catalyst, before restoring treated in air at 130 ° C and 500 ° C, are given in the table.

Catalysts with different component contents are prepared similarly.

A decrease in the boron content in the catalyst below 0.6 wt.% Leads to a decrease in the strength of the granules.

An amount of B ,, 0 C equal to 9% by weight is maximum. This content of boron in the catalyst receive

after processing the granules for a long time in concentrated solutions.

Further increase in the concentration of the acid, which is achievable only at high temperatures, leads to the dissolution of the granules.

As can be seen from the table, the mechanical strength of the catalyst according to the invention after high-temperature treatment of the latter is 2.5-6 times higher than the strength of a known catalyst calcined at 500 ° C, which indicates a high thermal stability of the proposed catalyst. At the same time, its activity and selectivity remain at the level of the prototype.

Claims (2)

1. A catalyst for the dehydrogenation of cyclohexanol, including magnesium hydroxide and copper hydroxide, characterized in that, with a chain of increasing the thermal stability of the catalyst, it additionally contains boron oxide at the following content, wt.%: Magnesium hydroxide in terms of oxide 31.0-34.0 Boron oxide 0.6-9.0 Copper hydroxide in terms of oxide Else 2. A method for producing a catalyst for dehydrating cyclohexanol by precipitating copper hydroxide and magnesium hydroxide from solutions of magnesium nitrate and copper nitrate with sodium hydroxide, followed by drying and molding into granules, which are due to the fact that, to obtain a catalyst with increased thermal stability, the granules are treated with a solution of boric acid with a concentration of 5-100 g / l for 2-100 hours and dried. I I I I I I I cyivOO- vtr OObO-- rJCT CO -J O OO -o T av - iOfn- “x) ocoinoNO -o O O O O CO CO ff Ch O ON O O ON 0 & CO O I h oh; and S to t4 about sh o, ( 01 about ps; SS5 oh huh  § I I 33 about I u . o “1 i o. I about f H I about i ez n . about i i 3 .G w I o 2 I 013 about i. "and i u and about f- h o I to: p I- and o and I J X "G Il so. a y o u oo hh -. exo ieX and n to I I - - n oo t nu oooorJчD -fмOчтг o - о -о - I OOOO - Ltd. - o - LLC - LLC o o o o I I CON -tncnOOfnu O u nvOu rOO- A L (3 O (1 (bt ft iK "l t" I " I vO4OvO r - rx Of l J rnfN (N -rsjr r 4OvOG OOf I. I -cJeMm sir4m Nrjmc Jf4 - rf4eNcMm "(H m "..." "" .. oooooooooooooooooo oh oh oh oh one I.-dOvOr-iltNc oe- o ooo O -l sp o ate I PMK "P h K1b" I "1BMf" .M I about the article OCH STch O GO O 00 O ON O O ON Ch CT O 00 I (NrJCNfSeNfNjtNj (Nf4 | «M (N n r« gh I t I G - YuOOOUOCHOO- XJiA - 4j nin TiOaOinON Lr tK "lt" 4M (b "lMK." "4" AMf4fSM t " | mm-4 mcn N j-r r-oooocor rnc4- ff e oo About rsi NO chO vO O D L vO vO vO vD chO chO ch o l o Oh ch o l h h) O one i | ОООЮОООЧ1Л - ЮЮ-СГО ЛООО О - чО- 1Л "., AKN (CHMK" To MAM "A" M I n -cn MmOrorgrNi -mnr 4T-m-m - - O - O I R r -r ccoooococ f - oooocooooo g g o OC n NCJCM (Nr4CNji-sj-tnn-. .nnc imcnroncnfnmcnroromcicocon en ro ch n i I g gog oooojsh oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo soo for o I "m" ъkMAAaPmk "" am "" "i. B “K I mmin -nmin4tst t OOOO4O4OfnrO O4D1LYu 4OvO3% o cs (Nr r - - -OOOOtNrxiinm th 1O w M «« PC «AYA | MM | "P t" M  - rvj Nrnm f-j O ONC4ONtNC4fMcs о о о о о I one I I one I I I I I about. with i t-t-c X sh " g§ I o m I i SS c tNOOOOMCMC-JtMOOOOOOOO 1L Li-1 L L1LOOOOOOOO A LOO L1LOOOOOOOO - - ; en I am 01 X x WITH H about h (Oh, l and oh oh in oooooooooooooooooo o nOnOfOO Of OroO OfnO O (1 - lO - 1L "- 1Pt- in- - CvlcnvJinvOr OOa O- (T about, with ON 00 st so -about -  - about oh oh I u o n U and oh a e 1 o. but one Ltd, with t about about SP 2 5 o. with 0 1-v I x. I about I n I s: r - I rt rvl I tl - id to fe § g 5 & Th 0) a u o § § l§ x U 3n 4) Ct P. About From to B d and n 01and about l about n o and oh oh VO about Ltd oh oh oh oh oh oh 1L oh oh sh about P X pta1c a 4 aoh O a.- ftf ah-j tN tJ (N (JCSS OrN) w 9 S o o o o :. e about o 00 t and ku „ W x U 0) about a 5 I 5S but § and s about. w c o s X about w «h to X oh oh About us