CS195960B1 - Process for preparing butanoles - Google Patents

Description

The present invention relates to a process for the preparation of butyl alcohols which are used as solvents, as plasticizer components and otherwise

One of the most important industrial processes for the production of aliphatic alcohols at this time is oxosynthesis. Aldehydes are obtained as the main product by the hydroformylation of alkenes, which are hydrogenated to the corresponding primary aliphatic alcohols.

Methods for producing aliphatic alcohols such as butyl alcohols are known by liquid-phase hydrogenation of the respective aldehydes, e.g. butyraldehydes, at high pressure (up to 50 MPa) and at elevated temperature in the presence of various heterogeneous catalysts. usually rovád ^{P even when} the chtad ^and happenings IHO ^ pray ^ composition of the agent in ^the MO ^{of manufacture} Atal ^y reads zone (zone ^for REA ^ce).

The aforesaid disadvantages ^ nal methods ^Gd hair dryers ^ka price 'device ^(IR invest the n-Lact) and increased operating costs, especially energy costs.

They tqké known methods for preparing aliphatic alcohols, for example butanol, the hydrogenation of the corresponding aldehydes in the vapor phase at a pressure close to atmospheric pressure ^0, L - 1 № ^a) and p ^{s t} ep ^{* l} a ^t e l ^{00-2 00} ° ≤ VP ^ tomnostt early ^^ yzétóorů · ^O devaaen ⁱ

195 960. 2. . . . ... -. .

The heat of the exothermic aldehyde hydrogenation reaction can be carried out by supplying the coolant directly to the kieselguhr. For low heat capacity. Parn ^í or ^- p ^l ynn ^{ého c c} í resource hungry but is this - way ODVA en ^{d i - t} ej? ^l a. has ^ effect, ^{which is about} white. ⁿ uneven temperature distribution in the catalytic field of view and, consequently, reduced process selectivity ·

There is a known process for producing aliphatic alcohols by hydrogenating aldehydes in a vapor phase in a reactor, which encloses the successive catalyst and heat recovery zones of the reacases which contain no catalyst and serve to control the temperature in the reactor.

When the mode discussed method ^{characterized} not require usin ^ Aný Principle ^d váιděn heat ^{and com} p ^on van ^{if Y is} CH. and costly control devices ·

In all of the above processes, various hydrogenation catalysts are used, ^such as Q ^{and, for} example, platinum, mercaptan, zinc chromium. Hunting ^also an ^s k ^{t t} ory ANALYSIS ·

One of the best catalysts for this purpose .is' catalyst is a nickel-chromium · Application DOS designated tetdyzátoru amortized ^Ah Nou ^{t. Virtually} p ^{l of} strap No P ^{y -} e ^ld and ^Hydes with .vysokým yield ^{(and also} 99%) of final alcohol PTO ^ m-Tone temperature (120 ° C ^{1J0) -} straight and ^even with ^the button btozk microns toaku atmospheric C °, ⁰ 3 ^- - ^Mp and ^0.2) · High ivity and ^ k ^{t y} Zátor al. ^AK hinders the reliable temperature control zone katalyzní ·

Methods of thermally modifying a nickel-chromium catalyst are known which reduce activity and facilitate regulation. ^t ep ^l for ^those in ^the atalyzni. Zone ^E · UME ^la redutoe briefcases - ^k and ^{t LY AT} oru mouth ^{is running} nu ^t Nose ^{T, it} may ^hl AVN ^s feature ^s process ^during Snej ^{i (Vol YS} alkylated ^{s t} e]? ^l by ^the a ^{button to).} which complicates technology ·

The object of the invention is to eliminate the above mentioned disadvantages.

The invention has the object of a process for producing butanol hydrogenation of butyraldehyde in the steam ^ z ^ p ^ ^s tep I from 90 to ¹⁸⁰ ° ⁰ and the largest toaku ^{e 0, p,} and M 5, the executioner ^ Qi Zátor ^to l.chrcm ^with ODV ^By heat transfer from the reaction by means of a cooling agent, conditions for hydrogenation as well as conditions for dissipating the heat of reaction to be able to carry out the hydrogenation with a high degree of conversion at elevated conditions are to be developed. selectivity and stability of the catalyst, the use of simple ^T ec ^h ndogic ^alkyl CPA CH ^cl en ^s which ^would zajWfova ^ - te control spoledivou Lot ^{p y.} in the catalytic zone ·

This object is achieved by proposing a process for the preparation of butylaldehydes by hydrogenating butyraldehydes. in ^{steam f} AZI, PTO ^t ep ^lo the ⁰ and 9 ^{of the 180} ° C and at Dajk more than ^0, 5 ^- the executioner ^{MPa ly} Zátor nickel-chromium in the reactor in which-they are. retained katalyzní zone and a zone for discharging the reaction heat via a cooling formulations to be, and according to - the invention, the aldehyde - ^to load ^Ly spots ^d ata from ^about the N ^of U is ^ UD ^1, 5-5 »^ ⁰ m / m ² · h · ^h odně above at ^- 2.5 to 4 ^ ⁰ ^ rn / r ² · h · ^s and aldehyde are formaldehyde zatleni zj ^ íuje ratio between the volume of aldehyde vniášeným Nepočteno ^ ^- kappa ^L n da ^{y ý} aldehyde ^to cross ^t al ^y Zn ^are zones ^ ^{kt ER nen, the} payments ^ feta ^ zátoreml water & oic za195 980 thirst with - in katalýzní zone is maintained at a level which 600 to 1800-fold, preferably 1000 to 1200 N ^s Multiples exceeds LOAD ^{and women, and of} aldehydes, ^{and the} holding is vodtoové for women ^{and children} zj ^ISI U is ^p ccording volume of hydrogen under normal conditions; hydrogenation. carried out in a reactor in which the zone of discharge of the reaction Tepka from katalyzní zones separated by a metal wall, wherein the ratio between the size of the cooling surface of the metal wall of the volume katalyzní zone kept at 60 to the ^Star wall ^to c ^hl adicímu prostáedku is ^{0, 43-3, 4} m ^ 2 · AC / kW ^h odně above is ^1.05 - ² m ^ 5 ° C / / kW.

Způsotom according VYN ^AL EZÚ allows ^hy dro ENAC ^g per m ^{and s} rných Cond ^ ek ^(at a pressure close to atmospheric pressure and at a lower temperature) with a high degree of conversion (over 99.0 and a high selectivity ^(eg EC 99ιθ BC ^ EMZ with said ^{E h} tillering ^those preserved ^and VaJ ^even during a longer period kontinuelního of the catalyst (over 6000 hours). the removal of the heat of reaction in the process according to the invention is carried out using accessible technological measures. zaj ^ist U is maintained ^and it op ^{t 'and m, and} the LNI ^h for guidance. ^- te ^pl of ^those in kata ^ly destruction zone ^(reaction zone) · ¹

In the process according to the invention, an aldehyde derived from normal butyric acid and / or an aldehyde from isobutyric acid can be used as the starting material for the hydrogenation. If butyraldehydes are obtained by hydroformylating propylene, an excellent mixture of aldehydes can be directly used as the starting material.

When using a mixture of butyraldehydes as a starting material obtained by hydroformylating propylene, the product may contain the solvent used in the hydroformylation phase and as such may be butanol. Alternatively, the butyraldehyde mixture may be separated first and then hydrogenated with normal aldehyde and isobutyraldehyde. ,

Both pure hydrogen and hydrogen containing up to 30 percent by volume of inert gases can be used in the process of the invention. The carbon monoxide content of 0,05% vol is also acceptable.

As the hydrogenation catalyst, other nickel-chromium catalysts having a nickel content of 30 to 70 wt. %. The catalysts may contain modifying agents, for example other VP metals. groups of the periodic system.

Ůčeltó as c ^hl and ^di C. . Formulation ask ^ ⁱⁿ the method according to ^y n and ^l cut only the ^I in ^and the water, but may also be used organic liquids, and mixtures thereof with water in the meantime.

^Úč e ^l n ^E m ^A method according VYN ^s prov climb ^Aad §tv toubkov ^ reactors of the type which ^e correspond dříve'popsaným values (aldehyde and hydrogen load, the ratio between the size of the cooling surface and the volume katalyzní zone heat transfer resistance - from the cooled surface to ch ^ dtohau pro8 ^T Red ^to u ^{^).} To a reactor was charged trutok ^ ^ catalization-tor ^and into the interspace ^of the

19S 980 'supplies coolant * Tubes can be of any shape · When using finned tubes, the fin surface is included in the calculated heat transfer area * ie · the cooled surface ·

The necessary heat transfer resistance from the cooled surface to the coolant can be achieved by conventional * known technological measures, for example evaporative cooling * convective cooling * or a combination thereof ·

Feeding of the reactants to the reactor tubes and the coolant into the intermediate space can be carried out in a direct current or 1 countercurrent.

The proposed process can also be carried out in column type reactors having a jacket to dissipate heat. Suitably, the aldehyde is to be vaporised in the presence of hydrogen and the vapor-gas mixture to be fed to the reactor from top to bottom.

In order to better understand the nature of the invention, the following examples are provided

Example 1

4 liters of nickel-chromium catalyst (nickel content 49% by weight) are charged to the reactor *, which is a metal tube having an internal diameter of 33 mm and a wall thickness of 2 * 5 mm * provided with a cooling jacket *. The size of the cooling surface of the tube wall and the volume of the catalyst zone was 140 m ² / m 3. Then 3 * 4 l / h of isobutyric acid aldehyde (calculated as liquid aldehyde) were fed to the reactor. is supplied in an amount of 3 * 8 m m / h. The resulting steam-gas mixture is fed to the top of the reactor at a pressure of 0.5 MPa ·

The amount of reagents fed to the reactor is selected such that the aldehyde load in the catalyst zone is 4 m ^ / m ² h (the aldehyde load is determined as the ratio between the feed volume of the aldehyde calculated to the liquid aldehyde and in the catalytic zone exceeds 1100 times the aldehyde load (the hydrogen load is determined by the volume of hydrogen under normal conditions) ·

The water used as the coolant flows countercurrently through the reactor tube. The water temperature at the cooling jacket inlet is 100 ° C. The heat transfer resistance from the cooled surface. The pipe wall to the coolant is 2 * 58 ° C / kW.

The temperature distribution on the reactor axis (according to the reagent flow) within the catalyst zone is shown in Table 1.

Table 1

Reactor tube length, m

Temperature ^and ° C

19S 960

140

14?

115

106

101

Under these conditions, the isotothyrhyde conversion path is 99.9% with an isobutonol yield of 99.6%.

During the 6000 hours of continuous operation adjust the temperature distribution of the axis of the reactor (flow-based reagents within catalysis ^ zon ^y as follows (see sheet 2)

Table 2

Length of reactor tube,. m

Lota ^ep T ° C

0135

2140

4142

136

The conversion rate is 99.59% with an isobutanol yield of 99.10% · The vapor-gas mixture of the reaction products enters the reactor into a condenser where isobutanol condenses and is separated from the gas phase ·

Example 2

The process takes place analogous to Example 1. · The only difference is that in the presence of hydrogen k ^F every hour ^to evaporate 2.5 1 ApaI it ^é n -but ^y Raldi ^hy du. S ^p Otręba hydrogen is 3.0 m ^ / hr. The vapor-gas mixture of n-butyraldehyde with hydrogen is fed to the resictor at a pressure of 50 bar. It is aiidehydoto zatleni katalyzni in zone 3 m ^ ^/ m ² ha ^e vodí.kové loaded in the cat ^and l ^yzn to the zone exceeds the aforementioned amount to 12OOnásobek · the reactor tube was cooled as in Example 1 ^to ice but pH toptotě chl. adtoí. Water of 95 ° ^{Y 0} · d ^p or ^O ptostupu heat by cooling it ^{é p} ovrchu tube wall ^yk is a cooling jacket ^2, 58 ^m2 ° C / kW.

Distribution. te ^p lot on the reactor axis ^{(referred to} in this REA Enciu ^g.) inside ksÍtetlyzní zone is shown in Table 3 ·

19S 9β0

Table 3

Reactor tube length, m Temperature ° C 0 110 1 142 2 116 3 109 5 96

The conversion rate of n-butyraldehyde is 99> 98% and the yield of n-butanol 98.60% ·

Example 3

The process is carried out as described in Example 1, except that the aldehyde loading in the catalyst zone is 1.5 m @ 2 / m @ ² h, starting from a mixture of normal and isobutyric acid aldehydes obtained by propylene hydroformylation. · The hydrogen load exceeds the aldehyde load 800 times · The vapor-gas mixture of butyraldehydes and hydrogen is fed under a pressure of 0.02 MPa to the top of the reactor tube, which is filled with a nickel-chromium catalyst (nickel content> 1 wt.%). maintains temperature of 180 ° C · Heat removal from exothermic hydrogenation reaction is carried out by boiling water under pressure · The ratio between the cooling surface size of the reactor tube wall and the volume of the catalyst zone is 60 m ² / m \ to the coolant is 0.43 m ² ° 0 / kW ·

The degree of conversion of butyraldehydes is 99 »9%» n-butanol yield 9% 2% and isobutanol yield 99> 4% ·

Example 4

A nickel-chromium catalyst (nickel content of 52% by weight) is introduced into the reactor in the form of a metal tube provided with a cooling jacket. The amount of catalyst is selected such that the ratio between the cooling surface area of the reactor tube wall and the volume of the catalyst zone is 400 m ² / m 2. · '

The isobutyraldehyde is evaporated in the presence of hydrogen and added to the reactor in such a way that the aldehyde load is in the catalyst zone 5 > 0 m < 2 > / m ^{< 2 &gt};

The reactor tube is countercurrently flowed by the boiling water used as the coolant medium. The heat transfer resistance from the cooled surface of the pipe wall to the coolant is 2.23 m ² ° C / kW ·

195 960

The hydrogenation is carried out at a temperature of 110-140 ° C and a pressure of 0.05 MPa. The degree of conversion of isobutyraldehyde is 98.5% and the isobutanol yield is 99> 1.

BEFORE THE INVENTION

Claims (2)

BEFORE THE INVENTION Process for the preparation of butyl alcohols by hydrogenating butyraldehydes in the vapor phase at a temperature 90 to 180 ° C and a pressure of not more than 0.5 MPa on a nickel-chromium catalyst in a reactor having a catalyst zone and a reaction heat dissipation zone by a coolant, characterized in that the aldehyde load in the catalyst zone is maintained at 1.5 to 5 »m ^ / m ² .h, wherein the aldehyde is a load ratio between the volume of aldehyde fed to calculated liquid and aldehyde cross katalyzní zone which is not filled with the catalyst, hydrogen katalyzni load zone is maintained at a level which exceeds the load 800 to 1800násobně aldehyde, wherein the hydrogen loading is determined by the hydrogen volume under normal conditions, the hydrogenation being carried out in a reactor in which the heat dissipation zone is separated from the catalyst zone by a metal wall, the ratio of the cooling surface metal surface area to the catalyst zone volume being 60 to 400 m ² / m 2 and resistance heat transfer from the cooled surface of the metal wall to the cooling is maintained at 0.43 to 3.42 m ² ° C / kW · 2 · A process according to claim 1, characterized in that the aldehyde in the load zone is maintained katalyzní 2> 5 and 4.0 m ^ / m ² · h and a hydrogen load exceeds the load 1000 to the aldehyde 1200násobně _t ratio between the size of the cooling surface of the metal wall and the volume the catalyst zone is maintained at 80 to 200 m ² / m 2 and the heat transfer resistance from the cooled metal wall surface to the coolant is maintained from 1.03 to 2.58 m ² ° C / kW ·