CS200529B2 - Method of preparing maleinanhydride by the oxidation of n-butane,n-butenes,1,3-butadiene or mixtures thereof with molecular oxygen - Google Patents

Description

The invention relates to a process for the preparation of malannic anhydride by gas-phase oxidation of n-butane, n-butenes, 1,3-butadiene or mixtures thereof with molecular oxygen.

Belgian patent 828074 discloses the use of catalysts containing phosphorus, molybdenum, bismuth, copper, at least one of iron, nickel, cobalt and potassium and optionally lithium, sodium, rubidium, cesium, beryllium, magnesium, calcium, strontium or barium in the preparation of maleic anhydride from 1-butene, 2-butene, butadiene, pentane, pentadiene, cyclopentadiene and benzene. Comparative Example 4 on pages 20 and 21 of the aforementioned patent demonstrates that the use of a catalyst formed by a combination corresponding to the general formula

Pi, OMo122B10, 36CU0.54039.6 on oxidation of 1-butene gives a 27.9% yield of maleic anhydride calculated on the amount of starting 1-butene.

French Patent No. 1 601 955 describes the use of a catalyst consisting of a combination of elements corresponding to the general formula

OO3 —- B2O5 — Μ2θ5 — Ν _χ Ο —R20, where>

And the atom of chromium, molybdenum, tungsten through the uranium,

B a vanadium or niobium atom,

M atom of phosphorus, arsenic, antimony or vismuth,

N an atom of copper, silver, iron, cobalt or nickel,

R is lithium, sodium, potassium, cesium or rubidium.

Preferred compositions are 15 to 55% of atomic component A, 30 to 70% of atomic component B, 0 to 15% of atomic component M, 0.1 to 20 ° atomic. N and Q components up to 15% of atomic R components

The invention is the result of research into a more efficient catalyst for the oxidation of n-butane, n-butenes and 1,3-butadiene,

The catalyst used in the process of the invention is unexpectedly more advantageous in the preparation of maleic anhydride from n-butane, n-butenes and 1,3-butadiene. When using the catalyst according to the invention, particularly good yields are obtained from 1,3-butadiene or n-butenes.

It has been found that a process for the preparation of maleic anhydride by oxidation of n-butane, n-butenes, 1,3-butadiene or a mixture thereof with molecular oxygen in the gas phase at a reaction temperature of 250 to 600 C in the presence of a catalyst containing phosphorus, molybdenum, oxygen, arsenic , d ^ ertní mošiič [s proiSOtor, qrpojjřj- ?, j ^^ S ^ itomríéiští ITO jseVžle ^ ^ i ^ e ^ e ^ that \ popžije catalysts tvořéňélíó -Wfiwinkcí elements ¹ corresponding to the general vzorci.-I, ·,.

i Δ; 9 ·

X _a Moi2P _b As _c O _x ί: ......................... (I), denoting 'i / ¹ ' / ί

X at least one drink selected from the group consisting of tin, rare earth metal, zirconium, rhodium, manganese, rhenium, ruthenium, copper, -o, lead, zinc, titanium, chromium, niobium, aluminum, gallium and alkaline earth metal and a positive number greater than zero but less than 20, b and c, and the number of oxygen atoms needed to saturate the valences of the other elements contained.

The use of the catalyst of formula (I) in the above-described maleic anhydride process results in high yields and high selectivity in a convenient and economical manner at a relatively low temperature. The exothermic nature of the reaction is low, allowing easy control of the reaction.

The most important agent in the process of the invention is the catalyst used. Any catalyst can be used as a catalyst and can be used as a catalyst of formula (I). Particularly preferred are catalysts of formula (I) wherein a is a positive number greater than _? zero, but less than 12, catalysts wherein b is from 0.01 to 5 and catalysts of formula I, where c is from 0.01 to 5. Very good results are obtained with catalysts of formula I, where b is a number 0.5 to 1.5 and 0.1 to 1.0; Preferred catalysts are those in which each element, referred to as X, is introduced separately on the catalyst. Particularly preferred are catalysts in which X is copper in combination with at least one element referred to as X.

The catalyst according to the invention can be prepared in various ways. These methods are known to those skilled in the art. Preparations such as coprecipitation, evaporation of drying or mixing of oxides followed by calcination of the resulting catalyst are successfully used.

Preferably, the catalysts of formula (I) are prepared in an aqueous suspension or in an aqueous solution of compounds containing molybdenum, arsenic and / or phosphorus and the addition of the remaining component. Suitable molybdenum compounds for the preparation of the catalyst of formula I include molybdenum oxide, phosphomolybdic acid, molybdic acid and ammonium heptamolybdate. Excellent results are obtained using the catalysts of the invention in which at least a portion of the molybdenum used to prepare the catalyst is supplied in the form of molybdenum oxide.

'Suitable phosphorus compounds that ^Mu4: that used in the preparation of the catalyst is orthophosphoric acid, metaphosphoric acid, trifluoroacetic acid osforečná halides, phosphorus oxyhalides rumebo ^. The remaining components of the catalyst may be added in the form of oxides, acetates, formates, sulfates, nitrates, carbonates, halides and oxyhalides.

It is important to note that catalysts prepared to refuse phosphoric acid and molybdenum trioxide in water for 1.5 to 3 hours provide good results, but phosphomolybdic acid can be used more efficiently by adding the remaining components to the aqueous suspension and welding to a thick paste, to which at least one component is added in the form of halides or oxyhalides and air-dried at 110 to 120 ° C, followed by calcination.

The calcination can be carried out by heating

- dry catalyst components to a temperature of 300 to 700 ° C, the calcination preferably being carried out at a temperature of 325 to 450 ° C.

The reacting hydrocarbons may be n-butane, n-butenes, 1,3-butadiene or a mixture thereof. Preference is given to using 1,3-butadiene, n-butenes or mixtures of hydrocarbons obtained in the refinery. The molecular oxygen is generally added in the form of air, but it can also be a suitable molecular oxygen-containing synthetic gas. In addition to hydrocarbons and molecular oxygen, other gases may also be present in the reaction. For example, steam or nitrogen may be added to the reactants.

The ratio of reactants may vary in wide countries and is not critical. The ratio of hydrocarbons to molecular oxygen may be from about 2 to 30 moles of oxygen per mole of hydrocarbon. A ratio of about 4 to 20 moles of oxygen per mole of hydrocarbon is preferred.

The reaction temperature can vary within wide limits, depending on the hydrocarbon used and the catalyst used. Normally, temperatures of about 250 to 600 ° C are used, with 250 to 450 ° C being preferred.

The catalyst may be used alone or on a support. Suitable carriers include silica, alumina, alundum, (synthetic abrasive, substantially fused alumina), silicon carbide, boron phosphate, zirconia, and titanium dioxide. The catalysts are typically used in a solid-bed reactor in the form of tablets, pellets, or the like, or in a fluidized bed reactor in the form of particles smaller than about 300 µm. The contact time can be a fraction of a second or up to 20 seconds or even longer. The reaction may be carried out at atmospheric pressure, higher or lower than atmospheric pressure.

Excellent results are obtained by using a coated catalyst consisting essentially of an inert riosic material with a diameter of at least 20 μτα, an outer surface and a continuous coating of said active catalyst on an inert no200529 adhesion to the outer surface of the support. · ... ·: · · ·

When using coated catalysts in the reaction to prepare maleic anhydride, the reaction proceeds as very low exothermic, allowing good reaction control. In one pass, a high yield of α is achieved _; eliminates the formation of unwanted by-products.

A particular coated catalyst consists of an internal supported; an outer surface material and a coating of active catalyst material on the outer surface. These catalysts can be prepared in various ways.

The catalyst support material forms the inner core of the catalyst. It is a substantially inert carrier which may have substantially any particle size, but a shape with a diameter greater than 20 μτΐϊ is preferred. Particularly preferred according to the invention are carriers which are spherical and have a particle diameter of about 0.2 to 2 cm. Suitable examples of such inert carriers include alundum, silica, alumina, alumina, silicon carbide, titanium dioxide and zirconium oxide. Of these carriers, alundum, silica, alumina and alumina silica are particularly preferred.

The catalysts may contain substantially any proportion of support and catalytically active material. The limit of this ratio is given only by the mutual adaptability of the catalyst and the support. Preferred catalysts contain 10 to about 100 wt. catalytically active substances, based on the weight of the carrier.

Various methods can be used to prepare these coated catalysts. The basic method of preparing these catalysts is to partially wet the carrier with liquid. The carrier should not be damp on the outer surface of all material. It should appear dry to the touch. When the surface is wet, the active catalyst material is agglomerated to separate aggregates upon coating of the support. The partially wetted supports are then contacted with the powder of the catalytically active material and the mixture is stirred gently until the catalyst is formed. Typically, gentle mixing is carried out by placing the partially wetted carrier in a rotating drum or vessel and adding the active catalyst material. This is really an economic way.

By using the catalysts of the invention in the preparation of maleic anhydride, excellent yields are obtained in a convenient process to give small amounts of by-products.

Example 1

Moli2Pl, 32AS0,5Cu0,25O _x

A suspension containing 317.8 g of ammonium heptamolybdenum of formula (]4) δΜθ7θ25.4 H2O and 1500 ml of distilled water is boiled under stirring, to which 11,91 g of ammonium ammonium sulphate of formula · r is added.

NH.1H2ASO4 and heated for a total of 20 minutes; the color is white. After addition of 7.5 g of copper acetate, the color becomes light blue. To this mixture was added 22.8 g of phosphoric acid (85% rostok) and after 10 minutes 7.5 g of hydrazine to give a dark blue solution which was evaporated to a thick paste, dried overnight at 100 to 120 ° C. , it is ground and sieved to a particle size of less than 50 mesh. The resulting catalyst was calcined for one hour at 371 ° C in an air flow of 40 ml / min.

Example 2

MotolPl, 32AS0.5Cu0.20Cr4O _x

A suspension is prepared containing 105.9 g of ammonium heptamolybdate, 700 ml of distilled water at 60 ° C and 3.97 g of ammonium arsenate as a solution in 25 ml of water; The white precipitate formed is heated to boiling for 45 minutes. To this mixture is added 15.2 g of chromium oxide; 2.4 g of copper acetate are added over 15 minutes; 7.6 g of 85% phosphoric acid are added in half an hour. Evaporate the solution to a thick paste; oven dried at 110-120 ° C overnight; grind and sieve to a particle size of less than 50 meshes. The calcination is carried out as described in Example 1.

Example 3% Motopi, 32Aso, 5Cuo, 2oCr40 _x + 75% alundum (coated)

This catalyst was prepared in the same manner as described in Example 2 except that the catalyst particles were applied to 3.175 mm diameter alunda (SA 5223) beads, while 50 g of alunda were partially wetted with 1.8 g of water and 16 g of water were added. 7 g of active catalyst, prepared as in Example 2, in five equal proportions. During each addition and after each addition, the alundum is rolled in a glass vessel. The surface of the alunda is evenly powder coated and the product is finally dried. A hard, uniformly coated catalyst is obtained which consists of an alundic support with a continuous, firmly adherent coating of the active catalyst. The catalyst was then calcined for two hours at 371 ° C and 40 ml / min air flow. Examples 4 to 18

Preparation of maleic anhydride from 1,3-butadiene

Part of the catalyst particles, · prepared as described in Example 1-3 was charged into a fixed-bed reactor, of a 20 cm ^3, equipped with a stainless steel tube of internal diameter 1.02 cm. The reactor is heated to the reaction temperature under air flow. A mixture of 1,3-butadiene and air of the composition shown in the table is passed through the catalyst at an apparent contact time of 3 to 4 seconds and the properties of the catalyst are evaluated by collecting and analyzing the products. .

The test results are shown in Table 1 below.

The following equations are used to assess the carbon balance in feedstock and products:

% yield per mole of obtained maleic anhydride moles of hydrocarbon feedstock total conversion = selectivity = moles of reacted hydrocarbon moles of hydrocarbon feedstock yield per pass total conversion

Φ Xm

Φ ^ · w> 5

TO Φ W. !>, í>

rd CO CO CO Vi CM CM i

H> CC KOO t) l O η N T-Γ CO co xr -φ xr co tn t>

tx ao 00 00 CM 00 00. oo oo oo

what WHAT • o OO • Φ CM 00 what WHAT í < r-i WHAT OQ 00 00 WHAT· 00

CO 05 co 'CM CO in-CM rH 00 CO tn O · Η r-j. CJ OO Oř tn CM Xr CM ~ o “what Xr what what” l <Xř Xř

CO tn xr xr .xr χφ xr _: xr

tH what what ΙΌ what CM ~ in irT 0? · t-H cm " O what .

! íd>

O

Λϋ r-H

Φ

About honor β

• «« 4

Φ

IN)

Λ

Q o

Λ

4_i 4— »

O O

ÍU φ

Φ

H

HcoOTOTOTcorHxřinrø Xø CO rø_ OT rø. OT. tn CD Cx co co o o o cm in r-o o cocoinrHinintninin

O what rd O rH O WHAT WHAT r-T what t < CO ~ IO • Ml Ml Me Ml

WHAT OT 09 WHAT tn cn t>. rH O what 00 what WHAT WHAT O tn << vn in co co CM Me oo O rH Ml WHAT what what CM what what what what WHAT WHAT what ME M < Me

Table 1

Preparation of maleic anhydride from 1,3-butadiene using a catalyst of the formula> φ β

I 'β «° Ο> .Pi g Λ 3

C-t

O tM r— (

Honors

M β

tt

I Tti 'rM β> t-l r — I & 4 Λ!

CO O MI 00 tH CB what what what what r-i what T ~ í what oo CO 00 O) o in co o o th O CM what what rH CM CM CM CM CM CM CO CO what WHAT what what what ME

ooooooinococococ ^ CM 00 W CM in rd ΙΛ © CM r> in what what σί mi what and what in CMCMCMCMCMCMCMCMCMCM

Me CM WHAT M < O 00 OO r-f trT irT Me* CM CM CM CM

MI!>.

CM

CM «XX o o N 8 8 o * irt CJ 09 € q

XXX ooo

Ml xt * SU-í (<<CM CM CM \ \ \ \............)

OCOf10

Ml φ Ml Q3 MI JU x> tx> o P o * o

IO io <- »ΙΛ

O O O

M <-rjt

Sx ÍU

O O

SU o

oooooooo β β β ooo tp p trt ςΓ o o iS β β O O WWW

W ΙΛ o W W <<<

C9 5 * 4 to xH t — t i—,

Dx Ox Ox

S2S

0x Ox

O o SS

3) 3 OOO

LO io IO ^ o θ o o

- - - 73 c

rX

CU * X i o t tn tn tn

Oxχ Οχ Ox a and ooo SSS £ ³ Rg w £ 2 Px β

-M O w s w gravity

W 3 tX Ox 3 Ox «9 O ® O θ 'θ' β β

O o

ΙΛ ΙΛ.

cT θ w w CO <<

to tO ° 1 θ ’β

O

ΙΛ $ yn ^ o> C ** t * · »m CM in CM - CM

TřinCOtsOOCnOrřCMCO Η Η Η H rH ϋ k 'β β w 3 3 O · w SS> u - m · * co ¹

Φ

S ^{> Q} _ φ · Φ »-X« _ r— <- i— <_ »- <

>; S>; §> <? >

O O-f f f f f f f f f f f f CO CO CO CO CO CO

Claims (4)

PftEDMBT A process for the preparation of maleic anhydride by oxidizing n-butane, n-butenes, 1,3-butadiene or mixtures thereof with molecular oxygen in the gas phase at a reaction temperature of 250 to 600 ^° C in the presence of a catalyst comprising phosphorus, molybdenum, oxygen, arsenic and optionally an inert carrier having a particle size of 0.2 to 2 cm and a promoter characterized in that a catalyst consisting of a combination of elements corresponding to formula I is used X _and Mo 12 P _b As _c O _x (I), where is X at least one of tin, rare earth metal, zirconium, rhodium, manganese, rhenium, ruthenium, copper, lead, zinc, titanium, chromium, niobium, aluminum, gallium and alkaline earth metal, and a positive number greater than zero but less than 20 B, c, each number 0.001 a, 10 and x the number of oxygen atoms needed to saturate the valences of the other elements contained. 2. A process according to claim 1, wherein a catalyst comprising a combination of elements corresponding to formula I is used, wherein a is a positive number greater than alcohol but less than 12, b a number of 0.01 to 5, c a number of 0.01 to 5 and X and x are as defined in point 1. 3. A process according to claim 1, wherein the catalyst is a combination of elements corresponding to formula I, wherein h is from 0.5 to 1.5 c is from 0 to i and 1.0 and X and x are as defined in 1. 4. A process according to claim 1, wherein the catalyst is a combination of elements corresponding to formula I, wherein X is a copper atom or where X is a copper and chromium atom, aa, b, c, x are as defined in point 1 . nvneiraa *. n.