DE1253242B - Process for the preparation of a nickel hydrogenation catalyst - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Int. Cl .:

BOIj

GERMAN

PATENT OFFICE

EDITORIAL

German class: 12 g -11/22

Number: 1253 242

File number: B 76465 IV a / 12 g

Filing date: April 23, 1964

Open date: November 2, 1967

The invention relates to the production of nickel catalysts by reducing nickel formate to nickel.

Nickel formate is known, can be reduced at temperatures in the order of 25O ⁰ C without going through the oxide as an intermediate directly to nickel. The response can be expressed by the following equation:

Method of making a
Nickel hydrogenation catalyst

Applicant:

The British Petroleum Company Limited,

London

2 (HCOO) ₂ Ni 2 Ni + 3 CO ₂ + CO + H ₂ + H ₂ O i ₀ representatives:

It is customary to carry out the reduction in a gas stream in order to remove the reaction products. This gas must of course not be oxidizing. The choice of gas depends on a number of Considerations. For example, pure nitrogen or hydrogen are suitable, but these are gases not always readily available or, when available, may be expensive. Every attempt one Reducing costs by recycling the gases brings the risk of undesirable side reactions with it, which result from the circulation of the reaction products. One-time is therefore preferred Passage with a gas that occurs in large quantities on site, but here too the Choice will be limited. For example, this is predominantly made up of hydrogen and methane Residual gas from a steam cracking plant is suitable, but the amounts are often too small during the most abundant source of hydrogen in the field of petroleum refining, the exit gas from the catalytic reforming, is unsuitable because the catalyst is a strongly exothermic reaction between the components of the gas and thus cause the temperature to runaway.

The only gas that is certain to be available in sufficient quantities in any industry is water vapor. It has now been found that this gas can be used for the production of nickel catalysts provided that certain precautionary measures outlined below are taken.

The invention relates to a process for producing a nickel hydrogenation catalyst by reducing nickel formate, optionally on a support, to elemental nickel in a gas stream at temperatures up to 400 ^° C., which is characterized in that nickel formate is first applied in a steam-free atmosphere a temperature between 110 and 150 ° C and passed therethrough once brings then in a substantially water vapor existing gas stream at 150 to 400 ⁰ C reduced to elemental nickel.

Dr.-Ing. A. ν. Kreisler, Dr.-Ing. K. Schönwald,
Dr.-Ing. Th. Meyer and Dr. JF Fues,
Patent attorneys, Cologne 1, Deichmannhaus

Named as inventor:

Peter Thomas White,

Sunbury on Thames, Middlesex (Great Britain)

Claimed priority:

Great Britain April 24, 1963 (16 127) - -

The nickel formate can be brought to a temperature of 110 to 150 ^° C. in any suitable manner. For example, the material can be heated in a dry static atmosphere, such as by electrical heaters within the catalyst layer or by infrared heating, but the use of a dry, preheated gas stream is usually simpler. Temperatures of 110 to 150 ^° C. are below the limit at which a reduction begins, so that small amounts of other gases which may be present during the actual reduction do not interfere. Furthermore, the time which is required to bring the nickel formate to the aforementioned moderate temperatures is relatively short, so that the problems with regard to the available amount of gases are reduced. For example, nitrogen, hydrogen, C ₁ to C ₄ hydrocarbons or mixtures of these gases can be used, and if reuse of the gases used is desired, recycling during this preheating time is possible. Oxidizing gases, e.g. B. air can also be used, especially at the lower temperatures within the stated range, provided that care is taken that

709 680/402

these gases are carefully removed from the system before the final higher temperatures are reached are. The pressure applied and the duration of the heating are not critical, but will expediently in the range from 0 to 3.5 atmospheres or from

Worked 1 to 20 hours. If you are working with flowing gas, its amount is appropriate between 10 and 1000 V / V / hour.

After a uniform temperature in the range of 110 to 150 ° C has been reached, any further temperature correction that may be necessary and the actual heating in flowing steam are carried out. Temperatures of 200 to 300 ° C are preferred, since at these temperatures good effectiveness is normally achieved within an acceptably short time. The temperatures mentioned are the catalyst temperatures. As explained in more detail below, the catalyst can consist of nickel on a heat-resistant carrier. In the preparation of catalysts of this type it is customary to supply the necessary heat to the system, passing the gas stream is preheated to a temperature above 150 to 400 ⁰ C. In this context, the use of water vapor is more advantageous than the use of hydrogen, since the former has a higher heat capacity (8.4 cal / degree mol compared to 7.0 cal / degree mol for hydrogen at 227 ° C.) and a lower heat transfer coefficient. The higher heat capacity means that the temperature to which the gas must be preheated can be lower, and the lower heat transfer coefficient means that less heat is given off to the part of the layer with which the gas comes into contact first, so that the Temperature gradient through the bed is less steep. Conveniently, the water vapor is not preheated 400 ⁰ C. The speed of the gas flow can be between 10 and 1000 V / V / hour. Normally, as high a space flow velocity as possible is preferred because an increased gas flow rate promotes rapid removal of the reaction products from the vicinity of the nickel. The duration is appropriately between

2 and 100 hours and the pressure between normal pressure and 3.5 atmospheres. The minimum temperature to which the nickel formate is preheated is to tune to the pressure and to increase with increasing pressure so that at 3.5 atm, the preheating temperature advantageously in the vicinity of the upper end (15O ⁰ C) of range.

When producing a fixed catalyst bed, the steam is preferably from top to bottom passed through the catalyst bed. Any condensate that collects at or below the foot of the bed is advantageously drained during its formation.

After manufacture, it may be desirable to cool the catalyst to a temperature below 110 ^0C. In this case, cooling below 110 ° C should also be carried out in a steam-free atmosphere. The methods proposed for the heating stage can also be used for the cooling stage, but the use of oxidizing gases must be avoided.

The nickel catalyst is preferably composed of nickel on a heat-resistant support, the Nickel content especially 1 to 50 percent by weight, in particular 5 to 25 percent by weight, based on the total catalyst. The heat-resistant support is appropriate among those used Manufacturing conditions inert. For example, aluminum oxide, lime, or chamotte are suitable a material containing silica, e.g. B. silica gel or kieselguhr. Is particularly preferred as a carrier Sepiolite. Sepiolite is a commercially available mineral that occurs naturally and is also synthetic can be produced. He has the ideal formula

H ₄ Mg ₉ Si ₂ O ₃₀ (OH) ₁₀

and is also known as meerschaum.

The nickel formate is either mechanically mixed with the carrier or in an aqueous ammoniacal solution Solution dissolved and applied to the carrier by impregnation. The impregnated carrier is then dried, with a substantial proportion of the ammonia being driven off.

Nickel catalysts produced by the process according to the invention can be used in all hydrogenation processes for which nickel catalysts have proven suitable. They are particularly suitable for the selective hydrogenation of diolefins in the presence of monoolefins. For example, they can be used in the processes that are the subject of British Patents 848 232 and 899 651. A particularly suitable feedstock with catalytic nickel may be selectively hydrogenated, the gasoline obtained as a by product of a thermal cracking unit, which is operated primarily for olefin production at a temperature of at least 590 to 900 ⁰ C.

example

Granulated sepiolite with a particle size of 3.4 to 6.2 mm was impregnated with an aqueous ammoniacal solution of nickel formate and then ^{dried at 105 °} C., a nickel formate-sepiolite catalyst containing 8.2 percent by weight nickel being obtained. 3 portions of 250 cm ³ each of this catalyst were then reduced to nickel as follows:

Catalyst A (according to the invention)

The catalyst layer was atm under dry nitrogen at 2.1 heated at a rate of 50 ° C / hour to 105 ⁰ C. After the temperature of 105 ^° C. had been reached, steam was released under pressure to normal pressure and passed over the catalyst in an amount of 100 V / V / hour, while the temperature of the bed was increased to 250 ^° C. at the same rate. The catalyst was activated with steam ^{at 250 ° C. for 5 hours.} The steam supply was then shut off and the reactor cooled to ambient temperature under slowly flowing nitrogen.

Catalyst B

The production process for catalyst A is used with the difference that water vapor is fed at a temperature of 105 ° C.

Catalyst C

This catalyst is reduced in hydrogen by a standard procedure; H. for 4 hours heated to 250 ° C. in a stream of hydrogen which is passed through at a flow rate of 100 V / V / hour will.

The three reduced nickel catalysts A, B and C were tested for their hydrogenation activity, using a gasoline from steam cracking as feed was used, which had the key figures given in the table.

Specific gravity at 15.6 ° C / 15.6 ° C. ASTM distillation, ⁰ C

Start of boiling

2 percent by volume passed until ...

5 percent by volume passed to ... 10 percent by volume passed to ... 20 percent by volume passed to ... 30 percent by volume passed to ... 40 percent by volume passed to ... 50 percent by volume passed to 60 percent by volume passed to 70 percent by volume passed to 80 percent by volume passed to 90 percent by volume passed to the end of boiling

0.7606

45

50.5

53.5

57

63

70

79

90 102 117 133.5 156 192

Product recovery, volume percent 97.5

Residue, percent by volume 1

Loss, volume percent 1.5

Passed over, percent by volume

to 7O ⁰ C 30

to 100 ^° C 58.5

to 140 ⁰ C 83

Total sulfur, weight percent 0.021

Resins,

Gum exists, mg / 100 cm ³ 11 5 *

Gum accelerated (120 minutes),

mg / 100 cm ³ 33 23 *

Gum accelerated (240 minutes),

mg / 100 cm ³ 157 152 *

Induction Period (ASTM), minutes 263

Bromine number 69.7

Diene index 5.11

Styrene correction 4.04

Octane numbers

Research method,

without lead 92.9

+3 cm ³ TEL / IG 97.6

*) After n-heptane washing.

The following working conditions were used:

Pressure 17.5 atm

Room flow rate 2 V / V / hour

Temperature set to one

Hydrogen consumption of 23.4 m ³ / m ³

Gas circuit 90m ³ / m ³

Make-up gas hydrogen

The process temperatures required for the three catalysts to set a hydrogen consumption of 23.4 m ³ / m ³ were as follows:

Catalyst A 125 ⁰ C

Catalyst B 127 ° C

Catalyst C 132 ° C

The adjustment to the hydrogen consumption and the measurements of the hydrogen consumption were made carried out after approximately 350 hours of the procedure. From this it can be seen that all catalysts are one show satisfactory and sufficient activity.

ίο During the preparation of the catalyst B, in which the transition from nitrogen to water vapor was carried out at a temperature of 105 ⁰ C, it was found, however, that the water vapor condensed in the initial stages had a pale green color.

This is a sign of a slight loss of nickel from the catalyst. By increasing the transition temperature to 110 ^° C. - as provided according to the invention - this nickel loss was eliminated. The numerical comparison of the effectiveness

ao of the catalysts shows that catalyst A according to the invention is at least as active as that in conventionally in the presence of hydrogen reduced catalyst C. In fact, even that Comparison temperature for catalyst A is the lowest of the three specified values.

The invention thus offers, among other things, the important advantage that the reduction stage in the Catalyst preparation can be done in the absence of hydrogen. For the practice that means a significant relief. The reduction to the nickel metal catalyst must be known usually be carried out in situ because the nickel metal catalysts are pyrophoric. Large amounts of hydrogen, as required for conventional catalyst reduction, are available not always available. However, superheated water vapor is cheap and plentiful in all places too procure. According to the invention it is possible to achieve this without adversely affecting the catalyst activity To use auxiliaries for catalyst production.

Claims (3)

Patent claims: 1. A process for the preparation of a nickel hydrogenation catalyst by reducing nickel formate, optionally on a support, to elemental nickel in a gas stream at temperatures up to 400 ^° C., characterized in that the nickel formate is first heated to temperatures of 110 to 150 in a steam-free atmosphere ⁰ C is heated and then reduced to elemental nickel in a gas stream consisting essentially of water vapor at 150 to 400 ^{0 C, which has been carried out once.} 2. The method according to claim 1, characterized in that the reduction of Nickelformiats at 200 to 300 ⁰ C is performed. 3. The method according to claim 1 and 2, characterized in that the reduction of the nickel formate at a water vapor flow rate of 10 to 1000 V / V / hour and preferably a pressure of 0 to 3.5 atmospheres is made. 709 680/402 10.67 © Bundesdruckerei Berlin