Cobalt-based catalysts activation process

This invention relates to catalysts. More particularly, the present invention relates to a process for preparing a Fischer-Tropsch catalysts and a supported catalyst obtained by this method.

As for Fischer-Tropsch catalysts, it is well known that precursors of such catalysts are prepared using the metal-containing precursor and a carrier in the form of particles. Preparation of the catalyst precursor comprises a number of different stages, and then the catalyst precursor during the activation process or one of its stages is reduced using hydrogen, to obtain an active Fischer-Tropsch catalyst, which contains metal crystallites as the active component of the catalyst. Typically, the metal can be cobalt.

In known activation processes, namely recovery precursors Fischer-Tropsch catalyst based on cobalt in flowing hydrogen or a hydrogen containing gas stream at elevated temperatures, the applicant knows about, the preferred catalyst precursor is a compound mainly comprising Co3O4. Further, hydrocarbon synthesis catalyst activity is maximized by adjusting the maximum water partial pressure (which is influenced by factors such as temperature ramp and the quantity of bulk gas velocity) during the activation step; activation step can take up to 24 hours. Activation periods (and thus cycle times during the semi-continuous activated catalyst precursor based on cobalt supported on a commercial scale) can not be easily cut without the risk of losing control over the maximum water partial pressure and consequently obtaining a hydrocarbon synthesis catalyst, not having maximum activity. This risk is even greater when the catalyst precursor is a compound, which depends on the control of maximum water partial pressure (under comparable conditions, such as changes in temperature and gas space velocity) to a greater extent than is the case for the catalyst precursor, mainly comprising Co3O4. Thus, the purpose of this invention is to provide a process for producing Fischer-Tropsch catalysts on a carrier, wherein the risk is absent, or at least reduced.

According to the present invention provides a process for preparing a Fischer-Tropsch catalyst on a carrier which comprises:

processing in the first stage activation of the catalyst precursor Fischer-Tropsch cobalt based on the carrier in the form of particles, which comprises a catalyst support impregnated with cobalt containing resilience cobalt oxide in calcined state having a formula-unit in which each mole of cobalt atoms is associated more than 4/3 moles of oxygen atoms and characterized by a surface area capable of reducing cobalt oxide, at least equal to the corresponding characteristic of Co3O4 spinel pure hydrogen with a first specific feed gas space velocity, SV1, the first heating rate, HR1, to obtain a partially reduced catalyst precursor, and subsequent treatment of the partially reduced catalyst precursor at the second activation step with pure hydrogen to a second specific volumetric feed rate, SV2, at a second heating rate, HR2, to obtain an activated Fischer-Tropsch catalyst on a carrier, wherein SV2≤SV1 and / or HR2≥HR1 provided that when SV2 = SV1, HR2 ≠ HR1 and when HR2 = HR1, SV2 ≠ SV1.

Thus, when SV2 is equal to SV1, HR2 is not equal to HR1, and when HR2 is equal to HR1, SV2 is not equal to SV1.

Examples of typical formula-units of the supported cobalt oxide, ie formula that can be used are SoOaNb where a≥1,7 and b> 0 as disclosed in WO 01/39882 A1, or the hydrotalcite type compound monometallic Soii 0 , 74Soiii 0,26 (OH) 2,01 (NO3) 0.21 (CO3) 0.02 × 0,6H2O, as described in Chem. Matter, 2000, 12, 3459-3465.

This ability to recover cobalt oxide phase, which differs from Co3O4, hereinafter called "labilizirovannoy cobalt oxide."

Surprisingly, it was found that Fischer-Tropsch catalyst based on cobalt on a carrier having high intrinsic activity is obtained from a precursor in which all the ability to recover the cobalt contained in the form labilizirovannoy cobalt oxide provided that the reduction or activation of the present invention is used for Activation predecessor.

Thus, the catalyst precursor before reduction entire resilience cobalt of oxidation state> 0 contained in the catalyst precursor is in the form of cobalt oxide labilizirovannoy. The catalyst precursor comprises thus a catalyst support which has been impregnated with cobalt and calcined in such a controlled manner that the whole capacity to recover the cobalt contained in the carrier, namely the cobalt that is associated with oxygen and elements such as hydrogen, nitrogen, and / or carbon, in the absence of interaction between cobalt - the carrier, such as the formation of cobalt aluminates or cobalt silicates, that would reduce its ability to recover, it is in the form of cobalt oxide labilizirovannoy. The term 'formula-unit' in relation to the cobalt oxide reflects the normalized atomic ratio between the elements Co and O, also including one or more elements selected from H, N and / or C are all capable of reducing cobalt oxide contained in the catalyst precursor before reduction (namely, calcined intermediate) ie cobalt oxide, which is not involved in an appreciable interaction with the selected vehicle, e.g., Al2O3, SiO2, Al2O3-SiO2, ZnO or TiO2, such as the formation of cobalt aluminate or silicate cobalt, resulting to reduction of resiliency. The formula unit of all of these species capable of reducing cobalt oxide agglomerated together, does not contain typical support elements, eg, Al, Si, Zn or Ti, and is expressed as CoOaHbNcCd, where a> 4/3, b> 0, and each of and with d≥0, then there is the previously described cobalt oxide.

The metal precursors labilizirovannoy cobalt oxide result in large amounts of water at a rate of at least high, per unit amount of resilience cobalt during its conversion to CoO as part of the activation process (recovery using H2) to the metal state, compared with spinel Co3O4 . Therefore the conditions for activation, which would lead to the preparation of a cobalt catalyst of the Fischer-Tropsch process with a high factor of initial relative intrinsic activity in the Fischer-Tropsch ('RIAFx, i'), when used as the metal containing precursor spinel Co3O4, are not necessary in the case where labilizirovannaya metal precursor is a cobalt oxide.

Factor relative intrinsic activity in the Fischer-Tropsch ('RIAFx') cobalt slurry of the supported catalyst precursor which was obtained strictly in accordance with this invention by the procedure X, ie catalyst precursor X, is defined as follows:

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Where

a) Ax denotes preeksponentsialny Arrhenius factor X precursor catalyst activated according to an arbitrary method of recovery;

b) Ax, b denotes preeksponentsialny Arrhenius factor X precursor catalyst, measured after 15 hours of stirring the suspension of the body continuous reactor (CSTR) in carrying out the Fischer-Tropsch synthesis in real conditions using a reference next reduction procedure:

fixed bed (inner diameter: 20 mm) 15 ± 5g catalyst precursor X (i.e., the catalyst before reduction) at atmospheric pressure using an undiluted H2 reducing (purity 5.0), feeding at a flow rate 1300 ml of N per gram reducible cobalt per hour according to the following temperature program: heating from 25 to 425 ° C at a rate of 1 ° C / min and isothermal hold at 425 ° C for 16 hours.

c) Preeksponentsialny factor A, applicable to Ax and Ax, b is determined by the conventional empirical kinetic equation for cobalt Fischer-Tropsch catalysts:

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In this way:

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Where

rFT expresses the number of moles of CO converted to products of the Fischer-Tropsch unit time per unit mass of the catalyst precursor in its predvosstanovlennom condition.

Next, an initial RIAFx, ie RIAFx, i, is defined as follows:

RIAFx, i = RIAFx at 16,5 ± 1.5 hours of operation suspension in the implementation CSTR Fischer-Tropsch synthesis in real conditions, when these conditions are:

reaktora220,0 temperature ± 0,5 ° Compression in reaktore20,5 ± 0,7 bar% conversion (H2 + CO) 60 ± 13

Composition of feed gas:

N2okolo 50 vol.% SOokolo 25 vol.% OstalnoeAr, N2, CH4 and / or CO2.

Processing the first and second activation stages may, at least in principle, be carried out using any suitable configuration of the catalyst precursor, contacting with a reducing gas such as a fluidized bed catalyst precursor particles, when the reducing gas acting as the fluidizing medium fixed bed of precursor catalyst, through which the reducing gas or the like However, the preferred configuration is a fluidized bed.

With regard to the method of activation of the catalyst, it is possible to consider the following standard approach: SV2 = SV1 = SVc and HR2 = HR1 = HRc. In other words, the feed gas space velocity and the heating rate are kept constant throughout the activation process, i.e. the first and second activation stages, index "c" indicates that the space velocity and the heating rate are constant throughout the activation process.

You can see different combinations and SVc HRc, we can estimate their impact on RIAFx, i. Assuming that

RIAFx, i &lt;0,8 is undesirable,

0,8≤RIAFx, i≤1,0 is preferred and

RIAFx, i&gt; 1,0 is most preferred,

values ​​of "unwanted", "preferred" and "most preferred" for combinations of HR1 and SV1 can be defined as follows (hereinafter discussed in more detail with reference to Figure 2):

HRc, 1 is defined as the maximum value of HRc, which results in a RIAFx, i≥0,8 at selected values ​​of SVc, thus implying that HRc, 1 = f (SVc). HRc, 2 is defined as the maximum value of HRc, which results in a RIAFx, i≥1,0 at selected values ​​of SVc, thus implying that HRc, 2 = f (SVc). Undesired, preferred and most preferred ranges for HR1 are defined as follows:

0 &lt;HR1 &lt;HRc, 2 - the most preferred,

HRc, 2≤HR1≤HRc, 1 - preferred,

HR1&gt; HRc, 1 - unwanted ,.

If the reduction is carried out in a fluidized bed, then quantifying the minimum allowable SV1 (ie SV1min) and maximum allowable SV1 (ie SV1max) dictated by the condition of proper fluidization during the whole of the first catalyst activation stage. Thus, SV1 &lt;SV1min; as well as SV1&gt; SV1max not included in the interval, that is, are not applicable. The same condition applies proper fluidization and to the whole of the second stage of activation, which also implies the existence of the minimum allowable SV2 (ie SV2min) and maximum allowable SV2 (ie SV2max). Proper fluidization depends on the reactor configuration and catalyst properties. Preferred regimes of fluidization are the turbulent, churning and bubbling - slug, with the turbulent and churning regimes being preferred and churning - preferred (see. Design Manual of the Particulate Solid Research Institute (PRSI), USA, September, 1993). One skilled in using the PRSI Design Manual and the selected reactor configuration and properties of the catalyst, can thus determine the appropriate values ​​for SV1min, SV1max, SV2min and SV2max, which will ensure the desired mode of fluidization. In addition, SV2≤SV2β (SV2β which is the minimum of SV1 and SV2max) and HR2≥HR1. With these limitations, you can see different combinations of HR2 and SV2, and assess their impact on RIAFx, i. Based on the assumption that:

RIAFx, i &lt;0,8 is undesirable,

0,8≤RIAFx, i≤1,0 is preferred and

RIAFx, i&gt; 1,0 is most preferred,

"undesirable", "preferred" and "most preferred" ranges for allowable combinations of HR2 and SV2 for a specific number of HR1 and SV1, have been identified as follows (as described below in more detail with reference to Figure 3):

HR2β is defined as the maximum value of HR2, which will lead to RIAFx, i≥0,8 at a chosen value SV2, ie SV2min≤SV2≤SV2β, where SV2β is the minimum value of the SV1 and SV2max; HR2α and is defined as the maximum value of HR2, which will lead to RIAFx, i≥1,0 at a chosen value SV2, ie SV2min≤SV2≤SV2β, where SV2β is the minimum value of the SV1 and SV2 max.

The basic premise of what is described above, is that constant space velocities are maintained during the treatment in the first activation stage, ie SV1 is constant, as well as during treatment in the second activation stage, ie SV2 is constant, with SV2≤SV1 . All this is in accordance with a first embodiment of this aspect of the invention.

The first activation stage begins with the fact that the pure catalyst precursor (ie the intermediate product containing all the ability to recover cobalt as labilizirovannoy cobalt oxide in the absence of any substance which has accumulated during storage and / or preparation, such as physically adsorbed moisture) is subjected to pure hydrogen at SV1 with the immediate application of HR1. In cases where the non-reduced catalyst precursor has adsorbed moisture, to recover cobalt oxide purity labilizirovannoy preliminary drying can be used. Then the first stage of activation may be continued until all of the ability to recover the cobalt has been converted quantitatively to CoO is obtained when the partially reduced catalyst precursor; It is expected at a bed temperature of from 150 to 280 ° C, ie at T * in Figure 1, described below. Thus, in the beginning of the second stage of the activation temperature of the second activation stage, ie the temperature of the partially reduced catalyst precursor, will be equal to a value ranging from 150 to 280 ° C. Can then continue the second activation step as long as the temperature in the second treatment stage, ie the temperature of the activated Fischer-Tropsch catalyst becomes equal to a value in the range from about 300 ° C to about 600 ° C, the preferred value is in the range from 300 to 500 ° C, most preferred value - in the range from 300 to 450 ° C. According to a second embodiment of the invention, space velocities during the first and / or second stage of activation may vary, provided that the following conditions are met:

The first activation stage (Stage I): SV1t defined as the prevailing pure hydrogen space velocity at time t during stage 1 and SV1f defined as the pure hydrogen space velocity at the end of stage 1. The restrictions imposed on SV1t and SV1f: SV1t≥SV1f, SV1t≤SV2max and the combination of (HR1, SV1f) is in the preferred or best in the most preferred range applicable for the combinations HR1, SV1, as previously described.

The second stage of activation (stage 2): SV2t. is defined as the prevailing pure hydrogen space velocity at time t in the step 2 and SV2f defined as the pure hydrogen space velocity at the end of stage 2. The restrictions imposed on SV2t and SV2f: SV2t≥SV2f, SV2t≤SV2β (SV2β wherein in case of changing volume velocities is the minimum value of SV1f and SV2max), and the combination of (HR2, SV2f) is in the preferred or best in the most preferred range applicable to combinations of HR2 and SV2.

This embodiment of the first aspect of the invention relates to situations where it is desired to fix the superficial gas velocity during activation stage 1 and / or activation stage 2, while still getting the catalyst RIAFx, i≥0,8. Superficial or linear velocity is the volumetric flow rate (at a temperature and pressure in the reactor) of gas per unit cross-sectional area of ​​the reactor for recovery. To convert linear (superficial) velocity SV (SV1t; SV2t) required adjustment of temperature, pressure, cross-sectional area and the mass of the ability to recover cobalt.

By 'pure hydrogen reducing "which is used on the two activation stages, is meant a hydrogen-containing gas mixture comprising ≥90 vol.% H2 and ≤10 vol.% Of inert gas, preferably, ≥97 vol.% H2 and about ≤3.% Of an inert gas. The inert gas can be any combination of Ar, He, N2 and H2O with the preferred dewpoint of pure hydrogen-containing reducing gas ≤4 ° C, preferably ≤-30 ° C.

The processing in both the first and second activation stages may be conducted at about atmospheric pressure, preferably in a range from 0.6 to 1.5 bar (a), and most preferably between 0.8 and 1.3 bar (a).

Freshly activated Fischer-Tropsch catalyst, ie the catalyst at the end of the second activation stage, which is thus still at elevated temperature, can be cooled down in pure hydrogen to a temperature Tc and then cooled further to room temperature in substantially pure nitrogen. The temperature Tc must be low enough that the nitrogen behaved as an inert gas during the final stage of the cooling phase.

Temperature switch Tc is readily determined from the dependence of Tc RIAF. A preferred value for Tc is such a temperature that provides RIAFx, i between 0.8 and 1.0, and most preferred value of Tc is the temperature that will provide RIAFx, i≥1,0.

Not recovered cobalt catalyst precursor Fischer-Tropsch synthesis on a particulate carrier may be any suitable catalyst precursor requiring activation or reduction to obtain an active Fischer-Tropsch catalyst. However, the catalyst precursor is preferably prepared by forming a slurry of the catalyst support, a cobalt compound as an active component precursor, and water; impregnating the catalyst carrier compound of cobalt; drying the impregnated carrier and calcining the impregnated catalyst carrier. The catalyst precursor thus obtained must, however, be activated and then restored to its use to catalyze the Fischer-Tropsch reaction, and this reduction or activation is carried out in accordance with the method according to the present invention. The resulting catalyst is an activated Fischer-Tropsch catalyst.

It is possible to use any commercially available preformed porous oxide catalyst support, such as Al2O3, silicon oxide (SiO2), titanium oxide (TiO2), magnesium oxide (MgO), SiO2-Al2O3, and zinc oxide (ZnO). The carrier has an average pore diameter of from 8 to 50 nm, more preferably from 10 to 15 nm. The pore volume of the carrier may range from 0.1 to 1.0 ml / g, preferably from 0.3 to 0.9 ml / g. The average particle size is from 1 to 500 microns, more preferably from 10 to 250 microns, more preferably from 45 to 200 microns.

The support may be a protected modified catalyst support, containing, for example, silicon as modifying component, as described in EP №99906328.2 (European Publication №1058580), which is incorporated herein by reference.

Cobalt loading can be between 5 g Co / 100g support to 70g Co / 100g support, preferably between 20g Co / 100g support to 40g Co / 100g support. Cobalt salt may, in particular, cobalt nitrate, Co (NO3) 2 · 6H2O.

Impregnation of the catalyst carrier can in principle be performed by any known method or technique, such as by impregnation to incipient wetness impregnation or slurry. However, impregnation, in particular, can be carried out in the manner described in US Patent 6455462 or 5733839 which are incorporated herein by reference. Impregnation of the carrier may thus include 2-step impregnation of the slurry, which is dependent on the desired cobalt content and the pore volume of the catalyst support.

Impregnation of the carrier and drying may be carried out in a conical vacuum drier with a rotating screw or drum vacuum dryer.

During impregnation of the cobalt as an additive, the recovery of the active ingredient may be added a water-soluble salt of platinum (Pt), palladium (Pd), ruthenium (Ru) or a mixture thereof. The weight ratio of the additive, when used, to cobalt may be between 0,01: 100 to 0,3: 100.

Calcination of the impregnated and dried material may be done in any manner known to the expert, for example in a fluidized bed, rotary kiln-drier, a kiln at 200-350 ° C. This calcination may be carried out as described in PCT application WO 01/39882, which is incorporated herein by reference.

Step impregnation and / or drying and / or burning step are selected so that the whole of the catalyst precursor capable of cobalt contained in the carrier was in the form of cobalt oxide labilizirovannoy. This may for instance be achieved during the baking step, described in the application WO 01/39882.

The present invention also relates to an activated Fischer-Tropsch catalyst obtained by the method according to the first aspect of the invention.

The activated Fischer-Tropsch catalyst can be used in the method for producing hydrocarbons, which includes contacting synthesis gas comprising hydrogen (H2) and carbon monoxide (CO) at an elevated temperature between 180 and 250 ° C and at elevated pressures of 10 to 40 bar in the presence of activated Fischer-Tropsch catalyst, described above, using a Fischer-Tropsch slurry phase, comprising reacting hydrogen with carbon monoxide.

The present invention will be described below in more detail with reference to the following figures and examples, without limiting the scope of the invention.

Figure 1 shows the profile of a temperature-programmed reduction at (TPR) XI cobalt catalyst precursor of Example 1 (reduction at atmospheric pressure; reducing gas - pure hydrogen; linear heating rate of 2 ° / min, gas flow rate 10.7 m3 n / SACU · h; fixed bed differential operates at conditions that are close to the almost-gradient conditions for fluidized beds.

Figure 2 is a schematic graphical representation showing the data characterizing the cobalt catalyst precursor X1 to illustrate the definitions of 'undesired', 'preferred' and 'most preferred' ranges for allowable combinations of HR1 and SV1.

3 is a schematic diagram showing the data characterizing the cobalt catalyst precursor X1 to illustrate the definitions of 'undesired', 'preferred' and 'most preferred' ranges for allowable combinations of HR2 and SV2 for a specific set of (HR1 and SV1), and it HR1 = 1,0 ° C / min and SV1 = 13,7 m3 N / h · SACU).

Example 1.

As a concrete example, the catalyst precursor, the catalyst of the Fischer-Tropsch slurry 30g Co / 100g Al2O3, developed by the Applicant, described in detail in WO 01/39882. If the non-reduced catalyst precursor or intermediate (labeled X1), prepared in strict accordance with the procedure next subjected to further recovery procedure:

fixed bed (inner diameter: 20 mm) 15 ± 5g of the catalyst precursor X1 (ie unreduced catalyst) was reduced at atmospheric pressure using undiluted H2 (purity of 5.0) at a flow rate 1300 ml of N per gram reducible cobalt per hour, using the The following temperature program: heating from 25 to 425 ° C at a rate of 1 ° C / min and isothermal hold at 425 ° C for 16 hours

- Get the next value preeksponentsialnogo factor Arrhenius:

AX1b = 138 546 [mol CO / (g obozhzh.kat. · A · bar2)]

Representative linkage of unreduced catalyst precursor (ie precursor X1) was obtained as follows. A solution of 17.4 kg Co (Ho3) 2 · 6N2O, 9.6g (NH3) 4Pt (NO3) 2 and 11 kg of distilled water was mixed with 20 kg of carrier 0 - gamma-alumina (Purlox SCCa 5/150, volume then 0.48 ml / g, SASOL Germany GmbH, Uberseering 40, 22297, Hamburg, Germany) by adding the support to the solution. The suspension was added to a conical vacuum drier and continuously mixed. The temperature of this slurry was increased to 60 ° C, and then used at 20 kPa (a). During the first stage 3:00 drying temperature was slowly raised, it reaches 95 ° C after 3 hours. After 3 hours, the pressure was reduced to 3-15 kPa (a) was used and the drying rate of 2.5 m% / h at the point of incipient wetness. The complete impregnation and drying were achieved after 9 hours, after which the impregnated and dried catalyst support was immediately and directly loaded into the kiln with fluidized bed. The temperature and the dried impregnated catalyst support was about 75 ° C during loading the kiln. Loading lasted for about 1-2 minutes, the furnace temperature remained at the initial - about 75 ° C. The dried impregnated catalyst support was heated from 75 to 250 ° C at a heating rate of 0.5 ° C / min and a space velocity of 1.0 m2 Air n / kg Co (NO3) 2 · 6N2O / h and maintained at 250 ° C for 6 hours. To prepare catalyst with a cobalt loading of 30 g Co / 100g Al2O3, a second impregnation step was carried out / drying / calcining. A solution of 9.4 kg of Co (NO3) 2 · 6N2O, 15.7 g of (NH3) 4Pt (NO3) 2 in 15.1 kg of distilled water was mixed with 20, 0 kg of catalyst precursor after the first impregnation and calcination, by adding the catalyst precursor in solution. The suspension was added to a conical vacuum drier and continuously mixed. The temperature of this slurry was increased to 60 ° C, and then used at 20 kPa (a). During the first stage 3:00 drying temperature was slowly raised, it reaches 95 ° C after 3 hours. After 3 hours, the pressure was reduced to 3-15 kPa (a) was used and the drying rate of 2.5 m% / h at the point of incipient wetness. The complete impregnation and drying were achieved after 9 hours, after which the impregnated and dried catalyst support was immediately and directly loaded into the kiln with fluidized bed. The temperature and the dried impregnated catalyst support was about 75 ° C during loading the kiln. Loading lasted for about 1-2 minutes, the furnace temperature remained at the initial - about 75 ° C. The dried impregnated catalyst support was heated from 75 to 250 ° C at a heating rate of 0.5 ° C / min and a flow rate of air of 1.0 m 3 n / kg Co (NO3) 2 · 6H2O / h and maintained at 250 ° C for 6 hours. Thus obtained precursor cobalt catalyst.

Example 2.

For cobalt catalyst precursor of Example 1 (i.e., the catalyst precursor X1) was carried out with a programmed temperature recovery (TPR). TPR performed at atmospheric pressure using a heating rate (HR) of 2 ° C / min and feeding pure hydrogen at a rate of about 10.7 m 3 N / h · SGL in a fixed bed reactor. The results are shown in Figure 1. From Figure 1 it is seen that the activation takes place in two stages, and the end of activation stage 1 determines T * = 250 ° C.

Example 3.

The precursor of the cobalt catalyst prepared in Example 1, were reduced by different methods, as indicated in Table 1 and Table 2, and were tested in the implementation of the following Fischer-Tropsch synthesis:

10-30 g of reduced catalyst particles 38-150 .mu.m was suspended in 300 ml molten wax and loaded in a CSTR with an internal volume of 500 ml. The feed gas consisted of hydrogen and carbon monoxide in a molar ratio of H2 / CO ranging from 1.5 / 1 to 2.3 / 1. The reactor is heated by electricity and to eliminate mass transfer limitations in the gas-liquid mixers stirred at a sufficiently high speed. The feed flow was controlled by means of Brooks flow controller, used space velocities of from 2 to 4 m 3 N / Kgcat * h. In order to characterize the range of products using the GC gases and volatile hydrocarbons head.

After carrying out these tests in a CSTR slurry Fischer-Tropsch determined corresponding RIAFX1, i, as shown in Table 5, and correlated with activation methods shown in Table 1 and Table 2 and in Figures 2 and 3.

Example 4.

Precursors of cobalt-containing catalyst of Example 1 was reduced in a stream of hydrogen with a dew point clear, as shown in Table 3, and then used in the experiments for the Fischer-Tropsch synthesis in a slurry in CSTR as shown in Table 5.

Example 5.

Precursors of cobalt-containing catalyst of Example 1 was reduced in a gas flow with a certain content of hydrogen, as shown in Table 4 and used in the synthesis of the Fischer-Tropsch process, described in Example 3. The results of these experiments are calculated corresponding RIAFX1, i, as shown in Table 5 .

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The space velocity of the feed gas during catalyst activation is the normal volume of reducing gas fed to the reactor per unit time and per unit mass of reducible cobalt (m3 n / kgCo · h) during stage 1 activation and step 2 activation, where the subscript Co With denotes restored. In contrast, the feed gas space velocity during Fischer-Tropsch refers to the normal volume of gas supplied to the reactor per unit time and per unit mass of the calcined catalyst.

When carrying out the reduction of the catalyst precursor according to the invention during loading into a reactor for recovery, wherein the reduction is carried out, and during heating, which may include multiple exposures to a final temperature not exceeding 600 ° C, preferably a final temperature not exceeding 500 ° C, and more preferably a final temperature not exceeding 450 ° C, holding at the final temperature, followed by cooling to the unloading temperature not exceeding 180 ° C, and is usually carried out at about room temperature, the following various phases.

The drying step precedes the first activation stage. During the drying step, the following are valid combinations of process conditions (presence of gas and temperature): a dynamic pure hydrogen (with a preferred dewpoint ≤4 ° C, more preferably ≤-30 ° C) and the temperature that is slightly lower than the temperature in the first stage activation, but at the same time it is sufficiently high that the drying phase (ie the quantitative removal of moisture that was adsorbed during storage and / or preparation) was completed within one hour; or a dynamic inert gas, eg pure nitrogen (with a preferred dewpoint ≤4 ° C, more preferably ≤-30 ° C) and a temperature high enough (but not exceeding the calcination temperature used in the production of unreduced catalyst precursor) for to complete the drying phase for one hour. The drying step is complete when the delta dew point (ie the difference between the dew point of the tail gas and a dew point of the feed gas) ≤2 ° C. Once this difference in the drying step becomes a dynamic inert gas is less than 2 ° C, the inert gas must be replaced with pure hydrogen at a temperature which is slightly lower than the temperature normally used for the activation step 1, followed by application of HR1. Once the dew point difference in the drying step becomes a dynamic pure hydrogen is less than 2 ° C can be used HR1.

Step 1 activation starts with processing a pure un-reduced catalyst precursor (ie the intermediate product containing all the ability to recover cobalt as labilizirovannoy cobalt oxide in the absence of any matter that was accumulated during storage and / or preparation, such as physically adsorbed moisture) pure hydrogen at SV1 with the immediate application of HR1. Stage 1 ends with the activation temperature (for a specific heating program) when all the ability to recover the cobalt has been restored to the oxidation state of 2+. This can be determined by deconvolution of a typical TPR profile, obtained by using the same heating program. The result of such a deconvolution is shown in Figure 1, where T * indicates the end of activation stage 1. This temperature T * will be higher than the temperature peaks between the troughs.

Activation Step 2: Achievement of reduction temperature layer T * (Figure 1) using HR1 signals the beginning of the second stage. This stage ends at a temperature not exceeding 600 ° C, preferably not exceeding 500 ° C, and most preferably not exceeding 450 ° C when the desired degree of restoration of the ability to recover the cobalt was achieved. The preferred degree of resilience recovery of cobalt is from 50 to 100%, more preferably from 60 to 80%.

The cooling phase is started after completion of activation stage 2, and is also conducted in pure hydrogen. The reduction temperature is reduced to layer ≤Tc temperature in the presence of pure hydrogen. At temperatures ≤Tc pure hydrogen may be substituted with an inert gas of 100% (i.e. not containing H2 and O2, for example, pure nitrogen) and then in the fully recovered catalyst may be deposited wax used in the reactor the Fischer-Tropsch synthesis, the method described in ZA 2000/5666, incorporated herein by reference.

2 and 3, were constructed based on the values ​​given in Tables 1 and 2. Figure 2 illustrates the definition of "unwanted", "preferred" and "most preferred", as mentioned above, for allowable combinations of HR2 and SV2 for the case as NR1 = 1 ° C / min and SV1 = 13.7 m3 n / (kgCo · h). It will be appreciated that for each set of (HR1, SV1) should be structured separate graph, similar to that shown in Figure 3.

Proceeding from the prior art in this field, it was expected that an activation process to obtain a Fischer-Tropsch catalyst on a carrier with high intrinsic activity should include:

- The metal-containing precursor, after the final stage, usually after the baking step, is basically Co3O4;

- The recovery rate of Co3O4, inhibited contained water vapor; therefore, the activation conditions, such as gas space velocities and heating rate should be such as to ensure a water partial pressure below certain limits during the entire process of activation;

- Activation (reduction) to the state of Co3O4 metal not flowing in one step but in several, for example, in two successive stages, and

- Or using pure hydrogen, or diluted hydrogen containing inert diluents such as nitrogen.

However, the Applicant has unexpectedly found that:

- If the end of the metal containing precursor in the production process, such as after the last stage of the impregnation and calcination, in the beginning of the activation process is not Co3O4, whereas prior art conditions activate cobalt oxide precursors, consisting mainly of Co3O4 to obtain catalysts Fischer Tropsch carrier with high intrinsic activity may not be applicable;

- Recovery speed metal containing precursor when it is Co3O4 and quantifying the inhibitory effect of water vapor on this rate, as is known in the art do not apply when the metal-containing precursor is not Co3O4. Also, the activation conditions, eg gas space velocities and heating rates, see for Co3O4, i.e. to maintain the partial pressure of water is lower than a certain level can not be applied when the metal-containing precursor is not Co3O4;

- During the activation process should only use pure hydrogen; and

- If the metal containing precursors to activated metal state in two or more consecutive activation stages, it is possible to reject common, ie applicable to all the activation stages, activation conditions and apply separate, ie applicable to a single stage, activation conditions. Specific chemical substances that characterize the beginning and end of any specific activation step, the rate of recovery at this stage, and the inhibitory effect of water vapor on the rate of recovery at this stage, define a set of activation conditions for this particular stage. For example, the negative effect of the water vapor formed on the catalyst activity may be more pronounced for an earlier stage than for a later stage. Thus, at an earlier stage (ies) can not be used as low space velocities (eg to reduce hydrogen feed) and high heating rate (e.g., to reduce the time required for full recovery), as a later stage (ies) and still maintain a certain partial pressure of water. In other words, in the method of the invention involves obtaining a catalyst of the Fischer-Tropsch process, will produce more water atom reducible cobalt (by nitrate reduction, recovery of carbonates and / or recovery of cobalt oxide in a high degree of oxidation to the oxide of cobalt (II) ) than would be expected during the first activation stage

- The rate of water is higher (possibly because of the fact that the preferred phase (s) labilizirovannoy cobalt oxide is more porous) than in the case of Co3O4 on the first activation stage;

- This means that the control over water partial pressure is more important during the first activation stage (compared to using Co3O4) than during the second activation stage, necessitating use of lower heating rates / higher space velocities during the first activation stage .

Thus, the inventors have created a way to activate the cobalt catalysts which behave perfectly during the implementation of the Fischer-Tropsch process. Surprisingly, it was found that the activation of the precursor cobalt catalysts in which all of the ability to recover cobalt can be represented by the formula, wherein per mole of cobalt atoms contains more than 4/3 moles of oxygen atoms (e.g. SoOaNb where a≥1,7 and b &gt; 0, as described in WO 01 / 39882A1, or a compound of hydrotalcite type monometallic Soii 0,74Coiii 0,26 (OH) 2,01 (NO3) 0.21 (CO3) 0.02 × 0,6N2O or Coii 0,74Coiii 0.26 (OH), 1,99 (CO3) 0.13 (NO3) 0.01 × 0,7N2O as described in Chem. Matter. 2000, 12, 3459-3465) may be carried out in two stages of activation, and in the second activation stage, a higher heating rate and / or a lower feed gas space velocity.