CN102233268A - Fischer-Tropsch synthesis catalyst and application thereof - Google Patents

Abstract

A Fischer-Tropsch synthesis catalyst and application thereof, containing a carrier and an active metal component, characterized in that the carrier is obtained by roasting a pseudo-boehmite containing a transition metal additive component, calculated as an oxide and expressed as Based on the dry basis of the pseudo-boehmite, the content of the transition metal additive component in the pseudo-boehmite is 0.05-20% by weight, and the pseudo-boehmite includes at least one of 1.1≤n≤ The pseudo-boehmite P1 of 2.5; wherein, n=D(031)/D(120), the D(031) represents the crystal plane represented by the 031 peak in the XRD spectrum of the pseudo-boehmite crystal grains Grain size, D (120) represents the grain size of the crystal plane represented by the 120 peak in the XRD spectrum of the pseudo-boehmite grain, and the 031 peak refers to the 2θ in the XRD spectrum that is 34-43 ° Peak, the 120 peak refers to the peak of 2θ in the XRD spectrogram that 2θ is 23-33°, D=Kλ/(Bcosθ), K is the Scherrer constant, λ is the diffraction wavelength of the target material, and B is the half peak of the diffraction peak width, 2θ is the position of the diffraction peak.

Description

A kind of Fischer-Tropsch synthesis catalyst and its application

field of invention

The invention relates to a Fischer-Tropsch synthesis catalyst and its application, more specifically to a Fischer-Tropsch synthesis catalyst with transition metal-containing component alumina as a carrier and its application.

Background technique

In 1923, Fischer and Tropsch discovered the synthesis of hydrocarbon products from a mixture of CO and _H2 . In the 1930s, FT synthesis (Fischer-Tropsch synthesis) was first industrialized in Germany. Later, the United States, France, the former Soviet Union and China also established similar synthetic oil plants. After World War II, the cost of this route was high, and the benefits could not be compared with oil Due to the competition, only South Africa has developed the FT synthesis technology of coal-to-oil based on its rich coal resources. At present, the FT synthesis technology of Sasol Company is still developing and perfecting. In the 1970s, the Dutch Shell company started the research on FT synthesis. The cobalt catalyst they developed was put into production in Malaysia in 1993. In recent years, with the increasing shortage of petroleum resources, rising crude oil prices, increasingly stringent fuel requirements, and increasing proven reserves of coal and natural gas, the research in this field of FT synthesis is very active, and many companies are working on FT synthesis Conducted research and development.

A good catalyst for FT synthesis should have adsorption activity for CO and _H2 , have a hydrogenation effect on the adsorbed CO, contribute to chain growth, and promote hydrogenation mildly, while at the same time, it should not be too strong hydrogenation, excessive water-gas shift, and the formation of non- Activated carbide, etc. The first step in FT synthesis is the chemisorption of CO and _H2 . From the viewpoint of structural chemistry, transition elements with 3d and 4f bonds and energy levels are mostly used as active components of FT synthesis catalysts. Among them, there are many studies on Ni, Fe, Co, and Ru. Except that Ni is mainly used for methanation and is not suitable as an active component for the synthesis of polymer wax catalysts due to its strong hydrogenation activity, which makes the chain growth rate too high, the other three metal catalysts can be used for FT synthesis. However, Co and Fe catalysts are of commercial application value. Because of Co’s high FT synthesis activity, mild reaction conditions, less water-gas shift reaction, stable performance, and longer life, people have carried out more research and application on Co catalysts. Extensive research.

For Co catalysts for F-T, unsupported oxides were used in the early stage, such as pure cobalt oxides, cobalt-chromium oxides and cobalt-zinc oxides; later it was found that adding thorium oxide and magnesium oxide can increase the activity of the catalyst; Currently, carrier-supported Co catalysts are the mainstream of research and industrial applications. For the Co catalyst for F-T synthesis, the researchers selected a variety of additives to modify it in order to improve its catalytic performance.

Disclosed in the patent CN89109859 and 93106465 is a kind of catalyst preparation method and use method, and this catalyst comprises the cobalt of the catalytic activity amount that is loaded on the aluminum oxide carrier and is selected from platinum, iridium, rhodium, and the mixture thereof that is also sensitive to the loading amount. second metal. Metal oxide promoters may be added.

Patents CN01810769.9 and 01810773 disclose a method for preparing and using a catalyst, the catalyst includes a catalytically active amount of cobalt, the content of which is 5gCo/100g-70gCo/100g carrier, and Pd and Pt can also be added as a catalyst with enhanced Co Reductive dopants.

Patent CN01118173 discloses a F-T synthesis catalyst, which is a Ln-Co-based supported catalyst, wherein LnO represents one or more than one alkali metal, alkaline earth metal, transition metal or rare earth element oxide, and the oxide and The loading amount of Co relative to the carrier is: Co: 1.0-20% by weight, LnO: 0.1-20% by weight. Where Ln represents La, Ce, Mg, Mn, Zr, Ni, K.

Patent CN200680022459 discloses a catalyst and a method for preparing the catalyst. The catalyst includes 5-75wt% cobalt supported on an oxidized carrier, and the oxidized carrier includes aluminum and 0.01-20wt% lithium. The catalyst can be used in the F-T synthesis of hydrocarbons.

Disclosed in the patent CN88107330 and 91104473 is a kind of catalyst preparation method and use method, and this catalyst comprises the cobalt that has catalytic activity amount, and its content can be up to 60% (weight) and the rhenium that has catalytic activity amount, and its content is about catalyst cobalt content 0.5-50% (weight) of cobalt and rhenium are loaded on alumina. An alkali metal component can also be added to the catalyst as an auxiliary agent.

Contents of the invention

The technical problem to be solved by the present invention is to provide a Fischer-Tropsch synthesis catalyst with modified properties and a Fischer-Tropsch synthesis method using the catalyst on the basis of the prior art.

The invention provides a Fischer-Tropsch synthesis catalyst, which contains a carrier and an active metal component, and is characterized in that the carrier is obtained by roasting a pseudo-boehmite containing a transition metal component, calculated as an oxide And based on the dry basis of the pseudo-boehmite, the content of transition metal components in the pseudo-boehmite is 0.05-20% by weight, and the pseudo-boehmite includes at least one 1.1≤n Pseudo-boehmite P1 of ≤2.5; wherein, n=D(031)/D(120), said D(031) represents the crystal plane represented by peak 031 in the XRD spectrum of pseudo-boehmite grains D (120) represents the grain size of the crystal face represented by the 120 peak in the XRD spectrum of the pseudoboehmite grain, and the 031 peak means that 2θ in the XRD spectrum is 34-43 ° The 120 peak refers to the peak with 2θ of 23-33° in the XRD spectrum, D=Kλ/(Bcosθ), K is the Scherrer constant, λ is the diffraction wavelength of the target material, and B is half of the diffraction peak Peak width, 2θ is the position of the diffraction peak.

The present invention further provides a Fischer-Tropsch synthesis method, comprising contacting and reacting a mixture of carbon monoxide and hydrogen with a catalyst under Fischer-Tropsch synthesis reaction conditions, characterized in that the catalyst is the aforementioned catalyst provided by the present invention.

The Fischer-Tropsch synthesis catalyst provided by the invention adopts a support prepared by including at least one pseudo-boehmite P1 of 1.1≤n≤2.5 containing transition metal additive components, so that the performance of the catalyst is improved.

For example, in the case of the catalyst having the same content of active metal components and the same preparation conditions, compared with the reference agent, the CO conversion activity of the catalyst provided by the present invention can be increased by 4-8%, and the selectivity of methane can be reduced by 2-3%.

Detailed ways

According to the catalyst provided by the present invention, wherein, the pseudo-boehmite containing the transition metal addition component is calculated as oxide and based on the dry basis of the pseudo-boehmite, and the transition metal addition component The content of can be selected between 0.05-20% by weight, and the preferred content is 0.1-10% by weight. The dry basis here refers to the percentage of the weight ratio of the pseudo-boehmite after being calcined at 600° C. for 4 hours to the weight before calcining.

According to the pseudo-boehmite provided by the present invention, the content and type of transition metal components may be different depending on the final use purpose of alumina. For example, in order to improve the transformation of γ-alumina to α-alumina phase during high-temperature calcination, and improve the thermal stability of γ-alumina, the pseudo-boehmite preferably contains metals selected from lanthanides, group IVB metals (such as One or more transition metal components in Zr), VB group metals (such as Ta), VIB group metals (such as W), VIIB group metals (such as Mn), IIB group metals (such as Zn), wherein, with oxidation There are several types of pseudo-boehmite on a dry basis, and the content of the transition metal component can be selected between 0.05-20% by weight, and the preferred content is 0.1-10% by weight.

In order to improve the activity of the F-T synthesis catalyst, the pseudo-boehmite preferably contains metals selected from Group VB (such as Ta), Group VIB metals (such as Mo, W), Group IB metals (such as Cu), metals from Group VIII ( For example, one or several transition metal components in Ru, Re), wherein, in terms of oxides and the pseudo-boehmite dry basis is several, the content of the transition metal components can be 0.05-20% by weight Choose between, the preferred content is 0.1-10% by weight.

In order to improve the selectivity of the C5+ of the F-T synthesis catalyst, the pseudo-boehmite preferably contains one or more selected from Group IVB metals (such as Ti, Zr), Group VIII metals (such as Ru) and rare earth metals Transition metal components, wherein, in terms of oxides and the pseudo-boehmite dry basis, there are several types, the content of the transition metal components can be selected between 0.05-20% by weight, and the preferred content is 0.1-10% weight%.

In order to improve the regeneration performance of the Co-based F-T synthesis catalyst, the pseudo-boehmite preferably contains one or more selected from Group IVB metals (such as Hf), Group VIII metals (such as Ru, Re) and rare earth metals. Transition metal components, wherein, in terms of oxides and the pseudo-boehmite dry basis, there are several types, the content of the transition metal components can be selected between 0.05-20% by weight, and the preferred content is 0.1-10% weight%.

On the premise that the content of the added component in the pseudo-boehmite meets the requirements, the present invention has no particular limitation on the introduction method of the transition metal added component. For example, it may be a method of introducing a compound containing a transition metal additive component in the process of preparing the pseudo-boehmite P1 with 1.1≤n≤2.5, or it may be that the pseudo-boehmite P1 with 1.1≤n≤2.5 is prepared first. Boehmite P1, which is then introduced by mixing it with a compound containing a transition metal addition component. Wherein, the compounds containing transition metal components may be their salts, oxides or acids (including, for example, molybdic acid, tungstic acid, etc.), preferably the water-soluble compounds therein.

The preparation method of pseudo-boehmite P1 with 1.1≤n≤2.5 includes: contacting an aluminum-containing compound solution with acid or alkali for precipitation reaction, or contacting an organic aluminum-containing compound with water for hydrolysis reaction to obtain hydrated alumina Aging the alumina hydrate obtained above, wherein, the contact of the aluminum-containing compound solution with acid or alkali or the contact of the organic aluminum-containing compound with water and the aging of the alumina hydrate are carried out in the crystal grains The process is carried out in the presence of a growth regulator, which is a substance capable of regulating the growth rate of crystal grains on different crystal planes.

Although the object of the present invention can be achieved as long as any one of the hydrolysis reaction or the precipitation reaction and the aging process is carried out in the presence of a grain growth regulator, preferably, the hydrolysis reaction and the aging process or the precipitation reaction Both the aging process and the aging process are carried out in the presence of a grain growth regulator, so that the n of the obtained pseudo-boehmite can be preferably in the range of 1.2≤n≤2.2.

Wherein, there is no particular limitation on the amount of the grain growth regulator, preferably the amount of the grain growth regulator in the hydrolysis reaction is 0.5-10% by weight of the weight of the organic aluminum-containing compound to be hydrolyzed, more preferably 1-8.5% by weight , more preferably 5-8.5% by weight; the amount of the grain growth regulator in the precipitation reaction is 0.5-10% by weight of the weight of the inorganic aluminum-containing reactant, more preferably 1-8.5% by weight, even more preferably 5- 8.5% by weight; during the aging process, the grain growth regulator can be used in an amount of 0.5-10% by weight of the alumina hydrate, preferably 1-8.5% by weight, and more preferably 5-8.5% by weight. Unless otherwise specified, in the present invention, the amount of the grain growth regulator is calculated based on the weight of the organic aluminum-containing compound, the inorganic aluminum-containing compound and the corresponding alumina in the hydrated alumina. That is, in terms of alumina, in the precipitation reaction, the amount of the grain growth regulator is 0.5-10% by weight of the weight of the inorganic aluminum-containing compound; in the hydrolysis reaction, the amount of the grain growth regulator is The amount used is 0.5-10% by weight of the weight of the organic aluminum-containing compound, and the amount of the grain growth regulator used during the aging process is 0.5-10% by weight of the weight of the hydrated alumina.

In the present invention, the grain growth regulator can be various substances capable of regulating the growth rate of grains on different crystal planes, especially substances capable of regulating the growth rates of grains on the 120 crystal plane and the 031 crystal plane, It is preferably polyhydric sugar alcohol and carboxylate thereof, specifically, it may be one or more of sorbitol, glucose, gluconic acid, gluconate, ribitol, ribobic acid, and ribose salt. Each of the gluconate and ribose salt can be their soluble salts, for example, one or more of potassium salt, sodium salt and lithium salt.

In the preparation process of the pseudo-boehmite described in the present invention, there is no particular limitation on the adding method of the grain growth regulator, the grain growth regulator can be added separately, or the grain growth regulator can be mixed with the grain growth regulator in advance. One or more of the raw materials are mixed, and then the raw materials containing the grain growth regulator are reacted.

Wherein, the inorganic aluminum-containing compound solution can be various aluminum salt solutions and/or aluminate solutions, and the aluminum salt solution can be various aluminum salt solutions, such as aluminum sulfate, aluminum chloride, aluminum nitrate One or several aqueous solutions. Because the price is low, aluminum sulfate and aluminum chloride solution are preferred. Aluminum salts can be used alone or in combination of two or more. The aluminate solution is any aluminate solution, such as sodium aluminate solution and/or potassium aluminate solution. Sodium aluminate solutions are preferred because of their availability and low cost. Aluminate solutions can also be used alone or in combination.

The concentration of the aluminum salt solution and/or aluminate solution is not particularly limited, and is preferably 0.2-1.1 mol/liter calculated as alumina.

The acid can be various protonic acids or acidic oxides in aqueous medium, for example, it can be one or more of sulfuric acid, hydrochloric acid, nitric acid, carbonic acid, phosphoric acid, formic acid, acetic acid, citric acid, oxalic acid, Preferred protic acid is selected from one or more of nitric acid, sulfuric acid, hydrochloric acid. The carbonic acid can be generated in situ by passing carbon dioxide into the aluminum salt solution and/or aluminate solution. The concentration of the acid solution is not particularly limited, preferably the concentration of H ⁺ is 0.2-2 mol/liter.

The alkaline solution can be a hydroxide or a salt that is hydrolyzed in an aqueous medium to make the aqueous solution alkaline, and the preferred hydroxide is selected from one or more of ammonia, sodium hydroxide, and potassium hydroxide; preferred The salt is selected from one or more of sodium metaaluminate, potassium metaaluminate, ammonium bicarbonate, ammonium carbonate, sodium bicarbonate, sodium carbonate, potassium bicarbonate, and potassium carbonate. The concentration of the alkaline solution is not particularly limited, and the concentration of OH ^- is preferably 0.2-4 mol/liter. When sodium metaaluminate and/or potassium metaaluminate is used as the base, the amount of corresponding aluminum oxide in sodium metaaluminate and/or potassium metaaluminate is also considered when calculating the dosage of the grain growth regulator.

The organic aluminum-containing compound can be one or more of various aluminum alkoxides that can undergo hydrolysis reactions with water to produce alumina hydrate precipitation, such as aluminum isopropoxide, aluminum isobutoxide, triisobutoxide One or more of aluminum propoxide, aluminum tri-tert-butoxide and aluminum isooctoxide. The ratio of the amount of the organic aluminum-containing compound to water is not particularly limited, and the amount of water is preferably greater than the stoichiometrically required amount.

In the preparation process of pseudo-boehmite described in the present invention, the conditions for the precipitation reaction are not particularly limited, preferably the pH value is 3-11, more preferably 6-10; the temperature can be 30-90°C, Preferably it is 40-80°C.

Among them, the method of precipitating aluminum by controlling the amount of alkali or acid used in the reactant is well known to those skilled in the art.

The conditions of the hydrolysis reaction are not particularly limited, as long as the water contacts with the aluminum alkoxide and undergoes a hydrolysis reaction to generate hydrated alumina, and the specific conditions for the hydrolysis to occur are known to those skilled in the art.

Among them, the compound that can regulate the grain growth can be added to the slurry of alumina hydrate obtained from the hydrolysis reaction or precipitation reaction or the slurry prepared by adding water to the filter cake after filtration, and the pH value can also be adjusted by adding an alkali solution or an acid solution. to 7-10, and then aged at an appropriate temperature. Then separate, wash and dry.

The acid solution or base solution may be the same as or different from that described above.

The aging temperature is preferably 35-98°C, and the aging time is preferably 0.2-6 hours.

According to the method provided by the present invention, the separation is a well-known technique in the art, such as filtration or centrifugation or evaporation.

In the preparation process of pseudo-boehmite according to the present invention, after aging, the steps of washing and drying that are often included in the process of preparing pseudo-boehmite are also included, and the method of washing and drying is to prepare pseudo-boehmite idiomatic method. For example, drying, blast drying or spray drying can be used. Generally speaking, the drying temperature can be 100-350°C, preferably 120-300°C.

According to the preparation method of pseudo-boehmite of the present invention, a preferred embodiment comprises the following steps:

(1) Add the aluminum-containing compound solution containing the grain growth regulator and the alkali solution or the acid solution in parallel or intermittently to the reaction vessel for precipitation reaction to obtain a hydrated alumina slurry; or add grain growth in deionized water The regulator and the aluminum alkoxide undergo a hydrolysis reaction to obtain a hydrated alumina slurry;

(2) Add water to the alumina slurry obtained after filtering the hydrated alumina slurry obtained in step (1), add a grain growth regulator, adjust the pH to 7-10, and heat the filter cake at 35-98°C Aging for 0.2-6 hours; the alumina hydrate slurry obtained in the above step (1) can also be aged at 35-98° C. for 0.2- 6 hours;

(3) filtering, washing the product obtained in step (2);

(4) drying the product obtained in step (3) to obtain the pseudo-boehmite with 1.1≤n≤2.5 provided by the present invention.

When the compound containing the transition metal additive component is introduced in the process of preparing the pseudo-boehmite P1 with 1.1≤n≤2.5, the transition metal compound can be added in the above steps (1), (2), (3 ) or (4) introduced in any one or several steps.

According to the catalyst provided by the present invention, wherein, the pseudo-boehmite may also include pseudo-boehmite P2 other than pseudo-boehmite with 1.1≤n≤2.5, where P2 is n<1.1 The pseudo-boehmite is preferably pseudo-boehmite with a P2 of 0.8<n<1.1, more preferably a pseudo-boehmite with a P2 of 0.85≤n≤1.05. When the composition contains P2, based on the total amount of pseudo-boehmite, the content of P2 is not more than 70% by weight, more preferably not more than 50% by weight, more preferably not more than 30% by weight. The pseudo-boehmite whose P2 is 0.8<n ₂ <1.1 can be selected from commercially available products or pseudo-boehmite prepared by any prior art.

The pseudo-boehmite containing transition metal additive components of the present invention is calcined to obtain the alumina containing metal additive components of the present invention, and the roasting method is a conventional method and condition. For example, when the target alumina is γ-alumina, the calcination conditions include: the calcination temperature is 350-950°C, preferably 450-900°C, and the calcination time is 1-12 hours, preferably 2-8 hours. Hour.

According to the catalyst provided by the present invention, wherein the active metal component is a usual active metal component in FT synthesis catalysts. For example, a Group VIII cobalt and/or iron metal component is chosen. The content of the metal component is a conventional content, based on the oxide and based on the catalyst, the preferred content of the active metal component is 5 to 70% by weight, more preferably 10 to 50% by weight, more preferably 12 to 30% by weight.

According to the catalyst provided by the present invention, if necessary, it can be made into any moldings that are easy to handle, such as spherical, compressed tablet and strip. The molding can be carried out by conventional methods, such as tableting, ball rolling, extrusion and other methods.

The catalyst provided by the invention can be prepared by conventional methods. For example, when the catalyst provided by the invention is a strip catalyst, its preparation method includes: (1) adding the pseudo-boehmite P1 (containing or without P2) extrusion molding, drying and roasting to prepare the carrier; wherein, during extrusion molding, water and extrusion aids can be added to the pseudo-boehmite containing transition metal additive components And/or adhesive, then extruded molding; The type and consumption of described extruding aid, peptizing agent are well known to those skilled in the art, for example common extruding aid can be selected from kale powder, methyl cellulose, starch, One or more of polyvinyl alcohol and polyethylene alcohol; the drying temperature can be 100-200°C, preferably 120-150°C; the calcination temperature is 350-950°C, preferably 450-900°C, and the calcination time 1-12 hours, preferably 2-8 hours; (2) introducing active metal components into the carrier by impregnation, drying and calcining; wherein, the drying temperature can be 100-200°C, preferably It is 120-150°C. The firing temperature can be 400-650°C, preferably 450-600°C, and the firing time is 1-15 hours, preferably 3-10 hours. The impregnation method is a conventional method, such as preparing a solution of the compound containing the active metal component, and then impregnating, drying and roasting by soaking or spraying. The compound containing the active metal component is selected from one or more of these soluble compounds, for example, it can be nitrate, acetate, carbonate, chloride, soluble complexes of these metals one or more of.

One or more additive components selected from Cu, Mo, Ta, W, Ru, Zr, Ti, REO, Re, Hf, Ce, Mn, V and noble metals, wherein the noble metals are selected from Pt, One or more of Pd, Rh, Ir, and the more preferred noble metal is Pt, which is a commonly used additive component for Fischer-Tropsch synthesis catalysts known in the art. According to the catalyst of the present invention, if necessary, it may optionally contain one or more selected from the above auxiliary components. In addition to noble metals, the content of the auxiliary components is preferably not more than 30% by weight, more preferably not more than 20% by weight, and more preferably not more than 15% by weight, based on oxides and catalysts. When the auxiliary component is selected from noble metals, the content of the auxiliary component is preferably less than 10% by weight, more preferably less than 1% by weight, based on the metal and catalyst.

When the catalyst also contains the auxiliary component, the preparation method of the catalyst further includes a step of introducing the auxiliary component into the catalyst. According to the usual method for preparing FT synthesis catalysts, the auxiliary component can be introduced before, after or simultaneously with the active metal component. For example, it is introduced by impregnating with a solution containing the compound of the auxiliary component before, after or simultaneously with loading the metal component.

According to the Fischer-Tropsch synthesis method provided by the present invention, wherein the Fischer-Tropsch synthesis reaction conditions are conventional reaction conditions for Fischer-Tropsch synthesis reactions. For example, according to the conventional methods in this field, the catalyst is first reduced, and suitable reduction conditions include: the reduction temperature is 100°C to 800°C, preferably 200°C to 600°C, more preferably 300°C to 450°C; the reduction time is 0.5-72 hours, preferably 1-24 hours, more preferably 2-8 hours, the reduction can be carried out in pure hydrogen, also can be carried out in a mixture of hydrogen and inert gas, such as hydrogen and nitrogen and/or Or in the mixed gas of argon, the hydrogen pressure is 0.1-4MPa, preferably 0.1-2MPa.

According to the FT synthesis method provided by the present invention, the conditions for the contact reaction of the mixture of carbon monoxide and hydrogen with the catalyst: preferably the temperature is 160-280°C, more preferably 190-250°C, and the pressure is preferably 1-8MPa, further Preferably 1-5 MPa, the molar ratio of hydrogen to carbon monoxide is 0.4-2.5, preferably 1.5-2.5, more preferably 1.8-2.2, and the gas hourly space velocity is 200-10000h ^-1 , preferably 500-4000h ^-1 .

The invention will be illustrated below by way of examples. The reagents used in the examples are chemically pure reagents unless otherwise specified.

Examples 1-6 illustrate that the present invention provides the pseudo-boehmite, alumina and preparation methods thereof.

Example 1

(1) Pseudo-boehmite containing transition metals

In a 2-liter reaction tank, add 600 milliliters of concentration of 96 grams of alumina per liter, which contains 3.6 grams of ribitol and 0.7 grams of ammonium metatungstate ((NH ₄ ) 6H ₂ W ₁₂ 0 ₄₀ ·XH ₂ O, The weight content of WO ₃ is about 88%) aluminum nitrate solution and the ammonia solution of 8 weight percent carry out precipitation reaction, and reaction temperature is 40 ℃, and the reaction time is 10 minutes, and the flow rate of control ammonia solution makes the pH of reaction system be 7. After the precipitation reaction is over, add ammonia water to the slurry to make the pH of the slurry 8.5, age the slurry at 55°C for 60 minutes and then filter, beat and wash the filter cake twice with deionized water, and dry the filter cake at 120°C for 24 hours , to obtain hydrated alumina P1-1, characterized by XRD, P1-1 has a pseudo-boehmite structure.

XRD was measured on a SIMENS D5005 X-ray diffractometer, CuKα radiation, 44 kV, 40 mA, and a scanning speed of 2°/min. According to the Scherrer formula: D=Kλ/(Bcosθ) (D is the grain size, λ is the diffraction wavelength of the target material, B is the half-maximum width of the corrected diffraction peak, and 2θ is the position of the diffraction peak) with 2θ as The parameters of the 23-33 ° peak calculate the grain size of (120) to be D (120), and the parameters of the 34-43 ° peak calculate the grain size of (031) to be D (031) with 2θ, and calculate n=D(031)/D(120), the n value of P1-1 obtained through XRD characterization and calculation is listed in Table 1.

(2) Aluminum oxide containing metal additive components

Mix the mixed solution of 3 grams of nitric acid and 120 grams of deionized water with 200 grams of P1-1, then knead it into a plastic body on a twin-screw extruder, and extrude it into a clover-shaped strip of ф1.2 mm. The wet strip is subjected to 120 ° C After drying for 4 hours, it was calcined at 600° C. for 4 hours to obtain carrier Z1, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Comparative Examples 1-5 refer to pseudoboehmite, alumina and their preparation methods.

Comparative example 1

(1) Pseudo-boehmite containing transition metals

Prepare pseudo-boehmite according to the method of Example 1-(1), the difference is that the aluminum nitrate solution containing ribitol is replaced by the aluminum nitrate solution with a concentration of 96 grams of alumina/liter, that is, there is no aluminum nitrate solution in the aluminum nitrate solution Containing ribitol, get hydrated alumina P2-1. According to the method of Example 1, XRD was used to characterize. P2-1 had a pseudo-boehmite structure.

(2) Aluminum oxide containing metal additive components

According to the method of Example 1-(2), P2-1 was used to prepare alumina to obtain carrier CZ1, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Example 2

(1) Pseudo-boehmite containing transition metals

In a 2-liter reaction tank, add 800 milliliters of 60 grams of alumina/liter, 3.9 grams of gluconic acid and 10.4 grams of ammonium metatungstate ((NH ₄ ) 6H ₂ W ₁₂ O ₄₀ XH ₂ O, the weight content of WO ₃ is about 88%) aluminum nitrate solution and 300 milliliters of sodium metaaluminate solution containing 200 grams of alumina/liter, caustic coefficient is 1.58 to carry out precipitation reaction, reaction temperature is 55 ℃, Regulate the reactant flow rate so that the neutralizing pH value is 7.0, filter after the reaction stays for 15 minutes, beat the gained solid with deionized water, then add a sodium bicarbonate solution with a concentration of 150 grams per liter in the resulting slurry to adjust the pH of the slurry to 9.0, and warming up to 65°C, aging for 5 hours, and then filtering with a vacuum filter, after the filtration, add 20 liters of deionized water (temperature 65°C) on the filter cake to rinse the filter cake for about 30 minutes. The filter cake was dried at 120°C for 24 hours to obtain hydrated alumina P1-2. According to the method of Example 1, XRD was used to characterize, P1-2 had a pseudo-boehmite structure, and the n value of P1-2 obtained through XRD characterization was listed in Table 1.

(2) Aluminum oxide containing metal additive components

According to the method of Example 1-(2), P1-2 was used to prepare alumina to obtain carrier Z2, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Comparative example 2

(1) Pseudo-boehmite containing transition metals

Pseudo-boehmite was prepared according to the method of Example 2-(1), except that the aluminum nitrate solution containing glucose was replaced with an aluminum nitrate solution with a concentration of 60 g alumina/liter to obtain hydrated alumina P2-2. Characterized by XRD according to the method of Example 1, P2-2 has a pseudo-boehmite structure, and the n value of P2-2 obtained through XRD characterization is listed in Table 1.

(2) Aluminum oxide containing metal additive components

According to the method of Example 1-(2), P2-2 was used to prepare alumina to obtain carrier CZ2, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Example 3

(1) Pseudo-boehmite containing transition metals

In a 2.5 liter three-necked flask with stirring and reflux condenser, adding sodium ribonate content is 0.5% by weight of isopropanol-water azeotrope (water content is 15% by weight) 1000 grams, heated to 90 ° C, 500 grams of molten triisopropoxy aluminum was slowly added dropwise to the flask through a separatory funnel, and after 24 hours of reflux reaction, the dehydrated isopropanol was evaporated, and then 3.3 grams of ammonium molybdate ((NH ₄ ) ₆ Mo was added in three batches. ₇ O ₂₄ ·4H ₂ O) 1.5 liters of deionized water with a sodium ribonate content of 0.5% by weight, aged at 90° C. for 4 hours, steamed the isopropanol containing water while aging, filtered the hydrated aluminum oxide after aging, and Dry at 120°C for 24 hours to obtain hydrated alumina P1-3. According to the method of Example 1, XRD was used to characterize. P1-3 had a pseudo-boehmite structure.

(2) Aluminum oxide containing metal additive components

According to the method of Example 1-(2), P1-3 was used to prepare alumina to obtain carrier Z3, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Comparative example 3

(1) Pseudo-boehmite containing transition metals

Prepare pseudo-boehmite according to the method of Example 3-(1), the difference is that the azeotrope of isopropanol-water (water content is 15% by weight) and deionized water do not add sodium ribonate to obtain hydrated Alumina P2-3. Characterized by XRD according to the method of Example 1, P2-3 has a pseudo-boehmite structure, and the n value of P2-3 obtained through XRD characterization is listed in Table 1.

(2) Aluminum oxide containing metal additive components

According to the method of Example 1-(2), P2-3 was used to prepare alumina to obtain carrier CZ3, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Example 4

(1) Pseudo-boehmite containing transition metals

In a 2.5 liter three-necked flask with stirring and reflux condenser, adding sodium ribonate content is 0.5% by weight of isopropanol-water azeotrope (water content is 15% by weight) 1000 grams, heated to 85 ℃, 500 grams of melting triisopropoxy aluminum was slowly added dropwise into the flask through a separatory funnel, and after reflux reaction for 24 hours, steamed dehydrated isopropanol, and then added 2.8 grams of manganese nitrate (as Mn(NO ₃ ) ₂ Added in the form of a solution) and 3.2 grams of zirconium nitrate (Zr(NO ₃ ) ₄ 5H ₂ O) with a sodium ribonate content of 0.5% by weight, 1.5 liters of deionized water, aged at 85°C for 4 hours, and steamed out the water content while aging Isopropanol, the aged alumina hydrate was filtered and dried at 120°C for 24 hours to obtain alumina hydrate P1-4. According to the method of Example 1, XRD was used to characterize, P1-4 had a pseudo-boehmite structure, and the n values of P1-4 calculated by XRD characterization were listed in Table 1.

(2) Aluminum oxide containing metal additive components

According to the method of Example 1-(2), P1-4 was used to prepare alumina to obtain carrier Z4, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Comparative example 4

(1) Pseudo-boehmite containing transition metals

Prepare pseudo-boehmite according to the method of Example 4-(1), the difference is that the azeotrope of isopropanol-water (water content is 15% by weight) and deionized water do not add sodium ribonate to obtain hydrated Alumina P2-4. Characterized by XRD according to the method of Example 1, P2-4 has a pseudo-boehmite structure, and the n value of P2-4 obtained through XRD characterization is listed in Table 1.

(2) Aluminum oxide containing metal additive components

According to the method of Example 1-(2), P2-4 was used to prepare alumina to obtain carrier CZ4, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Example 5

(1) Pseudo-boehmite containing transition metals

In a 2-liter three-neck flask with stirring and reflux condenser, add 1000 grams of isopropanol-water azeotrope (water content is 15% by weight), heat to 60 ° C, and pass 500 grams of molten aluminum isopropoxide through the The liquid funnel was slowly added dropwise in the flask, and after reflux reaction for 20 hours, the dehydrated isopropanol was steamed, and then the ribose acid content 7% by weight of 7.3 grams of lanthanum nitrate (La(NO ₃ ) ₃ 6H ₂ O) was added in 3 times. 1.5 liters of deionized water, aged at 60°C for 6 hours, and the pH value of the aging was 8, distilled out isopropanol containing water while aging, filtered the aged hydrated alumina, and dried at 120°C for 24 hours to obtain hydrated oxide Aluminum P1-4. Characterized by XRD according to the method of Example 1, P1-5 has a pseudo-boehmite structure, and the n values of P1-5 obtained through XRD characterization are listed in Table 1.

(2) Aluminum oxide containing metal additive components

According to the method of Example 1-(2), P1-5 was used to prepare alumina to obtain carrier Z5, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Comparative example 5

(1) Pseudoboehmite

Take the commercial pseudo-boehmite product SB powder sold by Sasol Company, the number is P2-5, and it is characterized by XRD according to the method of Example 1. P2-5 has a pseudo-boehmite structure, and P2-5 is obtained through XRD characterization calculation. The values of n are listed in Table 1. Lanthanum nitrate is introduced by impregnation.

(2) Alumina

According to the method of Example 1-(2), P2-5 was used to prepare alumina to obtain carrier CZ5, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Comparative example 6

1) Pseudoboehmite

Get the commercial pseudo-boehmite product SD powder sold by China Aluminum Co., Ltd. Shanlv Company, the number is P2-6, and it is characterized by XRD according to the method in Example 1. P2-6 has a pseudo-boehmite structure. The n value of the SD powder obtained through characterization calculation is listed in Table 1. Lanthanum nitrate is introduced by impregnation.

(2) Alumina

According to the method of Example 1-(2), P2-6 was used to prepare alumina to obtain carrier CZ6, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Example 6

(1) Pseudo-boehmite containing transition metals

According to Example 1, in a 2-liter reaction tank, 600 milliliters of 96 grams of alumina/liter, containing 3.6 grams of ribitol and 0.7 grams of ammonium metatungstate ((NH ₄ ) 6H ₂ W ₁₂ O ₄₀ , were added in parallel. XH ₂ O, the weight content of WO ₃ is about 88%) aluminum nitrate solution and concentration are the ammonia solution of 8 weight % to carry out precipitation reaction, and reaction temperature is 40 ℃, and reaction time is 10 minutes, and the flow rate of control ammonia solution makes The pH of the reaction system was 7. After the precipitation reaction, ammonia water was added to the slurry to make the pH of the slurry 8.5. The slurry was aged at 55° C. for 60 minutes and then filtered to obtain a filter cake.

According to the method of Comparative Example 1-(1), pseudo-boehmite was prepared to obtain a filter cake.

According to the ratio of mass parts 85:15, two kinds of filter cakes were mixed, beat and washed twice with deionized water, and the filter cake was dried at 120°C for 24 hours to obtain hydrated alumina P1-6, which was characterized by XRD, and P1-6 had Pseudo-boehmite structure. The n values of P1-6 calculated by XRD characterization are listed in Table 1.

(2) Aluminum oxide containing metal additive components

Mix the mixed solution of 3 grams of nitric acid and 120 grams of deionized water with 200 grams of P1-6, then knead it into a plastic body on a twin-screw extruder, and extrude it into a clover-shaped strip of ф1.2 mm. The wet strip is subjected to 120 ° C After drying for 4 hours, it was calcined at 600° C. for 4 hours to obtain carrier Z6, which was characterized by XRD as γ-alumina. Fluorescence method was used to measure the content of added metal components, and BET nitrogen adsorption method was used to measure pore volume, specific surface area and programmable pore diameter. The results are listed in Table 2.

Table 1

*The crystallinity of each sample was measured based on Condea's commercial SB powder.

Table 2

Examples 7-12 illustrate the Fischer-Tropsch synthesis catalysts prepared from the alumina-shaped support provided by the present invention.

Saturated impregnation of Z1, Z2, Z3, Z4, Z5 and Z6 supports with a mixed solution containing cobalt nitrate and ruthenium chloride, followed by drying and roasting to obtain catalysts C1, C2, C3, C4, C5 and C6. Wherein, the drying temperature is 120°C, the drying time is 4 hours, the calcination temperature is 400°C, and the calcination time is 3 hours. The amounts of cobalt nitrate and ruthenium chloride are such that the content of cobalt oxide in the final catalyst is 15% by weight and the content of ruthenium is 0.1%.

Comparative Examples 7-12

The CZ1, CZ2, CZ3, CZ4, CZ5 and CZ6 supports are impregnated with a mixed solution containing cobalt nitrate and ruthenium chloride, followed by drying and roasting to obtain catalysts CC1, CC2, CC3, CC4, CC5 and CC6. Wherein, the drying temperature is 120°C, the drying time is 6 hours, the calcination temperature is 400°C, and the calcination time is 3 hours. The amounts of cobalt nitrate and ruthenium chloride are such that the content of cobalt oxide in the final catalyst is 15% by weight, and the content of ruthenium is 0.1% by weight.

Examples 13-18 illustrate the application and effect of the catalyst provided by the present invention.

The Fischer-Tropsch synthesis reaction performance of catalysts C1, C2, C3, C4, C5 and C6 were evaluated in a fixed-bed reactor.

Raw material gas composition: H ₂ /CO/N ₂ =64%/32%/4% (volume percentage).

Catalyst reduction reaction conditions: the pressure is normal pressure, the temperature rise rate is 5°C/min, the hydrogen space velocity is 600h ^-1 , the reduction temperature is 400°C, and the reduction time is 5 hours.

Reaction conditions: pressure 2.5MPa, temperature 200°C, synthesis gas (raw material gas) space velocity 2000h ^-1 .

Reaction carried out after 24 hours and got gas sample and carried out chromatographic analysis, wherein, the conversion ratio of carbonized carbon and methane selectivity are listed in Table 3.

Comparative Examples 13-18 illustrate comparative catalyst performance

Catalysts CC1, CC2, CC3, CC4, CC5 and CC6 were evaluated in the same manner as in Example 13, respectively. Among them, the conversion rate of carbon dioxide and methane selectivity are listed in Table 3.

Table 2

Example number sample name CO conversion rate, % Methane selectivity, % 13 C1 40.4% 7.4% Comparative example 13 CC1 33.1% 10.5% 14 C2 38.9% 6.9% Comparative example 14 CC2 34.5% 9.8% 15 C3 39.2% 7.0% Comparative example 15 CC3 35.4% 10.1% 16 C4 42.0% 6.2% Comparative example 16 CC4 36.9% 8.9% 17 C5 41.2% 7.5% Comparative example 17 CC5 36.0% 9.8% Comparative example 18 CC6 29.5% 11% 18 C6 38.5% 7.8%

As can be seen from Table 2, the alumina obtained after roasting the pseudo-boehmite provided by the invention is used as a catalyst carrier, and then prepared into a FT synthesis catalyst, which has better FT under the same conditions. Synthetic performance, i.e. higher CO conversion, lower methane selectivity.

Claims (16)

1. fischer-tropsch synthetic catalyst, contain carrier and active metal component, it is characterized in that, described carrier is obtained through roasting by a kind of boehmite that contains transition metal interpolation component, in oxide and with the butt of described boehmite is benchmark, transition metal interpolation components contents is 0.05-20 weight % in the described boehmite, and described boehmite comprises the boehmite P1 of at least a 1.1≤n≤2.5; Wherein, n=D (031)/D (120), the crystallite dimension of the crystal face of 031 peak representative in the XRD spectra of described D (031) expression boehmite crystal grain, the crystallite dimension of the crystal face of 120 peak representatives in the XRD spectra of D (120) expression boehmite crystal grain, described 031 peak is meant that 2 θ in the XRD spectra are 34-43 ° peak, described 120 peaks are meant that 2 θ in the XRD spectra are 23-33 ° peak, D=K λ/(Bcos θ), K is the Scherrer constant, λ is the diffraction wavelength of target section bar material, B is the half-peak breadth of diffraction maximum, and 2 θ are the position of diffraction maximum.

2. catalyst according to claim 1 is characterized in that, described P1 is 1.2≤n ₁≤ 2.2 boehmite; In oxide and with the butt of described boehmite is benchmark, transition metal interpolation components contents is 0.1-10 weight % in the described boehmite, and described transition metal interpolation component is selected from one or more in IB, IIB, IVB, VB, VIB, VIIB, VIII family or the rare earth metal component.

3. catalyst according to claim 1 and 2 is characterized in that, described transition metal interpolation component is selected from one or more among Zr, Ta, Mo, W, Mn, Ta, Zn, Cu, Ru, Re, the Hf.

4. catalyst according to claim 1 is characterized in that, the condition of described roasting comprises: sintering temperature is 350-950 ℃, and roasting time is 1-12 hour.

5. catalyst according to claim 4 is characterized in that, described roasting condition comprises: sintering temperature is 450-900 ℃, and roasting time is 2-8 hour.

6. catalyst according to claim 1 is characterized in that, described active metal component is selected from cobalt and/or ferrous metal component, in oxide and with catalyst be benchmark, the content of described active metal component is 5～70 weight %.

7. catalyst according to claim 6 is characterized in that, described active metal component is selected from cobalt and/or ferrous metal component, in oxide and with catalyst be benchmark, the content of described active metal component is 10～50 weight %.

8. catalyst according to claim 7 is characterized in that, described active metal component is selected from cobalt and/or ferrous metal component, in oxide and with catalyst be benchmark, the content of described active metal component is 12～30 weight %.

9. catalyst according to claim 1 is characterized in that, described boehmite comprises the boehmite P2 of 0.8＜n＜1.1, is benchmark with described boehmite total amount, and the content of described P2 is not more than 50 weight %.

10. catalyst according to claim 9 is characterized in that, described P2 is the boehmite of 0.85≤n≤1.05, is benchmark with described boehmite total amount, and the content of described P2 is not more than 30 weight %.

11. catalyst according to claim 1, it is characterized in that, contain one or more adjuvant components that are selected among Cu, Mo, Ta, W, Ru, Zr, Ti, REO, Re, Hf, Ce, Mn, the V in the described catalyst, in oxide and with catalyst be benchmark, the content of described adjuvant component is no more than 30 weight %.

12. catalyst according to claim 11 is characterized in that, in oxide and with catalyst be benchmark, the content of described adjuvant component is no more than 20 weight %.

13. catalyst according to claim 12 is characterized in that, in oxide and with catalyst be benchmark, the content of described adjuvant component is no more than 15 weight %.

14. catalyst according to claim 1, it is characterized in that, contain one or more precious metal additive components that are selected among Pt, Pd, Rh, the Ir in the described catalyst, in metal and with catalyst be benchmark, the content of described adjuvant component is no more than 1 weight %.

15. catalyst according to claim 14 is characterized in that, described precious metal additive component is Pt.

16. a Fischer-Tropsch synthesis method is included under the Fischer-Tropsch synthesis condition the mixture and the catalyst haptoreaction of carbon monoxide and hydrogen, it is characterized in that described catalyst is the described catalyst of each claim of aforementioned claim 1-15.