Hydropyrolysis process

Abstract

The invention provides a method for hydropyrolyzing biomass, which comprises the following steps of: contacting the biomass with a hydropyrolysis catalyst in a bubbling fluidized bed reactor in a hydrogen atmosphere, wherein the hydropyrolysis catalyst is prepared by a method comprising the steps of: impregnating a gamma alumina support with a first impregnation solution comprising a tungsten salt; drying the tungsten-impregnated carrier; the dried tungsten-impregnated support is then impregnated with a second impregnation solution comprising a metal source selected from metals in Group 8, Group 9 and Group 10 of the Periodic Table of Elements and optionally a molybdenum source, the fully impregnated support is dried and then calcined.

Description

Technical Field

[0001] The present invention relates to a hydrothermal pyrolysis method and a method for preparing a catalyst for use in such hydrothermal pyrolysis method. Background Art

[0002] With the increasing demand for liquid transportation fuels, the decreasing reserves of "easy-to-produce oil" (crude oil that can be easily accessed and recovered), and the growing restrictions on the carbon footprint of such fuels, it has become increasingly important to develop ways to produce liquid transportation fuels from alternative sources in an efficient manner.

[0003] Biomass provides a source of renewable carbon and refers to biological materials derived from living or recently deceased organisms, and includes lignocellulosic materials (e.g., wood), aquatic materials (e.g., algae, aquatic plants, and seagrass), and animal by-products and wastes (e.g., viscera, fats, and sewage sludge). Liquid transportation fuels produced from biomass are sometimes referred to as biofuels. Thus, the use of such biofuels may achieve more sustainable CO2 emissions than petroleum-derived fuels.

[0004] However, in conventional biomass pyrolysis, fast pyrolysis is typically carried out in an inert atmosphere to obtain a dense, acidic, reactive liquid bio-oil product that contains water, oil, and coke formed during the process. Thus, there are several disadvantages in using bio-oils produced by conventional pyrolysis. These disadvantages include increased chemical reactivity, water miscibility, high oxygen content, and low calorific value of the product. Generally, these products are difficult to upgrade to alternative liquid hydrocarbon fuels.

[0005] An efficient method for processing biomass into high-quality liquid fuels is described in WO2010117437 and subsequent patents such as US10005965, US9868909, US10005964, US20170009143, US10167429, US10526544, US11174438, US10822545, US10174259, US10190056, US10774270, US10829695, US10647924, US10822546, US9657232, US10183279, and WO2022133224 that describe the IH 2 method developed by Shell and Gas Technology Institute. The method for converting biomass into liquid hydrocarbon fuels described in WO2010117437 and subsequent patents uses a first hydrothermal pyrolysis reaction and subsequent hydroconversion reactions to convert biomass into useful products.

[0006] Due to the ability to use solid raw materials on a large scale, such as raw materials containing waste plastics and raw materials containing lignocellulose (e.g., lignocellulosic biomass, agricultural residues, forestry residues, residues from wood products and pulp and paper industries, and municipal solid waste containing lignocellulosic materials), they have become important raw materials for methods of converting biomass into fuels. Lignocellulose contains a mixture of lignin, cellulose, and hemicellulose in any proportion, and usually also contains ash and moisture.

[0007] The hydrothermal pyrolysis stage of the method described in WO2010117437 and subsequent patents utilizes a hydrothermal pyrolysis catalyst. A typical hydrothermal pyrolysis catalyst for this method contains a mixture of cobalt or nickel combined with molybdenum and phosphorus on a γ-alumina support. The hydrothermal pyrolysis reaction occurs in a bubbling fluidized bed reactor, in which the biomass is fed into the bottom of the reactor. The biomass is rapidly heated upon contact with the hot hydrothermal pyrolysis catalyst in a hydrogen atmosphere. To achieve a fluidized bed with the necessary flow rate and reaction rate, the catalyst must have specific size and density characteristics. Some catalysts will flow out of the top of the bed and must be separated from the hydrothermal pyrolysis products and coke. Optimizing the density of the catalyst particles will facilitate separation from the coke and enable the catalyst to quickly pass through the downcomer and return to the main reactor body with minimal heat loss.

[0008] In addition to having the correct size and density for performing the hydrothermal pyrolysis method, the hydrothermal pyrolysis catalyst must also retain the metal loading capacity and surface area required to provide the necessary catalytic activity. It would also be advantageous to customize the hydrothermal pyrolysis method to produce the desired product species. Summary of the Invention

[0009] The present invention provides a method for hydrothermal pyrolysis of biomass, the method comprising the steps of: contacting the biomass with a hydrothermal pyrolysis catalyst in a hydrogen atmosphere in a bubbling fluidized bed reactor, wherein the hydrothermal pyrolysis catalyst is prepared by a method comprising the steps of: impregnating a γ-alumina support with a first impregnation solution containing a tungsten salt; drying the impregnated tungsten support; and then impregnating the dried impregnated tungsten support with a second impregnation solution containing a metal source selected from metals in Groups 8, 9, and 10 of the Periodic Table of the Elements and optionally a molybdenum source, drying the completely impregnated support, and then calcining it. Detailed Description

[0010] One or more specific embodiments of the present disclosure will now be described. These described embodiments are examples of the presently disclosed technology. Additionally, to provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions will be made to achieve the developer's specific goals, such as meeting system-related and business-related constraints, which may vary from one implementation to another. Furthermore, it should be understood that such development efforts may be complex and time-consuming, but would still be a routine task of design, production, and manufacturing for those of ordinary skill in the art who would benefit from the present disclosure.

[0011] When introducing elements of the various embodiments of the present disclosure, the articles "a", "an", and "the" are intended to mean that there is one or more of the elements. The terms "comprising", "including", and "having" are intended to be inclusive and mean that there may be additional elements other than those listed. Additionally, it should be understood that references to "one embodiment" or "an embodiment" of the present disclosure are not to be construed as excluding the existence of additional embodiments that also incorporate the recited features.

[0012] The inventors have surprisingly found that a hydrothermal pyrolysis catalyst can be used to perform a method for the rapid hydrothermal pyrolysis of biomass, which is prepared by first impregnating a suitable support with a tungsten salt and then impregnating it with at least one suitable metal salt. The catalyst thus prepared has been shown to provide excellent catalyst density for effectively using the type of bubbling fluidized bed reactor used in the rapid hydrothermal pyrolysis reaction (such as those used in the IH 2 method), while providing excellent catalyst activity within the fluidized catalyst bed.

[0013] The catalyst prepared in the present invention comprises a γ-alumina support. The support may optionally contain other refractory oxides, such as silica and / or titania. However, the preferred support consists essentially of γ-alumina.

[0014] The average particle size of the catalyst for a commercial fluidized bed reactor for hydrothermal pyrolysis is preferably in the range of 0.30 mm to 0.60 mm, more preferably in the range of 0.40 mm to 0.60 mm, and most preferably in the range of 0.45 mm to 0.55 mm.

[0015] To achieve such an average catalyst particle size, a support with particle formation within the same average particle size limits must be used.

[0016] The shape of the γ-alumina support used in the method of the present invention can be any shape that is generally suitable for use in commercial reactors. The γ-alumina support used in the method of the present invention is preferably a spherical support. Most preferably, the form of the γ-alumina support is spherical support particles, wherein the average particle diameter is in the range of 0.45 mm to 0.55 mm.

[0017] In the first step of preparing the catalyst for the method of the present invention, the γ-alumina support is impregnated with a first impregnation solution containing a tungsten salt. The impregnation can be achieved by contacting the catalyst support with a solution of a suitable soluble tungsten salt in a small amount of solvent. Suitable tungsten salts include, but are not limited to, ammonium metatungstate and tungstic acid. A particularly preferred tungsten salt is ammonium metatungstate.

[0018] The first impregnation solution can be incorporated into the γ-alumina support by any suitable manner or method known to those skilled in the art. Such methods can include standard impregnation by the incipient wetness method, or even soaking the shaped support with an excess of the metal-containing impregnation solution to be used in dry impregnation or incipient wetness impregnation. A typical support impregnation method is pore volume impregnation, which involves using an amount of salt solution equivalent to the pore volume of the filled support.

[0019] Considering the pore volume of the support into which the first impregnation solution is to be impregnated, the concentration of the tungsten compound in the first impregnation solution is selected so as to achieve the desired tungsten content in the hydrocracking catalyst. Generally, the concentration of the tungsten compound in the first impregnation solution is in the range of 0.01 mol / L to 20 mol / L.

[0020] Tungsten is incorporated into the catalyst support in an appropriate amount such that the amount of tungsten present in the hydrocracking catalyst is in the range of 10 wt% to 35 wt%, preferably 15 wt% to 30 wt%, and most preferably 20 wt% to 30 wt% based on the total weight of the catalyst.

[0021] Then the tungsten-impregnated support is dried under drying conditions that include a drying temperature below the calcination temperature. The drying temperature of the step of drying the tungsten-impregnated support should not exceed the calcination temperature. Thus, the drying temperature should not exceed 400 °C, and preferably, the drying temperature for drying the tungsten-impregnated support does not exceed 300 °C, and most preferably, the drying temperature does not exceed 250 °C. It should be understood that this drying step will generally be carried out at a temperature lower than the aforementioned temperature, and generally, the drying temperature will be carried out at a temperature in the range of 60 °C to 150 °C.

[0022] Preferably, then the dried tungsten-impregnated support is calcined in the presence of air or oxygen. The calcination is preferably carried out at a temperature in the range of 450 °C to 600 °C.

[0023] The dried tungsten-impregnated support is then subjected to impregnation with an additional metal source in order to incorporate the desired substances into the hydrocracking catalyst. In the process of the present invention, a metal source selected from the metals in Groups 8, 9 and 10 of the Periodic Table of the Elements is used. Preferably, a molybdenum source is also used. For the sake of clarity, Groups 8, 9 and 10 of the Periodic Table of the Elements are those groups that conform to the 2005 IUPAC recommendations "Nomenclature of Inorganic Chemistry". The preferred metals in Groups 8, 9 and 10 of the Periodic Table of the Elements are selected from one or more of cobalt, iron, nickel, copper and manganese. Even more preferably, one or more of the metals in Groups 8, 9 and 10 of the Periodic Table of the Elements are one or more of cobalt and nickel.

[0024] Suitable cobalt sources may be selected from any suitable cobalt salts, but are preferably selected from one or more of cobalt(II) hydroxide, cobalt hydroxide, cobalt oxide, cobalt(II) nitrate hexahydrate, cobalt hydroxycarbonate and cobalt oxide.

[0025] Preferred nickel sources are selected from one or more of nickel hydroxide, nickel hydroxycarbonate, nickel nitrate and nickel oxide

[0026] Suitable molybdenum sources include but are not limited to ammonium heptamolybdate and molybdenum trioxide, ammonium dimolybdate, molybdenum dioxide. Suitably, the metal source is combined with a solvent to provide a second impregnation solution.

[0027] The second impregnation solution can be incorporated into the dried tungsten-impregnated support by any suitable means or method known to those skilled in the art. Such methods can include standard impregnation by the incipient wetness method, or even soaking the shaped support with an excess of the metal-containing impregnation solution to be used in dry impregnation or incipient wetness impregnation. A typical support impregnation method is pore volume impregnation, which involves using an amount of impregnation solution equivalent to the volume of the pores of the catalyst support present.

[0028] Taking into account the pore volume of the dried tungsten-impregnated support into which the second impregnation solution is to be impregnated, the concentration of the metal source in the second impregnation solution is selected so as to achieve the desired metal content in the hydrocracking catalyst. Generally, the concentration of each metal compound in the metal compounds in the second impregnation solution is in the range of 0.01 mol / L to 10 mol / L.

[0029] When the metal source includes a cobalt source, the preferred metal content of cobalt in the hydrocracking catalyst is generally an amount in the range of 0.5 wt% to 20 wt%, preferably 1 wt% to 15 wt%, and most preferably 2 wt% to 12 wt% based on the total weight of the catalyst.

[0030] When the metal source includes a nickel source, the preferred metal content of nickel in the hydrothermolysis catalyst is generally an amount in the range of 0.5 wt% to 20 wt%, preferably 1 wt% to 15 wt%, and most preferably 2 wt% to 12 wt% based on the total weight of the catalyst.

[0031] The metal content of molybdenum (if present) in the hydrothermolysis catalyst is generally an amount in the range of 5 wt% to 20 wt%, preferably 8 wt% to 20 wt%, and most preferably 12 wt% to 20 wt% based on the total weight of the catalyst.

[0032] Phosphorus can also be incorporated into the hydrothermolysis catalyst as an active substance by incorporating a phosphorus source into the second impregnation solution. The content of phosphorus (if present) in the hydrothermolysis catalyst is generally an amount in the range of 1 wt% to 5 wt%, preferably 2 wt% to 4 wt%, and most preferably 2 wt% to 3 wt% based on the total weight of the catalyst.

[0033] If a phosphorus source is also included, the preferred phosphorus source is phosphoric acid.

[0034] Then the fully impregnated support is dried and calcined.

[0035] As with the previous drying step, the drying temperature of the step of drying the fully impregnated support should not exceed the calcination temperature. Therefore, the drying temperature should not exceed 400 °C, and preferably, the drying temperature for drying the fully impregnated support does not exceed 300 °C, and most preferably, the drying temperature does not exceed 250 °C. It should be understood that this drying step will generally be carried out at a temperature lower than the aforementioned temperature, and generally, the drying temperature will be carried out at a temperature in the range of 60 °C to 150 °C.

[0036] Then the dried fully impregnated support is calcined in the presence of air or oxygen. The calcination is preferably carried out at a temperature in the range of 450 °C to 600 °C.

[0037] In the hydrothermolysis method of the present invention, a biomass feedstock and a fluidizing gas containing hydrogen are supplied to a fluidized bed reactor containing a hydrothermolysis catalyst. The fluidized bed reactor operates at elevated temperature and pressure. The term "hydrothermolysis" is generally used to refer to a method of rapidly heating and thermally decomposing a biomass feedstock in an atmosphere mainly composed of hydrogen in the presence of solid catalyst particles. The hydrothermolysis method provides a way to remove oxygen from biomass and other feedstocks containing a large amount of carbon and chemically bonded oxygen to produce light hydrocarbon products, in which most of the oxygen is removed from the liquid derived from the feedstock. The hydrothermolysis method has been described in detail in US8492600 and US8841495, etc.

[0038] A fluidized bed reactor suitable for use in the hydrothermal pyrolysis process of the present invention generally includes a mixing zone, a main reactor zone, and optionally an enlarged solid disengagement zone (i.e., a section where the reactor diameter or cross-sectional area is enlarged relative to the diameter or cross-sectional area of the fluidized bed) at a suitable height above the main reactor zone to facilitate the separation of solid coke particles from solid catalyst particles. The fluidized bed reactor also includes one or more downcomers that fluidly connect the main reactor zone located at or near the top of the reactor to the mixing zone located at or near the bottom part of the reactor.

[0039] Considering the nature of the biomass feedstock, the conditions within the reactor, and the specific fluidizing gas used, the fluidization in the mixing zone and the main reactor zone of the fluidized bed reactor can be carried out with a fluidizing gas having an apparent velocity effective for the desired type of fluidization (e.g., bubbling bed fluidization). Generally, a fluidizing gas containing hydrogen will have an apparent velocity typically greater than about 0.1 meters per second (m / s) (e.g., about 0.1 m / s to about 20 m / s), greater than 0.2 m / s (e.g., about 0.2 m / s to about 1.5 m / s), typically greater than about 0.3 m / s (e.g., about 0.3 m / s to about 1.2 m / s), and often greater than about 0.5 m / s (e.g., about 0.5 m / s to about 1 m / s). A suitable fluidizing gas stream mainly contains hydrogen, but may also contain other non-condensable gases (e.g., CO, CO2, and / or CH4).

[0040] Preferably, the apparent gas velocity of the fluidizing gas in the mixing zone is equal to or higher than the apparent gas velocity in the main reactor zone. Generally, compared with a standard fluidized bed, a higher apparent gas velocity in the mixing zone enables the use of larger biomass particles because they do not sink to the bottom and form deposits. Selecting a suitable combination of the apparent gas velocity, the length of the mixing zone, and the diameter of the mixing zone, considering, for example, the rate at which the biomass feedstock is fed into the mixing zone, the amount of recycled catalyst, and the hydrogen partial pressure within the reactor, and the desired residence times of the biomass, the catalyst, and the fluidizing gas, is within the capabilities of those skilled in the art. Determining a suitable combination of the apparent gas velocity, the length of the mixing zone, and the diameter of the mixing zone such that the backmixing of the biomass from the main reactor zone located above the mixing zone is negligible is also within the capabilities of those skilled in the art.

[0041] The conditions in the fluidized bed reactor include temperature, which is typically in the range of 330 °C to 500 °C, preferably in the range of 350 °C to 480 °C, and more preferably in the range of 370 °C to 450 °C. The exact operating temperature depends on the composition of the feedstock to be hydrothermolyzed, the characteristics of the hydrothermolysis catalyst, and the desired composition of the product to be obtained. The pressure inside the reactor is typically in the range of 0.50 MPa to 7.50 MPa. The exact operating pressure of the fluidized bed reactor depends on the composition of the feedstock to be hydrothermolyzed, the choice of catalyst, the composition of the fluidizing gas (i.e., the purity of the hydrogen-rich gas), and the desired composition of the product to be obtained. The weight hourly space velocity (WHSV) in the reactor, calculated by dividing the combined weight flow rate of the biomass feedstock by the weight of the catalyst inventory in the reactor, is typically from about 0.1 hr -1 to about 10 hr -1 and typically from about 0.5 hr -1 to about 5 hr -1 and often from about 0.8 hr -1 to about 3 hr -1 . Typically, the fluidization velocity, the catalyst size and bulk density, and the feedstock size and bulk density are selected such that the deoxygenation catalyst remains in the fluidized bed while the coke produced is entrained out of the reactor.

[0042] Such hydrothermolysis processes produce a hydrothermolysis reactor effluent comprising a partially deoxygenated hydrothermolysis product (e.g., in the form of condensable vapors), at least one non-condensable gas (e.g., CO, CO2, and / or CH4), and coke particles. As used herein, "partially deoxygenated hydrothermolysis product" may include oxygenated hydrocarbons (e.g., derived from cellulose, hemicellulose, and / or lignin), which may be subjected to more complete deoxygenation in a subsequent (downstream) hydroconversion process (e.g., to produce hydrocarbons and remove oxygen in the form of CO, CO2, and / or water). The representative oxygen content of the partially deoxygenated hydrothermolysis product is generally in the range of about 1 wt% to about 30 wt%, or about 5 wt% to about 25 wt%.

[0043] After hydrothermolysis, all or substantially all of the coke particles and / or other solid particles (e.g., catalyst fines) are removed from the hydrothermolysis reactor effluent to provide a purified hydrothermolysis reactor vapor stream with a reduced coke content. The methods for removing coke and catalyst fines are generally not limited and may include any method suitable for use with such hydrothermolysis processes. The preferred method for removing coke and catalyst fines from the vapor stream is by cyclone separation. Catalyst particles may also be present in the hydrothermolysis reactor effluent, and these will be separated. The catalyst used in the process of the present invention advantageously has a suitable density such that the catalyst particles can be easily separated and returned to the fluidized bed without significant heat loss.

[0044] The present invention will now be further illustrated by reference to the following non-limiting examples.

[0045] Example

[0046] Example 1 (This Invention)

[0047] The catalyst was prepared by the method described herein. The first step involves impregnating a spherical γ-alumina support with an average diameter of 0.5 mm with an ammonium metatungstate solution. The concentration of ammonium metatungstate in the solution was 400 g / l. After impregnation, the support was dried at a temperature of 120 °C for 6 hours and then calcined at a temperature of 483 °C for 1 hour. The tungsten-impregnated support was secondarily impregnated with an acidic solution containing cobalt, molybdenum, and phosphorus. After impregnation, the catalyst was dried at a temperature of 120 °C for 6 hours and then calcined at a temperature of 483 °C for 1 hour. The physical properties of the catalyst are summarized in Table 1.

[0048] Table 1

[0049] Co, wt% 2.3 Mo, wt% 8 W, wt% 28 Tap density, g / cc 1.2 Particle density, g / cc 2 <![CDATA[BET surface area, m 2 / g]]> 70 N2 BET pore volume, cc / g 0.18 N2 BET pore diameter, nm 9.5

[0050] The catalyst prepared in Example 1 was used as a hydrocracking catalyst in a bubbling fluidized bed reactor. The catalyst was ground and sieved to a particle size range of 300 to 500 microns. A second hydrotreating catalyst (containing nickel and molybdenum on alumina) (Catalyst B) was dried to remove moisture and then weighed. The dried hydrotreating catalyst (in the form of extrudates with a diameter of 1.3 mm and a length of about 3 to 6 mm) was used as the catalyst in a second fixed bed reactor. Neither the hydrocracking catalyst nor the hydrotreating catalyst underwent any activation treatment (such as sulfiding) prior to loading into the reactor. The solid feedstock used was sawdust generated as a by-product in paper mills and pulp mills. The sawdust was sieved to a particle size of 250 to 500 microns.

[0051] The hydrocracking catalyst in the first reactor is fluidized with a hydrogen stream preheated to a temperature of about 435 °C. After the hydrocracking catalyst has been fluidized, biomass is introduced into the reactor and processed continuously. The processing rate of the biomass gradually rises to a target rate of 4.14 g / min, corresponding to a weight hourly space velocity of about 1.26 kg of biomass per kilogram of catalyst per hour for the biomass feedstock entering the first-stage reactor. During the duration of biomass processing, the weighted average temperature of the fluidized bed of the catalyst is 414.0 °C. In the first reactor, the biomass feedstock is converted into a mixture of char, ash, and vapor. The fluidization velocity is adjusted such that the solid products (coke, ash) and the gas-phase products are carried out of the reactor, while the catalyst remains in the reactor. Some of the catalyst is ground into fine particles, and the fine particles are also carried out of the bed. The solid products are separated from the gas-phase products in a filter, and the vapor is sent to the second reactor.

[0052] The average temperature of the second-stage hydrotreating catalyst is maintained at 388.0 °C. The biomass feed rate gradually rises to the final WHSV, reaching 0.36 kg of biomass per kilogram of catalyst per hour for the second stage. The operating pressure for both the first stage and the second stage is 2260 kPa. The gas-phase products of the second-stage reactor are cooled in stages to -46 °C, and two liquid products containing a hydrocarbon layer floating on a water layer are recovered. The hydrocarbon liquid is separated from the aqueous liquid and analyzed. The off-gases generated by this method are sent to an on-line GC, and the composition of the gas is analyzed throughout the run. The mass balance and carbon balance of the process are calculated based on the mass of the liquid products and the analysis results as well as the composition information of the gas products, and the yield distribution is calculated based on this. It is found that the hydrocarbon liquid product is essentially oxygen-free (below the detection limit of the instrument or <0.01 wt%), and the aqueous product generated contains only 0.01 wt% carbon. Thus, complete hydrodeoxygenation of the biomass is achieved, producing an oxygen-free hydrocarbon product and an essentially carbon-free aqueous phase.

[0053] Table 2 presents the results of the catalyst in Example 1.

[0054] Table 2 also includes "standard range" results, which are the expected levels obtained when using a typical hydrotreating catalyst (Catalyst A) containing cobalt and molybdenum on alumina as the "hydrocracking" catalyst for the first stage.

[0055] Table 2

[0056]

[0057] These results indicate that, compared with the standard method, the catalyst prepared in Example 1 achieved biomass conversion results within the desired range through hydrodeoxygenation, hydrothermal pyrolysis, and hydroconversion processes. However, compared with the standard catalyst (Catalyst A - 1 g / cm 3 ) used in the typical method, the catalyst prepared in Example 1 has a higher particle density (2 g / cm 3 ). This improves the downcomer flux in the fluidized bed reactor and results in excellent fluidization behavior within the bed, thus providing efficient thermal management for the entire reactor system.

[0058] Example 2

[0059] Many hydrothermal pyrolysis catalysts were prepared. The formulations of these catalysts are listed in Table 3. Examples 2A, 2B, and 2C are catalysts according to the present invention. Catalyst A is a typical hydrotreating catalyst (Catalyst A) containing cobalt and molybdenum on alumina.

[0060] Table 3

[0061] Catalyst A Example 2A Example 2B Example 2C Co, wt% 2.3 0 0 2.3 Mo, wt% 8.0 0 5.0 8.0 Ni, wt% 0 6.4 3.8 0 W, wt% 0 35 35 30 P, wt% 1.3 0 1.3 1.3 Tap density, g / cc 0.67 1.13 1.17 1.18 Particle density, g / cc 1.0 1.77 1.83 1.84 Water pore volume, cc / g - 0.34 0.3 0.3 <![CDATA[BET surface area, m 2 / g]]> 200 125 75 88 BET PV, cc / g 0.6 0.25 0.2 0.19

[0062] In the same manner as described in Example 1, the catalysts were used as hydrothermal pyrolysis catalysts in a bubbling fluidized bed reactor. Table 4 shows the results of Example 2.

[0063] In addition to demonstrating excellent hydrothermal pyrolysis results consistent with those achieved by the expected standard hydrothermal pyrolysis catalyst, as specified in the "standard range" and demonstrated for Catalyst A, the catalysts prepared in a two-step method that requires impregnation with tungsten followed by further impregnation with other metals produced product species with a significantly increased gasoline-to-diesel ratio. This ratio is considered to be the amount of C4 - C10 to C11+ hydrocarbons formed.

[0064] Table 4

[0065]

Claims

1. A method for hydrothermal pyrolysis of biomass, the method comprising the following steps: Contact biomass with a hydro-pyrolysis catalyst in a bubbling fluidized bed reactor in a hydrogen atmosphere, wherein the hydro-pyrolysis catalyst is prepared by a method comprising the following steps: impregnate a γ-alumina support with a first impregnation solution containing a tungsten salt; dry the impregnated tungsten support; then impregnate the dried tungsten-impregnated support with a second impregnation solution containing a metal source selected from metals in Groups 8, 9, and 10 of the Periodic Table and optionally a molybdenum source, dry the fully impregnated support, and then calcine it.

2. The method according to claim 1, wherein the second impregnation solution further comprises a molybdenum source.

3. The method according to claim 1 or claim 2, wherein the metal selected from metals in Groups 8, 9, and 10 is selected from cobalt and / or nickel.

4. The method according to any one of claims 1 to 3, wherein the second impregnation solution further comprises a phosphorus source.

5. The method according to any one of claims 1 to 4, wherein the tungsten salt is present in the first impregnation solution in an amount such that the amount of tungsten present in the hydro-pyrolysis catalyst is in the range of 10 wt% to 35 wt% based on the total weight of the catalyst.

6. The method according to any one of claims 1 to 5, wherein the tungsten salt is selected from ammonium metatungstate, tungstic acid, and mixtures thereof.

7. The method according to any one of claims 1 to 6, wherein the γ-alumina support is in the form of spherical support particles, wherein the average particle diameter is in the range of 0.45 mm to 0.55 mm.

8. The method according to any one of claims 1 to 7, wherein the bubbling fluidized bed reactor operates at a temperature in the range of 330°C to 500°C, a pressure in the range of 0.50 MPa to 7.50 MPa and a weight hourly space velocity in the range of 0.1 h -1 to 10 h -1 -1.

9. The method according to any one of claims 1 to 8, wherein the method of hydro-pyrolyzing biomass produces an output from the bubbling fluidized bed reactor, the output comprising a partially deoxygenated hydro-pyrolysis product, at least one non-condensable gas, coke particles, and catalyst particles.

10. The method according to claim 9, wherein the catalyst particles are removed from the output and returned to the bubbling fluidized bed reactor.

11. The method according to claim 9 or claim 10, wherein the partially deoxygenated hydro-pyrolysis product is subjected to a subsequent hydroconversion process.

Images