Hydrogenation combined system of biological oil and hydrogenation combined method thereof

Abstract

A hydrogenation combined system of biological oil and a hydrogenation combined method thereof, the hydrogenation combined system comprises a fixed bed reactor, a hot high-pressure separator and a downstream separation unit, wherein the upper part of the hot high-pressure separator is filled with a hydrogenation dechlorination catalyst, the lower part of the hot high-pressure separator is filled with a hydrogenation dechlorination catalyst, the middle part of the hot high-pressure separator is provided with a reaction effluent feeding port, and the downstream separation unit is provided with a hydrogenated refined oil product outlet, a water outlet and a hydrogen-rich gas outlet. By using the hydrogenation combined system and the method thereof, the organic chlorine in the biological oil can be efficiently removed at low cost, and the problem of corrosion of chlorine ions to the device during long-period processing of chlorine-containing biological oil is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of bio-oil processing, and more specifically to a bio-oil hydrogenation combination system and method. Background Technology

[0002] Currently, the oil and petrochemical industry, as a major source of carbon emissions, faces increasingly severe challenges and tests, making energy transition imperative. Liquid biofuels are the most important and promising form of biofuel. Due to their abundant and renewable raw material sources and product diversity, liquid biofuels possess unique advantages for achieving sustainable development compared to fossil fuels. They can be integrated with modern transportation systems and have become one of the important ways to address the scarcity of oil resources and carbon emissions.

[0003] Biodiesel can be directly produced from waste bio-oils through a hydrorefining process. This green and low-carbon process is a major pathway for the high-value conversion of bio-oils. However, several problems exist in the high-value conversion of waste catering oils. One problem is the high chlorine and oxygen content in waste catering oils. During hydrorefining, hydrogen chloride and water are easily generated. Under liquid phase conditions, especially at the dew point of water, hydrogen chloride and water can form highly concentrated hydrochloric acid. This not only causes severe corrosion to reactors, heat exchangers, and related pipelines but also forms ammonium chloride salts that clog equipment and pipelines. These problems pose serious safety hazards to the safe and stable operation of the equipment. Therefore, the removal of chlorine from waste catering oils has become a key technical challenge.

[0004] Currently reported methods for removing organochlorine compounds mainly include adsorption dechlorination, nucleophilic substitution reaction dechlorination, metal reduction dechlorination, and catalytic hydrodechlorination. Adsorption dechlorination primarily targets the removal of HCl gas generated after organochlorine conversion, using physical adsorbents (molecular sieves / activated carbon) and chemical adsorbents (alkaline earth metal oxides) as adsorption media. It is effective in removing HCl from the gas phase with high chlorine capacity, but ineffective in removing HCl from the liquid phase with low chlorine capacity. Nucleophilic substitution dechlorination mainly uses nucleophilic substitution reagents (alcohol solutions / ammonia solutions / alkali solutions) to remove organochlorine compounds, but suffers from long reaction times and high costs. Metal reduction dechlorination uses nanoscale Pd / Fe as catalysts to remove organochlorine compounds through reduction reactions. Its advantages include a large catalyst surface area and high reaction rate, but it suffers from high catalyst cost and energy consumption. Catalytic hydrodechlorination uses hydrodechlorination catalysts to remove organochlorine compounds, focusing on converting organochlorine compounds into inorganic chlorine (HCl) without considering the adsorption and removal of HCl.

[0005] CN104560413B discloses a method for hydrogenating waste cooking oil. The waste cooking oil enters the hydrogenation reactor from the top, while hydrogen enters from the bottom. Under hydrogenation reaction conditions, the waste cooking oil and hydrogen flow countercurrently through a bed containing a hydrogenation catalyst within the hydrogenation reactor. The top effluent from the hydrogenation reactor directly enters a dechlorination reactor. Under dechlorination reaction conditions, the effluent passes through a bed containing a dechlorinating agent. The bottom effluent from the hydrogenation reactor and the effluent from the dechlorination reactor enter a separation system for gas-liquid separation, yielding hydrogenated refined waste cooking oil. The main components of the dechlorinating agent, based on the dechlorinating agent, include 50-80% by mass of alkaline earth metal oxides, 10-40% by mass of alumina, and 2-30% by mass of bentonite. This invention uses a dechlorination adsorbent in a post-dechlorination reactor to adsorb hydrogen chloride generated during the refining process; however, the use of a high-pressure dechlorination reactor incurs additional equipment investment. Summary of the Invention

[0006] The present invention aims to solve the technical problems of high cost and chlorine corrosion of equipment in the existing technology for processing chlorine-containing bio-oils.

[0007] The first aspect of this invention provides a hydrogenation combination system for bio-oils, comprising:

[0008] (1) Fixed bed reactor, the fixed bed reactor is filled with hydrogenation catalyst, the fixed bed reactor is equipped with a feed inlet of bio-oil and hydrogen mixture, and the fixed bed reactor is equipped with a reaction effluent outlet;

[0009] (2) A hot high pressure separator, the upper part of which is filled with a hydrodechlorination catalyst, the lower part of which is filled with a hydrodechlorination catalyst, the middle part of which is provided with a reaction effluent inlet, the top of which is provided with a first gas phase stream outlet, the bottom of which is provided with a first liquid phase stream outlet, and the reaction effluent outlet of the fixed bed reactor is connected to the reaction effluent inlet of the hot high pressure separator;

[0010] The hydrodechlorination catalyst comprises a modified support and an active metal component supported on the modified support. The modified support includes a support and an alkaline earth metal. The active metal component includes at least one Group VIB metal component and at least one Group VIII metal component. The support is alumina. Based on the total weight of the modified support, the content of alkaline earth metal, calculated as oxides, is 20-50% by weight, and the breakthrough chlorine capacity of the hydrodechlorination catalyst is not less than 20%.

[0011] (3) Downstream separation unit, the downstream separation unit is equipped with a first gas phase stream inlet and a first liquid phase stream inlet, as well as a hydrorefined oil product outlet, a water outlet and a hydrogen-rich gas outlet.

[0012] In this invention, the fixed-bed reactor can be either an upflow fixed-bed reactor or a downflow fixed-bed reactor, and the specific locations of the feed inlet and the effluent outlet of the mixture in the fixed-bed reactor are not limited. In one embodiment of this invention, the feed inlet for the mixture of bio-oil and hydrogen is located at the top of the fixed-bed reactor, and the effluent outlet is located at the bottom of the fixed-bed reactor.

[0013] In one embodiment of the invention, the hydrotreating catalyst comprises alumina and at least one Group VIB metal component and at least one Group VIII metal component supported on the alumina.

[0014] In a preferred embodiment of the present invention, based on the total weight of the hydrotreating catalyst, the content of the Group VIB metal component is 5-30% by weight and the content of the Group VIII metal component is 1-10% by weight, calculated as oxides; the Group VIB metal component is molybdenum and / or tungsten; the Group VIII metal component is nickel and / or cobalt.

[0015] In the hydrogenation catalyst described in this invention, the sum of the contents of each component is 100%.

[0016] In one embodiment of the present invention, in the hot high-pressure separator, the volume ratio of the upper-filled hydrodechlorination catalyst to the lower-filled hydrodechlorination catalyst is 20:1-1.

[0017] The hydrodechlorination catalyst of this invention has a high chlorine breakthrough capacity and exhibits good chlorine adsorption activity. In one embodiment of this invention, the chlorine breakthrough capacity of the hydrodechlorination catalyst is 20-32%.

[0018] The breakthrough chlorine capacity of the catalyst described in this invention was determined by the method of "Test Method for Chlorine Capacity of Alkaline Earth Metal High-Temperature Dechlorinating Agents" (GB / T38108-2019).

[0019] The inventors of this invention have discovered that alkaline earth metals in the modified support of a hydrodechlorination catalyst are beneficial for improving the catalyst's chlorine adsorption activity. In one embodiment of this invention, the content of alkaline earth metals in the hydrodechlorination catalyst, based on the total weight of the modified support and calculated as oxides, is 20-40% by weight, preferably 25-35% by weight.

[0020] The content of alkaline earth metals in the catalyst of the present invention was determined by X-ray fluorescence spectroscopy (XRF).

[0021] In one embodiment of the present invention, the alkaline earth metal is magnesium and / or calcium, preferably magnesium; under this preferred embodiment, the catalyst has higher structural stability.

[0022] The modified support described in this invention has a large specific surface area and suitable pore volume, appropriate interaction force with active metal components, and high structural stability, which makes the hydrodechlorination catalyst of this invention have good dechlorination activity and chlorine adsorption activity, as well as high dechlorination stability.

[0023] In one embodiment of the present invention, the specific surface area of ​​the modified carrier is 150-250 m². 2 / g, preferably 180-220m 2 / g. In one embodiment of the present invention, the pore volume of the modified carrier is 0.5-0.7 cm³. 3 / g, preferably 0.55-0.65cm 3 / g.

[0024] The specific surface area and pore volume of the modified carrier of this invention were measured by the BET physical adsorption-desorption analysis method.

[0025] In one embodiment of the present invention, in the hydrodechlorination catalyst, based on the total weight of the hydrodechlorination catalyst and calculated as oxides, the content of the Group VIB metal component is 5-20% by weight, preferably 5-15% by weight; the content of the Group VIII metal component is 0.5-10% by weight, preferably 0.8-5% by weight; the Group VIB metal component is molybdenum and / or tungsten; the Group VIII metal component is nickel and / or cobalt.

[0026] In the hydrodechlorination catalyst of the present invention, the sum of the contents of each component is 100%.

[0027] The content of the active metal component in the catalyst of the present invention was determined by X-ray fluorescence spectroscopy (XRF).

[0028] In one embodiment of the present invention, the pressure of the hot high-pressure separator is the same as the pressure of the fixed-bed reactor.

[0029] In one embodiment of the present invention, a cooling device is provided between the effluent outlet of the fixed-bed reactor and the effluent inlet of the thermal high-pressure separator. The cooling device is not limited to heat exchangers, water coolers, air coolers, etc.

[0030] In one embodiment of the present invention, the downstream separation unit may include an optional hot low-pressure separator, a cold high-pressure separator, a cold low-pressure separator, a stripping tower, and a fractionation tower. The present invention does not limit the specific separation equipment, fractionation equipment, or their connection methods in the downstream separation unit, as long as they can separate the hydrorefined oil, water, and hydrogen-rich gas.

[0031] A second aspect of the present invention provides a method for hydrogenating bio-oils using any of the above-described systems, comprising:

[0032] (1) A mixture of bio-oil and hydrogen enters the fixed-bed reactor through the feed inlet and reacts with the loaded hydrotreating catalyst. The resulting effluent flows out from the effluent outlet of the fixed-bed reactor.

[0033] (2) After entering the reaction effluent from the reaction effluent inlet in the middle of the thermal high-pressure separator, the reaction effluent is divided into reaction effluent W1 and reaction effluent W2. After reaction effluent W1 reacts with the hydrodechlorination catalyst packed in the upper part of the thermal high-pressure separator, the first gaseous stream is obtained. After reaction effluent W2 reacts with the hydrodechlorination catalyst packed in the lower part of the thermal high-pressure separator, the first liquid stream is obtained.

[0034] (3) The first gaseous stream and the first liquid stream are fed into the downstream separation unit, and after separation, hydrorefined oil, water and hydrogen-rich gas are obtained.

[0035] In one embodiment of the present invention, the reaction conditions in the fixed-bed reactor are as follows: temperature 200-450℃, preferably 280-400℃; pressure 3-15MPa, preferably 5-8MPa; liquid hourly space velocity (LISH) 0.1-10h. -1 Preferably, it is 0.2-5.0h. -1 The hydrogen-to-oil volume ratio is 300-3000, preferably 800-1500.

[0036] In one embodiment of the present invention, the operating conditions of the hot high-pressure separator are: temperature of 200-350℃, preferably 250-300℃; and pressure of 3-15MPa, preferably 5-8MPa.

[0037] In a preferred embodiment of the present invention, the preparation method of the hydrodechlorination catalyst includes the following steps:

[0038] (a) The carrier precursor is mixed with the alkaline earth metal precursor and then optionally dried and calcined to obtain the modified carrier;

[0039] (b) Introduce active metal components onto the modified support obtained in step (a) by impregnation.

[0040] In one embodiment of the present invention, the alkaline earth metal precursor is an alkaline earth metal oxide and / or an alkaline earth metal acid salt; the alkaline earth metal acid salt is selected from at least one of alkaline earth metal carbonates, alkaline earth metal nitrates, alkaline earth metal phosphates, and alkaline earth metal sulfates.

[0041] In one embodiment of the present invention, the preferred form is an alkaline earth metal carbonate, and more preferably a basic alkaline earth metal carbonate.

[0042] In one embodiment of the present invention, the carrier precursor is selected from at least one of boehmite, boehmite, aluminum sol, amorphous hydrated alumina, alumina trihydrate and boehmite monohydrate.

[0043] In a preferred embodiment of the present invention, the mixing in step (a) is carried out under stirring conditions. Water may or may not be added during the mixing process in step (a). Generally, from the perspective of improving the uniformity of mixing, it is preferred to add water during the mixing process. The present invention does not have a particular limitation on the amount of water used, as long as it ensures smooth subsequent molding. Preferably, the weight ratio of water to alkaline earth metal precursor is 3-15:1.

[0044] The present invention does not particularly limit the molding method described in step (a), and commonly used molding methods in the art can be adopted. Preferably, the molding method described in step (a) is extrusion molding, spray molding, spheroidization molding, or sheet molding, with extrusion molding being the most preferred.

[0045] The present invention does not impose any particular limitation on the shape of the molded article obtained by the molding in step (a), and it can be one or more of the following: spherical, honeycomb, bird's nest, sheet, strip (such as clover, saucer, cylinder and Raschig ring).

[0046] The drying and calcination described in step (a) can be carried out using methods conventional in the art.

[0047] The drying process described in step (a) can be either oven drying or vacuum drying.

[0048] In one embodiment of the present invention, the drying conditions in step (a) include: a temperature of 60-280°C, preferably 110-200°C; and a time of 1-48 hours, preferably 2-12 hours.

[0049] The conditions for roasting in step (a) include: a temperature of 300-600℃, preferably 350-550℃; and a time of 1-10 hours, preferably 2-8 hours.

[0050] The roasting is generally carried out in an air atmosphere, which may include a flowing atmosphere or a stationary atmosphere.

[0051] The present invention does not impose any particular limitation on the order of introduction of the Group VIB metal component and the Group VIII metal component in step (b). They can be introduced together or separately.

[0052] In one embodiment of the present invention, the impregnation method in step (b) can be a saturated impregnation method or a supersaturated impregnation method. There are no particular limitations on the environment for the impregnation method; it can be carried out under sealed conditions or in an open environment according to conventional methods in the art.

[0053] In a preferred embodiment of the present invention, step (b) includes: impregnating the modified carrier in an impregnation solution containing an active metal component compound, and then drying and calcining it.

[0054] The present invention does not particularly limit the conditions for the impregnation, and the specific impregnation method is a conventional choice in the art. For example, the impregnation conditions include an impregnation temperature of 20-300°C and an impregnation time of 1-20 hours.

[0055] The drying and calcination described in step (b) can be carried out using methods conventional in the art, and under the same conditions as the drying and calcination described in step (a).

[0056] In one embodiment of the present invention, the hydrogenation catalyst is sulfided before use. The present invention does not particularly limit the specific conditions for the sulfidation, and can refer to conventional methods in the art.

[0057] In one embodiment of the present invention, the hydrodechlorination catalyst may be sulfided before loading, or it may be sulfided simultaneously during the hydrotreatment of the catalyst during the reaction. The present invention does not particularly limit the specific conditions of the sulfidation, and can refer to conventional methods in the art.

[0058] The present invention has a wide range of choices for the types of biological oils, which can be plant oils or animal oils, such as one or more mixtures of fatty acids, fatty acid methyl esters, fatty alcohols, waste cooking oil, and algal oil derived from oils.

[0059] The method of the present invention is applicable to the treatment of bio-oils with different organochlorine concentrations.

[0060] In one embodiment of the present invention, the content of organochlorine in the bio-oil is not less than 10 μg / g, preferably 50-100 μg / g. The organochlorine comes from chlorinated organic compounds in the bio-oil, and the chlorinated organic compounds include at least one of chlorinated alkanes, chlorinated alkenes, and chlorinated aromatics.

[0061] The present invention provides a combined system for hydrogenation of bio-oils, comprising a fixed-bed reactor, a thermal high-pressure separator, and a downstream separation unit, with hydrodechlorination catalysts loaded in the upper and lower parts of the thermal high-pressure separator, respectively. In the fixed-bed reactor, oxygen-containing compounds in the bio-oils are refined and removed, while most chlorides are converted to hydrogen chloride. The resulting reaction effluent enters the thermal high-pressure separator, where gas-liquid separation occurs, resulting in a gas phase (reaction effluent W1) and a liquid phase (reaction effluent W2). Reaction effluent W1 contacts the hydrodechlorination catalyst loaded in the upper part of the thermal high-pressure separator for adsorption and dechlorination, yielding a first gas phase stream. Reaction effluent W2 reacts with the hydrodechlorination catalyst loaded in the lower part of the thermal high-pressure separator, adsorbing most of the hydrogen chloride generated in the liquid phase onto the hydrodechlorination catalyst, and further removing some of the difficult-to-remove organic chlorines while also adsorbing hydrogen chloride in situ onto the hydrodechlorination catalyst, thereby achieving efficient removal of chlorine from the bio-oils.

[0062] This invention saves the cost of setting up an additional post-dechlorination reactor by filling a hydrodechlorination catalyst into a hot high-pressure separator, and at the same time solves the technical problem of chlorine corrosion in the equipment during long-cycle production. Detailed Implementation

[0063] The present invention will be further described below with reference to embodiments, but this does not limit the present invention in any way.

[0064] In the following examples, the organic chlorine content parameter was measured by X-ray fluorescence spectroscopy; the inorganic chlorine content was measured by ion chromatography.

[0065] In the examples and comparative examples, the hydrotreating catalyst used was a Ni-W type supported hydrotreating catalyst. Based on the total hydrotreating catalyst, by weight, WO3 ≥ 28.0%, NiO ≥ 4.0%, and the remainder was alumina support. The hydrodechlorination catalyst used was prepared by the following preparation example.

[0066] Before feeding, the hydrotreating catalyst and the hydrodechlorination catalyst are pre-sulfurized using straight-run kerosene containing 2% dimethyl disulfide as the sulfiding oil. The temperature is increased from 110°C to 230°C at a rate of 20°C / h and held for 6 hours; then the temperature is increased to 360°C at a rate of 20°C / h and held for 6 hours.

[0067] Preparation Example 1

[0068] (1) Preparation of modified carrier: 1 kg of pseudoboehmite dry adhesive powder (70% by weight Al2O3), 300 g of magnesium oxide, and 30 g of guar gum powder were mixed evenly, and then 1200 mL of water and 20 mL of nitric acid were added. The mixture was kneaded and extruded on a twin-screw extruder to obtain a butterfly strip with a diameter of 1.3 mm. The strip was then dried at 120 °C for 3 hours and calcined at 500 °C in air atmosphere for 3 hours to obtain modified carrier A1.

[0069] (2) Preparation of hydrodechlorination catalyst: Molybdenum oxide and basic cobalt carbonate were dispersed in water to form an impregnation solution. The Al-modified support was saturated with this impregnation solution at 25°C for 1 hour, then dried at 120°C for 2 hours, and calcined at 400°C in air atmosphere for 3 hours to obtain hydrodechlorination catalyst C1. The composition and performance parameters of the catalyst are shown in Table 1.

[0070] Preparation Example 2

[0071] (1) Preparation of modified carrier: 1 kg of pseudoboehmite dry adhesive powder (70% by weight Al2O3), 377 g of calcium oxide, and 30 g of guar gum powder were mixed evenly, and then 1200 mL of water and 20 mL of nitric acid were added. The mixture was then kneaded and extruded on a twin-screw extruder to obtain a butterfly strip with a diameter of 1.3 mm. The strip was then dried at 120 °C for 3 hours and calcined at 500 °C in air atmosphere for 3 hours to obtain modified carrier A2.

[0072] (2) Preparation of hydrodechlorination catalyst: Molybdenum oxide and basic nickel carbonate were dispersed in water to form an impregnation solution. The A2 modified support was saturated with the impregnation solution at 25°C for 1 hour, then dried at 120°C for 2 hours, and calcined at 400°C in air atmosphere for 3 hours to obtain hydrodechlorination catalyst C2. The composition and performance parameters of the catalyst are shown in Table 1.

[0073] Preparation Example 3

[0074] The preparation method was carried out according to Example 1, except that the amount of magnesium oxide was changed so that the content of alkaline earth metals, calculated as oxides, was 22% by weight, based on the total weight of the modified carrier.

[0075] The hydrodechlorination catalyst C3 was obtained, and its composition and performance parameters are shown in Table 1.

[0076] Comparative Preparation Example 1

[0077] The method of Example 1 was followed, except that step (1) was omitted. Instead, the pseudo-boehmite dry adhesive powder was first extruded into strips, dried at 120°C for 3 hours, and calcined at 500°C in air for 3 hours to obtain an alumina carrier. A magnesium nitrate aqueous solution (1 g / mL) was impregnated on the modified alumina carrier, dried at 120°C for 3 hours, and calcined at 500°C in air for 3 hours. The above impregnation-drying-calcination operation was then repeated twice to obtain the modified carrier S1.

[0078] The hydrodechlorination catalyst D1 was obtained, and its composition and performance parameters are shown in Table 1.

[0079] Comparative Preparation Example 2

[0080] The preparation method of Example 1 was followed, except that in step (1), magnesium oxide was not added. The pseudo-boehmite dry adhesive powder was first extruded into strips, dried at 120°C for 3 hours, and then calcined at 500°C in air atmosphere for 3 hours to obtain alumina carrier S2.

[0081] Following step (2) in Preparation Example 1, the hydrodechlorination catalyst D2 was obtained, and its composition and performance parameters are shown in Table 1.

[0082] Table 1

[0083]

[0084] The hydrogenation combination system of bio-oils used in Examples 1-3 and Comparative Examples 1-2 mainly includes:

[0085] (1) Fixed bed reactor, the fixed bed reactor is filled with hydrogenation catalyst, the total filling volume is 100mL, the top of the fixed bed reactor is set with a feed port for the mixture of bio-oil and hydrogen, and the bottom of the fixed bed reactor is set with a reaction effluent outlet.

[0086] (2) A hot high pressure separator, the upper part of which is filled with a hydrodechlorination catalyst, the lower part of which is filled with a hydrodechlorination catalyst, the middle part of which is provided with a reaction effluent inlet, the top of which is provided with a first gas phase stream outlet, the bottom of which is provided with a first liquid phase stream outlet, and the reaction effluent outlet of the fixed bed reactor is connected to the reaction effluent inlet of the hot high pressure separator;

[0087] (3) Downstream separation unit, the downstream separation unit is provided with a first gas phase stream inlet and a first liquid phase stream inlet, the downstream separation unit is provided with a hot low-pressure separator, a cold high-pressure separator and a cold low-pressure separator, and the cold low-pressure separator is provided with a hydrorefined oil product outlet, a water outlet and a hydrogen-rich gas outlet.

[0088] Example 1

[0089] In the bio-oil hydrogenation system of this invention, a mixture of bio-oil and hydrogen enters a fixed-bed reactor through the feed inlet, reacting with the hydrotreating catalyst. The reaction effluent is extracted from the outlet and enters the hot-pressure separator through the feed inlet in the middle of the hot-pressure separator. Gas-liquid separation occurs, resulting in reaction effluents W1 and W2. Reaction effluent W1 reacts with the hydrodechlorination catalyst C1 (50 mL packing volume) at the top of the hot-pressure separator to obtain a first gaseous stream, which is extracted from the top of the hot-pressure separator. Reaction effluent W2 reacts with the hydrodechlorination catalyst C1 (50 mL packing volume) at the bottom of the hot-pressure separator to obtain a first liquid stream, which is extracted from the bottom of the hot-pressure separator. The resulting first gaseous stream and first liquid stream enter a downstream separation unit, where separation yields hydrorefined oil, water, and hydrogen-rich gas.

[0090] The fixed-bed reactor operates under the following conditions: pressure 5.0 MPa, bio-oil flow rate 100 mL / h, hydrogen flow rate 120 L / h, and average bed temperature 310℃. The thermal high-pressure separator operates under the following conditions: average temperature 270℃ and pressure 5.0 MPa.

[0091] The organic chlorine content, oxygen content, and inorganic chlorine content of the hydrorefined oil products after different reaction times were analyzed, and the results are shown in Table 3.

[0092] Example 2

[0093] In the bio-oil hydrogenation system of this invention, a mixture of bio-oil and hydrogen enters a fixed-bed reactor through the feed inlet, reacting with the hydrotreating catalyst. The reaction effluent is extracted from the outlet and enters the hot-pressure separator through the feed inlet in the middle of the hot-pressure separator. Gas-liquid separation occurs, resulting in reaction effluents W1 and W2. Reaction effluent W1 reacts with the hydrodechlorination catalyst C2 (40 mL packing volume) at the top of the hot-pressure separator to obtain a first gaseous stream, which is extracted from the top of the hot-pressure separator. Reaction effluent W2 reacts with the hydrodechlorination catalyst C2 (40 mL packing volume) at the bottom of the hot-pressure separator to obtain a first liquid stream, which is extracted from the bottom of the hot-pressure separator. The resulting first gaseous stream and first liquid stream enter a downstream separation unit, where separation yields hydrorefined oil, water, and hydrogen-rich gas.

[0094] The fixed-bed reactor operates under the following conditions: pressure 6.4 MPa, bio-oil flow rate 100 mL / h, hydrogen flow rate 100 L / h, and average bed temperature 300℃. The thermal high-pressure separator operates under the following conditions: average temperature 280℃ and pressure 6.4 MPa.

[0095] The organic chlorine content, oxygen content, and inorganic chlorine content of the hydrorefined oil products after different reaction times were analyzed, and the results are shown in Table 3.

[0096] Example 3

[0097] The procedure was carried out according to the method of Example 1, except that the hydrodechlorination catalyst C3 prepared in Preparation Example 3 was used instead.

[0098] The organic chlorine content, oxygen content, and inorganic chlorine content of the hydrorefined oil products after different reaction times were analyzed, and the results are shown in Table 3.

[0099] Comparative Example 1

[0100] The procedure was carried out according to Example 1, except that the hydrodechlorination catalyst D1 prepared in Comparative Preparation Example 1 was used instead.

[0101] The organic chlorine content, oxygen content, and inorganic chlorine content of the hydrorefined oil products after different reaction times were analyzed, and the results are shown in Table 3.

[0102] Comparative Example 2

[0103] The procedure was carried out according to Example 1, except that the hydrodechlorination catalyst D2 prepared in Comparative Preparation Example 2 was used instead.

[0104] The organic chlorine content, oxygen content, and inorganic chlorine content of the hydrorefined oil products after different reaction times were analyzed, and the results are shown in Table 3.

[0105] Comparative Example 3

[0106] The total catalyst loading volume in the fixed-bed reactor is 100 mL, and it is filled with hydrodeoxygenation catalyst RJW-3 (produced by Changling Catalyst Factory). The dechlorination adsorbent WGL-A (produced by Wenzhou Catalyst Factory) is loaded in the upper part of the hot high-pressure separator, with a catalyst loading of 50 mL.

[0107] Hydrogen and bio-oil feedstock (composition shown in Table 2) are mixed and then fed into a fixed-bed reactor for hydrodeoxygenation. The hydrodeoxygenation product enters a high-pressure thermal separator for gas-liquid separation. The separated gas phase is contacted with a dechlorination adsorbent packed in the upper part of the high-pressure thermal separator for adsorption and dechlorination, resulting in a gaseous stream. The separated liquid phase passes through the lower part of the high-pressure thermal separator and is then extracted to obtain a liquid stream, which sequentially enters a low-pressure thermal separator and a low-pressure cold separator to separate the hydrotreated oil. The gaseous stream mainly contains hydrogen-rich gas and water vapor. After separation in the high-pressure cold separator, the water vapor is cooled to water, and the hydrogen-rich gas is recycled. The water and a small amount of hydrotreated oil enter the low-pressure cold separator for further separation.

[0108] The fixed-bed reactor operates under the following conditions: pressure 5.0 MPa, bio-oil flow rate 100 mL / h, hydrogen flow rate 120 L / h, and average deoxygenation bed temperature 320℃. The thermal high-pressure separator operates under the following conditions: average temperature 270℃ and pressure 5.0 MPa.

[0109] The organic chlorine content, oxygen content, and inorganic chlorine content of the hydrorefined oil products after different reaction times were analyzed, and the results are shown in Table 3.

[0110] Comparative Example 4

[0111] The total catalyst loading volume in the fixed-bed reactor is 100 mL, and it is filled with hydrodeoxygenation catalyst RJW-3 (produced by Changling Catalyst Factory). The dechlorination adsorbent WGL-A (produced by Wenzhou Catalyst Factory) is loaded in the lower part of the hot high-pressure separator, with a catalyst loading of 50 mL.

[0112] Hydrogen and bio-oil feedstock (composition shown in Table 2) are mixed and then fed into a fixed-bed reactor for hydrodeoxygenation. The hydrodeoxygenation product enters a high-pressure thermal separator for gas-liquid separation. The resulting gas phase is extracted from the high-pressure thermal separator after passing through the upper part, yielding a gaseous stream. The resulting liquid phase is dechlorinated by a dechlorination adsorbent packed in the lower part of the high-pressure thermal separator, then extracted and sequentially fed into a low-pressure thermal separator and a low-pressure cold separator to separate the hydrotreated oil. The gaseous stream mainly contains hydrogen-rich gas and water vapor. After separation in the low-pressure cold separator, the water vapor is cooled to water, and the hydrogen-rich gas is recycled. The water and a small amount of hydrotreated oil then enter the low-pressure cold separator for further separation.

[0113] The fixed-bed reactor operates under the following conditions: pressure 5.0 MPa, bio-oil flow rate 100 mL / h, hydrogen flow rate 120 L / h, and average deoxygenation bed temperature 320℃. The thermal high-pressure separator operates under the following conditions: average temperature 270℃ and pressure 5.0 MPa.

[0114] The organic chlorine content, oxygen content, and inorganic chlorine content of the hydrorefined oil products after different reaction times were analyzed, and the results are shown in Table 3.

[0115] Table 2

[0116]

[0117]

[0118] Table 3

[0119]

[0120] In Table 3, the organic chlorine content in hydrotreated oil products reflects the dechlorination activity of the hydrotreatment catalyst and the hydrodechlorination catalyst, while the chlorine (HCl) content in the generated water reflects the chlorine adsorption activity of the hydrodechlorination catalyst.

[0121] As can be seen from the results in Table 3, the combined system and method provided by this invention have significantly better dechlorination effect, which can effectively solve the problem of chloride ion corrosion of the device during long-cycle processing of bio-oils, and at the same time, it can refine and remove oxygen-containing compounds in the raw materials to produce high-quality refined oil products.

[0122] In Examples 1-3, the organic chlorine content in the hydrorefined oil and the chlorine (HCl) content in the water were both low after 100 h and 1000 h of reaction, indicating that the hydrodechlorination catalyst used in this invention has high dechlorination activity and chlorine adsorption activity. It also shows that the hydrodechlorination catalyst still maintains a high chlorine capacity after 1000 h of reaction. The hydrodechlorination catalyst described in this invention has high stability and can avoid equipment corrosion and pipeline blockage caused by high liquid chlorine content during long-term operation.

[0123] In comparison, the chlorine content in the water after 100 hours of reaction was higher in Comparative Example 1, reaching 42 mg / L; in Comparative Example 2, the chlorine content was higher, reaching 200 mg / L; in Comparative Example 3, the chlorine content was as high as 85 mg / L; and in Comparative Example 4, the chlorine content was as high as 220 mg / L. Moreover, the chlorine content in the water of Comparative Examples 1-4 was even higher after 1000 hours of reaction. Such high chlorine content would cause serious corrosion to the equipment.

Claims

1. A hydrogenation system for bio-oils, comprising: (1) Fixed bed reactor, the fixed bed reactor is filled with hydrogenation catalyst, the fixed bed reactor is equipped with a feed inlet of bio-oil and hydrogen mixture, and the fixed bed reactor is equipped with a reaction effluent outlet; (2) A hot high pressure separator, the upper part of which is filled with a hydrodechlorination catalyst, the lower part of which is filled with a hydrodechlorination catalyst, the middle part of which is provided with a reaction effluent inlet, the top of which is provided with a first gas phase stream outlet, the bottom of which is provided with a first liquid phase stream outlet, and the reaction effluent outlet of the fixed bed reactor is connected to the reaction effluent inlet of the hot high pressure separator; The hydrodechlorination catalyst includes a modified support and an active metal component supported on the modified support. The modified support comprises a support and an alkaline earth metal. The active metal component includes at least one Group VIB metal component and at least one Group VIII metal component. The support is alumina. Based on the total weight of the modified support, the content of alkaline earth metals, calculated as oxides, is 20-50% by weight, and the breakthrough chlorine capacity of the hydrodechlorination catalyst is not less than 20%. (3) Downstream separation unit, the downstream separation unit is equipped with a first gas phase stream inlet and a first liquid phase stream inlet, as well as a hydrorefined oil product outlet, a water outlet and a hydrogen-rich gas outlet.

2. The system according to claim 1, characterized in that, The hydrotreating catalyst comprises alumina and at least one Group VIB metal component and at least one Group VIII metal component supported on the alumina; Preferably, based on the total weight of the hydrotreating catalyst, the content of the Group VIB metal component is 5-30% by weight and the content of the Group VIII metal component is 1-10% by weight, calculated as oxides; the Group VIB metal component is molybdenum and / or tungsten; and the Group VIII metal component is nickel and / or cobalt.

3. The system according to claim 1, characterized in that, In the hot high-pressure separator, the volume ratio of the upper-filled hydrodechlorination catalyst to the lower-filled hydrodechlorination catalyst is 20:1-1.

4. The system according to claim 1, characterized in that, In the hydrodechlorination catalyst, based on the total weight of the modified support, the content of alkaline earth metals, calculated as oxides, is 20-40% by weight, preferably 25-35% by weight. The alkaline earth metal is magnesium and / or calcium, preferably magnesium; The breakthrough chlorine capacity of the hydrodechlorination catalyst is 20-32%.

5. The system according to claim 1 or 4, characterized in that, The specific surface area of ​​the modified carrier is 150-250 m². 2 / g, preferably 180-220m 2 / g; the pore volume of the modified support is 0.5-0.7cm³. 3 / g, preferably 0.55-0.65cm 3 / g.

6. The system according to claim 1, characterized in that, In the hydrodechlorination catalyst, based on the total weight of the hydrodechlorination catalyst and calculated as oxides, the content of the Group VIB metal component is 5-20% by weight, preferably 5-15% by weight; the content of the Group VIII metal component is 0.5-10% by weight, preferably 0.8-5% by weight; the Group VIB metal component is molybdenum and / or tungsten; the Group VIII metal component is nickel and / or cobalt.

7. The system according to claim 1, characterized in that, The downstream separation unit may include an optional hot low-pressure separator, a cold high-pressure separator, a cold low-pressure separator, a stripping tower, and a fractionation tower.

8. The system according to claim 1, characterized in that, The pressure in the thermal high-pressure separator is the same as the pressure in the fixed-bed reactor. A cooling device is installed between the effluent outlet of the fixed-bed reactor and the inlet of the reaction effluent of the thermal high-pressure separator.

9. A method for hydrogenating bio-oils using any one of the systems of claims 1-8, comprising: (1) A mixture of bio-oil and hydrogen enters the fixed-bed reactor through the feed inlet and reacts with the loaded hydrotreating catalyst. The resulting effluent flows out from the effluent outlet of the fixed-bed reactor. (2) After entering the reaction effluent from the reaction effluent inlet in the middle of the thermal high-pressure separator, the reaction effluent is divided into reaction effluent W1 and reaction effluent W2. After reaction effluent W1 reacts with the hydrodechlorination catalyst packed in the upper part of the thermal high-pressure separator, the first gaseous stream is obtained. After reaction effluent W2 reacts with the hydrodechlorination catalyst packed in the lower part of the thermal high-pressure separator, the first liquid stream is obtained. (3) The first gaseous stream and the first liquid stream are fed into the downstream separation unit, and after separation, hydrorefined oil, water and hydrogen-rich gas are obtained.

10. The method according to claim 9, characterized in that, The reaction conditions in the fixed-bed reactor are as follows: temperature 200-450℃, preferably 280-400℃; pressure 3-15MPa, preferably 5-8MPa; liquid hourly space velocity (LISH) 0.1-10h. -1 Preferably, it is 0.2-5.0h. -1 The hydrogen-to-oil volume ratio is 300-3000, preferably 800-1500.

11. The method according to claim 9, characterized in that, The operating conditions for the hot high-pressure separator are: temperature 200-350℃, preferably 250-300℃; pressure 3-15MPa, preferably 5-8MPa.

12. The method according to claim 9, characterized in that, The preparation method of the hydrodechlorination catalyst includes the following steps: (a) The carrier precursor is mixed with the alkaline earth metal precursor and then optionally dried and calcined to obtain the modified carrier; (b) Introduce active metal components onto the modified support obtained in step (a) by impregnation.

13. The method according to claim 12, characterized in that, Alkaline earth metal precursors are alkaline earth metal oxides and / or alkaline earth metal acid salts. The alkaline earth metal acid salt is selected from at least one of alkaline earth metal carbonates, alkaline earth metal nitrates, alkaline earth metal phosphates and alkaline earth metal sulfates, preferably alkaline earth metal carbonates, and more preferably alkaline earth metal basic carbonates. The carrier precursor is selected from at least one of boehmite, boehmite, aluminum sol, amorphous hydrated alumina, alumina trihydrate and boehmite monohydrate.

14. The method according to claim 12, characterized in that, The drying conditions for step (a) include: a temperature of 60-280°C, preferably 110-200°C; and a time of 1-48 hours, preferably 2-12 hours. The conditions for roasting in step (a) include: a temperature of 300-600℃, preferably 350-550℃; and a time of 1-10 hours, preferably 2-8 hours.

15. The method according to claim 9, characterized in that, In bio-oils, the content of organochlorine compounds is not less than 10 μg / g, preferably 50-100 μg / g.

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