Hydrogenation method of waste biological oil containing chlorine

Abstract

The present application relates to a kind of hydrogenation methods of waste biological oil containing chlorine, comprising: waste biological oil containing chlorine is in the presence of hydrogen, in turn with first hydrotreating catalyst and second hydrotreating catalyst Contact reaction, the second hydrotreating catalyst includes modified carrier and active metal component supported on modified carrier, the modified carrier includes carrier and alkaline earth metal, the obtained reaction effluent is separated, and hydrogenation refined oil product is obtained.The method can efficiently remove organic chlorine in waste biological oil containing chlorine, and effectively solve the corrosion problem of chloride ion to device in the process of long-period processing waste biological oil containing chlorine.

Description

Technical Field

[0001] This invention relates to the field of bio-oil processing, and more specifically to a method for hydrogenating chlorine-containing waste bio-oil. 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 oils. One problem is the high chlorine and oxygen content in waste 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 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 low dechlorination stability and chlorine corrosion of equipment during long-term production in the process of treating chlorine-containing waste bio-oils.

[0007] This invention provides a method for hydrogenating chlorine-containing waste bio-oil, comprising: reacting the chlorine-containing waste bio-oil with a first hydrogenation catalyst and a second hydrogenation catalyst in the presence of hydrogen, wherein the loading volume ratio of the first hydrogenation catalyst and the second hydrogenation catalyst is 20:1-20.

[0008] The first hydrotreating catalyst comprises alumina and at least one Group VIB metal component and at least one Group VIII metal component supported on the alumina;

[0009] The second hydrotreating 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, and the content of alkaline earth metal is 20-50% by weight, based on the total weight of the modified support and calculated as oxides.

[0010] The breakthrough chlorine capacity of the second hydrogenation catalyst is not less than 20%.

[0011] The present invention has a wide range of choices for the types of chlorine-containing waste bio-oils, which can be vegetable oils or animal oils, such as fatty acids, fatty acid methyl esters, fatty alcohols, waste cooking oil, algal oils, or one or more mixtures derived from oils.

[0012] The method of the present invention is applicable to the treatment of chlorine-containing waste bio-oils with different organochlorine concentrations.

[0013] In one embodiment of the present invention, the content of organochlorine in the chlorinated waste bio-oil is not less than 10 μg / g, preferably 50-100 μg / g. The organochlorine comes from chlorinated organic matter in the waste bio-oil, and the chlorinated organic matter includes at least one of chlorinated alkanes, chlorinated alkenes, and chlorinated aromatics.

[0014] The chlorine-containing waste bio-oils described in this invention may also contain sulfur, as well as mechanical impurities such as iron, nickel, vanadium, sodium, and calcium.

[0015] In one embodiment of the present invention, the total content of mechanical impurities in chlorine-containing waste bio-oil is not higher than 0.1% by weight.

[0016] In one embodiment of the present invention, the sulfur content in chlorine-containing waste bio-oil is not higher than 30 μg / g.

[0017] In one embodiment of the present invention, the first hydrotreating catalyst and the second hydrotreating catalyst are packed in different catalyst beds in a fixed-bed reactor, and the reaction effluents between the first hydrotreating catalyst bed and the second hydrotreating catalyst bed are not separated. In the present invention, the first hydrotreating catalyst bed and the second hydrotreating catalyst bed can be respectively arranged in two fixed-bed reactors connected in series, or they can be arranged in a single fixed-bed reactor.

[0018] In one embodiment of the present invention, the reaction conditions of the first hydrogenation treatment catalyst bed include: a temperature of 200-450°C, a pressure of 3-15 MPa, and a liquid hourly space velocity of 0.1-10 h⁻¹. -1 The standard hydrogen-to-oil volume ratio is 300-3000.

[0019] The reaction conditions for the second hydrotreating catalyst bed include: a temperature of 200-450℃, a pressure of 3-15 MPa, and a liquid hourly space velocity of 0.1-20 h⁻¹. -1 The standard hydrogen-to-oil volume ratio is 300-3000.

[0020] In one embodiment of the present invention, the reaction conditions of the first hydrogenation treatment catalyst bed include: a temperature of 250-400°C, a pressure of 5-8 MPa, and a liquid hourly space velocity of 0.2-5.0 h⁻¹. -1 The standard hydrogen-to-oil volume ratio is 800-1500.

[0021] The reaction conditions for the second hydrotreating catalyst bed include: a temperature of 280-400℃, a pressure of 5-8 MPa, and a liquid hourly space velocity of 0.2-10.0 h⁻¹. -1 The standard hydrogen-to-oil volume ratio is 800-1500.

[0022] In this invention, chlorine-containing waste bio-oil undergoes hydrodeoxygenation and partial hydrodesulfurization reactions in the presence of hydrogen in a first hydrotreating catalyst bed. The effluent is not separated and directly enters a second hydrotreating catalyst bed, where it undergoes hydrodechlorination. This process converts most of the organic chlorides into HCl and adsorbs the HCl in situ onto the second hydrotreating catalyst, thereby achieving efficient removal of organic chlorides from the chlorine-containing waste bio-oil and effectively solving the corrosion problem of the equipment caused by chloride ions during the processing of chlorine-containing waste bio-oil.

[0023] In one embodiment of the present invention, in the first hydrogenation catalyst, based on the total weight of the first hydrogenation 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.

[0024] In the first hydrogenation catalyst of the present invention, the sum of the contents of each component is 100%.

[0025] The second hydrotreating catalyst of this invention has a high chlorine penetration capacity and exhibits good chlorine adsorption activity. In a preferred embodiment of this invention, the chlorine penetration capacity of the second hydrotreating catalyst is 20-32%.

[0026] 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).

[0027] The inventors of this invention have discovered that alkaline earth metals in the modified support of the second hydrotreating 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 second hydrotreating catalyst, based on the total weight of the modified support and calculated as oxides, is 20-40% by weight, preferably 25-35% by weight.

[0028] The content of alkaline earth metals in the catalyst of the present invention was determined by X-ray fluorescence spectroscopy (XRF).

[0029] 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.

[0030] The modified support described in this invention possesses a large specific surface area and suitable pore volume, appropriate interaction forces with the active metal component, and high structural stability. This results in the second hydrotreating catalyst of this invention exhibiting good dechlorination and chlorine adsorption activity, as well as high dechlorination stability. In one embodiment of this invention, the specific surface area of ​​the modified support 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.

[0031] The specific surface area and pore volume of the modified carrier of this invention were measured by the BET physical adsorption-desorption analysis method.

[0032] In one embodiment of the present invention, in the second hydrogenation catalyst, based on the total weight of the second hydrogenation 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.

[0033] In the second hydrogenation catalyst of the present invention, the sum of the contents of each component is 100%.

[0034] The content of the active metal component in the catalyst of the present invention was determined by X-ray fluorescence spectroscopy (XRF).

[0035] In one embodiment of the present invention, the preparation method of the second hydrogenation catalyst includes the following steps:

[0036] (a) The carrier precursor is mixed with the alkaline earth metal precursor and then optionally dried and calcined to obtain the modified carrier;

[0037] (b) Introduce active metal components onto the modified support obtained in step (a) by impregnation.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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).

[0044] The drying and calcination described in step (a) can be carried out using methods conventional in the art.

[0045] The drying process described in step (a) can be either oven drying or vacuum drying.

[0046] 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.

[0047] 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.

[0048] The roasting is generally carried out in an air atmosphere, which may include a flowing atmosphere or a stationary atmosphere.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] In a preferred embodiment of the present invention, the first and second hydrogenation catalysts are 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.

[0055] In one embodiment of the present invention, the reaction products are subjected to gas-liquid separation to obtain hydrorefined oil, water produced by the reaction, and hydrogen-rich gas. The present invention does not particularly limit the method of gas-liquid separation and can refer to conventional methods in the art.

[0056] The hydrogenation method provided by this invention can treat chlorinated waste bio-oils. Through the synergistic effect of the first and second hydrogenation catalysts, it can remove oxygen-containing and sulfur-containing compounds from the chlorinated waste bio-oils, as well as most of the chlorides. Furthermore, it can adsorb most of the hydrogen chloride generated in the reaction onto the second hydrogenation catalyst. Therefore, this invention achieves highly efficient removal of organochlorines from chlorinated waste bio-oils and effectively solves the corrosion problem of chloride ions on the equipment during long-cycle processing of chlorinated waste bio-oils, while simultaneously obtaining high-quality hydrorefined oil products. Detailed Implementation

[0057] The present invention will be further described below with reference to embodiments, but this does not limit the present invention in any way.

[0058] 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.

[0059] In the examples and comparative examples, the first hydrogenation catalyst used was a Ni-W type hydrogenation catalyst, which, based on the entire first hydrogenation catalyst, contained WO3 ≥ 28.0% and NiO ≥ 4.0% by weight, with the remainder being an alumina support. The second hydrogenation catalyst used was prepared by the following preparation example.

[0060] Before feeding, the first and second hydrotreating catalysts 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.

[0061] Preparation Example 1

[0062] (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.

[0063] (2) Preparation of the second hydrotreating 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 the second hydrotreating catalyst C1. The composition and performance parameters of the catalyst are shown in Table 1.

[0064] Preparation Example 2

[0065] (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 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.

[0066] (2) Preparation of the second hydrotreating 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 the second hydrotreating catalyst C2. The composition and performance parameters of the catalyst are shown in Table 1.

[0067] Preparation Example 3

[0068] 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.

[0069] The second hydrogenation catalyst C3 was obtained, and its composition and performance parameters are shown in Table 1.

[0070] Comparative Preparation Example 1

[0071] The method of Preparation Example 1 was followed, except that in step (1), 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; magnesium nitrate aqueous solution (1g / 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, and then the above impregnation-drying-calcination operation was repeated twice to obtain the modified carrier S1.

[0072] Following step (2) in Preparation Example 1, the second hydrogenation catalyst D1 was obtained, and its composition and performance parameters are shown in Table 1.

[0073] Comparative Preparation Example 2

[0074] 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.

[0075] Following step (2) in Preparation Example 1, the second hydrogenation catalyst D2 was obtained, and its composition and performance parameters are shown in Table 1.

[0076] Table 1

[0077]

[0078] The chlorine-containing waste bio-oil used in the examples and comparative examples is catering waste oil, the main properties of which are shown in Table 2, and its organic chlorine content is 70 μg / g.

[0079] Example 1

[0080] The total packing volume of the catalyst in the fixed-bed hydrogenation reactor is 100 mL. Along the flow direction, a first hydrogenation treatment catalyst bed (filled with the first hydrogenation treatment catalyst) and a second hydrogenation treatment catalyst bed (filled with the second hydrogenation treatment catalyst C1) are arranged sequentially. The packing volume ratio of the first hydrogenation treatment catalyst to the second hydrogenation treatment catalyst is 7:3.

[0081] In the presence of hydrogen, chlorine-containing waste bio-oils are sequentially fed into the first and second hydrogenation catalyst beds for reaction, and the reaction effluents between the first and second hydrogenation catalyst beds are not separated.

[0082] The reaction products are separated into gas and liquid phases to obtain hydrorefined oil, water, and hydrogen-rich gas. The operating conditions of the fixed-bed hydrotreating reactor are: pressure 6.4 MPa, flow rate of chlorinated waste bio-oil 100 mL / h, hydrogen flow rate 120 L / h, and average reaction temperature of the first hydrotreating catalyst bed 300℃.

[0083] 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.

[0084] Example 2

[0085] The total packing volume of the catalyst in the fixed-bed hydrogenation reactor is 100 mL. Along the flow direction, a first hydrogenation treatment catalyst bed (filled with the first hydrogenation treatment catalyst) and a second hydrogenation treatment catalyst bed (filled with the second hydrogenation treatment catalyst C2) are arranged sequentially. The packing volume ratio of the first hydrogenation treatment catalyst to the second hydrogenation treatment catalyst is 8:2.

[0086] In the presence of hydrogen, chlorine-containing waste bio-oils are sequentially fed into the first and second hydrogenation catalyst beds for reaction, and the reaction effluents between the first and second hydrogenation catalyst beds are not separated.

[0087] The reaction products are separated into gas and liquid phases to obtain hydrorefined oil, water, and hydrogen-rich gas. The operating conditions of the fixed-bed hydrotreating reactor are: pressure 6.4 MPa, flow rate of chlorinated waste bio-oil 100 mL / h, hydrogen flow rate 100 L / h, average reaction temperature of the first hydrotreating catalyst bed 310℃, and average reaction temperature of the first hydrotreating catalyst bed 320℃.

[0088] 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.

[0089] Example 3

[0090] The total packing volume of the catalyst in the fixed-bed hydrogenation reactor is 100 mL. Along the flow direction, a first hydrogenation treatment catalyst bed (filled with the first hydrogenation treatment catalyst) and a second hydrogenation treatment catalyst bed (filled with the second hydrogenation treatment catalyst C3) are arranged sequentially. The packing volume ratio of the first hydrogenation treatment catalyst to the second hydrogenation treatment catalyst is 7:3.

[0091] In the presence of hydrogen, chlorine-containing waste bio-oils are sequentially fed into the first and second hydrogenation catalyst beds for reaction, and the reaction effluents between the first and second hydrogenation catalyst beds are not separated.

[0092] The reaction products are separated into gas and liquid phases to obtain hydrorefined oil, water, and hydrogen-rich gas. The operating conditions of the fixed-bed hydrotreating reactor are: pressure 6.4 MPa, flow rate of chlorinated waste bio-oil 100 mL / h, hydrogen flow rate 120 L / h, and average reaction temperature of the first hydrotreating catalyst bed 300℃.

[0093] 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.

[0094] Comparative Example 1

[0095] The procedure was carried out according to Example 1, except that the second hydrogenation catalyst bed was filled with the second hydrogenation catalyst D1 prepared in Comparative Preparation Example 1.

[0096] 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.

[0097] Comparative Example 2

[0098] The procedure was carried out according to Example 1, except that the second hydrogenation catalyst bed was filled with the second hydrogenation catalyst D2 prepared in Comparative Preparation Example 2.

[0099] 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.

[0100] Comparative Example 3

[0101] The total catalyst loading volume in the fixed-bed hydrogenation reactor is 100 mL. Along the flow direction, a first hydrogenation catalyst bed (filled with the first hydrogenation catalyst) and a second bed (filled with inert ceramic balls) are sequentially arranged, with a loading volume ratio of the first hydrogenation catalyst to the inert ceramic balls of 7:3. A dechlorination reactor is located downstream of the fixed-bed hydrogenation reactor, and 100 mL of dechlorination adsorbent WGL-A (produced by Wenzhou Catalyst Plant) is loaded into the dechlorination reactor. The main components of WGL-A dechlorination agent are alkaline earth metal oxides, alumina, and bentonite, which adsorb hydrogen chloride generated during the hydrogenation process.

[0102] In the presence of hydrogen, chlorine-containing waste bio-oils sequentially enter the first hydrogenation treatment catalyst bed and the second bed. The reaction effluent between the first hydrogenation treatment catalyst bed and the second bed is not separated. The reaction effluent from the fixed-bed hydrogenation reactor directly enters the dechlorination reactor for adsorption and dechlorination.

[0103] The reaction products are separated into gas and liquid to obtain hydrorefined oil, reaction-generated water, and hydrogen-rich gas. The operating conditions of the fixed-bed hydrotreating reactor are: pressure 6.4 MPa, flow rate of chlorinated waste bio-oil 100 mL / h, hydrogen flow rate 100 L / h, average reaction temperature of the first hydrotreating catalyst bed 320℃, and average temperature of the dechlorination reactor 280℃.

[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] Table 2

[0106] project Waste oil from catering <![CDATA[Density at 20°C, kg / m 3 > 919.5 Carbon content, % (w) 76.66 Hydrogen content, % (w) 11.71 Organochlorine content, μg / g 70 Sulfur content, μg / g 40 Nitrogen content, μg / g 151 Oxygen content, % (w) 10.69 Fe, μg / g 20 Ni, μg / g <1 V, μg / g <1 Na, μg / g 23 Mg, μg / g 1.2 Ca, μg / g <1 P, μg / g 21

[0107] Table 3

[0108]

[0109]

[0110] In Table 3, the organic chlorine content in the hydrotreated oil reflects the dechlorination activity of the first and second hydrotreating catalysts, while the chlorine (HCl) content in the generated water reflects the chlorine adsorption activity of the second hydrotreating catalyst.

[0111] As can be seen from the results in Table 3, the method provided by this invention has a significantly better dechlorination effect, which can effectively solve the problem of chloride ion corrosion of the device during the long-cycle hydrogenation process of chlorine-containing waste bio-oils. At the same time, it can refine and remove oxygen-containing compounds from the raw materials to produce high-quality refined oil products.

[0112] In Examples 1-3, the organic chlorine content in the hydrorefined oil and the chlorine (HCl) content in the generated water were both low after 100 hours and 1000 hours of reaction, indicating that the first and second hydrotreating catalysts used in this invention have high dechlorination and chlorine adsorption activities. Furthermore, the second hydrotreating catalyst still maintained a high chlorine capacity after 1000 hours of reaction, indicating that the second hydrotreating catalyst of this invention has high stability and can avoid equipment corrosion and pipeline blockage caused by high liquid-phase chlorine content during long-term operation.

[0113] In comparison, while both the first and second hydrogenation catalysts in Comparative Examples 1 and 2 exhibited high dechlorination activity, the second hydrogenation catalyst in Comparative Examples 1 and 2 showed low chlorine adsorption activity. After 100 hours of reaction, the chlorine content in the resulting water in Comparative Examples 1 and 2 was relatively high, reaching 45 mg / L and 170 mg / L, respectively. In Comparative Example 3, although a post-dechlorination reactor was used, the conventional dechlorination adsorbent employed had lower chlorine adsorption activity than the second hydrogenation catalyst of this invention. After 100 hours of reaction, the chlorine content in the water in Comparative Example 3 reached as high as 150 mg / L.

[0114] Furthermore, after 1000 hours of reaction, the chlorine content of the water produced in Comparative Examples 1, 2, and 3 was even higher, and such a high chlorine content would cause severe corrosion to the equipment.

Claims

1. A method for hydrogenating chlorine-containing waste bio-oil, comprising: In the presence of hydrogen, chlorine-containing waste bio-oil reacts sequentially with a first hydrogenation catalyst and a second hydrogenation catalyst, with a loading volume ratio of 20:1-20 between the first and second hydrogenation catalysts. The first hydrotreating catalyst comprises alumina and at least one Group VIB metal component and at least one Group VIII metal component supported on the alumina; The second hydrotreating 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, and the content of alkaline earth metal is 20-50% by weight, based on the total weight of the modified support and calculated as oxides. The breakthrough chlorine capacity of the second hydrogenation catalyst is not less than 20%.

2. The method according to claim 1, characterized in that, The first and second hydrotreating catalysts are packed in different catalyst beds in a fixed-bed reactor, and the reaction effluents between the first and second hydrotreating catalyst beds are not separated. The reaction conditions for the first hydrogenation catalyst bed include: a temperature of 200-450℃, a pressure of 3-15 MPa, and a liquid hourly space velocity of 0.1-10 h⁻¹. -1 The standard hydrogen-to-oil volume ratio is 300-3000. The reaction conditions for the second hydrotreating catalyst bed include: a temperature of 200-450℃, a pressure of 3-15 MPa, and a liquid hourly space velocity of 0.1-20 h⁻¹. -1 The standard hydrogen-to-oil volume ratio is 300-3000.

3. The method according to claim 2, characterized in that, The reaction conditions for the first hydrotreating catalyst bed include: a temperature of 250-400℃, a pressure of 5-8 MPa, and a liquid hourly space velocity of 0.2-5.0 h⁻¹. -1 The standard hydrogen-to-oil volume ratio is 800-1500. The reaction conditions for the second hydrotreating catalyst bed include: a temperature of 280-400℃, a pressure of 5-8 MPa, and a liquid hourly space velocity of 0.2-10.0 h⁻¹. -1 The standard hydrogen-to-oil volume ratio is 800-1500.

4. The method according to claim 1, characterized in that, In the first hydrotreating catalyst, based on the total weight of the first 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.

5. The method according to claim 1, characterized in that, In the second hydrogenation 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 second hydrotreating catalyst is 20-32%.

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

7. The method according to claim 1 or 5, characterized in that, In the second hydrotreating catalyst, based on the total weight of the second hydrotreating 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.

8. The method according to claim 1, characterized in that, The preparation method of the second hydrogenation 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.

9. The method according to claim 8, 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.

10. The method according to claim 8, characterized in that, The molding process described in step (a) is extrusion molding, spray molding, spheroidization molding, or sheet molding, preferably extrusion molding; 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.

11. The method according to claim 1, characterized in that, In chlorinated waste bio-oils, the content of organochlorine is not less than 10 μg / g, preferably 50-100 μg / g.

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