Preparation method and application of bifunctional catalyst based on catalytic hydrodechlorination and deoxygenation

Abstract

The invention discloses a preparation method and application of a bifunctional catalyst based on catalytic hydrogenation, dechlorination and deoxidation, and particularly relates to a preparation method of a bifunctional catalyst based on catalytic hydrogenation, dechlorination and deoxidation, which comprises the following steps: selecting a corresponding precipitator to prepare a metal oxide with acid-base dual-property sites as a carrier, and loading metal Ni on the carrier through the steps of dipping, aging, drying, calcining, activating and the like. The activity of the catalyst is further improved by using an assistant Mo, and finally, the bifunctional catalyst capable of simultaneously dechlorinating and deoxidizing is obtained and can be applied to the hydrogenation upgrading process of plastic pyrolytic oil. The bifunctional catalyst provided by the invention is simple in preparation process and high in catalytic activity, and when the bifunctional catalyst is used for hydrogenation upgrading of chlorine-containing and oxygen-containing waste plastic pyrolytic oil, the bifunctional catalyst has the main advantages that compared with a single dechlorination and deoxidation catalyst, the bifunctional catalyst is more suitable for upgrading of pyrolytic oil with complex components, and the hydrogenation upgrading process flow is simplified.

Description

Technical Field

[0001] The invention relates to the technical field of industrial catalysts, and in particular to a preparation method and application of a bifunctional catalyst based on catalytic hydrogenation, dechlorination and deoxygenation. Background Art

[0002] Pyrolysis is an effective way to recycle waste polymer materials such as waste plastics. During the pyrolysis process, chlorine, oxygen and other elements in waste plastics will be removed from the polymer chain and exist in the form of chlorinated hydrocarbons or oxygen-containing compounds. However, the presence of chlorinated hydrocarbons such as ethylene dichloride and chlorobenzene will cause certain harm to the processing equipment, such as corrosion of refining equipment, pipeline blockage and catalyst poisoning. The presence of oxygen-containing substances such as furfural and phenol makes the oil acidic and reduces the calorific value of pyrolysis oil.

[0003] Traditional methods for treating chlorinated hydrocarbons and oxygen-containing substances include plasma treatment, supercritical water treatment, catalytic decomposition, catalytic hydrolysis, etc. However, the previous methods are prone to secondary pollution, or the technology is immature, or the treatment cost is too high. Catalytic hydrogenation quality improvement technology, that is, under the action of pressurized hydrogen atmosphere and catalyst, chlorinated hydrocarbons are selectively catalytically converted to convert chlorine into small molecular hydrogen chloride gas and oxygen into H2O molecules, thereby achieving the elimination of chlorinated hydrocarbons and oxygen-containing substances in pyrolysis oil and improving the quality. However, at present, hydrodechlorination and deoxygenation are usually carried out separately using different catalysts, which is complex and has large losses. In addition, in the step-by-step removal process, the dechlorination effect significantly affects the oxygen removal efficiency. Therefore, achieving dechlorination and deoxygenation in one step can improve the efficiency of hydrogenation quality improvement. The key lies in the development of a bifunctional catalyst that takes into account both dechlorination and deoxygenation effects.

[0004] At present, the hydrodechlorination catalyst is mainly a metal active component supported by an alkaline carrier, such as Ni / Al2O3, Ni / CaO, etc. The presence of alkaline sites can effectively solidify the HCl produced during the hydrogenation process, avoid chlorine poisoning of the metal active sites, and improve the catalytic stability and activity. Studies have shown that after adding alkaline substances to metal Ni-based catalysts, the active metal can be well dispersed during the hydrodechlorination process, and the hydrogenation activity is enhanced. Hydrodeoxygenation catalysts mainly use metal active components supported by acidic carriers, such as Ni / ZSM-5, Pt / ZSM-5, etc. Studies have shown that acidic sites are necessary for dehydration and alkylation reactions in the HDO process. When a certain amount of acidic sites are added to the Ni catalyst, its deoxygenation effect is significantly improved. The hydrogenation catalysts used in current patent documents are mainly aimed at the removal and quality improvement of a single substance, and cannot effectively remove chlorine-containing and oxygen-containing substances at the same time. There is also no treatment for complex chlorine-containing and oxygen-containing pyrolysis oils. Therefore, a type of catalyst with both dechlorination and deoxygenation functions is needed to achieve the removal of chlorine and oxygen in oil products in one step. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a preparation method and application of a bifunctional catalyst based on catalytic hydrogenation dechlorination and deoxygenation, so as to efficiently remove 1-2 dichloroethane and chlorobenzene while efficiently removing furfural and phenol, thereby achieving the simultaneous and efficient removal of chlorinated hydrocarbons and oxygen-containing substances.

[0006] In order to achieve the above object, the technical scheme of the present invention is as follows: a preparation method of a bifunctional catalyst based on catalytic hydrodechlorination and deoxygenation, the preparation method specifically comprises: loading metal Ni on a metal oxide having an acid-base dual site, so that the loading amount of Ni is 10%, and obtaining a bifunctional catalyst;

[0007] Wherein, the metal oxide having both acid and base sites is prepared by the following steps:

[0008] Add 10-50g of ZrOCl2 to 100-200ml of water, stir evenly, add a precipitant until the pH value of the resulting solution is 9-10, and age at 40-50°C for 3h; wash with 40-60°C water for multiple times until the pH value of the solution is neutral, filter to obtain a solid precipitate, dry and remove moisture (put in a drying oven at 105°C overnight), grind into powder, place in a muffle furnace and calcine for 2-4h to obtain a metal oxide with acid-base dual sites.

[0009] Furthermore, the metal oxides with acid-base dual sites include t-ZrO2, a-ZrO2, and m-ZrO2. When preparing the t-ZrO2, the precipitant is a mixed solution of NaHCO3 and Na2CO3, and the calcination temperature is 500-600°C. When preparing the a-ZrO2, the precipitant is ammonia water, and the calcination temperature is 350°C. When preparing the m-ZrO2, the precipitant is Na2CO3, and the calcination temperature is 500-600°C.

[0010] Furthermore, the metal Ni is loaded on the metal oxide with acid-base dual sites, specifically: water is added to nickel nitrate hexahydrate until it is fully dissolved, and after sufficient stirring, a Mo-containing compound is added to the solution as an auxiliary agent so that the mass ratio of element Ni and Mo is 1:2, and an aging treatment is performed at 50-60°C for 10-14h; the metal oxide with acid-base dual sites is added as a carrier so that the loading amount of element Ni is 10%, and sufficient stirring is performed; vacuum rotary evaporation is performed to remove water, dried, and the obtained solid material is calcined for 2-4h; the solid obtained after the calcination is ground into powder and reduced in an atmosphere of 90% H2 / N2 with a flow rate of 100ml / min, and the temperature is maintained at 350-400°C for 3-4h to obtain the bifunctional catalyst.

[0011] Furthermore, in the vacuum rotary evaporation, the vacuum degree is maintained at -0.1 to 0.2 MPa, the temperature is maintained at 60-75° C., and the rotation speed is 50-60 rpm.

[0012] Furthermore, the calcination is carried out in a muffle furnace with a heating rate of 5°C / min. When t-ZrO2 is used to prepare the bifunctional catalyst, the calcination temperature is 500-600°C, when a-ZrO2 is used to prepare the bifunctional catalyst, the calcination temperature is 350°C, and when m-ZrO2 is used to prepare the bifunctional catalyst, the calcination temperature is 500-600°C; the drying is carried out in a drying oven at 120°C for 6 hours.

[0013] The present invention also provides a bifunctional catalyst based on catalytic hydrogenation dechlorination and deoxygenation prepared by the preparation method.

[0014] The present invention also provides an application of the bifunctional catalyst based on catalytic hydrogenation dechlorination and deoxygenation in deoxygenation and dechlorination in oxygen-containing and chlorine-containing pyrolysis oil, wherein the oxygen-containing and chlorine-containing pyrolysis oil contains 1,2-dichloroethane, chlorobenzene, furfural and phenol.

[0015] Furthermore, the application is specifically as follows: the application is carried out in a continuous micro-fixed bed, the bifunctional catalyst is fixed in a reaction tube, both ends are fixed with quartz wool, and the reactants are added to the reaction tube at a rate of 0.2 ml / min using a high-pressure pump. The reaction is continued for 1-4 hours under the conditions of 350°C-400°C, hydrogen pressure 1-2Mpa, hydrogen flow rate 50-100sccm, and mass space velocity 30-60h / 1. The reaction is condensed at 4-8°C using a constant temperature cooling box, and the condensed liquid product is collected.

[0016] The beneficial effects of the present invention are:

[0017] The present invention selects effective catalyst carriers and additives to load active materials Ni and Mo and other additives on t-ZrO2 carriers through coprecipitation, calcination, and activation. The additives and t-ZrO2 carriers can improve the hydrogenation dechlorination and deoxygenation activity of Ni. The main reason why the catalyst has dechlorination and deoxygenation performance is that there are two kinds of active sites, acid and alkaline, in the catalyst, and t-ZrO2 has both acidic and alkaline active sites. Among them, the alkaline site can effectively absorb the byproduct hydrogen chloride produced by the reaction in the chlorine removal reaction, avoiding its reaction with Ni to cause catalyst poisoning, thereby improving the overall stability of the catalyst; the presence of the acidic site can be used as an active site to crack the CO bond, which helps to improve the hydrogenation deoxygenation effect. The main advantage of the catalyst proposed in the present invention when used for hydrogenation and upgrading of chlorine-containing and oxygen-containing waste plastic pyrolysis oil is that it has low cost, simple preparation process, high catalytic activity, and can be adapted to the hydrogenation and upgrading of complex component pyrolysis oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a comparison chart of the effects of the catalysts in Comparative Examples 1, 2, 3, and 4.

[0019] Figure 2 It is a comparison chart of the effects of the catalysts in Comparative Examples 5, 6, 7, and 8.

[0020] Figure 3 This is a comparison chart of the effects of various catalysts in Comparative Example 9.

[0021] Figure 4 This is the XRD spectrum of the catalytic absorbent Ni / Mo / ZrO2 prepared in Example 1.

[0022] Figure 5 This is the CO2-TPD result of Ni / Mo / ZrO2 prepared in Example 1.

[0023] Figure 6 This is the NH3-TPD result of Ni / Mo / ZrO2 prepared in Example 1. DETAILED DESCRIPTION

[0024] The present invention first prepares a metal oxide having an acid-base dual site, including obtaining different forms of t-ZrO2, a-ZrO2, and m-ZrO2 under different calcination conditions by selecting different precipitants, including the following steps:

[0025] (1) Dissolve 10-50 g of ZrOCl2 in 100-200 ml of deionized water (preferably 150 ml), stir evenly, add the corresponding precipitant to keep the pH value of the solution between 9 and 10, and age at 40-50 ° C for 3 h.

[0026] Among them, the corresponding precipitants are: when used to prepare t-ZrO2, use 20-30ml of a mixed solution of NaHCO3 (mass fraction of 5-10%, preferably 5%) and Na2CO3 (mass fraction of 10-20%, preferably 10%); when used to prepare a-ZrO2, use 30-60ml of ammonia water (mass fraction of 28-30%); when used to prepare m-ZrO2, use 20-50ml of Na2CO3 (10wt%).

[0027] (2) The aged solution is washed multiple times with deionized water at 40-60° C. until the pH value of the solution is neutral, and a solid precipitate is obtained after filtration. The solid precipitate is placed in a drying oven to dry and remove moisture, and then ground into powder, which is then placed in a muffle furnace for calcination to obtain the corresponding metal oxide having acid-base amphoteric sites.

[0028] Wherein, the calcination heating rate is 5°C / min, the calcination time is 2-4h, and the temperature is: 500-600°C for preparing t-ZrO2, 350°C for preparing a-ZrO2, and 500-600°C for preparing m-ZrO2.

[0029] The present invention uses the prepared metal oxide with acid-base dual sites to further prepare a bifunctional catalyst, and the bifunctional catalyst can effectively dechlorinate and deoxygenate in one step. The specific method is as follows:

[0030] (1) 2-5 g of nickel nitrate hexahydrate containing Ni is fully dissolved in deionized water, and after being fully stirred, 1-3 g of a compound containing an auxiliary element is added to the solution to form a solution A, which is then aged at 50-60° C. for 10-14 h.

[0031] Wherein, the auxiliary element may be Mo, and its compound may be ammonium molybdate.

[0032] (2) Add 1-3 g of the acid-base dual-property metal oxide support prepared above to the aged solution A in step (1), and stir thoroughly.

[0033] (3) The aged solution is subjected to vacuum rotary evaporation to remove water, and the resulting solid material is dried and calcined in a muffle furnace for 2-4 hours.

[0034] The best conditions for vacuum rotary evaporation are to maintain a vacuum degree of -0.1 to 0.2 MPa, a temperature of 60-75°C, and a rotation speed of 50-60 rpm. When t-ZrO2 is used to prepare a bifunctional catalyst, the calcination temperature is 500-600°C, when a-ZrO2 is used to prepare a bifunctional catalyst, the calcination temperature is 350°C, and when m-ZrO2 is used to prepare a bifunctional catalyst, the calcination temperature is 500-600°C.

[0035] (4) Grinding the solid obtained after calcination into powder, and reducing it in an atmosphere of 90% H2 / N2 (100 ml / min) at a temperature of 350-400°C for 3-4 hours to finally obtain the bifunctional catalyst.

[0036] The amounts of the components added in steps (1) and (2) are such that the mass ratio of Ni to Mo is 1:2, and the final Ni loading of the obtained catalyst is 10%.

[0037] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but the protection scope of the present invention is not limited thereto.

[0038] Example 1

[0039] Take 10g of zirconium oxychloride and add 150ml of deionized water to prepare an aqueous solution, add 20-30ml of 5% (w) NaHCO3 and 10% (w) Na2CO3 solution as precipitants, so that the pH of the resulting solution is maintained at 9-10, and the resulting precipitate is placed in the mother liquor at 40°C for aging treatment for 3h.

[0040] The precipitate was washed with 50°C deionized water through a filtration device until the pH value of the mother liquor reached neutral, and the obtained precipitate was placed in a drying oven at 105°C overnight.

[0041] The dried solid was ground into powder and then placed in a muffle furnace and calcined at 550°C for 3 h at a heating rate of 5°C / min to obtain white solid t-ZrO2.

[0042] Take 3 g of nickel nitrate hexahydrate and add 200 ml of deionized water to prepare a nickel nitrate solution. Add 1.5 g of ammonium molybdate to the solution, stir well, and age at 50°C for 12 hours.

[0043] Add 1.56g of t-ZrO2 into the solution obtained above, stir thoroughly and put it into a round-bottom flask, use a vacuum rotary evaporator to remove surface moisture under the conditions of -0.1MPa, temperature 65℃, and rotation speed 60rpm. Then put it into a drying oven and dry it at 120℃ for 6h to remove internal moisture.

[0044] The dried solid was placed in a muffle furnace and calcined at 550°C at a heating rate of 5°C / min for 4 hours.

[0045] After calcination, the solid was ground into powder and activated at 400°C for 3 h in an atmosphere of 90% H2 / N2 (100 ml / min) to obtain the final Ni / Mo / ZrO2 bifunctional catalyst with a Ni loading of 10%.

[0046] Example 2-3

[0047] The method for preparing the Ni-based catalyst in Example 1 is adopted, except that different forms of ZrO2 (a-ZrO2, m-ZrO2) are prepared. The specific differences are shown in Table 1:

[0048] Table 1 Comparative Table of Catalyst Preparation of Examples 1-3

[0049]

[0050]

[0051] Among them, only the differences from the examples are shown. The precipitants selected in Examples 2 and 3 are: 30-60 ml of ammonia water (28-30%), 20-50 ml of Na2CO3 (10wt%).

[0052] Example 4: Application of Hydrodechlorination and Deoxygenation Catalyst

[0053] The catalyst prepared in Examples 1-3 was used to carry out a hydrodechlorination and deoxygenation experiment on a chlorine-containing and oxygen-containing mixed oil containing 1,2-dichloroethane, chlorobenzene, furfural, and phenol. The reaction was carried out in a continuous feeding fixed bed, with chlorobenzene (8wt.%) and 1,2-dichloroethane (2wt.%) as representative substances of chlorinated hydrocarbons, and furfural (6wt.%) and phenol (4wt.%) as oxygen-containing organic matter. Octane (10wt.%), octene (20wt.%) and p-xylene (50wt.%) were added to prepare 100ml of chlorine-containing and oxygen-containing pyrolysis oil. With a feed rate of 0.2ml / min, the temperature was maintained at 350°C, the pressure was 2Mpa, the gas flow rate was 100sccm, and the mass space velocity was 30h -1 The continuous reaction time was 4 hours, a constant temperature cooling box was used to maintain 6°C condensed water circulation, and the liquid product obtained after the reaction was collected.

[0054] The components of the liquid product were quantitatively detected by gas chromatography-mass spectrometry (Agilent 8860-5977c / MS). The quantitative analysis method was determined by the external standard method. First, the standard substance was prepared. The raw materials mainly included dichloroethane (chromatographic grade, >99%), chlorobenzene (chromatographic grade, >99%), octane (chromatographic grade, >99%), octene (chromatographic grade, >99%) and p-xylene (chromatographic grade, >99%). A standard mixed organic solution was prepared according to a volume ratio of 1:4:5:10:30. The standard mixed solution was diluted 10 times step by step to obtain 4 groups of standard mixed solutions with concentration gradients. The characteristic ions and peak times of the calibration substances were determined based on the qualitative data. The specific parameters are shown in Table 2. The standard mixed solutions were injected in sequence from high to low concentrations to obtain the calibration curve and then perform quantitative detection of the samples.

[0055] Table 2 Characteristic ions and peak timetable of each compound

[0056]

[0057]

[0058] The GC parameters were set to an injection port temperature of 350°C and a chromatographic column model of HP-5MS.

[0059] (30m*0.25mm*0.25um), the program temperature is 50℃ for 3 minutes, then the temperature is raised to 150℃ at 20℃ / min and held for 1 minute, and finally the temperature is raised to 300℃ at 50℃ / min, and it takes a total of 12 minutes. Normal hexane is used as the solvent, the solvent ratio is 10:1, and the split ratio is set to 80. The MS parameters are set to solvent delay of 2.4min and mass-to-charge ratio range between 30-300. Table 3 shows the results of the catalysts prepared in each embodiment.

[0060] Table 3 Catalyst experimental results of Examples 1-3

[0061]

[0062] Comparative Examples 1-4

[0063] Molecular sieves (HY, ZSM-5) or alkaline hydrotalcites (Ca-HTLCs, Zn-HTLCs) are added as carriers into a Ni-based aged solution, dried, calcined and activated to prepare a Ni-based catalyst having only acidic or alkaline sites.

[0064] Comparative Examples 5-8

[0065] A molecular sieve (HY, ZSM-5) is selected and a basic hydrotalcite (Ca-HTLCs, Zn-HTLCs) is selected, mixed in a mass ratio of 1:1, and then added into a Ni-based aging solution as a carrier, dried, calcined and activated. A Ni-based catalyst having an acidic or basic site is prepared.

[0066] Comparative Example 9

[0067] Pd / C was selected as the noble metal-based catalyst.

[0068] Table 4 Catalyst parameter table of comparative examples 1-9

[0069]

[0070]

[0071] Among them, Ca-HTLCs and Zn-HTLCs are prepared hydrotalcite-like carriers.

[0072] Table 5 shows the results obtained in Example 4 for the catalysts prepared in Comparative Examples 1-9.

[0073] Table 5 Comparative Examples 1-9 Catalyst Experimental Results

[0074]

[0075] Comparative Examples 1-4; Ni / Mo / HY; Ni / Mo / ZSM-5; Ni / Mo / Ca-HTLCs; Ni / Mo / Zn-HTLCs.

[0076] Example 1 is compared with Comparative Examples 1-4 to compare the dechlorination and deoxygenation effects of carriers with acidic and alkaline active sites and carriers with only acidic or alkaline sites. The method in Example 4 was used to conduct the experiment, and the comparison results are as follows: Figure 1 As shown. Compared with Ni / Mo / ZrO2 catalysts with acidic and basic sites, Ni / Mo / ZSM-5 and Ni / Mo / HY acidic carrier catalysts have a dechlorination rate of 72.4% and 63.3% in treating oil products with complex components. Ni / Mo / Ca-HTLCs and Ni / Mo / Zn-HTLCs alkaline carriers have a deoxygenation effect of 75.1% and 71.6%. Only t-ZrO2 catalysts loaded with acidic and basic sites have a higher dechlorination and deoxygenation effect.

[0077] Comparative Examples 5-8: Ni / Mo / HY / Ca-HTLCs; Ni / Mo / ZSM-5 / Ca-HTLCs;

[0078] Ni / Mo / HY / Zn-HTLCs; Ni / Mo / ZSM-5 / Zn-HTLCs.

[0079] Example 1 was compared with Comparative Examples 5-8 to compare the active ingredients loaded on t-ZrO2 with an acid-base amphoteric carrier and loaded on a composite carrier with acidic sites (HY or ZSM-5) and basic sites (Ca-HTLCs or Zn-HTLCs). The experiment was carried out using the method in Example 4, and the comparison results are shown in FIG. Figure 2 As shown. The dechlorination and deoxygenation effects of the catalyst prepared in Example 1 are significantly higher than those of the catalysts prepared in Comparative Examples 5, 6, 7, and 8. Compared with the carrier prepared by mixing acid and alkaline substances, the catalyst carrier with acid and alkaline in one has higher hydrogenation catalytic activity in oxygen-containing and chlorine-containing mixtures.

[0080] Comparative Example 9: Pd / C

[0081] The catalyst prepared in Example 1 was compared with the precious metal catalyst pd / c, and the experiment was carried out using the method in Example 4. The comparison results are as follows Figure 3 As shown. For the Ni / Mo / ZrO2 bifunctional catalyst, the removal rate of chloride is 91.4%, and the removal rate of oxygen-containing substances is 91.2%; for the Pd / C catalyst, the removal rate of chloride is 95%, and the removal rate of oxygen-containing substances is 71.8%. It can be seen that the bifunctional catalyst proposed in the present invention can achieve high dechlorination and deoxygenation effects in treating complex components. Compared with traditional precious metal catalysts, it improves the catalytic effect and saves costs.

[0082] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Without making creative work, any modification, equivalent replacement, improvement, etc., shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a bifunctional catalyst based on catalytic hydrodechlorination and deoxygenation, characterized in that: The preparation method is specifically as follows: loading metal Ni on a metal oxide having an acid-base dual site, so that the loading amount of Ni is 10%, thereby obtaining a bifunctional catalyst; Wherein, the metal oxide having both acid and base sites is prepared by the following steps: Add 10-50g of ZrOCl2 to 100-200ml of water, stir evenly, add a precipitant until the pH value of the resulting solution is 9-10, and age at 40-50°C for 3h; wash with 40-60°C water for multiple times until the pH value of the solution is neutral, filter to obtain a solid precipitate, dry and remove moisture, grind into powder, place in a muffle furnace and calcine for 2-4h to obtain a metal oxide with acid-base dual sites.

2. The preparation method according to claim 1, characterized in that: The metal oxides with acid-base dual sites include t-ZrO2, a-ZrO2, and m-ZrO2. When preparing the t-ZrO2, the precipitant is a mixed solution of NaHCO3 and Na2CO3, and the calcination temperature is 500-600°C. When preparing the a-ZrO2, the precipitant is ammonia water, and the calcination temperature is 350°C. When preparing the m-ZrO2, the precipitant is Na2CO3, and the calcination temperature is 500-600°C.

3. The preparation method according to claim 1 or 2, characterized in that: The method of loading metal Ni on a metal oxide having an acid-base dual site comprises the following steps: adding water to nickel nitrate hexahydrate until it is fully dissolved, adding a Mo-containing compound as an auxiliary agent to the solution after sufficient stirring, so that the mass ratio of element Ni to Mo is 1:2, and performing an aging treatment at 50-60°C for 10-14h; adding the metal oxide having an acid-base dual site as a carrier, so that the loading amount of element Ni is 10%, and sufficient stirring; performing vacuum rotary evaporation to remove moisture, drying, and calcining the obtained solid material for 2-4h; grinding the solid obtained after the calcination into powder and reducing it in an atmosphere of 90% H2 / N2 and a flow rate of 100ml / min, and maintaining the temperature at 350-400°C for 3-4h to obtain the bifunctional catalyst.

4. The preparation method according to claim 3, characterized in that: The vacuum rotary evaporation is carried out with a vacuum degree of -0.1 to 0.2 MPa, a temperature of 60 to 75° C., and a rotation speed of 50 to 60 rpm.

5. The preparation method according to claim 3, characterized in that: The calcination is carried out in a muffle furnace with a heating rate of 5°C / min. When t-ZrO2 is used to prepare the bifunctional catalyst, the calcination temperature is 500-600°C, when a-ZrO2 is used to prepare the bifunctional catalyst, the calcination temperature is 350°C, and when m-ZrO2 is used to prepare the bifunctional catalyst, the calcination temperature is 500-600°C. The drying is carried out in a drying oven at 120°C for 6 hours.

6. A bifunctional catalyst based on catalytic hydrodechlorination and deoxygenation prepared by the preparation method according to claim 1.

7. An application of the bifunctional catalyst based on catalytic hydrogenation dechlorination and deoxygenation according to claim 6 in deoxygenation and dechlorination of oxygen-containing and chlorine-containing pyrolysis oil, characterized in that: The oxygen-containing and chlorine-containing pyrolysis oil contains 1,2-dichloroethane, chlorobenzene, furfural and phenol.

8. The use according to claim 7, characterized in that: The application is specifically as follows: the bifunctional catalyst is fixed in a reaction tube, the oxygen-containing and chlorine-containing pyrolysis oil is added into the reaction tube at a rate of 0.2 ml / min, the reaction is continuously carried out for 1-4 hours under the conditions of 350°C-400°C, hydrogen pressure of 1-2 MPa, hydrogen flow rate of 50-100 sccm, and mass space velocity of 30-60 h / 1, and the condensation is carried out at 4-8°C in a constant temperature cooling box, and the condensed liquid product is collected.

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