A method for producing low-chlorine waste plastic oil and / or waste tire oil

Abstract

The present application relates to a method for producing low-chlorine waste plastic oil and / or waste tire oil, the waste plastic oil and / or waste tire oil is contacted with an extractant in an extraction column to carry out an extraction reaction, the extractant is a mixture of a reaction reagent and an extraction reagent, a low-chlorine product is extracted from the top of the extraction column, and high-chlorine materials extracted from the bottom of the extraction column are regenerated and then partially returned to the extraction column as a circulating extraction agent. The present application can process various waste plastic oils and waste tire oils converted by a process, effectively remove chlorine impurities, and provide high-quality raw materials for subsequent deep processing processes.

Description

Technical Field

[0001] This invention relates to the field of dechlorination technology for hydrocarbon oil feedstocks, specifically to a method for producing low-chlorinated waste plastic oil and / or waste tire oil. Background Technology

[0002] With the continuous development of urbanization in my country, the urban population is increasing year by year, people's living standards are constantly improving, and the amount of urban domestic waste is also increasing. Currently, the main methods of urban waste disposal include landfill and incineration. Both incineration and landfill have a series of subsequent environmental problems.

[0003] Chemical conversion methods can transform plastic waste into valuable industrial raw materials or fuel oil, not only eliminating environmental pollution but also achieving sustainable resource development and utilization, making it an effective way to control "white pollution." Currently, the waste plastic refining industry is flourishing across China, with some companies having built small-scale pyrolysis demonstration plants. However, the issue of high-value utilization of waste plastic pyrolysis products still needs to be effectively addressed.

[0004] Waste plastic oil and waste tire oil derived from various processes differ significantly from traditional petroleum-based oils. They contain high levels of impurities, especially chlorine, which is far higher than that found in crude oil. Processing high-chlorine raw materials in refineries using hydrogenation and catalytic converters can severely corrode these equipment, causing significant problems and safety hazards for subsequent processing.

[0005] Oil dechlorination technology falls into two categories: inorganic chlorine removal, which uses solid adsorbents to adsorb hydrogen chloride from the oil, and organic chlorine removal. Organic chlorine removal typically involves hydrogenation to convert it into inorganic chlorine before adsorption. However, high chlorine content in the feedstock poses significant safety hazards to high-temperature, high-pressure hydrogenation units. Therefore, organic chlorine removal is a challenging aspect of oil dechlorination.

[0006] CN102127464A discloses a method for removing organochlorines from hydrocarbon oils. The method involves mixing a demulsifier, an alkaline compound, a phase transfer agent, water, and hydrocarbon oil. Under the influence of heat and / or an electric field, oil-water separation is performed, converting organochlorines into inorganic chlorides, which are then removed with the aqueous phase, achieving dechlorination. This method is applicable to conventional crude oil, heavy crude oil, and distillate oils containing organochlorines.

[0007] CN105885935A discloses a method for removing organochlorides from wastewater, comprising: circulating wastewater tangentially into the reactor to form a swirling flow followed by an upward flow; converting the upward flow to fully fluidize the solid reducing agent or catalyst-loaded solid reducing agent particles in the reactor, allowing the wastewater and the solid reducing agent or catalyst-loaded solid reducing agent to fully contact and react; after passing through the main reaction zone, the upward flow velocity is gradually reduced; the upward flow enters the sedimentation separation zone, where the fluid is approximately laminar, and the reacted solid reducing agent or catalyst-loaded solid reducing agent particles effectively settle, removing organochlorides from the wastewater. This invention also provides a device for removing organochlorides from wastewater, which is suitable for mixing and reacting high-density metal particles with wastewater, is non-scaling and non-clogging, can operate continuously, has an adjustable reducing agent dosage, and is easy to operate and manage.

[0008] CN104726134A discloses a method for producing high-quality gasoline and diesel from chlorinated plastic oil. The method involves injecting the chlorinated plastic oil into a high-temperature dechlorination tower containing activated alumina for high-temperature dechlorination. A small amount of NaOH aqueous solution is sprayed from the top of the high-temperature dechlorination tower. The dechlorinated plastic oil then enters a catalytic distillation tower containing a molecular sieve / alumina catalyst for reaction and distillation. After catalytic distillation, the plastic oil is pressurized and enters a hydrorefining tower. The hydrorefined distillate is then distilled at atmospheric pressure and cut into gasoline and diesel based on the distillation temperature. The heavy oil at the bottom of the tower is mixed with the raw material chlorinated plastic oil for re-reaction. The dechlorination catalyst and sulfide catalyst used in this invention are prepared by selecting appropriate methods based on the composition and properties of the plastic oil.

[0009] CN104560414A discloses a method for hydrogenating chlorinated 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. Between the hydrogenation reactor beds, the waste cooking oil is divided into multiple streams entering the hydrogenation reactor, and the effluent from the top of the hydrogenation reactor directly enters a dechlorination reactor. Under dechlorination reaction conditions, it passes through a bed containing a dechlorinating agent. The effluent from the bottom of the hydrogenation reactor and the effluent from the dechlorination reactor enter a separation system for gas-liquid separation, yielding hydrogenated refined waste cooking oil. Using the method provided by this invention, the problem of chloride ion corrosion in the separation system of the hydrogenation device during the hydrogenation of waste cooking oil can be effectively solved, while simultaneously reducing the axial temperature difference of the catalyst bed and improving the overall utilization rate of the hydrogenation catalyst. Summary of the Invention

[0010] The present invention aims to solve the technical problems of poor dechlorination effect and high dechlorination cost when processing waste plastic oil and / or waste tire oil raw materials in the prior art.

[0011] The present invention provides a method for producing low-chlorine waste plastic oil and / or waste tire oil, comprising: the waste plastic oil and / or waste tire oil being hydrocarbon raw materials entering the extraction tower from the bottom of the extraction tower, contacting the extractant fed from the top of the extraction tower, and carrying out an extraction reaction under certain conditions, wherein the extractant is a mixture of a reaction reagent and an extraction reagent, wherein the reaction reagent is a basic compound or salt compound of at least one Group IA metal, and the extraction reagent is at least one polar organic solvent with a boiling point not lower than 150°C;

[0012] The low-chlorine material extracted from the top of the extraction tower is a low-chlorine product with a chlorine content of no more than 50 μg / g. The high-chlorine material extracted from the bottom of the extraction tower is regenerated and part of it is returned to the top of the extraction tower as a circulating extractant.

[0013] In one embodiment of the present invention, the waste plastic oil is a hydrocarbon material obtained from waste plastics through one or more conversion methods such as thermal cracking, catalytic cracking, and solution liquefaction; the waste plastic oil has a distillation range of 30–600°C, with more than 50% of the fraction below 350°C, and a chlorine content of 100–100,000 μg / g. In the composition of the waste plastic oil, the volume fraction of olefins is 5–80%, preferably 5–60%; the volume fraction of aromatics is less than 90%, preferably 2–60%; and the volume fraction of alkanes is less than 90%, preferably 5–60%.

[0014] In this invention, the waste plastic is one or more of the following: waste plastic from fresh household waste, waste plastic from industrial and agricultural production, and waste plastic from aged waste. The type of waste plastic is selected from one or more of PE, PP, PS, and PVC.

[0015] In one embodiment of the present invention, the waste tire oil is a hydrocarbon material obtained from waste tires through one or more conversion methods such as thermal cracking, catalytic cracking, and solution liquefaction; the waste tire oil has a distillation range of 30–700°C, with more than 50% of the fraction below 350°C, and a chlorine content of 100–100,000 μg / g. In the composition of the waste tire oil, the volume fraction of olefins is 5–80%, preferably 5–60%; the volume fraction of aromatics is less than 90%, preferably 2–60%; and the volume fraction of alkanes is less than 90%, preferably 5–60%.

[0016] In this invention, the waste tires are various waste tires made from natural rubber and / or synthetic rubber.

[0017] In this invention, the thermal cracking reaction refers to the reaction in which hydrocarbon molecules, including waste plastics and waste tires, decompose into smaller molecules under high-temperature conditions and in the absence of air. In this invention, the catalytic cracking reaction refers to the reaction in which hydrocarbon molecules, including waste plastics and waste tires, decompose into smaller molecules under high-temperature conditions and in the presence of a catalyst. In this invention, the dissolution-liquefaction reaction refers to the reaction in which waste plastics and waste tires change from a solid state to a liquid state in the presence of solvent oil and / or organic solvents.

[0018] In this invention, the hydrocarbon feedstock entering the extraction tower is the full fraction of waste plastic oil and / or waste tire oil, or any fraction after cutting. Furthermore, the extraction dechlorination method described in this invention can be used in any combination with other dechlorination methods, which are not limited to existing dechlorination technologies such as hydrodechlorination and adsorption dechlorination.

[0019] In one embodiment of the present invention, waste plastic oil and / or waste tire oil are cut to obtain light and heavy fractions. The cutting point is 100°C to 300°C, preferably 150°C to 250°C. The obtained light fraction enters an extraction tower for reaction.

[0020] In one embodiment of the present invention, the heavy fraction obtained after cutting is subjected to hydrodechlorination treatment.

[0021] In one embodiment of the present invention, waste plastic oil and / or waste tire oil are extracted and dechlorinated, and the resulting low-chlorine product is then hydrogenated and refined.

[0022] In one embodiment of the present invention, the extraction reagent is one or more selected from ethylene glycol, diethylene glycol, triethylene glycol, glycerol, glycerol, and ethanolamine.

[0023] In one embodiment of the present invention, the reaction reagent is one or more selected from NaOH, KOH, NaHS, KHS, Na2CO3, and Na2S2O3.

[0024] In one embodiment of the present invention, the mass ratio of the reaction reagent to the extraction reagent in the extractant is 1:1 to 1:2.

[0025] In one embodiment of the present invention, the molar ratio of chlorine atoms in the reaction reagent to that in the hydrocarbon raw material is 1:1 to 20:1.

[0026] In one embodiment of the present invention, the extractant further contains a catalyst, wherein the catalyst is KI, and the amount of the catalyst is 0.5% to 10% of the mass fraction of the raw material.

[0027] In one embodiment of the present invention, the extraction tower is any one or a combination of several of the following: a spray tower, a packed tower, a sieve plate tower, and a rotary tower.

[0028] In one embodiment of the present invention, the extraction reaction conditions are: top pressure of the column 0.01–5 MPa, extraction reaction temperature 100°C–350°C, and mass ratio of extractant to hydrocarbon feedstock of 0.1–10:1. Preferred extraction reaction conditions are: top pressure of the column 0.05–3 MPa, extraction reaction temperature 100°C–300°C, and mass ratio of extractant to hydrocarbon feedstock of 0.3–5:1.

[0029] In one embodiment of the present invention, the regeneration process of the high-chloride material at the bottom of the extraction tower involves separating the inorganic chloride salts generated in the reaction using one or more methods selected from centrifugation and filtration. Furthermore, the high-chloride material from which the inorganic chloride salts have been removed is recycled back to the extraction tower as a circulating extractant.

[0030] Features of this invention:

[0031] (1) This invention can process waste plastic oil and waste tire oil from various processes, effectively remove their chlorine impurities, and provide high-quality raw materials for subsequent deep processing processes, such as hydrogenation and catalytic processes for producing vehicle fuels and chemical raw materials.

[0032] (2) The extraction dechlorination method provided by the present invention solves the problem of low dechlorination rate when using adsorption dechlorination to process high-chlorine raw materials, and solves the problems of high cost and safety hazards caused by chloride ion corrosion when high-chlorine raw materials are directly dechlorinated by hydrogenation.

[0033] (3) This invention can completely remove organic chlorine from high-chlorine feedstock by combining it with hydrogenation process, thereby improving product value. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of one embodiment of the method for producing low-chlorine waste plastic oil and / or waste tire oil provided by the present invention.

[0035] Figure 2 This is a schematic diagram of one embodiment of the method for producing low-chlorine waste plastic oil and / or waste tire oil provided by the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings, but this description does not limit the scope of the invention.

[0037] Figure 1 This is a schematic diagram of one embodiment of the method for producing low-chlorine waste plastic oil and / or waste tire oil provided by the present invention. Figure 1As shown, waste plastic oil obtained from the waste plastic pyrolysis unit 1 enters the extraction tower 3 from the bottom via pipeline 2, where it comes into contact with the extractant fed from the top of the extraction tower 3. An extraction reaction occurs under certain conditions. The extractant is a mixture of reaction reagents and extraction reagents. The low-chlorine material drawn from the top of the extraction tower 3 is the low-chlorine product and is drawn out via pipeline 4. The high-chlorine material from the bottom of the extraction tower 3 enters the regeneration unit 6 via pipeline 5. After regeneration, a portion of the high-chlorine material is returned to the top of the extraction tower 3 as circulating extractant via pipeline 7.

[0038] Figure 2 This is a schematic diagram of one embodiment of the method for producing low-chlorine waste plastic oil and / or waste tire oil provided by the present invention. Figure 2 As shown, the waste plastic oil obtained from the waste plastic pyrolysis unit 1 enters the fractionation tower 3 via pipeline 2 for cutting. The resulting light fraction enters the extraction tower 6 from the bottom via pipeline 4, where it contacts the extractant fed from the top of the extraction tower 6 and undergoes an extraction reaction under certain conditions. The low-chlorine material extracted from the top of the extraction tower is withdrawn via pipeline 7. The high-chlorine material at the bottom of the extraction tower 6 enters the regeneration unit 9 via pipeline 8. After regeneration, part of the high-chlorine material is returned to the top of the extraction tower 6 as circulating extractant via pipeline 10. The heavy fraction obtained from the fractionation tower 3 enters the hydrogenation unit 12 via pipeline 5 for hydrodechlorination. The hydrodechlorinated heavy fraction is withdrawn via pipeline 13 and mixed with the low-chlorine product withdrawn via pipeline 7 to obtain low-chlorinated hydrocarbon oil, which is then withdrawn via pipeline 11.

[0039] The present invention will be further described below with reference to embodiments, but this does not limit the present invention in any way.

[0040] In this embodiment, the chlorine content in the liquid material was determined by coulometric method, specifically according to the method of "Determination of Total Chlorine Content in Crude Oil by Coulometric Method" (RIPP 64-90) in the Petrochemical Analytical Methods (RIPP Test Methods). The instrument used was a microcoulometric analyzer, and the sample was a liquid material.

[0041] The commercial brands of the hydrogenation catalysts used in the examples are RSA-100 and RS-2100, both produced by Sinopec Catalyst Changling Branch.

[0042] The hydrocarbon raw materials used include:

[0043] Hydrocarbon feedstock 1: Waste plastic oil, chlorine content 3700 μg / g, distillation range 97~481℃;

[0044] Hydrocarbon feedstock 2: waste plastic oil, chlorine content 109.3 μg / g, distillation range 122~431℃;

[0045] Hydrocarbon feedstock 3: Waste tire pyrolysis oil, chlorine content 127 μg / g, distillation range 27~546℃.

[0046] Examples 1-2

[0047] In this embodiment, the hydrocarbon feedstock 1 used is waste plastic oil. Hydrocarbon feedstock 1 enters the extraction tower from the bottom and comes into contact with the extractant fed from the top of the extraction tower. Under certain conditions, an extraction reaction occurs. Low-chlorine product is extracted from the top of the extraction tower, while high-chlorine material extracted from the bottom of the extraction tower enters a centrifugal separation unit to separate the inorganic chloride salts generated in the reaction. The high-chlorine material, after the inorganic chloride salts have been removed, is recycled as extractant. The extractant used, the process conditions of the extraction tower, and the chlorine content of the low-chlorine product are listed in Table 1. In Table 1, the solvent-to-hydrocarbon feedstock mass ratio refers to the mass ratio of extractant to hydrocarbon feedstock, and the same applies below.

[0048] Example 3

[0049] In this embodiment, the hydrocarbon feedstock 2 used is waste plastic oil. Hydrocarbon feedstock 2 enters the extraction tower from the bottom and comes into contact with the extractant fed from the top of the extraction tower. Under certain conditions, an extraction reaction occurs. Low-chlorine product is extracted from the top of the extraction tower, while high-chlorine material extracted from the bottom of the extraction tower enters a centrifugal separation unit to separate the inorganic chloride salts generated in the reaction. The high-chlorine material, after the inorganic chloride salts have been removed, is recycled as a circulating extractant. The extractant used, the process conditions of the extraction tower, and the chlorine content of the low-chlorine product are listed in Table 1.

[0050] Table 1

[0051]

[0052]

[0053] Example 4

[0054] In this embodiment, the hydrocarbon feedstock 1 used is waste plastic oil. Hydrocarbon feedstock 1 enters the extraction tower from the bottom and comes into contact with the extractant fed from the top of the tower. Under certain conditions, an extraction reaction occurs. A low-chlorine product is drawn from the top of the extraction tower, while the high-chlorine material drawn from the bottom enters the filtration and separation unit to separate the inorganic chloride salts generated in the reaction. The high-chlorine material, after the inorganic chloride salts have been removed, is recycled as a recirculating extractant. The extractant used, the process conditions of the extraction tower, and the chlorine content of the low-chlorine product are listed in Table 2.

[0055] Example 5

[0056] In this embodiment, the hydrocarbon feedstock 3 used is waste tire oil. Hydrocarbon feedstock 3 enters the extraction tower from the bottom and contacts the extractant fed from the top of the tower. Under certain conditions, an extraction reaction occurs. A low-chlorine product is drawn from the top of the extraction tower, while the high-chlorine material drawn from the bottom enters the filtration and separation unit to separate the inorganic chloride salts generated in the reaction. The high-chlorine material, after the inorganic chloride salts have been removed, is recycled as a recirculating extractant. The extractant used, the process conditions of the extraction tower, and the chlorine content of the low-chlorine product are listed in Table 2.

[0057] Table 2

[0058]

[0059]

[0060] Examples 6-7

[0061] In this embodiment, the hydrocarbon feedstock 1 used is waste plastic oil. The hydrocarbon feedstock 1 enters the extraction tower from the bottom and comes into contact with the extractant fed from the top of the extraction tower. Under certain conditions, the extraction reaction takes place. The low-chlorine product drawn from the top of the extraction tower then enters the hydrogenation unit for hydrogenation refining to obtain the hydrogenated low-chlorine product. The high-chlorine material drawn from the bottom of the extraction tower is filtered in the regeneration unit, and part of it is returned to the top of the extraction tower as a circulating extractant.

[0062] The extractant used, the process conditions of the extraction tower, the process conditions of the hydrogenation unit, and the chlorine content of the low-chlorine product are listed in Table 3.

[0063] Table 3

[0064]

[0065]

[0066] Examples 8-9

[0067] In this embodiment, the hydrocarbon feedstock 1 used is waste plastic oil. Hydrocarbon feedstock 1 is fed into a fractionation tower for cutting. The resulting light fraction enters the extraction tower from the bottom and contacts the extractant fed from the top, undergoing an extraction reaction under certain conditions. A low-chlorine product is extracted from the top of the extraction tower. The high-chlorine material at the bottom of the extraction tower is centrifuged and regenerated, with a portion returned to the top of the extraction tower as recycled extractant. The heavy fraction obtained from the fractionation tower is mixed with the low-chlorine product to obtain low-chlorine hydrocarbon oil.

[0068] The distillation range of the light fraction, the extractant used, the process conditions of the extraction tower, and the chlorine content of the low-chlorinated hydrocarbon oil are listed in Table 4.

[0069] Table 4

[0070]

[0071] Examples 10-11

[0072] In this embodiment, the hydrocarbon feedstock 1 used is waste plastic oil. Hydrocarbon feedstock 1 is fed into a fractionation tower for cutting. The resulting light fraction enters the extraction tower from the bottom and contacts the extractant fed from the top, undergoing an extraction reaction under certain conditions. The low-chlorine product is drawn from the top of the extraction tower. The high-chlorine material at the bottom of the extraction tower is centrifuged and regenerated, with a portion returned to the top of the extraction tower as circulating extractant. The heavy fraction obtained from the fractionation tower enters the hydrogenation unit for hydrodechlorination. The hydrodechlorinated heavy fraction is mixed with the low-chlorine product to obtain low-chlorine hydrocarbon oil.

[0073] The distillation range of the light fraction, the extractant used, the process conditions of the extraction tower, the process conditions of the hydrogenation unit, and the chlorine content of the low-chlorine hydrocarbon oil are listed in Table 5.

[0074] Table 5

[0075]

[0076]

Claims

1. A method for producing low-chlorine waste plastic oil and / or waste tire oil, characterized in that, Waste plastic oil and / or waste tire oil, as hydrocarbon raw materials, enter the extraction tower from the bottom and come into contact with the extractant fed from the top of the extraction tower. An extraction reaction is carried out under certain conditions. The extractant is a mixture of a reaction reagent and an extraction reagent. The reaction reagent is a basic compound or salt compound of at least one Group IA metal, selected from one or more of NaOH, KOH, NaHS, KHS, Na2CO3, and Na2S2O3. The extraction reagent is at least one polar organic solvent with a boiling point not lower than 150℃, selected from one or more of ethylene glycol, diethylene glycol, triethylene glycol, glycerol, glycerol, and ethanolamine. In the extractant, the mass ratio of the reaction reagent to the extraction reagent is 1:1 to 1:

2. The molar ratio of chlorine atoms in the reaction reagents to those in the hydrocarbon raw materials is 1:1 to 20:

1. The low-chlorine material extracted from the top of the extraction tower is a low-chlorine product with a chlorine content of no more than 50 μg / g. The high-chlorine material extracted from the bottom of the extraction tower is regenerated and part of it is returned to the top of the extraction tower as a circulating extractant.

2. The method according to claim 1, characterized in that, The waste plastic oil is a hydrocarbon material obtained from waste plastics through one or more conversion methods such as thermal cracking, catalytic cracking, and dissolution liquefaction; the distillation range of the waste plastic oil is 30-600℃, more than 50% of the fraction in the waste plastic oil is below 350℃, and the chlorine content is 100-100000μg / g. The waste tire oil is a hydrocarbon material obtained from waste tires through one or more conversion methods such as thermal cracking, catalytic cracking, and dissolution liquefaction; the waste tire oil has a distillation range of 30 to 700°C, more than 50% of the fractions in the waste tire oil are below 350°C, and the chlorine content is 100 to 100,000 μg / g.

3. The method according to claim 1, characterized in that, The extractant also contains a catalyst, which is KI, and the amount of catalyst used is 0.5% to 10% of the raw material mass fraction.

4. The method according to claim 1, characterized in that, Extraction reaction conditions: top pressure of the column 0.01~5MPa, extraction reaction temperature 100℃~350℃, mass ratio of extractant to hydrocarbon feedstock 0.1~10:

1.

5. The method according to claim 1, characterized in that, Extraction reaction conditions: top pressure of the column 0.05~3MPa, extraction reaction temperature 100℃~300℃, mass ratio of extractant to hydrocarbon feedstock 0.3~5:

1.

6. The method according to claim 1, characterized in that, The regeneration process of the high-chlorine material at the bottom of the extraction tower involves separating the inorganic chloride salts generated by the reaction using one or two methods selected from centrifugation and filtration.

7. The method according to claim 1, characterized in that, Waste plastic oil and / or waste tire oil are cut to obtain light and heavy fractions. The cutting point is 100℃~300℃. The obtained light fraction enters the extraction tower for reaction.

8. The method according to claim 7, characterized in that, The cut-off point between the light and heavy fractions is 150℃~250℃.

9. The method according to claim 1, characterized in that, The resulting heavy fraction was subjected to hydrodechlorination treatment.

Images