CN113462432B

CN113462432B - Waste oil processing method and skid-mounted modular integrated device for waste oil processing

Info

Publication number: CN113462432B
Application number: CN202110587500.XA
Authority: CN
Inventors: 蒋东红; 谭丽; 陈水银; 赵旭廷; 郭贵贵; 石玉林
Original assignee: Pujiang Sixingtong Technology Development Co ltd
Current assignee: Pujiang Sixingtong Technology Development Co ltd
Priority date: 2021-05-27
Filing date: 2021-05-27
Publication date: 2023-03-14
Anticipated expiration: 2041-05-27
Also published as: CN113462432A

Abstract

The invention relates to the technical field of waste oil processing, and discloses a waste oil processing method and a skid-mounted modular integrated device for waste oil processing, wherein the method comprises the following steps: (1) waste oil pretreatment: mixing the waste oil and the filter aid, and then performing membrane filtration to reduce the content of chlorine elements and metal ions in the waste oil to obtain clear oil; the filter aid is a composition comprising organic amine, an alcohol compound and water; (2) hydrogenation reaction: sequentially carrying out hydrodemetallization and ungluing reactions, hydrotreating reactions and hydro-upgrading isomerization reactions on the clear oil to obtain a hydrogenated full fraction product; (3) separation treatment: and separating the hydrogenated full-fraction product to obtain target products with different distillation ranges. The method can obtain high-quality naphtha, diesel oil and lubricating oil base oil, has the characteristics of simple process and high economic value of products, and is suitable for small-scale dispersed processing of waste oil polluting the environment.

Description

Waste oil processing method and skid-mounted modular integrated device for waste oil processing

Technical Field

The invention relates to the field of waste oil processing, in particular to a waste oil processing method and a skid-mounted modular integrated device for waste oil processing.

Background

China is a large population country and generates a large amount of waste cooking oil every year. The fresh edible oil is fried at high temperature, and the components such as salt and the like are added in the process, so that the fresh edible oil can generate a mixture containing various harmful substances, namely the waste cooking oil after being cooked.

In addition, with the increase of the quantity of motor vehicles in China and the development of national economy, the consumption of various lubricating oils is also greatly increased, and a large amount of waste lubricating oil is correspondingly generated. The waste lubricating oil is unreasonably discarded or burned, which causes waste of resources and environmental pollution. In view of environmental protection and full utilization of resources, the recycling and utilization of waste lubricating oil are increasingly receiving attention.

The common characteristics of the waste cooking oil and the waste lubricating oil are high impurity content and high processing difficulty, and the total amount of the waste oil is larger, but the source of the waste oil determines that the waste oil has wide dispersion range and high centralized collection and processing difficulty, the problems of long-distance transportation, safety, environmental protection and the like need to be overcome, and the economical efficiency of the waste oil processing and recycling is reduced.

Because of the difficulty in collection, transportation and processing, the treatment capacity of the existing small-scale waste oil treatment plant is hundreds to thousands of tons per year, even tens of thousands of tons per year, the investment of the small-scale plant is small, the recovered waste oil is simply treated by sedimentation, distillation and the like, the waste oil is prepared into low-grade oil, demoulding oil and fuel oil for sale and use, and the economic value of the product is low.

CN201510060139 discloses a hydrorefining process for waste lubricating oil, which comprises the steps of pretreating raw materials, dehydrating, removing impurities, removing asphaltenes and colloid in a propane extraction or wiped film evaporation device, and improving the product quality through a two-stage hydrorefining reactor. However, the lubricating oil product obtained by the method has the problems of unqualified chromaticity and low oxidation stability. CN201510903927 discloses a regeneration treatment method for waste lubricating oil, wherein a refining part comprises hydrorefining and adsorption supplementary refining, the refining process is complex, and the used adsorbent has the problem of secondary environmental pollution.

Therefore, it is desirable to provide a waste oil processing method and a corresponding integrated device, which have simple process and are suitable for dispersedly processing waste oil to produce high-quality naphtha, diesel oil and lubricant base oil.

Disclosure of Invention

The invention aims to solve the problems of simple small-scale waste oil treatment process, low product economic value and large waste oil dispersion refining processing investment in the prior art, and provides a waste oil processing method and a skid-mounted modular integrated device for waste oil processing. The method has the characteristics of simple flow and high product value, is suitable for small-scale dispersion processing of waste oil, and can flexibly process and treat waste cooking oil, waste lubricating oil and the like distributed in various regions.

In order to achieve the above object, an aspect of the present invention provides a waste oil processing method, comprising the steps of:

(1) Waste oil pretreatment: mixing the waste oil and the filter aid, and then performing membrane filtration to reduce the content of chlorine elements and metal ions in the waste oil to obtain clear oil; the filter aid is a composition comprising organic amine, an alcohol compound and water;

(2) Hydrogenation reaction: sequentially carrying out hydrodemetallization and ungluing reactions, hydrotreating reactions and hydro-upgrading isomerization reactions on the clear oil to obtain a hydrogenated full fraction product;

(3) Separation treatment: and separating the hydrogenated full fraction product to obtain oil products with different distillation ranges.

The invention provides a skid-mounted modular integrated device for waste oil processing, which is mounted on a movable base and comprises:

the raw material pretreatment system is used for reducing the content of chlorine elements and metal ions in the waste oil through membrane filtration to obtain clear oil;

the hydrogenation reaction system is used for sequentially carrying out hydrodemetallization and degumming reaction, hydrotreating reaction and hydrogenation modification isomerization reaction on the clear oil for modification to obtain a hydrogenation full-fraction product;

and the separation system is used for separating the hydrogenated full-fraction product to obtain oil products with different distillation ranges.

Through the technical scheme, the invention has the following beneficial technical effects:

1) According to the waste oil processing method provided by the invention, colloid and asphaltene components do not need to be removed in the waste oil pretreatment stage, the colloid and the asphaltene undergo hydrogenation reaction in hydrodemetallization and asphaltene removal reaction, the generated product components enter the final product, and the product yield is high;

2) According to the preferred embodiment of the invention, the filter aid containing water is adopted in the waste oil pretreatment stage, so that metal salts and chlorine-containing compounds in the waste oil can be effectively removed during filtration, and the pretreatment effect is improved;

3) According to the preferred embodiment of the invention, the catalyst for the hydrodemetallization and ungluing reaction, the hydrotreating reaction and the hydro-upgrading isomerization reaction is filled in a specific grading mode, the hydrogenation activity of the catalyst can be reasonably configured, and the obtained product has higher quality, particularly the lubricating oil base oil has low chroma and good oxidation stability;

4) The skid-mounted modular integrated device for processing waste oil, provided by the invention, is convenient to install, flexible to move, low in device investment, short in construction period, suitable for small-scale dispersed processing of waste oil, and capable of flexibly processing waste cooking oil, waste lubricating oil and the like distributed in various regions, wherein the processing amount is not more than 1000 tons/year;

5) The skid-mounted modular integrated device for processing waste oil provided by the invention comprises a specific filter aid and a specific catalyst grading scheme, and can realize fine processing of small-scale waste oil and obtain high-quality diesel oil and lubricating oil.

Drawings

FIG. 1 is a schematic view of a skid-mounted modular integrated unit for processing waste oil.

Description of the reference numerals

1. Waste oil pump 2, centrifugal separator 3, mixing valve 4 and membrane separator

5. Clean oil tank 6, hydrogen cylinder 7, heat exchanger 8 and first reactor

9. A second reactor 10, a third reactor 11, a high pressure separator 12, a low pressure separator

13. Stabilizer column 14, fractionating column

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In a first aspect of the invention, there is provided a process for processing waste oil, the process comprising the steps of:

(1) Waste oil pretreatment: mixing the waste oil and the filter aid, and then performing membrane filtration to reduce the content of chlorine elements and metal ions in the waste oil to obtain clear oil; wherein the filter aid is a composition comprising organic amine, an alcohol compound and water;

(3) Separation treatment: separating the hydrogenated full fraction product to obtain oil products with different distillation ranges.

In step (1):

the method of the invention is suitable for processing waste oil with high impurity content and high recovery value. In a preferred embodiment, the used oil comprises spent cooking oil and spent lubricating oil. The invention can process the food waste oil or the waste lubricating oil independently, and can also process the food waste oil and the waste lubricating oil after mixing.

In a preferred embodiment, the waste oil is subjected to a centrifugal separation process prior to mixing the waste oil with the filter aid, wherein the conditions of the centrifugal separation process comprise: the temperature of the waste oil is 50-200 ℃, preferably 80-120 ℃; the rotational speed of centrifugal separation is 4000-20000r/min, preferably 4000-6000r/min.

In the invention, the waste oil is heated to 80-120 ℃ to dissolve part of oil-soluble solid impurities so as to improve the recycling rate of the waste oil as much as possible.

In a preferred embodiment, the filter aid is added in an amount of 250 to 1500g, preferably 400 to 1000g, relative to 1 ton of used oil; wherein, in the composition, the mass concentration of the organic amine is 10-20%, preferably 12-18%, and the mass concentration of the alcohol compound is 1-10%, preferably 3-8%.

Before the waste oil is hydrotreated, the waste oil is dehydrated through a pre-distillation normal-pressure flash evaporation treatment, so that the water in the waste oil does not influence the activity of a hydrogenation catalyst. In the invention, the inventor researches and creatively discovers that the water-containing filter aid is selected in the waste oil pretreatment stage, although the burden of waste oil dehydration is increased, the impurity removal effect of the waste oil can be further improved. When the mass concentration of the organic amine is controlled to be 12-18 percent and the mass concentration of the alcohol compound is controlled to be 3-8 percent, the metal content and the water content can be considered, so that the water and impurity removing effect of the waste oil is best.

In a preferred embodiment, the organic amine is selected from at least one of monomethylamine, dimethylamine, trimethylamine, triethylamine and tert-butylamine, preferably dimethylamine; the alcohol compound is at least one selected from methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol and butylene glycol, and preferably ethanol.

Wherein, the organic amine with small molecular weight can react with the metal salt or the chlorine-containing compound in the waste oil, thereby converting the oil-soluble metal salt or the chlorine-containing compound into the water-soluble metal salt or the chlorine-containing compound, and facilitating the later removal by membrane filtration. The alcohol compound in the filter aid can increase the solubility of the generated metal salt or chlorine-containing compound in water. The organic amine, the alcohol compound and the water have synergistic effect, so that the water and impurity removing effects of the waste oil can be obviously improved.

In a preferred embodiment, the waste oil and the filter aid are mixed by means of a mixing valve, wherein the pressure difference across the mixing valve is in the range of from 10 to 100kPa, preferably from 25 to 35kPa.

Since the filter aid of the present invention contains water, it is preferable to mix the water and the oil by using a mixing valve in order to improve the mixing effect of the two phases. Compared with the conventional mechanical stirring and mixing method, the mixing effect can be improved by the mixing mode of the mixing valve, so that the impurity removal effect of the waste oil can be further improved.

In a preferred embodiment, the combined waste oil and filter aid is heated to a temperature of 50 to 200 ℃, preferably 80 to 120 ℃, mixed with hydrogen and subjected to a membrane filtration operation at 0.05 to 0.5MPa, preferably 0.1 to 0.5MPa, to obtain the clean oil.

In order to reduce the viscosity of the used oil and increase the filtration rate, the membrane filtration operation needs to be carried out at a certain high temperature. However, at the operating temperature of membrane filtration, some olefins, colloids and other substances in the waste oil are easily subjected to polymerization or oxidation reaction to generate macromolecular substances, which not only easily block the filtration pores, but also affect the subsequent hydrogenation effect. In order to maintain the stability of the filtering effect and the quality of the product, the invention preferably introduces hydrogen in the membrane filtering operation, so that the operating pressure of the membrane filtering is 0.05-0.5MPa, and the hydrogen is preferably added at 0.1-0.5MPa, thereby playing the role of reducing the oxidation of the clear oil by air and avoiding the polymerization reaction in the filtering process.

In a preferred embodiment, the membrane filtration is a multi-stage membrane filtration; wherein the filtering membrane used for the membrane filtration is a ceramic membrane, and the aperture of the filtering membrane is 0.5-5 μm, preferably 1-2 μm.

Because of the addition of the filter aid, the oil-soluble metal salt or chlorine-containing compound in the waste oil can be converted into the water-soluble metal salt or chlorine-containing compound with smaller molecular weight, so that the invention can adopt a small-aperture filter membrane with the diameter of 0.5-5 mu m, and has better filtering effect compared with a large-aperture filter membrane for avoiding the blockage of filter pores. In the invention, aiming at different waste oils, in order to further improve the filtering effect, the membrane filtration can adopt a first-stage to third-stage ceramic membrane component to be used in series, and the pore diameters of membranes in the series membrane components can be sequentially reduced or kept unchanged.

In a preferred embodiment, the conditions of the pre-treatment of the used oil are such that the water content in said clean oil is less than 0.1 wt.%, preferably less than 0.03 wt.%; the total chlorine content is less than 10mgNaCl/L, preferably less than 5mgNaCl/L; the total metal content is not more than 50 mug/g, preferably not more than 30 mug/g; the mechanical impurity content does not exceed 0.02 wt.%, preferably does not exceed 0.01 wt.%.

In the invention, mechanical impurities, water, metal salts and chlorine-containing compounds in the waste oil can be removed through centrifugal treatment, filter aid addition and hydrogenation membrane filtration operation, so that clear oil with higher purity can be obtained, the catalyst in the subsequent hydrogenation reaction can be protected, and the poisoning and inactivation of the catalyst can be avoided.

In step (2):

in a preferred embodiment, the clear oil and hydrogen enter the reactor from the bottom of the reactor, and the reactor comprises a first reactor, a second reactor and a third reactor, wherein the first reactor, the second reactor and the third reactor sequentially carry out hydrodemetallization and ungluing reaction, hydrotreating reaction and hydro-upgrading isomerization reaction.

Compared with the feeding mode from the upper part of the reactor to the top, the feeding mode from the bottom to the top of the reactor is favorable for protecting the hydrogenation reaction activity of the catalyst, prolonging the running period, reducing the pressure drop and improving the reaction conversion rate and the product quality.

In the first reactor, the second reactor and the third reactor, many different chemical reactions often occur, and a single catalyst is difficult to meet the requirements of each chemical reaction, so that a catalyst grading filling technology needs to be adopted, namely different catalysts are filled for different types of chemical reactions. The reasonable catalyst grading scheme can prolong the service life of the catalyst, reduce the control difficulty of the process and also contribute to improving the hydrogenation reaction effect of the catalyst.

In a preferred embodiment, the catalyst for the hydrodemetallization and degluing reactions is selected from at least one of RG-30, RG-30A and RG-30B, preferably RG-30, RG-30A and RG-30B. Wherein, when the hydrogenation protection catalyst is RG-30, RG-30A and RG-30B, RG-30A and RG-30B are sequentially loaded in the first reactor along the flow direction of the feed, and the loading volume ratio of RG-30, RG-30A and RG-30B is 4.

In the invention, the clear oil and hydrogen are subjected to demetallization and degumming reaction in the presence of the catalyst, and colloid, olefin, asphaltene and organic metal compounds and partial oxide in the clear oil can be removed by hydrogenation. Compared with a single catalyst, the mixed filling of RG-30, RG-30A and RG-30B has better effect of removing impurities by hydrogenation of the clear oil.

In a preferred embodiment, the conditions under which the hydrodemetallization and degummed reaction occurs include: hydrogen partial pressure of 3-20MPa, preferably 5-15MPa; the reaction temperature is 150-450 ℃, preferably 200-350 ℃; hydrogen to oil volume ratio of 50-2000Nm ³ /m ³ Preferably 200-1200Nm ³ /m ³ (ii) a Liquid hourly volume space velocity of 1-20h ^-1 Preferably 2-10h ^-1 。

In the invention, the product obtained after the clear oil is subjected to hydrodemetallization and ungluing reactions can be directly contacted with a hydrotreating catalyst to perform hydrotreating reactions without separation operation, so that the process flow can be simplified.

In a preferred embodiment, the catalyst for the hydrotreating reaction is selected from two or three of RJW-3, RL-2 and RN32V, preferably RJW-3, RL-2 and RN32V. Wherein, when the catalysts for the hydrotreating reaction are RJW-3, RL-2 and RN32V, the RJW-3, RL-2 and RN32V are sequentially filled in the second reactor along the feed flow direction, and the filling volume ratio of the RJW-3, RL-2 and RN32V is 1-2.

In the invention, the product obtained after the clear oil and hydrogen are subjected to hydrodemetallization and degumming reaction mainly has olefin aromatics hydrogenation saturation, hydrodesulfurization, hydrodenitrogenation and hydrodeoxygenation reactions with hydrogen in the presence of a hydrotreating catalyst, so that the composition of waste oil can be changed, and the property of a regenerated oil product is improved.

In a preferred embodimentThe conditions of the hydrotreating reaction include: hydrogen partial pressure of 3-20MPa, preferably 5-15MPa; the reaction temperature is 200-480 ℃, and the preferable temperature is 280-420 ℃; hydrogen to oil volume ratio of 100-2000Nm ³ /m ³ Preferably 300-1500Nm ³ /m ³ (ii) a The liquid hourly volume space velocity is 0.2-10h ^-1 Preferably 0.4 to 4h ^-1 。

In the invention, the product obtained after the hydrotreatment reaction can directly carry out hydrogenation modification isomerization reaction with hydrogen without separation operation, and a hydrogenation full-fraction product is obtained.

In a preferred embodiment, the catalyst for the hydro-upgrading isomerization reaction comprises a hydro-upgrading isomerization catalyst and a post-refining catalyst, wherein the hydro-upgrading isomerization catalyst is mainly used for catalyzing the isomerization reaction and is selected from at least one of RCF-1 and RHC-130, preferably the RHC-130; the post-refining catalyst is mainly used for catalyzing deep hydrogenation saturation and olefin saturation reaction of aromatic hydrocarbon, is selected from at least one of RCF-1 and RJW-3, and is preferably RJW-3. The filling sequence of the catalysts for the hydro-upgrading isomerization reaction in the third reactor along the flow direction of the feed is as follows: a mixture of a hydro-upgrading isomerization catalyst, a hydro-upgrading isomerization catalyst and a post-refining catalyst, wherein the volume ratio of the hydro-upgrading isomerization catalyst to the mixture (the mixture of the hydro-upgrading isomerization catalyst and the post-refining catalyst) is 1; wherein, in the mixture of the hydrogenation modification isomerization catalyst and the post-refining catalyst, the volume content of the post-refining catalyst is 10-30%.

In the present invention, the RCF-1 catalyst can be used as both a hydro-upgrading isomerization catalyst and a post-purification catalyst by performing different functions depending on the loading position in the third reactor. The products obtained after the hydrogenation reaction and hydrogen mainly undergo deep refining, cracking and isomerization reactions, so that the composition of waste oil can be changed, and the quality of the obtained oil product is improved.

In a preferred embodiment, the conditions of the hydro-upgrading isomerization reaction include: hydrogen partial pressure of 3-20MPa, preferably 5-10MPa; the reaction temperature is 200-450 ℃, preferably 280-420 ℃; hydrogen-oil volume ratio of 100-1500Nm ³ /m ³ Preferably 200-1000Nm ³ /m ³ (ii) a Liquid hourly volume space velocity of 0.3-10h ^-1 Preferably 0.5 to 3h ^-1 。

The catalysts used in the hydrogenation reaction stage for the hydrodemetallization and ungluing reaction, the hydrotreating reaction and the hydrogenation modification isomerization reaction are supported non-noble metal catalysts, and compared with noble metal catalysts, the catalyst has the advantages of lower cost, catalyst sulfur poisoning resistance and direct purchase from various mature hydrogenation catalyst manufacturers in the market. For example, a commercially available catalyst produced by petrochemical science research institute of petrochemical corporation, china, or long ridge of petrochemical catalyst.

In the preferred embodiment of the invention, the catalysts for the hydrodemetallization and ungluing reaction, the hydrotreating reaction and the hydro-upgrading isomerization reaction are graded in different modes respectively, so that the overall hydrogenation activity of the catalysts can be improved, the quality of the products naphtha, diesel fraction and lubricating oil base oil can be further improved, and especially the lubricating oil base oil can have higher viscosity index, lower chroma and better oxidation stability.

In step (3):

in the present invention, there is no particular requirement for the method of separation, as long as oils with different distillation ranges can be obtained. In a preferred embodiment, the separation is sequentially subjected to a high pressure separation, a low pressure separation, a first fractionation and a second fractionation.

Wherein the hydrogenated full-fraction product is preferably subjected to heat exchange with the clear oil before being subjected to the high-pressure separation operation. In the invention, the high-pressure separation is mainly used for separating hydrogen in the hydrogenated full-fraction product, the separated hydrogen can be recycled to the hydrogenation reaction, and the rest part is sent to be subjected to low-pressure separation treatment.

The low-pressure separation is mainly used for separating hydrogen sulfide and hydrogen dissolved in oil products and a small part of light hydrocarbon below C5, and the rest part is sent to carry out primary fractionation operation.

Wherein, the first fractionation is used for further separating light hydrocarbons below C5, the separated light hydrocarbons below C5 are sent to the outside of the battery limits, and the rest part is sent to the second fractionation operation.

Wherein the second fractionation is used to divide the remaining part after the first fractionation into naphtha, diesel, lube base oil, etc., and the distribution of the obtained products is related to the composition of the feedstock.

In a preferred embodiment, the diesel oil has a cetane number of 52-59, the lubricating base oil has a chroma of 0.5-1.0, and an oxidation stability of 190-210/min.

In a preferred embodiment, the waste oil processing method is performed in a waste oil processing skid-mounted modular integrated unit.

According to the waste oil processing method provided by the invention, the metal content in the waste oil is further reduced by adding the filter aid and the membrane filtration process, and the burden of hydrodemetallization in the hydrogenation stage is reduced; by reasonably arranging the grading scheme of the catalyst, the service life of the catalyst is prolonged, the hydrotreating capability of the catalyst is improved, and high-quality diesel oil and lubricating oil are obtained.

and the separation system is used for separating the hydrogenated full-fraction product to obtain oil products with different distillation ranges, and is shown in figure 1.

In a preferred embodiment, the integrated unit has a waste oil treatment capacity of not more than 1000 tons/year.

The conventional waste cooking oil and waste lubricating oil are scattered sporadically, the difficulty in centralized recovery is high, the equipment investment for hydrofining a small amount of waste oil is large, the conventional small-scale waste oil treatment plant generally only carries out simple treatment such as sedimentation and distillation on the recovered waste oil for reducing the cost, the waste oil is prepared into low-grade oil, demoulding oil and fuel oil for sale and use, and the economic value of the product is low. In order to solve the problem of overhigh cost of small-scale waste oil hydrofining, the invention provides a skid-mounted modular integrated device for waste oil processing. The device is installed on the movable base, is convenient to assemble, flexible to move, low in device investment and short in construction period, is suitable for small-scale decentralized processing, and can flexibly process and treat waste cooking oil and waste lubricating oil distributed in various regions.

In a preferred embodiment, the raw material pretreatment system comprises a waste oil pump 1, a centrifugal separator 2, a mixing valve 3, a membrane separator 4 and a clear oil tank 5 which are connected in sequence.

The waste oil is sent to a centrifugal separator through a waste oil pump for centrifugal separation, then is mixed with a filter aid through a mixing valve, and then enters a membrane separator together with hydrogen, so that mechanical impurities such as oil sludge, residues, large particle solids and the like, metal salts and chlorides can be separated to obtain clear oil, and the clear oil after pretreatment is stored in a clear oil tank.

In a preferred embodiment, the feed pretreatment system further comprises a filter aid according to the first aspect of the invention.

In a preferred embodiment, the hydrogenation reaction system comprises a heat exchanger 7, a first reactor 8, a second reactor 9 and a third reactor 10 which are connected in sequence. Wherein the heat exchanger 7 is used for recovering the heat of the product in the third reactor 10 to heat the clean oil entering the first reactor 8.

Wherein, the first reactor is used for hydrodemetallization and ungluing reaction, the second reactor is used for hydrotreating reaction, and the third reactor is used for hydro-upgrading isomerization reaction. The three reactors are connected in series and are respectively provided with respective temperature control systems to meet different operating conditions of the respective reactors. The product in the first reactor need not directly get into the second reactor through the separation, and the product in the second reactor need not directly get into the third reactor through the separation, and such setting can simplify the flow, reduces integrated device volume, convenient removal.

In a preferred embodiment, the first, second and

third reactors

8, 9, 10 each comprise catalyst packed according to the catalyst staging scheme of the first aspect of the invention.

In a preferred embodiment, the separation system comprises a high pressure separator 11, a low pressure separator 12, a stabilizer column 13 and a fractionation column 14 connected in series.

The product obtained in the third reactor enters a separation system after heat exchange, the noncondensable gas such as hydrogen is separated by a high-pressure separator, the separated noncondensable gas such as hydrogen is compressed and then returns to the first reactor for cyclic utilization, the rest part enters a low-pressure separator, hydrogen sulfide, hydrogen and a small part of gaseous hydrocarbon below C5 and the like dissolved in oil are further separated in the low-pressure separator, the rest part enters a stabilizer, light hydrocarbon below C5 is further separated under the steam stripping condition, the product extracted from the tower bottom of the stabilizer is cut into naphtha, diesel oil and lubricating oil base oil by a fractionating tower, and the cut products are respectively collected in each product tank.

In a preferred embodiment, the integrated device further comprises a gas utility system, the gases in the gas utility system comprising hydrogen, nitrogen and air. The air is used for driving the pneumatic instrument, the hydrogen comes from the hydrogen cylinder 6 and is used for participating in the waste oil treatment process, and the nitrogen is used for system replacement purging.

Specifically, hydrogen from a hydrogen cylinder can enter a hydrogen supercharger, an outlet buffer tank of the hydrogen supercharger is provided with a pressure sensor, and the pressure sensor can control the outlet pressure of the supercharger in a linkage manner. And a pressure reducing valve is arranged on an outlet pipeline of the buffer tank at the outlet of the hydrogen supercharger to control the pressure entering the reaction system. The hydrogen is decompressed by a pressure reducing valve and then enters a flow controller, and enters a reactor according to the set reaction conditions. Air comes from an air booster for driving the meter. In the present invention, a gas utility system other than the hydrogen cylinder is not shown in fig. 1.

In a preferred embodiment, the integrated device further comprises a utility and control system; among the utility project and the control system, utility project includes high pressure unloading buffer tank, low pressure unloading buffer tank and refrigerator, control system is used for realizing the automation of device, wherein, be equipped with LL, L, H, HH fourth grade alarm point respectively to liquid level, pressure and temperature control on the integrated device, only change according to the safety guarantee code by the instrument engineer. When the alarm state occurs, the display value is triggered to flash, the alarm information is input, and the sound alarm is triggered. Except for the flashing of the display value, the entering of alarm information and the sound alarm, certain interlocking actions are executed. In the present invention, the utility and control system is not shown in FIG. 1.

The skid-mounted modular integrated device for processing waste oil provided by the invention can be mounted on a movable base, is flexible to move, has small investment and is suitable for small-scale decentralized processing. Moreover, the skid-mounted modular integrated device for processing waste oil, provided by the invention, comprises a specific filter aid and a specific catalyst grading scheme, and can realize fine processing of small-scale waste oil and obtain high-quality diesel oil and lubricating oil.

The present invention will be described in detail below by way of examples. The commercial designations of the hydrogenation protection demetallization and dealumination catalysts described in the examples and comparative examples are RG-30, RG-30A, RG-30B, the commercial designations of the hydrotreating catalysts are RJW-3, RL-2, RN32V, the hydroisomerization cracking catalyst is RHC-130, and the post-refining catalyst is RJW-3. The catalyst is purchased from petrochemical engineering science research institute of petrochemical company Limited in China or produced by Yangtze division of petrochemical catalyst in China. Waste lubricating oil a was from beijing automotive waste lubricating oil, and waste cooking oil B was from mcdonald waste cooking oil, the properties of which are shown in table 1:

TABLE 1 Properties of the stock oils

Example 1

The waste lubricating oil A is used as a raw material, the method is adopted to process the waste oil, and the treatment capacity is 12kg/h. The waste lubricating oil A is firstly subjected to centrifugal separation at the rotating speed of 4000r/min at the temperature of 80 ℃ to remove large-particle precipitates in the waste lubricating oil A, then 6.0g/h of filter aid (aqueous solution with the content of dimethylamine of 18wt% and the content of ethanol of 8 wt%) is added, mixing is carried out under the condition that the pressure difference of a mixing valve is 30kPa, the obtained mixture is heated to 90 ℃, hydrogen is introduced into the mixture, filtering is carried out at the pressure of 0.2MPa by using a ceramic membrane, the aperture of the ceramic membrane is 2 mu m, the filtered clear oil enters a clear oil tank, and the composition of the obtained clear oil is shown in table 2.

The clear oil is preheated and then mixed with hydrogen and enters a first reactor, a second reactor and a third reactor in sequence. Along the flow direction of the feeding materials, the first reactor is sequentially filled with RG-30 with the particle size of 13mm, RG-30A with the particle size of 6mm and RG-30B with the particle size of 3mm, and the filling volume ratio of the catalyst is 4; the second reactor is sequentially filled with RJW-3, RL-2 and RN32V, and the filling volume ratio of the catalyst is 1; the third reactor is sequentially filled with a mixture of RHC-130, RHC-130 and RJW-3, and the filling volume ratio of the catalyst is 1, the volume content of the RJW-3 catalyst in the mixture of RHC-130 and RJW-3 is 30%; the process conditions of the three reactors are respectively as follows: hydrogen partial pressure 10.0MPa/10.0MPa/10.0MPa, temperature 320 deg.C/330 deg.C/300 deg.C, hydrogen-oil volume ratio 600Nm ³ /m ³ 、600Nm ³ /m ³ 、600Nm ³ /m ³ Liquid hourly space velocity of 5.0h ^-1 /1.0h ^-1 /2.0h ^-1 。

And (3) after the reaction is finished, feeding the mixture into a separation system, and respectively obtaining naphtha, diesel oil and lubricating oil base oil according to different boiling points, wherein the properties of the obtained product are listed in Table 3.

Example 2

The waste cooking oil B is used as a raw material, and the method is adopted to recycle the waste oil, wherein the treatment capacity is 60kg/h. The waste cooking oil B is firstly subjected to centrifugal separation at the rotating speed of 4000r/min at the temperature of 120 ℃ to remove large-particle precipitates in the waste cooking oil B, then 45g/h of filter aid (aqueous solution with the content of dimethylamine being 12wt% and the content of ethanol being 3 wt%) is added, mixing is carried out under the condition that the pressure difference of a mixing valve is 30kPa, the obtained mixture is heated to 100 ℃, hydrogen is introduced into the mixture, filtering is carried out at the pressure of 0.4MPa by utilizing a ceramic membrane, the pore diameter of the ceramic membrane is 1 mu m, and the filtered clear oil enters a clear oil tank, wherein the composition of the obtained clear oil is shown in Table 2.

The clear oil is preheated and then mixed with hydrogen and enters a first reactor, a second reactor and a third reactor in sequence. Along the flow direction of the feeding materials, sequentially filling RG-30 with the particle size of 13mm, RG-30A with the particle size of 6mm and RG-30B with the particle size of 3mm in a first reactor, wherein the filling volume ratio of the catalyst is 1; the second reactor is sequentially filled with RJW-3, RL-2 and RN32V, and the filling volume ratio of the catalyst is 1; the third reactor is sequentially filled with RHC-130, a mixture of RHC-130 and RJW-3, and the filling volume ratio of the catalyst is 1; the process conditions of the three reactors are respectively as follows: hydrogen partial pressure 6.0MPa/6.0MPa/6.0MPa, temperature 330 deg.C/360 deg.C/320 deg.C, hydrogen-oil volume ratio 500Nm ³ /m ³ 、500Nm ³ /m ³ 、500Nm ³ /m ³ Liquid hourly space velocity of 8.0h ^-1 /1.0 ^-1 /2.0h ^-1 。

TABLE 2

Analysis item	Waste lubricating oil A	Waste cooking oil B	Example 1	Example 2
					Water content/wt%	2.23	3.06	0.03	0.05
Mechanical impurities/(wt%)	0.42	0.25	0.01	0.02
					Total chlorine/(mg NaCl/L)	18.3	38.8	3.1	9.3
Total metal content/(μ g/g)	1868	237	27	36

TABLE 3

Comparative example 1

Similar to example 1, except for the pretreatment of the used oil, the composition of the obtained clear oil is shown in Table 5.

The waste oil pretreatment operation of comparative example 1 was as follows: the waste lubricating oil A is firstly kept stand for 4 hours in a settling tank at the temperature of 80 ℃, centrifugal separation is carried out, large-particle sediment and partial water in the waste lubricating oil A are removed, then two-stage electro-desalting series treatment is carried out at the temperature of 120 ℃, the retention time of each stage of electro-desalting is 1 hour, and the electric field strength is 500V/cm, so that the clear oil is obtained.

Comparative example 2

Similar to example 1, except that during the pretreatment of the used oil, 6g/h of dimethylamine were added directly, the composition of the obtained clear oil is shown in Table 4.

TABLE 4

Analysis item	Example 1	Comparative example 1	Comparative example 2
				Water content/wt%	0.03	0.26	0.22
Mechanical impurities/(wt%)	0.01	0.1	0.07
				Total chlorine/(mg NaCl/L)	3.1	12.8	9.8
Total metal content/(μ g/g)	27	352	267

According to the data in Table 4, it can be seen from the results of example 1 and comparative examples 1 and 2 that the waste oil treated by the pretreatment method of the present invention can obtain clear oil with a water content of 0.03wt%, mechanical impurities reduced to 0.01wt%, total chlorine content reduced to 3.1mgNaCl/L, total metal content reduced to 27. Mu.g/g, and better pretreatment effect. As can be seen from the results of example 1 and comparative example 2, the effect of the filter aid composition used in the present invention is significantly better than the effect of the pretreatment by addition of dimethylamine alone.

Comparative example 3

Similar to example 1, except that the catalyst grading loading scheme of example 1 was not used for the first and second reactors, the first reactor was loaded with RG-30A catalyst having a particle size of 6mm, and the second reactor was loaded with RN32V catalyst; and no third stage hydro-upgrading isomerization was carried out, i.e. no third reactor was present, and the product properties obtained are listed in table 5.

TABLE 5

According to the data in table 5, in example 1, the hydrogenation reaction method of the present invention is adopted, the reaction raw materials sequentially enter three hydrogenation reactors to perform hydrodemetallization and degumming reactions, a hydrotreating reaction, and a hydro-upgrading isomerization reaction, and the catalyst in the reactors adopts the grading loading scheme of the present invention. The hydrogenation process of comparative example 3, however, had only the first two hydrogenation reactions and the catalyst did not employ the graded packing scheme described in the present invention. The product yield of example 1 was 93.7wt%, the cetane number of the diesel fraction was 58.5, the oxidation stability of the lubricant base oil was 204min, and the chroma was 0.5; the product yield in the comparative example 3 is 90.4wt%, the cetane number of the diesel oil fraction is 52.6, the oxidation stability of the lubricating oil base oil is 178min, and the chroma is 2, so that the hydrogenation reaction method has the advantages of higher product yield, higher cetane number of the diesel oil, higher oxidation stability, lower chroma and obviously better product quality than the comparative example.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A method for processing used oil, said method comprising the steps of:

(1) Waste oil pretreatment: mixing the waste oil and the filter aid, and then performing membrane filtration to reduce the content of chlorine elements and metal ions in the waste oil to obtain clear oil; wherein the filter aid is a composition of organic amine, an alcohol compound and water;

(2) Hydrogenation reaction: sequentially carrying out hydrodemetallization and degumming reaction, hydrotreating reaction and hydrogenation modification isomerization reaction on the clean oil to obtain a hydrogenation full-fraction product;

(3) Separation treatment: separating the hydrogenated full fraction product to obtain oil products with different distillation ranges;

wherein, in the filter aid, the mass concentration of organic amine is 10-20%, and the mass concentration of alcohol compounds is 1-10%;

wherein the organic amine is selected from at least one of monomethylamine, dimethylamine, trimethylamine, triethylamine and tert-butylamine; the alcohol compound is selected from at least one of methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol and butanediol;

wherein the catalysts for the hydrodemetallization and degumming reaction are RG-30, RG-30A and RG-30B, RG-30A and RG-30B are sequentially filled in the first reactor along the flow direction of the feed, and the filling volume ratio of RG-30, RG-30A and RG-30B is 4;

wherein the catalysts for the hydrotreating reaction are RJW-3, RL-2 and RN32V, the RJW-3, RL-2 and RN32V are sequentially filled in the second reactor along the feed flow direction, and the filling volume ratio of the RJW-3, the RL-2 and the RN32V is 1-2;

wherein the catalyst for the hydro-upgrading isomerization reaction comprises a hydro-upgrading isomerization catalyst and a post-refining catalyst; the hydro-upgrading isomerization catalyst is selected from at least one of RCF-1 and RHC-130; the post-refining catalyst is at least one of RCF-1 and RJW-3;

wherein the filling sequence of the catalysts for the hydro-upgrading isomerization reaction in the third reactor along the flow direction of the feed is as follows: a mixture of a hydro-upgrading isomerization catalyst, a hydro-upgrading isomerization catalyst and a post-refining catalyst.

2. The process according to claim 1, wherein, in the step (1), the waste oil is subjected to a centrifugal separation treatment to remove solid impurities in the waste oil before the waste oil and the filter aid are mixed.

3. The method of claim 2, wherein the conditions of the centrifugation process comprise: the temperature of the waste oil is 50-200 ℃, and the rotation speed of centrifugal separation is 4000-20000r/min.

4. The method of claim 3, wherein the conditions of the centrifugation process comprise: the temperature of the waste oil is 80-120 ℃, and the rotation speed of centrifugal separation is 4000-6000r/min.

5. The process according to claim 1, wherein the filter aid is added in an amount of 250 to 1500g per 1 ton of the used oil in step (1).

6. The process according to claim 5, wherein, in step (1), the filter aid is added in an amount of 400 to 1000g per 1 ton of used oil.

7. The process of claim 1, wherein in step (1), the used oil and the filter aid are mixed through a mixing valve, wherein the pressure differential across the mixing valve is from 10 to 100kPa.

8. The method according to claim 1, wherein, in the step (1), the filtration membrane used in the membrane filtration is a ceramic membrane, the pore size of the filtration membrane is 0.5-5 μm, the filtration temperature is 50-200 ℃, and the filtration pressure is 0.05-0.5MPa.

9. The process according to claim 1, wherein the conditions of the pre-treatment of used oil are such that in said clean oil the moisture content is less than 0.1wt%; the total chlorine content is less than 10mg NaCl/L; the total metal content is not more than 50 mu g/g; the content of mechanical impurities is not more than 0.02wt%.

10. A process according to claim 9, wherein the conditions of the used oil pretreatment are such that in said clean oil the moisture content is less than 0.03wt%; the total chlorine content is less than 5mg NaCl/L; the total metal content is not more than 30 mu g/g; the content of mechanical impurities is not more than 0.01wt%.

11. The process of claim 1, wherein the hydrodemetallization and ungluing catalyst is RG-30, RG-30A, and RG-30b, RG-30A, and RG-30B are sequentially packed in the first reactor along the feed flow direction, and the packing volume ratio of RG-30, RG-30A, and RG-30B is 4.

12. The process of claim 1, wherein the conditions for the hydrodemetallation and degummed reaction comprise: partial pressure of hydrogen3-20MPa; the reaction temperature is 150-450 ℃; hydrogen to oil volume ratio of 50-2000Nm ³ /m ³ (ii) a Liquid hourly volume space velocity of 1-20h ^-1 。

13. The process of claim 12, wherein the conditions for the hydrodemetallation and degummed reaction comprise: hydrogen partial pressure is 5-15MPa; the reaction temperature is 200-350 ℃; hydrogen-oil volume ratio of 200-1200Nm ³ /m ³ (ii) a Liquid hourly volume space velocity of 2-10h ^-1 。

14. The process of claim 1, wherein the catalyst for the hydrotreating reaction is RJW-3, RL-2, RN32V, and RJW-3, RL-2, RN32V are sequentially packed in the second reactor along the feed flow direction, and the packing volume ratio of RJW-3, RL-2, RN32V is 1-1.5.

15. The method of claim 1, wherein the conditions of the hydrotreating reaction include: hydrogen partial pressure is 3-20MPa; the reaction temperature is 200-480 ℃; hydrogen-oil volume ratio of 100-2000Nm ³ /m ³ (ii) a Liquid hourly volume space velocity of 0.2-10h ^-1 。

16. The method of claim 15, wherein the conditions of the hydrotreating reaction include: hydrogen partial pressure is 5-15MPa; the reaction temperature is 280-420 ℃; hydrogen-oil volume ratio of 300-1500Nm ³ /m ³ (ii) a Liquid hourly volume space velocity of 0.4-4h ^-1 。

17. The process of claim 1, wherein the hydro-upgrading isomerization catalyst is RHC-130.

18. The process of claim 1, wherein the post-refining catalyst is RJW-3.

19. The process of claim 1, wherein the volume ratio of hydro-upgrading isomerization catalyst to the mixture is 1.

20. The process of claim 1, wherein the volume ratio of hydro-upgrading isomerization catalyst to the mixture is from 1.

21. The process of claim 1, wherein the conditions of the hydro-upgrading isomerization reaction comprise: hydrogen partial pressure is 3-20MPa; the reaction temperature is 200-450 ℃; hydrogen-oil volume ratio of 100-1500Nm ³ /m ³ (ii) a The liquid hourly volume space velocity is 0.3-10h ^-1 。

22. The process of claim 21, wherein the conditions of the hydro-upgrading isomerization reaction comprise: hydrogen partial pressure is 5-10MPa; the reaction temperature is 280-420 ℃; hydrogen-oil volume ratio of 200-1000Nm ³ /m ³ (ii) a Liquid hourly volume space velocity of 0.5-3h ^-1 。

23. An oil processing skid-mounted modular integrated unit for use in the method of any one of claims 1-22, wherein said integrated unit is mounted on a mobile base, comprising:

the hydrogenation reaction system is used for sequentially carrying out hydrodemetallization and ungluing reaction, hydrotreating reaction and hydrogenation modification isomerization reaction on the clear oil to obtain a hydrogenation full fraction product;

24. The integrated plant of claim 23, wherein the integrated plant waste oil throughput is no greater than 1000 tons/year.

25. The integrated apparatus of claim 23 or 24, wherein the feedstock pre-treatment system comprises a waste oil pump, a centrifugal separator, a mixing valve, a membrane separator and a clean oil tank connected in series;

and/or the hydrogenation reaction system comprises a heat exchanger, a first reactor, a second reactor and a third reactor which are connected in sequence; wherein the heat exchanger is used for recovering the product heat at the outlet of the third reactor so as to heat the clear oil entering the first reactor;

and/or the separation system comprises a high-pressure separator, a low-pressure separator, a stabilizing tower and a fractionating tower which are connected in sequence.