CN221117378U - Chemical pretreatment system for waste grease - Google Patents

Abstract

The utility model discloses a waste oil chemical pretreatment system, including a catalyst configuration device, a first esterification reactor, a first separation device, a second separation device, an evaporation device group, a cooling device and a methanol separation device, one of the outlet ends of the first esterification reactor is connected to the first separation device, the outlet end of the first separation device is connected to the inlet end of the second separation device, the first outlet end of the second separation device is connected to one of the evaporation devices, the second outlet end of the second separation device is connected to another evaporation device, the outlet ends of multiple evaporation devices are simultaneously connected to the cooling device, the cooling device is further connected to the methanol separation device, one of the outlet ends of the methanol separation device is connected to the reflux device, and the reflux device is connected to the first esterification reactor. This system can effectively reduce the acid value of waste oil and remove impurities such as metals, phospholipids, and unsaponifiable matter therein, and has high overall efficiency, low energy consumption, and good production benefits during operation.

Description

A waste oil chemical pretreatment system

Technical Field

The utility model relates to the technical field of renewable energy, in particular to a waste oil and fat chemical pretreatment system.

Background technique

Vigorously developing biodiesel production projects not only meets the country's needs for developing clean energy, but also fits the current national goal of "carbon peak and carbon neutrality". According to industry test data, every ton of biodiesel used in the entire cycle can achieve 2.0 to 2.5 tons of carbon emission reduction. Certified by the Dutch Double Counting of the European Union, the world's largest consumer of biomass energy, biodiesel produced from waste oils such as gutter oil, slop oil, and acidified oil has higher carbon emission reduction properties than biodiesel produced from plant oils such as palm oil, soybean oil, and rapeseed oil, and should be vigorously promoted and used. Waste oil is a widely available and stable by-product of the edible oil processing industry. Compared with animal and plant oils, microbial oils, etc., it is relatively cheap. Using it as a raw material for the preparation of second-generation biodiesel by the hydrodeoxygenation method has a very obvious cost advantage.

However, waste oils and fats have high fatty acid content and high acid value, and the hydrodeoxygenation reaction is carried out under high temperature conditions and will generate a large amount of water, which seriously affects the stability of the hydrogenation catalyst and causes the catalyst bed to be easily pulverized and deactivated. In addition, waste oils and fats also contain a large amount of impurities such as metals, phospholipids, and unsaponifiable matter, and their deposition on the surface of the hydrogenation catalyst will also affect its stability. Therefore, when waste oils and fats are used as raw materials to prepare second-generation biodiesel, the device needs to be frequently stopped to replace the catalyst, and it cannot operate stably for a long period of time, and the operating costs remain high. In the current technology for preparing second-generation biodiesel by hydrodeoxygenation, conventional water methods, acid washing, alkali washing, adsorption and other physical methods are usually used to pre-treat waste oils and fats. Although some impurities can be removed, the overall efficiency is low, and conventional physical pretreatment methods cannot fundamentally solve the problem of high acid value of waste oils and fats.

Utility Model Content

In view of the problem that the conventional physical methods such as water method, acid washing, alkali washing, adsorption, etc. used in the prior art for pre-treating waste oil and grease have low impurity removal efficiency and cannot effectively reduce the acid value of the waste oil and grease, the utility model provides a chemical pretreatment system that can effectively reduce the acid value of the waste oil and grease and remove impurities therein. The system has a low raw oil loss rate and low operating cost. The overall energy consumption during the system operation is low and the material recycling rate is high.

The utility model adopts the following technical solutions:

A waste oil and fat chemical pretreatment system, comprising a catalyst configuration device, a first esterification reactor, a first separation device, a second separation device, an evaporation device group, a cooling device, a methanol separation device, a reflux device and a raw oil supply device, wherein the catalyst configuration device is connected to an inlet end of the first esterification reactor and is used to introduce a catalyst for raw oil reaction into the first esterification reactor, the raw oil supply device is connected to another inlet end of the first esterification reactor and is used to provide raw oil and waste oil to the first esterification reactor, one of the outlet ends of the first esterification reactor is connected to the first separation device, and the first separation device is used to separate solids from the product discharged from the first esterification reactor; the outlet end of the first separation device is connected to the inlet end of the second separation device, and the second separation device The device is used to further separate the oil-water two phases in the product discharged from the first esterification reactor; the evaporation device group includes a first evaporation device and a second evaporation device, the first outlet end of the second separation device is connected to the first evaporation device, and the second outlet end of the second separation device is connected to the second evaporation device, and the evaporation device group is used to evaporate the oil-water two phases separated by the second separation device; the outlet end of the evaporation device group is also connected to the cooling device, and the outlet of the cooling device is further connected to the methanol separation device, and the outlet end of the methanol separation device is connected to the reflux device, the methanol separation device is used to distill and separate methanol and water, and the reflux device is connected to the first esterification reactor, and the methanol after distillation and separation by the methanol separation device is introduced into the first esterification reactor through the reflux device.

The inlet of the catalyst configuration device is connected to an external methanol supply device and an ionic liquid catalyst supply device, the external methanol supply device provides methanol to the catalyst configuration device, and the ionic liquid catalyst supply device provides ionic liquid catalyst to the catalyst configuration device;

Preferably, the catalyst configuration device is provided with a stirring device, and the stirring device is used to stir the ionic liquid and the methanol liquid.

The outlet end of the catalyst configuration device is communicated with the inlet end of the mixing device, the outlet of the mixing device is communicated with the inlet end of the first esterification reactor, and a transmission pump is arranged between the mixing device and the catalyst configuration device.

The catalyst configuration device is connected to at least one evaporation device in the evaporation device group through a pipeline, and a valve is arranged on the pipeline between the catalyst configuration device and the connected evaporation device.

The system also includes a second esterification reactor, the other outlet end of the first esterification reactor is connected to the inlet end of the second reactor, the outlet end of the second esterification reactor is connected to the first esterification reactor, and the second esterification reactor is used to further react the unreacted crude oil and methanol after the reaction in the first esterification reactor.

The evaporation device group includes a first evaporation device and a second evaporation device arranged in parallel, the first evaporation device is used to separate the oil phase product separated by the second separation device, and the second evaporation device is used to separate the water phase product separated by the second separation device.

The first evaporation device comprises a first evaporator and a first gas-liquid separator arranged in series, the first evaporator is used to heat the oil phase product, and the heated oil phase product is passed into the first gas-liquid separator connected thereto for further gas-liquid separation;

The second evaporation device includes a second evaporator and a second gas-liquid separator arranged in series. The second evaporator is used to heat the water phase product. The heated water phase product enters the connected second gas-liquid separator for further gas-liquid separation.

The first gas-liquid separation device and the second gas-liquid separation device are arranged in parallel, and the first gas-liquid separation device and the second gas-liquid separation device are connected to the cooling device at the same time, and the methanol and water discharged through the first gas-liquid separation device and the methanol and water discharged through the second gas-liquid separation device all enter the cooling device.

Preferably, both the first esterification reactor and the second esterification reactor are stirred tank reactors;

Preferably, the first separation device is a filter, and the second separation device is a chromatograph.

The technical solution of the utility model has the following advantages:

The waste oil and fat chemical pretreatment system provided by the utility model uses methanol and ionic liquid to prepare a catalyst solution, and mixes the methanol after a reaction cycle with the raw oil to be treated. Under the action of the catalyst, the methanol and the raw oil undergo an esterification reaction to generate fatty acid methyl esters and water, thereby achieving the purpose of reducing the acid value of the raw oil and removing impurities such as metals, phospholipids, and unsaponifiable matter therein, and the raw oil loss rate is low, the operating process cost is not high, and the overall energy consumption during the system operation process is less.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the specific implementation methods of the present utility model, the drawings required for use in the specific implementation methods will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of the overall structure of the waste oil chemical pretreatment system of the utility model (I);

FIG. 2 is a schematic diagram of the overall structure of the waste oil and fat chemical pretreatment system of the present invention (II).

The following are marked in the figure:

1-catalyst configuration device; 2-esterification reactor, 21-first esterification reactor, 22-second esterification reactor; 3-first separation device; 4-second separation device, 41-first outlet end, 42-second outlet end; 5-evaporation device group, 51-first evaporation device, 511-first evaporator, 512-first gas-liquid separator, 52-second evaporation device, 521-second evaporator, 522-second gas-liquid separation device; 6-cooling device; 7-methanol separation device; 8-reflux device; 9-methanol feed pump; 10-mixing device; 20-raw oil supply device.

Detailed ways

The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

As shown in Figures 1 and 2, the utility model provides a waste oil chemical pretreatment system, including a catalyst configuration device 1, a first esterification reactor 21, a first separation device 3, a second separation device 4, an evaporation device group 5, a cooling device 6, a methanol separation device 7, a reflux device 8 and a raw oil supply device 20, wherein the catalyst configuration device 1 is connected to an inlet end of the first esterification reactor 21, and is used to introduce a catalyst for raw oil reaction into the first esterification reactor 21, and the raw oil supply device 20 is connected to the other inlet end of the first esterification reactor 21, and is used to provide raw oil and waste oil to the first esterification reactor 21, and one of the outlet ends of the first esterification reactor 21 is connected to the first separation device 3, and the first separation device 3 is used to separate the solids in the product discharged from the first esterification reactor 21. The outlet end of the first separation device 3 is connected to the inlet end of the second separation device 4, and the second separation device 4 is used to further separate the oil-water two phases in the product discharged from the first esterification reactor 3. The evaporation device group 5 includes a first evaporation device 51 and a second evaporation device 52. The first outlet end 41 of the second separation device 4 is connected to the first evaporation device 51, and the second outlet end 42 of the second separation device 4 is connected to the second evaporation device 52. The evaporation device group 5 is used to evaporate the oil-water two-phase separated by the second separation device 4 to obtain methanol and water. The outlet end of the evaporation device group 5 is also connected to the cooling device 6, and the outlet of the cooling device 6 is further connected to the methanol separation device 7. The outlet end of the methanol separation device 7 is connected to the reflux device 8. The cooling device 6 is used to cool the methanol and water evaporated by the evaporation device group 5. The methanol separation device 7 is used to distill and separate methanol and water. The reflux device 8 is connected to the first esterification reactor 21. The methanol after distillation and separation by the methanol separation device 7 is introduced into the first esterification reactor 21 through the reflux device 8.

Furthermore, the inlet of the catalyst configuration device 1 is connected with an external methanol supply device and an ionic liquid catalyst supply device, the external methanol supply device provides methanol with a purity greater than 99% to the catalyst configuration device 1, and the ionic liquid catalyst supply device provides an ionic liquid catalyst with a purity greater than 99% to the catalyst configuration device 1. The external methanol supply device and the catalyst configuration device 1 are connected by a pipeline, and a valve is provided on the pipeline between the external methanol supply device and the catalyst configuration device 1. The flow rate of the methanol liquid introduced into the catalyst configuration device 1 by the external methanol supply device is adjusted by controlling the valve to improve the flexibility of catalyst preparation and adapt to the waste oil pretreatment requirements under different circumstances; the ionic liquid catalyst supply device introduces the ionic liquid catalyst into the catalyst configuration device 1, and the ionic liquid catalyst supply device is fixed directly above the catalyst configuration device 1 to be used to timely replenish the ionic liquid catalyst into the catalyst configuration device 1 to ensure sufficient preparation of the catalyst solution. In order to better utilize the remaining ionic liquid catalyst in the system reaction process, thereby reducing the consumption of ionic liquid catalyst in the waste oil chemical pretreatment process, the catalyst configuration device 1 is connected to at least one evaporation device in the evaporation device group 5, and the catalyst configuration device 1 is connected to the connected evaporation device through a pipeline. A valve is provided on the pipeline between the catalyst configuration device 1 and the connected evaporation device, and the flow rate of the ionic liquid catalyst introduced into the catalyst configuration device 1 from the corresponding evaporation device is adjusted by controlling the valve, thereby improving the production flexibility of the entire system; the ionic liquid catalyst remaining after evaporation of the evaporation device and recycled and used is discharged from the evaporation device and introduced into the catalyst configuration device 1 to configure the catalyst, and the catalyst is configured by partially using the recycled ionic liquid to reduce the consumption of ionic liquid in the catalyst preparation process, reduce the preparation cost, and also improve the material utilization rate of the system. A stirring device is provided in the catalyst configuration device 1, and the stirring device is used to stir the ionic liquid and the methanol liquid to promote the dissolution and mixing of the methanol and the ionic liquid. The ionic liquid catalyst is a Bronsted acid proton type ionic liquid.

The outlet of the catalyst configuration device 1 is connected to the mixing device 10 through a pipeline, and the mixing device 10 is connected to the inlet of the first esterification reactor 21. Specifically, a transmission pump is provided at the outlet of the catalyst configuration device 1, and the transmission pump is used to introduce the prepared catalyst solution from the catalyst configuration device 1 into the mixing device 10 for sufficient mixing, so that the catalyst solution can quickly participate in the reaction of methanol and crude oil when it enters the first esterification reactor 21, improve the reaction efficiency of the esterification reaction, and reduce the overall reaction time. In order to make the catalyst solution more effective in catalysis, the prepared catalyst solution is allowed to stand in the mixing device 10 for 5 to 10 minutes before being introduced into the first esterification reactor 21.

The first esterification reactor 21 is also connected to an external crude oil supply device. In order to further utilize the reacted materials in the system, the first esterification reactor 21 can be directly connected to the methanol separation device 7. The methanol separated by the methanol separation device 7 is introduced into the first esterification reactor 21 to continue the esterification reaction with the crude oil to generate fatty acid methyl ester and water; the generated fatty acid methyl ester and water are discharged from the first esterification reactor 21 and introduced into the first separation device 3 for subsequent separation.

In order to better react the crude oil and improve the reaction efficiency of the whole system, the system further includes a second esterification reactor 22, the outlet end of the first esterification reactor 21 is connected to the inlet end of the second esterification reactor 22, and the second esterification reactor 22 is used to further react the unreacted crude oil and methanol after the reaction in the first esterification reactor 21, and further promote the esterification reaction of the crude oil and methanol to generate fatty acid methyl esters and water. The first esterification reactor 21 and the second esterification reactor 22 are both stirred tank reactors, and the first esterification reactor 21 and the second esterification reactor 22 are both provided with spirally arranged heating pipes, and the first esterification reactor 21 and the second esterification reactor 22 are both provided with circulating heat exchangers outside, wherein steam condensate flows in the heating pipes located inside the first esterification reactor 21 and the second esterification reactor 22, and the methanol of the crude oil is heated by the steam condensate to promote the esterification reaction of the methanol of the crude oil; the circulating heat exchanger is also connected to the cooling water pipeline, and by introducing cold water into the cooling water pipeline, the temperature of the outer wall of the first esterification reactor 21 and the second esterification reactor 22 is adjusted and controlled. In order to more effectively control the pressure inside the first esterification reactor 21 and the second esterification reactor 22, the first esterification reactor 21 and the second esterification reactor 22 are respectively connected to nitrogen pipelines, and the pressure inside the first esterification reactor 21 and the second esterification reactor 22 is adjusted by introducing nitrogen into the first esterification reactor 21 and the second esterification reactor 22.

The products generated after the reaction in the first esterification reactor 21 and the second esterification reactor 22 are respectively discharged from the outlet of the first esterification reactor 21 and the outlet of the second esterification reactor 22 and introduced into the first separation device 3 for preliminary separation. The first separation device 3 is a filter, which can preliminarily remove solid impurities in the products after the reaction in the first esterification reactor 21 and the second esterification reactor 22; the outlet of the first separation device 3 is connected to the waste residue treatment storage tank, and the filtered solid impurities are discharged from the first separation device 3 and introduced into the waste residue treatment storage tank for centralized collection; the first separation device is preferably a plate and frame filter press.

The product separated by the first separation device 3 enters the second separation device 4, which is a chromatograph, and the two outlet ends of the second separation device 4 are respectively connected to the two evaporation devices. The second separation device 4 is used to separate the product filtered by the first separation device 3 into oil-water two-phases, and obtain oil phase products and water phase products respectively, wherein the oil phase product is mainly fatty acid methyl ester, methanol, water and part of the unreacted raw oil, and the water phase product is mainly methanol, ionic liquid and water generated by the reaction. The evaporation device group 5 includes a first evaporation device 51 and a second evaporation device 52, the first evaporation device 51 and the second evaporation device 52 are arranged in parallel with each other, and the first evaporation device 51 is used to separate the oil phase product separated by the second separation device 4. The first evaporation device 51 includes a first evaporator 511 and a first gas-liquid separator 512 that are interconnected, the first evaporator 511 is used to heat the oil phase product, and the oil phase product after heating is passed into the first gas-liquid separator 512 that is connected to each other for further gas-liquid separation, and the first gas-liquid separator 512 is used to separate the heated oil phase product between gas and liquid. Specifically, the oil phase product is heated by utilizing the boiling point difference of water, methanol and fatty acid methyl ester to separate methanol and water from the oil phase product; the crude product containing fatty acid methyl ester and unreacted raw material oil remaining after separating methanol and water from the oil phase product is discharged from the first gas-liquid separator 512 and introduced into a storage device for subsequent reaction. The first evaporation device 51 is connected to the steam heating pipeline, which is also connected to the first esterification reactor 21. By passing steam with a higher temperature into the steam heating pipeline, heat is transferred to the oil phase product in the first evaporation device 51 as the steam flows, so as to promote the heating of the oil phase product; by using steam to heat the oil phase product, the steam that is cooled after heating is then passed into the first esterification reactor 21 to control the reaction temperature in the first esterification reactor 21.

Similarly, the second evaporation device 52 is used to separate the water phase product separated by the second separation device 4. The second evaporation device 52 includes a second evaporator 521 and a second gas-liquid separator 522 which are interconnected. The second evaporator 521 is used to heat the water phase product. The heated water phase product enters the interconnected second gas-liquid separator 522 for further gas-liquid separation. The second gas-liquid separator 522 is used to separate the heated water phase product between gas and liquid. Specifically, the boiling point difference between the ionic liquid and methanol and water is used to separate the ionic liquid, methanol and water by flash evaporation, and methanol and water are obtained by evaporation, thereby separating methanol and water from the ionic liquid; the separated methanol and water are discharged from the second evaporation device 52 for subsequent further separation. In order to reuse the separated ionic liquid catalyst, reduce the catalyst consumption of the waste oil chemical pretreatment system, and reduce the pretreatment cost, the second gas-liquid separation device 522 is connected to the catalyst preparation device 1. After the separated ionic liquid catalyst is discharged from the second gas-liquid separation device 522, it can be passed into the catalyst preparation device 1 to prepare the catalyst solution, thereby reducing the cost of the system. There is a part of the deactivated ionic liquid in the separated ionic liquid catalyst. In order to reduce the influence of the deactivated ionic liquid catalyst on the subsequent reaction, a separation device is also provided on the second gas-liquid separation device 522. The separation device is used to separate the deactivated ionic liquid catalyst and the recyclable and reusable ionic liquid, and discharge the deactivated ionic liquid from the second gas-liquid separation device 522 for recycling and collection.

The second evaporation device 52 is connected to the steam heating pipeline, which is also connected to the first esterification reactor 21. By passing steam with a higher temperature into the steam heating pipeline, heat is transferred to the water phase product in the second evaporation device 52 as the steam flows, so as to promote the heating of the water phase product. The water phase product is heated by steam, and the heated and cooled steam is then passed into the first esterification reactor 21 to control the reaction pressure in the first esterification reactor 21.

The first gas-liquid separation device 512 and the second gas-liquid separation device 522 are arranged in parallel with each other, and the first gas-liquid separation device 512 and the second gas-liquid separation device 522 are simultaneously connected to the cooling device 6. The methanol and water discharged from the first gas-liquid separation device 512 and the methanol and water discharged from the second gas-liquid separation device 522 all enter the cooling device 6, and the cooling device 6 can further cool the methanol and water introduced from the first gas-liquid separation device 512 and the second gas-liquid separation device 522. The cooling device is a methanol condenser.

The outlet of the cooling device 6 is connected to the inlet of the methanol separation device 7. The methanol and water cooled by the cooling device 6 enter the methanol separation device 7. The cooling device 6 and the methanol separation device 7 are connected by a pipeline. A methanol feed pump 9 is provided on the pipeline connecting the cooling device 6 and the methanol separation device 7. The methanol feed pump 9 can increase the pressure in the pipeline so that the methanol and water can enter the methanol separation device 7 faster. The methanol separation device 7 can perform rectification and separation on the cooled methanol and water, and obtain methanol with a purity greater than 99%. In order to better promote the reaction of the crude oil and improve the recycling rate of the system, the outlet of the methanol separation device 7 is connected to the reflux device 8. The methanol with a purity greater than 99% after separation is passed into the reflux device 8. The reflux device 8 is connected to the first esterification reactor 21. The reflux device 8 can re-introduce the methanol with a purity greater than 99% into the first esterification reactor 21 for continuing to react with the crude oil and generating fatty acid methyl esters and water, thereby achieving the effect of reusing methanol. The waste water after rectification is discharged from the bottom of the methanol separation device 7 and introduced into the waste water storage device.

When used specifically, methanol and the ionic liquid catalyst are first introduced into the catalyst configuration device 1 at the same time. In order to reduce the consumption of raw materials by the system, the ionic liquid catalyst separated in the second gas-liquid separation device 522 is simultaneously introduced into the catalyst configuration device 1, and the methanol and the ionic liquid catalyst are mixed and stirred evenly by the catalyst configuration device 1 to form a catalyst solution. After the catalyst solution is discharged from the catalyst configuration device 1, it enters the mixing device 10 and stands in the mixing device 10 for 6 to 8 minutes, and then is introduced into the first esterification reactor 21. At this time, the raw oil and methanol are simultaneously introduced into the first esterification reactor 21 for esterification reaction. In order to effectively utilize the materials in the system and reduce the consumption of external raw materials, thereby reducing operating costs, the methanol separated by distillation in the methanol separation device 7 is introduced into the first esterification reactor 21; at the same time, the reaction temperature and reaction pressure in the first esterification reactor 21 are adjusted, and under the action of the ionic liquid catalyst, the methanol and the raw oil undergo an esterification reaction to generate fatty acid methyl esters and water; the methanol and raw oil that have not reacted completely are introduced into the second esterification reactor 22 through the first esterification reactor 21, and the reaction temperature and reaction pressure of the second esterification reactor 22 are adjusted so that the methanol and the raw oil undergo further esterification reaction.

The fatty acid methyl ester and water generated after the reaction in the first esterification reactor 21 and the second esterification reactor 22 are discharged from the first esterification reactor 21 and the second esterification reactor 22 respectively and enter the first separation device 3 for filtration to preliminarily remove solid impurities in the product; after filtration, the product is discharged from the first separation device 3 and introduced into the second separation device 4, and the product is separated into an oil phase product and a water phase product by the second separation device 4. The oil phase product enters the first evaporation device 51 connected to the second separation device 4, and the water phase product enters the second evaporation device 52 connected to the second separation device 4. By utilizing the boiling point difference between water, methanol and fatty acid methyl ester, the first evaporation device 51 further evaporates and separates the oil phase product to obtain methanol and water; by utilizing the boiling point difference between the ionic liquid and methanol and water, the second evaporation device 52 further evaporates and separates the water phase product to obtain methanol and water. The methanol and water evaporated from the first evaporation device 51 and the second evaporation device 52 simultaneously enter the cooling device 6 for condensation to obtain methanol and water liquid. The condensed methanol and water liquid are discharged from the cooling device 6 and enter the methanol separation device 7. The methanol separation device 7 further distills the introduced methanol and water liquid to obtain methanol with a purity greater than 99%. The waste water after distillation is discharged through the methanol separation device 7.

Anything not described in the present invention is applicable to the prior art.

Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present utility model.

Claims (9)

1. A waste oleochemical pretreatment system characterized by comprising a catalyst arrangement device (1), a first esterification reactor (21), a first separation device (3), a second separation device (4), an evaporation device group (5), a cooling device (6), a methanol separation device (7), a reflux device (8) and a raw oil supply device (20), wherein the catalyst arrangement device (1) is communicated with one inlet end of the first esterification reactor (21) for introducing a catalyst for raw oil reaction into the first esterification reactor (21), the raw oil supply device (20) is communicated with the other inlet end of the first esterification reactor (21) for providing raw oil waste oleo to the first esterification reactor (21), one outlet end of the first esterification reactor (21) is communicated with the first separation device (3), and the first separation device (3) is used for separating solids in a product discharged from the first esterification reactor (21); the outlet end of the first separation device (3) is communicated with the inlet end of the second separation device (4), and the second separation device (4) is used for further separating oil-water two phases in the product discharged from the first separation device (3); the evaporation device group (5) comprises a first evaporation device (51) and a second evaporation device (52), a first outlet end (41) of the second separation device (4) is communicated with the first evaporation device (51), a second outlet end (42) of the second separation device (4) is communicated with the second evaporation device (52), and the evaporation device group (5) is used for evaporating oil-water two phases separated by the second separation device (4); the outlet end of evaporation plant group (5) simultaneously with cooling device (6) intercommunication, the export of cooling device (6) again with methanol separation device (7) intercommunication, the outlet end of methanol separation device (7) with reflux unit (8) intercommunication, methanol separation device (7) are used for carrying out rectification separation to methyl alcohol and water, reflux unit (8) with first esterification reactor (21) intercommunication, the process methanol after methanol separation device (7) rectification separation passes through reflux unit (8) is imported in first esterification reactor (21).

2. The waste oleochemical pretreatment system according to claim 1, wherein: the inlet of the catalyst configuration device (1) is communicated with an external methanol supply device and an ionic liquid catalyst supply device, the external methanol supply device supplies methanol to the catalyst configuration device (1), and the ionic liquid catalyst supply device supplies an ionic liquid catalyst to the catalyst configuration device (1);

The catalyst configuration device (1) is provided with a stirring device which is used for stirring the ionic liquid and the methanol liquid.

3. The waste oleochemical pretreatment system according to claim 2, wherein: the outlet end of the catalyst configuration device (1) is communicated with the inlet of the mixing device (10), the outlet of the mixing device (10) is communicated with the inlet end of the first esterification reactor (21), and a transmission pump is arranged between the mixing device (10) and the catalyst configuration device (1).

4. A waste oleochemical pretreatment system according to claim 3, wherein: the catalyst configuration device (1) is communicated with at least one evaporation device in the evaporation device group (5) through a pipeline, and a valve is arranged on the pipeline between the catalyst configuration device (1) and the evaporation device which is communicated with the catalyst configuration device.

5. The waste oleochemical pretreatment system according to claim 4, wherein: the system further comprises a second esterification reactor (22), wherein the outlet end of the first esterification reactor (21) is communicated with the inlet end of the second esterification reactor (22), the outlet end of the second esterification reactor (22) is communicated with the first separation device (3), and the second esterification reactor (22) is used for further reacting unreacted raw oil and methanol after the reaction of the first esterification reactor (21).

6. The waste oleochemical pretreatment system according to claim 5, wherein: the evaporation device group (5) comprises a first evaporation device (51) and a second evaporation device (52) which are arranged in parallel, the first evaporation device (51) is used for separating an oil phase product obtained by separating the second separation device (4), and the second evaporation device (52) is used for separating an aqueous phase product obtained by separating the second separation device (4).

7. The waste oleochemical pretreatment system according to claim 6, wherein: the first evaporation device (51) comprises a first evaporator (511) and a first gas-liquid separator (512) which are arranged in series, the first evaporator (511) is used for heating an oil phase product, and the heated oil phase product is introduced into the first gas-liquid separator (512) which is communicated with the first evaporator for further gas-liquid separation;

The second evaporation device (52) comprises a second evaporator (521) and a second gas-liquid separator (522) which are arranged in series, the second evaporator (521) is used for heating and raising the temperature of the water phase product, and the water phase product after the temperature rise enters the second gas-liquid separator (522) which is communicated with the second evaporator to carry out further gas-liquid separation.

8. The waste oleochemical pretreatment system according to claim 7, wherein: the first gas-liquid separator (512) and the second gas-liquid separator (522) are arranged in parallel, the first gas-liquid separator (512) and the second gas-liquid separator (522) are simultaneously communicated with the cooling device (6), and methanol and water discharged through the first gas-liquid separator (512) and methanol and water discharged through the second gas-liquid separator (522) enter the cooling device (6).

9. The waste oleochemical pretreatment system according to claim 8, wherein: the first esterification reactor (21) and the second esterification reactor (22) are both stirred tank reactors;

The first separation device (3) is a filter, and the second separation device (4) is a chromatograph.