Advanced treatment system for adiponitrile waste residue oil

Abstract

The invention provides a deep treatment system for adiponitrile waste residue oil, and belongs to the technical field of adiponitrile waste residue oil. The adiponitrile waste residue oil deep treatment system comprises a solid treatment unit, the solid treatment unit comprises a deep extraction device, a low-temperature heat treatment device, a crushing device, a hydrothermal treatment device and a filtering device which are connected in sequence; the deep extraction device is used for treating adiponitrile waste residue oil to obtain crude nitrile and high-viscosity residue; the low-temperature heat treatment device is used for treating the high-viscosity slag charge to obtain solid waste slag and is provided with an oxygen-deficient air inlet; the smashing device and the hydrothermal treatment device are used for treating solid waste residues, and carbon balls are obtained after filtering and washing are conducted through the filtering device. The adiponitrile waste residue oil which is high in viscosity and difficult to subpackage and transport is efficiently converted into small-particle carbon spheres which are regular in form and stable in property, and convenience and economical efficiency of subsequent treatment and disposal are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of adiponitrile waste residue oil, and in particular to an adiponitrile waste residue oil deep treatment system. Background Art

[0002] In the production process of adiponitrile (ADN) synthesized from butadiene, butadiene is converted into adiponitrile with important industrial value through key steps such as one-step hydrogenation of butadiene, carbon chain isomerization, and two-step hydrogenation of butadiene.

[0003] After the two-step hydrocyanation of butadiene is completed, the reaction liquid is separated to remove the catalyst, unreacted second-step hydrocyanation feedstock, adiponitrile product, and the by-product 2-methylglutaronitrile (MGN). The remaining residue in the reactor is waste oil. This waste oil is a key processing challenge in current processes: it contains highly industrially valuable ADN and MGN that cannot be fully recovered, resulting in resource waste and economic loss. It also contains a mixture of various cyano-containing nitriles, deactivated catalysts / auxiliaries that may contain heavy metals (such as nickel and phosphorus), and a large amount of non-biodegradable coke, constituting a serious source of complex pollution.

[0004] At present, the industry generally lacks mature treatment technologies that are efficient, environmentally friendly and resource-based. Conventional direct discharge or simple landfill disposal methods not only pose serious and persistent environmental threats to soil and water ecosystems from cyanide compounds, heavy metals and coke pollutants, but also lead to the abandonment of valuable chemical raw materials such as ADN and MGN, seriously violating the principles of green chemistry and sustainable development.

[0005] Therefore, developing a deep treatment system for the waste oil generated during the production of adiponitrile by the butadiene process to achieve efficient recovery of key valuable components (ADN and MGN) and safe and harmless disposal of hazardous substances (including cyanonitriles, heavy metals, and coke) has urgent practical significance and important application value for improving process economics, reducing environmental pollution, and promoting green and sustainable development of the industry. This technical field urgently needs to break through the limitations of traditional treatment models and build a comprehensive solution that prioritizes resource recovery and environmental governance. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention discloses a deep treatment system for adiponitrile waste residue oil, so as to solve the problems of environmental pollution and waste of valuable components ADN and MGN caused by direct discharge or simple landfill disposal of adiponitrile waste residue oil.

[0007] To solve at least one of the above problems, the present invention provides a deep treatment system for adiponitrile waste residual oil, comprising a solid processing unit;

[0008] The solid processing unit includes a deep extraction device, a low-temperature heat treatment device, a crushing device, a hydrothermal treatment device and a filtering device connected in sequence;

[0009] The deep extraction device is used to process adiponitrile waste oil to obtain crude nitrile and high-viscosity residue;

[0010] The low-temperature heat treatment device is used to process the high-viscosity slag to obtain solid waste;

[0011] The crushing device and the hydrothermal treatment device are used to treat the solid waste residue, and carbon balls are obtained after filtering and washing through the filtering device.

[0012] The existing technologies for the treatment of adiponitrile waste oil often lack systematic and comprehensive solutions, and they focus more on a single link or simple treatment, making it difficult to achieve coordinated optimization of resource recovery and environmental emissions. The solid processing unit of the present invention significantly improves the resource utilization rate and harmlessness level of adiponitrile waste oil through a multi-stage coordinated treatment method: first, the deep extraction device efficiently recovers valuable crude nitrile components such as adiponitrile and 2-methylglutaronitrile remaining in the waste oil, greatly reducing resource waste. The separated high-viscosity slag then enters a low-temperature heat treatment device, which effectively decomposes residual cyano compounds and removes some volatile substances at a mild temperature, significantly reducing the toxicity and environmental risks of subsequent treatment. The solid waste formed by low-temperature heat treatment is refined by a pulverizing device and then enters a hydrothermal treatment device for deep purification and modification. After filtration and washing, a carbon ball product with a regular morphology is finally obtained. The carbon balls obtained in this application can be used in the fields of fuel, adsorbent, landfill, etc. Among them, since the preparation process of adiponitrile includes a phosphorus-containing catalyst, its waste residue oil is inevitably mixed with the catalyst. The carbon balls obtained after being treated with the technical solution of this application also contain phosphorus, which can be used as a better landfill to fertilize the soil.

[0013] In some embodiments, further comprising a gas processing unit;

[0014] The gas processing unit includes a gas-liquid condensation device, the gas phase outlet of the low-temperature heat treatment device is connected to the inlet of the gas-liquid condensation device, and the condensate outlet of the gas-liquid condensation device is connected to the inlet of the deep extraction device; the gas-liquid condensation device is provided with a non-condensable gas outlet.

[0015] Based on the joint setting of the solid processing unit and the gas processing unit, the two units operate in coordination. The solid processing unit processes the adiponitrile waste oil with high viscosity, which is difficult to package and transport, into small particles of carbon balls, making the transportation and treatment of the "three wastes" of the adiponitrile plant easier. In addition, the condensate of the gas processing unit after treatment by the gas-liquid condensation device contains part of the adiponitrile (ADN) and 2-methylglutaronitrile (MGN), which can be fed back to the deep extraction device of the solid processing unit to achieve resource recycling. This synergistic effect between the solid-gas processing units makes the entire processing system an organic whole. The various links cooperate and promote each other, achieving significant comprehensive effects in reducing the emission of "three wastes" and improving the production efficiency of adiponitrile.

[0016] In some embodiments, the gas processing unit is further provided with an SCR treatment-drying device and an ammonia recovery device in sequence after the gas-liquid condensation device;

[0017] The non-condensable gas outlet of the gas-liquid condensing device is connected to the inlet of the SCR treatment-drying device.

[0018] In some embodiments, the gas phase outlet of the hydrothermal treatment device is connected to the inlet of the SCR treatment-drying device.

[0019] The gaseous substances generated in the solid processing unit can enter the gas processing unit for processing in a timely manner, avoiding the unorganized emission of harmful gases.

[0020] In some embodiments, the deep extraction device is one or more of a falling film evaporator, a scraped surface evaporator, and a double-shaft self-cleaning mixer.

[0021] Existing technologies often fail to thoroughly extract adiponitrile (ADN) and 2-methylglutaronitrile (MGN) from adiponitrile waste oil, resulting in the loss of significant amounts of valuable materials. In the solid processing unit of the present invention, a deep extraction device serves as the primary step. Using deep extraction devices such as falling-film evaporators, scraped-plane evaporators, and biaxial self-cleaning mixers, the device can maximize the extraction of ADN and MGN from waste oil, significantly improving the recovery rate of the target products from the raw materials. Compared to existing technologies, this method offers higher extraction efficiency and resource utilization.

[0022] In some embodiments, the low-temperature heat treatment device is any one of a high-shear stirred tank, a spray tower, and a planetary mixer with a distributor.

[0023] The high-viscosity waste residue produced after treatment by the deep extraction device is treated using low-temperature heat treatment equipment such as a high-shear stirred tank, a spray tower, and a planetary mixer with a distributor. The low-temperature environment effectively avoids the decomposition of target products in the waste residue or unnecessary side reactions that may be caused by high temperature, and helps the high-viscosity waste residue become loose, hard and brittle, making it easier to crush and hydrothermally treat the waste residue.

[0024] In some embodiments, the hydrothermal treatment device is a mechanically stirred kettle or a drum reactor.

[0025] The hydrothermal treatment device is a thermochemical conversion device that utilizes a high-temperature and high-pressure hydrothermal environment to convert organic waste into carbon-based materials and other products. The waste residue powder treated by the crushing device is treated by a hydrothermal treatment device such as a mechanical stirring kettle or a drum reactor to form a carbon-containing solid (hydrothermal carbon). The adiponitrile waste residue oil with high viscosity and difficult to package and transport is processed into small-particle carbon balls, making the transportation and treatment of the "three wastes" of the adiponitrile plant simpler.

[0026] In some embodiments, the SCR treatment-drying device includes an SCR treatment device and a drying device connected in sequence.

[0027] The gas phase outlet of the gas-liquid condensation device discharges non-condensable gas, including nitrogen, a small amount of oxygen, ammonia and NO released during the reaction. x Entering the SCR treatment-drying device; the gas phase outlet of the hydrothermal treatment device discharges a small amount of water vapor and NO x This part of the gas also enters the SCR treatment-drying device. The gas discharged from the gas phase outlet of the gas-liquid condensation device and the gas discharged from the gas phase outlet of the hydrothermal treatment device are treated and dehydrated by the SCR treatment-drying device. The remaining nitrogen, a small amount of oxygen and ammonia are recovered by the ammonia recovery device. The remaining harmless exhaust gas is treated by the exhaust gas treatment device and then discharged.

[0028] In some embodiments, the SCR treatment device is an SCR reactor, and the drying device is a dehydration tower.

[0029] In some embodiments, the filtration device is a plate and frame filter press.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: through the solid processing unit, the adiponitrile waste residue oil with high viscosity and difficult packaging and transportation is efficiently converted into small-particle carbon balls with regular morphology and stable properties. The solid carbon balls are convenient for safe storage, standardized packaging and low-cost transportation, which greatly reduces the logistics and management difficulty and cost of the "three wastes"; at the same time, the carbon balls themselves, as resource products, can be used as fuel, adsorbent or especially phosphorus-containing soil improvement landfill agent for high-value utilization, which not only completely eliminates the environmental risks of the original waste residue oil, but also realizes the resource utilization of waste, with outstanding environmental protection and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 The invention shows a system for deep treatment of adiponitrile waste residue oil.

[0033] Figure 2 The present invention is shown by Figure 1 Image of hydrothermal carbon spheres prepared by the deep treatment system of adiponitrile waste oil.

[0034] The above drawings include the following reference numerals:

[0035] 1-deep extraction device; 2-low-temperature heat treatment device; 3-crushing device; 4-hydrothermal treatment device; 5-filtration device; 6-gas-liquid condensation device; 7-SCR treatment-drying device; 8-ammonia recovery device. DETAILED DESCRIPTION

[0036] To facilitate understanding of the present invention, the present invention will be described in more detail below, with preferred embodiments of the present invention provided. However, it should be understood that these embodiments are merely for the purpose of further explanation and are not to be construed as limiting the present invention in any form, i.e., they are not intended to limit the scope of protection of the present invention.

[0037] In the present invention, unless otherwise specified or limited, the term "connection" and other terms should be understood broadly. For example, it can mean fixed connection, detachable connection, or integration; it can mean direct connection or communication, or indirect connection or communication through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0038] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art. The devices used in the following examples, unless otherwise specified, are commercially available devices available to those skilled in the art.

[0039] Example 1

[0040] A deep treatment system for adiponitrile waste oil, such as Figure 1 As shown, it includes a solid processing unit; the solid processing unit includes a deep extraction device 1, a low-temperature heat treatment device 2, a crushing device 3, a hydrothermal treatment device 4 and a filtering device 5 connected in sequence.

[0041] The deep extraction device 1 is provided with a crude nitrile outlet and a high-viscosity waste material outlet, the high-viscosity waste material outlet is connected to the inlet of the low-temperature heat treatment device 2, the low-temperature heat treatment 2 is provided with an oxygen-depleted air inlet and a solid waste material outlet, the solid waste material outlet is connected to the inlet of the crushing device 3, the outlet of the crushing device 3 is connected to the inlet of the hydrothermal treatment device 4, the hydrothermal treatment device 4 is provided with a solid-liquid mixture outlet, the solid-liquid mixture outlet is connected to the inlet of the filtering device 5, and the filtering device 5 is provided with a wastewater outlet and a carbon ball outlet.

[0042] The specific equipment of the deep extraction device 1 is not limited. As a further optional solution, the deep extraction device 1 is one or more of a falling film evaporator, a scraper evaporator, and a double-shaft self-cleaning mixer.

[0043] The specific equipment of the low-temperature heat treatment device 2 is not limited. As a further optional solution, the low-temperature heat treatment device 2 is any one of a high-shear stirring kettle, a spray tower, and a planetary mixer with a distributor.

[0044] The specific equipment of the hydrothermal treatment device 4 is not limited. As a further optional solution, the hydrothermal treatment device 4 is any one of a mechanical stirring kettle and a drum reactor.

[0045] The specific device of the filtering device 5 is not limited. As a further optional solution, the filtering device 5 is a plate and frame filter press.

[0046] Example 2

[0047] Based on the deep treatment system of adiponitrile waste oil described in Example 1, this embodiment further includes a gas processing unit;

[0048] The gas processing unit includes a gas-liquid condenser 6. The gas phase outlet of the low-temperature heat treatment unit 2 is connected to the inlet of the gas-liquid condenser 6, and the condensate outlet of the gas-liquid condenser 6 is connected to the inlet of the deep extraction unit 1. The gas-liquid condenser 6 is provided with a non-condensable gas outlet. The condensate from the gas processing unit, after treatment by the gas-liquid condenser 6, contains a portion of adiponitrile (ADN) and 2-methylglutaronitrile (MGN), which can be fed back to the deep extraction unit 1 of the solid processing unit, achieving resource recycling.

[0049] Example 3

[0050] Based on the deep treatment system of adiponitrile waste oil described in Example 2, the gas treatment unit of this embodiment also includes an SCR treatment-drying device 7 and an ammonia recovery device 8 to achieve efficient removal of nitrogen oxides (NOx) in the tail gas, water removal and recycling of ammonia resources.

[0051] The gas treatment unit is provided with an SCR treatment-drying device 7 and an ammonia recovery device 8 in sequence after the gas-liquid condensing device 6; the non-condensable gas outlet of the gas-liquid condensing device 6 is connected to the inlet of the SCR treatment-drying device 7.

[0052] The gas phase outlet of the hydrothermal treatment device 4 is connected to the inlet of the SCR treatment-drying device 7 .

[0053] It should be noted that the SCR treatment-drying device 7 includes an SCR treatment device and a drying device connected in sequence.

[0054] The specific equipment 7 of the SCR treatment-drying device is not limited. As a further optional solution, the SCR treatment-drying device 7 is an SCR treatment device combined with a dehydration tower.

[0055] Example 4

[0056] A method for deep treatment of adiponitrile waste oil, which is operated by the system described in Example 1, comprises the following steps:

[0057] (1) Deep extraction: The adiponitrile waste oil is fed into a deep extraction device 1 and subjected to deep extraction at a temperature of 171.2° C. and a pressure of 750 Pa for 4 days to deeply extract the unextracted ADN and MGN in the adiponitrile waste oil. The extracted liquid phase is crude nitrile, which is sent back to the adiponitrile factory for refining. The extracted solid phase is a high-viscosity slag.

[0058] (2) Low-temperature heat treatment: The high-viscosity slag after deep extraction enters the low-temperature heat treatment device 2, and oxygen-deficient air containing 4% oxygen is introduced at a gas volume of 20SLM. The high-viscosity slag is treated at 184.4°C for 8 hours. The solid phase after low-temperature heat treatment is solid waste slag; the gas phase after low-temperature heat treatment is input into the gas-liquid condensation device 6. After gas-liquid condensation, the condensate is returned to the deep extraction device 1 for deep extraction.

[0059] (3) Hydrothermal carbonization: The solid waste residue after low-temperature heat treatment becomes a solid block after cooling. At this time, the waste residue oil has turned into black block coke. The solid waste residue is crushed by the crushing device 3 and the waste residue powder is mixed with water at a liquid-solid ratio of 20:1 and enters the hydrothermal treatment device 4. The hydrothermal temperature is 207.8℃, the time is 6.5h, and the stirring rate is 400rpm. The solid-liquid mixture after hydrothermal carbonization is filtered and washed by the filter device 5 to obtain carbon balls.

[0060] Example 5

[0061] A method for deep treatment of adiponitrile waste oil, which is operated by the system described in Example 3, comprises the following steps:

[0062] (1) Deep extraction: The adiponitrile waste oil is fed into a deep extraction device 1 and subjected to deep extraction at a temperature of 186.2° C. and a pressure of 1150 Pa for 5 days to deeply extract the unextracted ADN and MGN in the adiponitrile waste oil. The extracted liquid phase is crude nitrile, which is sent back to the adiponitrile factory for refining. The extracted solid phase is a high-viscosity slag.

[0063] (2) Low-temperature heat treatment: The high-viscosity slag after deep extraction enters the low-temperature heat treatment device 2, and oxygen-deficient air containing 1% oxygen is introduced at a gas volume of 430SLM. The high-viscosity slag is treated at 238.8°C for 3 hours. The solid phase after low-temperature heat treatment is solid waste slag; the gas phase after low-temperature heat treatment is input into the gas-liquid condensation device 6, and after gas-liquid condensation, the condensate is returned to the deep extraction device 1 for deep extraction. The gas phase after low-temperature heat treatment is input into the gas-liquid condensation device 6, and the non-condensable gas after gas-liquid condensation is sequentially sent to the SCR treatment-drying device 7 for selective catalytic reduction and dehydration treatment to remove NO x The reaction temperature of the selective catalytic reduction is 285°C, and the ammonia-nitrogen ratio is 1.33:1.

[0064] (3) Hydrothermal carbonization: The solid waste residue after low-temperature heat treatment is in the form of solid blocks after cooling. At this time, the waste residue oil has turned into black block coke. The solid waste residue is crushed by the crushing device 6. The waste residue powder is mixed with water at a liquid-solid ratio of 82:1 and enters the hydrothermal treatment device 4. The hydrothermal temperature is 217.9 ° C, the time is 4 hours, and the stirring rate is 335 rpm. The gas phase after hydrothermal carbonization is sequentially sent to the SCR treatment-drying device 7 for selective catalytic reduction and dehydration treatment to remove NO x The solid-liquid mixture after hydrothermal carbonization is filtered and washed by the filter device 5 to obtain carbon balls.

[0065] It should be noted that the above is a further detailed description of the present invention in conjunction with specific embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art to which the present invention belongs, simple improvements and modifications can be made without departing from the concept of the present invention, and all of these should be considered to fall within the scope of protection of the present invention.

Claims

1. A deep treatment system for adiponitrile waste oil, characterized in that: including a solids handling unit; The solid processing unit includes a deep extraction device, a low-temperature heat treatment device, a crushing device, a hydrothermal treatment device and a filtering device connected in sequence; The deep extraction device is used to process adiponitrile waste oil to obtain crude nitrile and high-viscosity residue; The low-temperature heat treatment device is used to process the high-viscosity slag to obtain solid waste; The crushing device and the hydrothermal treatment device are used to treat the solid waste residue, and carbon balls are obtained after filtering and washing through the filtering device.

2. The deep treatment system for adiponitrile waste oil according to claim 1, wherein: Also included is a gas processing unit; The gas processing unit includes a gas-liquid condensation device, the gas phase outlet of the low-temperature heat treatment device is connected to the inlet of the gas-liquid condensation device, and the condensate outlet of the gas-liquid condensation device is connected to the inlet of the deep extraction device; the gas-liquid condensation device is provided with a non-condensable gas outlet.

3. The deep treatment system for adiponitrile waste oil according to claim 2, wherein: The gas treatment unit is further provided with an SCR treatment-drying device and an ammonia recovery device in sequence after the gas-liquid condensation device; The non-condensable gas outlet of the gas-liquid condensing device is connected to the inlet of the SCR treatment-drying device.

4. The deep treatment system for adiponitrile waste oil according to claim 3, wherein: The gas phase outlet of the hydrothermal treatment device is connected to the inlet of the SCR treatment-drying device.

5. The deep treatment system for adiponitrile waste residue oil according to claim 1, characterized in that: The deep extraction device is one or more of a falling film evaporator, a scraper evaporator, and a double-shaft self-cleaning mixer.

6. The deep treatment system for adiponitrile waste oil according to claim 1, characterized in that: The low-temperature heat treatment device is any one of a high-shear stirring kettle, a spray tower, and a planetary mixer with a distributor.

7. The deep treatment system for adiponitrile waste oil according to claim 1, characterized in that: The hydrothermal treatment device is a mechanical stirring kettle or a drum-type reactor.

8. The deep treatment system for adiponitrile waste oil according to claim 3, characterized in that: The SCR treatment-drying device includes an SCR treatment device and a drying device connected in sequence.

9. The deep treatment system for adiponitrile waste oil according to claim 8, characterized in that: The SCR treatment device is an SCR reactor, and the drying device is a dehydration tower.

10. The deep treatment system for adiponitrile waste residue oil according to claim 1, characterized in that: The filtering device is a plate and frame filter press.

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