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CN-121971945-A - System and method for recovering multi-component tail gas in oil and plant extraction processing

CN121971945ACN 121971945 ACN121971945 ACN 121971945ACN-121971945-A

Abstract

The invention discloses a recovery system and a recovery method of multi-component tail gas in grease and plant extraction processing, wherein the recovery system comprises at least one working section system, each working section system is provided with a primary section condenser and a middle section freezing recoverer which are sequentially communicated, the recovery system is also provided with a deep section freezer communicated with a tail gas outlet of the middle section freezing recoverer, the working section systems are independently or commonly provided with a deep section freezer, and the tail gas outlet of the deep section freezer is communicated with an absorption tower. The system can treat mixed tail gas with wide temperature range and multiple components, and can maximize recovery efficiency while reducing cost, reduce cost and meet environmental protection requirements. The device can separate the tail gases with different components for cooling and recycling, realizes accurate recycling of mixed tail gases in each working section, has high recycling efficiency, can recycle cold sources by reasonably arranging the heat exchangers, improves the energy circulation utilization rate of the cold sources, ensures that each part can operate efficiently and is beneficial to prolonging the service life of equipment, and the tail gas emission after treatment meets the national standard, thereby reducing environmental pollution.

Inventors

  • BAO HAIJUN
  • KANG HUIYONG
  • YANG ZHEN
  • KONG WEIJUN
  • LI YING
  • Diao Zhengyang

Assignees

  • 营口晨光植物提取设备有限公司

Dates

Publication Date
20260505
Application Date
20260310

Claims (8)

  1. 1. A multi-component tail gas recovery system in oil and plant extraction processing is characterized by comprising at least one working section system, wherein each working section system is provided with a primary section condenser and a middle section freezing recoverer which are sequentially communicated, a deep section freezer communicated with a tail gas outlet of the middle section freezing recoverer is further arranged, the working section systems are independently or commonly used as a deep section freezer, and a tail gas outlet of the deep section freezer is communicated with an absorption tower (22).
  2. 2. The system for recovering oil and fat and multi-component tail gas in plant extraction process according to claim 1, wherein each working section system is provided with a condensed heat exchanger, a heat path of the condensed heat exchanger is communicated between the primary condenser and the middle freezing recoverer, and a cold path of the condensed heat exchanger is communicated between the middle freezing recoverer and the deep freezing recoverer or between the deep freezing recoverer and the absorption tower (22).
  3. 3. The system for recovering oil and fat and multi-component tail gas in plant extraction process as claimed in claim 2, wherein the system is further provided with a heat exchanger between refrigeration, the heat path of the heat exchanger between refrigeration is communicated between the heat exchanger after condensation and the middle-stage refrigeration recoverer, and the heat path of the heat exchanger between the deep-stage refrigeration and the absorption tower (22).
  4. 4. A system for recovering oil and fat and multi-component tail gas in plant extraction processing as claimed in claim 3, wherein the number of the working section systems is at least two, all the working section systems share one deep section refrigerator (2) and one refrigeration heat exchanger (1), the cold path of the condensed heat exchanger in one working section system is communicated between the refrigeration heat exchanger (1) and the absorption tower (22), and the cold path of the condensed heat exchanger in the other working section systems is communicated between the middle section refrigeration recoverer and the deep section refrigerator (2).
  5. 5. The system for recovering oil and fat and multi-component tail gas in plant extraction process according to claim 1, wherein the refrigerant medium adopted by the primary condenser is circulating low-temperature water, the refrigerant medium adopted by the middle-stage freezing recoverer is ethylene glycol, and the refrigerant medium adopted by the deep-stage freezer is Freon.
  6. 6. The system for recovering oil and fat and multi-component tail gas in plant extraction process according to claim 1-5, wherein the working section system is further provided with a fixed pretreatment unit, and the fixed pretreatment unit comprises a vacuum balance tank, a vacuum pump and/or a buffer tank.
  7. 7. A method for recovering multi-component tail gas in oil and plant extraction processing, which adopts the recovery system of any one of claims 1-5, is characterized in that the tail gas is condensed by a primary condenser, is subjected to middle-stage cooling by a middle-stage freezing recoverer, is used for recovering liquid obtained by middle-stage cooling, is subjected to deep-stage cooling by a deep-stage freezer, is used for recovering liquid obtained by deep-stage cooling, and is finally absorbed by an absorption tower (22) and is discharged.
  8. 8. The method for recycling the multi-component tail gas in the oil and plant extraction processing of claim 7, wherein the temperature adjustment range of the outlet of the primary condenser is 90-20 ℃, the temperature adjustment range of the outlet of the middle freezing recycling device is 20-20 ℃, and the temperature adjustment range of the outlet of the deep freezing device is-20-40 ℃.

Description

System and method for recovering multi-component tail gas in oil and plant extraction processing Technical Field The invention relates to the technical field of industrial tail gas recovery, in particular to a system and a method for recovering multi-component tail gas in oil and plant extraction processing. Background In industrial grease production and the like, complex tail gas is produced in a plurality of links, and the complex tail gas contains various solvents, steam, polar and nonpolar substances. 1. And (3) analyzing sources and components of tail gas generated in oil processing: In the process of oil processing and plant extraction (such as turmeric extraction), tail gas is mainly generated in the following links: Extracting the effective components by using organic solvents such as ethyl acetate, n-hexane and the like, and volatilizing the residual solvents to form mixed steam; a desolventizing section, namely generating tail gas containing acetone and acid-base substances when the solvent is removed at high temperature; Refining section, namely volatile nonpolar substances such as free fatty acid, glyceride and the like in the deodorization process. The tail gas has complex components and large difference of melting boiling points, and comprises the following main components: a. solvent vapors ethyl acetate (boiling point 77.1 ℃), n-hexane (69 ℃) acetone (56 ℃); b. polar/non-polar materials, acidic volatiles, unsaturated fatty acids, water vapor, and the like. 2. The existing tail gas treatment method and limitation are as follows: And the condensing method is to condense the steam and volatile matters in the tail gas into liquid by reducing the temperature of the tail gas for recovery. The method has the advantages that the purity of the recovered substances is higher, and the recovered substances can be directly recycled. The defects are that for multi-component tail gas with larger boiling point difference, the single condensation temperature is difficult to realize high-efficiency recovery, and the energy consumption is higher. The active carbon adsorption method is to adsorb harmful matters in the tail gas with adsorbent, such as active carbon, etc. The method has the advantages of high adsorption efficiency and capability of recycling some valuable substances. The disadvantage is that the adsorbent is easily saturated and needs to be regenerated or replaced periodically, and secondary pollution may be generated in the regeneration process. The membrane separation method is suitable for specific components, but has poor adaptability to multi-component mixed gas. The water washing/acid-base absorption method is to generate secondary wastewater, thereby increasing the treatment difficulty. The absorption method is that the harmful substances in the tail gas are absorbed by introducing the tail gas into the absorbent. Has the advantages of simple operation and capability of treating various tail gas components. Disadvantages are that the absorbent needs to be replaced periodically, the treatment cost is high, and the absorption efficiency may be affected by the kind and concentration of the absorbent. Disclosure of Invention The invention aims to solve the technical problems of providing a high-recovery-efficiency oil and multi-component tail gas recovery system in plant extraction processing, and a recovery method of the oil and multi-component tail gas in plant extraction processing. The technical scheme includes that the system comprises at least one working section system, a primary section condenser and a middle section freezing recoverer which are sequentially communicated, a deep section freezer which is communicated with a tail gas outlet of the middle section freezing recoverer, and a deep section freezer which is independently or commonly used by the working section system, wherein the tail gas outlet of the deep section freezer is communicated with an absorption tower. Further, each working section system is provided with a condensed heat exchanger, a heat path of the condensed heat exchanger is communicated between the primary condenser and the middle freezing recoverer, and a cold path of the condensed heat exchanger is communicated between the middle freezing recoverer and the deep freezing recoverer or between the deep freezing recoverer and the absorption tower. The refrigeration system is characterized by further comprising a refrigeration heat exchanger, wherein a heat path of the refrigeration heat exchanger is communicated between the condensed heat exchanger and the middle-section refrigeration recoverer, and the heat path of the refrigeration heat exchanger is communicated between the deep-section refrigerator and the absorption tower. Furthermore, the two working section systems are at least two, all working section systems share one deep section refrigerator and one freezing heat exchanger, the cold path of the condensed heat exchanger in one working section system is c