CN109999616A - A kind of tail gas absorbing system and technique in oil extraction workshop - Google Patents

Abstract

The invention discloses a tail gas absorption system and a process for a grease leaching workshop. The tail gas absorption system includes a tail gas pretreatment unit, which filters out particles and water mist in the tail gas; a paraffin oil absorption unit; The activated carbon adsorption tower connected to the exhaust end of the tower, and the desorption component capable of desorbing the solvent of the activated carbon adsorption tower. There are at least two activated carbon adsorption towers, and they are divided into two groups, one group is the working group, and the other group is the The standby group, when the working group is in the adsorption saturation state, the standby group is connected with the paraffin oil absorption tower, and the desorption component automatically desorbs the working group in the saturated state. The invention can not only realize the recovery rate of 95%-99.9% of the solvent in the tail gas, but also control the solvent concentration in the gas to be 0.08-0.1g/m ³ when emptying, which conforms to GB16297-1996 "Comprehensive Emission Standard of Air Pollutants" , Simple operation and low cost.

Description

A kind of tail gas absorption system and process for oil leaching workshop

technical field

The invention relates to a tail gas absorption system used in a grease leaching workshop, and also relates to a tail gas absorption process used in a grease leaching workshop.

Background technique

In the production process of the edible oil leaching workshop, the leached oil is the pre-pressed cake of the oil, the green body of the oil or the puffed particles of the oil. Since these oils have a certain porosity, a certain amount of oil must always be brought into the leaching system. Air; direct steam is injected into the mixed oil stripping and wet meal desolvation, and a part of the air is also brought into the leaching system; and due to the poor sealing of various equipment, especially the negative pressure evaporation process, a small amount of air also enters . These air and solvent contact, there are volatile solvent gas molecules, such gas molecules saturate the air to form solvent-containing air, this gas is called free gas, also known as tail gas, the gas is treated or recovered. The device is called an exhaust gas absorption system.

Since this part of the gas cannot be condensed by the condenser, long-term accumulation will increase the pressure in the container. If it is not discharged in time, it will affect the smooth progress of production and even cause dangerous accidents. At the same time, this part of the gas is mixed with a large amount of solvent. If it is directly discharged, it will not only increase the dissolution consumption, increase the cost, but also pollute the environment. Therefore, the solvent must be recovered before the exhaust gas is emptied.

From the above knowledge, there is always a certain amount of solvent vapor in the air discharged from each equipment in the grease leaching workshop. The content of solvent vapor in the own gas depends on the composition of the solvent fraction and on the temperature of the condenser.

Usually the solvent in this free gas is recovered in the recovery unit, the tail gas absorption system. At present, the absorption methods at home and abroad are as follows: using refrigerant freezing recovery method; using paraffin oil or vegetable oil absorption recovery method (liquid absorption); using activated carbon adsorption recovery method (solid adsorption). The selection of these methods is limited, depending on the concentration of the solvent vapor in its mixed gas with air, when the freezing method recovery is applied to the concentration of 170-250g/m3; the recovery of paraffin oil or vegetable oil is applied to the concentration of 140-170g/m3; When activated carbon recovery is used in a concentration of 50-140g/m3, if the solvent concentration exceeds these ranges, the effect of absorbing the solvent will be greatly reduced. In general, the absorption and recovery method of paraffin oil is the most used.

Specifically, the refrigerant freezing recovery method is divided into two types: low temperature water cooling recovery and refrigerant freezing recovery. Low-temperature water uses groundwater with a temperature of 7 to 15 °C, and is not recycled. This method has a low solvent recovery rate and a large amount of groundwater is used, so it will not be used in newly built or renovated oil processing plants. Refrigerants mainly use refrigerants with a cooling temperature of -20 to -10 °C. Commonly used ones are ammonia and freon, which have the risk of contaminating edible oil and are not conducive to environmental protection. The control during operation is very troublesome, and free gas can be recovered at most. 60% of the solvent contained in it, the effect is not ideal.

As for the liquid absorption method, paraffin oil is used as the absorbent, and the equipment used is an absorption tower and a desorption tower. As a result, the solvent recovery rate is low. In this way, the solvent consumption of the edible oil leaching workshop is controlled between 1.5 and 2.5 kg/(t raw material), which cannot be further reduced. Comprehensive Pollutant Emission Standard", in today's fierce market competition, which has caused great cost pressure and environmental protection pressure on oil processing enterprises.

For the activated carbon adsorption recovery method, it has a good recovery effect, but it has three problems, namely, the generation of adsorption heat and heat of desorption, the accumulation of solvent gas reaches the explosion limit, and the operation of activated carbon adsorption and regeneration is intermittent. Its application is greatly limited due to the above-mentioned troublesome and unsafe factors, and it is rarely used in industry now. (The adsorption heat of activated carbon is quite large, about 347~695J of heat will be generated for every 1g of solvent adsorbed. If this heat is not removed, it will accumulate on the activated carbon bed, causing the temperature to rise quickly, and it will cause spontaneous combustion in the presence of air. In addition, When the free gas enters the activated carbon bed, its composition changes continuously and inevitably reaches the explosion limit. Therefore, although the adsorption effect of activated carbon is very good, there are problems of local overheating and explosion limit.)

In summary, the three absorption methods currently used at home and abroad all have serious defects. In order to avoid troubles and even accidents caused by these defects in the production process, a large number of supporting equipment must be equipped for control, and special positions must be allocated. It is necessary to design a special equipment platform for it in the leaching workshop, etc., so there are technical problems and problems in terms of investment, production cost, absorption effect, environmental protection, food safety, etc. defect.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an improved tail gas absorption system for grease leaching workshops.

At the same time, the invention also relates to a tail gas absorption process used in a grease leaching workshop.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

A tail gas absorption system used in a grease leaching workshop, comprising:

The paraffin oil absorption unit includes a paraffin oil absorption tower, a desorption tower, a first condenser, and a first solvent reclaimer communicated with the exhaust end of the grease leaching workshop, wherein the desorption tower can absorb the paraffin oil in the paraffin oil in the tower. The contained solvent is resolved, the first condenser liquefies the gas resolved by the analysis tower, and the first solvent recoverer separates and recovers the liquefied solvent and paraffin oil;

A tail gas pretreatment unit, which is arranged between the paraffin oil absorption tower and the exhaust end of the grease leaching workshop and can filter out particles and water mist in the tail gas;

The activated carbon adsorption unit includes an activated carbon adsorption tower communicating with the exhaust end of the paraffin oil absorption tower, and a desorption component capable of desorbing the solvent from the activated carbon adsorption tower, wherein the activated carbon adsorption tower has at least two and is divided into two parts. When the working group is in the adsorption saturation state, the standby group is connected with the paraffin oil absorption tower, and the desorption component automatically desorbs the working group in the saturated state.

Preferably, there are two activated carbon adsorption towers, one is a working group and the other is a standby group; the tail gas absorption system also includes a three-way valve I for connecting the two activated carbon adsorption towers with the exhaust end of the paraffin oil absorption tower, When adsorbing, the three-way valve I connects one of the two activated carbon adsorption towers with the paraffin oil absorption tower; when one activated carbon adsorption tower is in a saturated state, the activated carbon adsorption tower in the saturated state stops feeding and is discharged from the paraffin oil absorption tower The three-way valve I switches to connect the other activated carbon adsorption tower with the paraffin oil adsorption tower.

According to a specific implementation and preferred aspect of the present invention, the desorption assembly includes a monitor arranged in the exhaust gas channel of each activated carbon adsorption tower and used for monitoring the flow rate of the exhaust gas, communicated with the monitor and capable of desorbing the activated carbon adsorption tower The attached desorption mechanism, and the PLC controller communicated with the monitor and the desorption mechanism, wherein the monitor has a setting module, and when the monitored value is less than or equal to the value set by the setting module, the PLC controller drives the tee Valve I is switched, and the desorption mechanism desorbs the activated carbon adsorption tower in a saturated state.

Here, the applicant explains the "set value". It is understood that the "flow safety value" of the activated carbon adsorption tower in a saturated state. As long as it is equal to or exceeds the limit, the exhaust gas supply will be stopped immediately and desorption will be carried out.

Preferably, the desorption mechanism includes a three-way valve II arranged on the gas pipeline, a direct steam heating component communicated with the three-way valve II, a second condenser communicated with each activated carbon adsorption tower, and communicated with the second condenser. The second solvent recoverer, and auxiliary components capable of drying and cooling the activated carbon adsorbent of the activated carbon adsorption tower to restore the adsorption capacity of the activated carbon adsorbent.

According to another specific implementation and preferred aspect of the present invention, each activated carbon adsorption tower also has a solvent recovery channel, the solvent recovery channel is communicated with the second condenser, and the exhaust gas channel and the solvent recovery channel are respectively provided with a first solvent recovery channel A control valve and a second control valve, wherein when the activated carbon adsorption tower is in the adsorption state, the first control valve is opened and the second control valve is closed; when it is in the desorption state, the second control valve is opened and the first control valve is closed.

Preferably, the auxiliary components include an exchanger capable of adding a hot or cold medium, a first fan for feeding the gas heated or cooled by the exchanger into the activated carbon adsorption tower to be desorbed.

Specifically, the heating medium is steam, and the cooling medium is cooling water.

Preferably, the activated carbon adsorption unit further includes a second fan arranged on the communication pipeline between the activated carbon adsorption tower and the paraffin oil absorption tower.

Preferably, the exhaust gas pretreatment unit includes a filter including a filter assembly.

In addition, the exhaust gas absorption system also includes a flame arrester, a check valve, an explosion vent, and a nitrogen safety protection unit communicated with the paraffin oil absorption unit and the activated carbon adsorption unit.

Another technical scheme of the present invention is: a kind of tail gas absorption process used in the grease leaching workshop, the process adopts the above-mentioned tail gas absorption system used in the grease leaching workshop, and the steps are as follows:

1) The tail gas discharged from the grease leaching workshop is filtered by the tail gas pretreatment unit to filter out the particles and water mist in the tail gas, and leads to the paraffin oil absorption unit;

2) The treated tail gas is absorbed by the paraffin oil absorption unit, and the solvent is recovered through the analytical tower, the first condenser, and the first solvent recovery device, and the discharged gas is directed to the activated carbon adsorption unit;

3) The exhaust gas adsorption treatment is carried out by the working group of the activated carbon adsorption unit. The treated exhaust gas is discharged from the working group of the activated carbon adsorption unit. When the working group is in the adsorption saturation state, the exhaust gas discharged from the paraffin oil absorption unit is discharged. The gas enters the standby group for adsorption treatment, and at the same time, the desorption component automatically desorbs the activated carbon adsorption tower under the adsorption saturation state, and recovers the solvent after desorption. At the same time, the desorbed activated carbon adsorbs The towers form the spare group.

Preferably, the desorption process is as follows:

a), adopt direct steam to pass into the activated carbon adsorption tower, and the solvent on the activated carbon adsorbent is brought out of the activated carbon adsorption tower by steam, and then liquefies to realize the recovery of the solvent;

b) Pass heated hot air into the activated carbon adsorption tower to dry the activated carbon adsorbent quickly;

c), pass the cooled cold air into the activated carbon adsorption tower, so that the activated carbon adsorbent is rapidly cooled to restore the adsorption capacity of the activated carbon adsorbent.

That is to say, the activated carbon adsorption unit process in this example is divided into four processes: adsorption, evaporation, drying, and cooling. When the exhaust gas passes through the activated carbon layer, the solvent is adsorbed, and the exhaust gas can reach the standard at this time (GB16297-1996 "Integrated Air Pollutants"). Emission Standard") is discharged into the atmosphere, when the adsorption capacity of the activated carbon in the adsorption tower is reduced to a certain level, the exhaust gas flow is converted into another adsorption tower, and the activated carbon saturated with the solvent can be heated by direct steam and heated by water. The steam takes away the solvent in the adsorbent and condenses in the second condenser, and then the solvent is recovered by the second solvent recovery device. In this way, a recovery rate of 95% to 99.9% can be achieved.

At the same time, in order to restore the adsorption capacity of the activated carbon after passing the steam, the steam added by the exchanger dries the air, and then the hot air is introduced into the adsorption tower by the first fan to dry the activated carbon; Into the cooling water, the air is cooled by the exchanger, and then the first fan guides the cold air to the activated carbon, in order to restore the adsorption capacity of the activated carbon, so that the adsorption tower can complete the desorption, so that the two adsorption towers can be used alternately.

Due to the implementation of the above technical solutions, the present invention has the following advantages compared with the prior art:

The invention can not only realize the recovery rate of 95%-99.9% of the solvent in the tail gas, but also control the solvent concentration in the gas to be 0.08-0.1g/m ³ when emptying, which conforms to GB16297-1996 "Comprehensive Emission Standard of Air Pollutants" , At the same time, the operation is simple and the cost is greatly reduced.

Description of drawings

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Fig. 1 is the structural schematic diagram of the exhaust gas absorption system of the present invention (the dotted line in the figure represents the direction of the exhaust gas);

Among them: 1. Exhaust gas pretreatment unit; 10. Filter;

2, paraffin oil absorption unit; 20, paraffin oil absorption tower; 21, analysis tower; 22, first condenser; 23, first solvent recovery device;

3. Activated carbon adsorption unit; 30, activated carbon adsorption tower; 30a, exhaust gas channel; 30b, solvent recovery channel; 31, desorption component; 310, monitor; 311, desorption mechanism; a, three-way valve II; b, Direct steam heating part; c, second condenser; d, second solvent recovery device; e, auxiliary part; e1, exchanger; e2, first fan; f1, first control valve; f2, second control valve; 32. The second fan;

4. Three-way valve I;

X. Oil leaching workshop.

Detailed ways

In order to make the above objects, features and advantages of the present application more clearly understood, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Back, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the application and simplifying the description, rather than indicating or implying the indicated device or Elements must have a particular orientation, be constructed and operate in a particular orientation and are therefore not to be construed as limitations on this application.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless expressly and specifically defined otherwise.

In this application, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In this application, unless otherwise expressly stated and defined, a first feature "on" or "under" a second feature may be in direct contact with the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature. It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or an intervening element may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Referring to FIG. 1 , the tail gas absorption system for a grease leaching workshop according to this embodiment includes a tail gas pretreatment unit 1 , a paraffin oil absorption unit 2 and an activated carbon adsorption unit 3 .

Specifically, the paraffin oil absorption unit 2 includes a paraffin oil absorption tower 20, a desorption tower 21, a first condenser 22, and a first solvent recoverer 23 that are communicated with the exhaust end of the grease leaching workshop X, wherein the desorption tower 21 The solvent contained in the paraffin oil absorption tower 20 is decomposed, the first condenser 22 liquefies the decomposed gas in the desorption tower 21, and the first solvent recovery device 23 separates and recovers the liquefied solvent from the paraffin oil.

As for the paraffin oil absorption tower 20 , the desorption tower 21 , the first condenser 22 , and the first solvent recoverer 23 , they are commonly used equipment in the art, and will not be described one by one here.

The tail gas pretreatment unit 1 is arranged between the paraffin oil absorption tower 20 and the exhaust end of the grease leaching workshop X and can filter out particles and water mist in the tail gas; it mainly includes a filter 10 containing a filter assembly, that is It is said that as long as the particles and water mist in the exhaust gas can be removed, it is also a common equipment in the field, and will not be described in detail here.

The activated carbon adsorption unit 3 includes an activated carbon adsorption tower 30 communicated with the exhaust end of the paraffin oil absorption tower 20, and a desorption assembly 31 capable of desorbing the solvent from the activated carbon adsorption tower 30, wherein there are two activated carbon adsorption towers 30, And divided into two groups, one is the working group and the other is the standby group. When the working group is in the adsorption saturation state, the standby group is communicated with the paraffin oil absorption tower 20, and the desorption component 31 automatically desorbs the working group in the saturated state. attached.

The tail gas absorption system also includes a three-way valve I4 for connecting the two activated carbon adsorption towers 30 with the exhaust ends of the paraffin oil absorption tower 20. When adsorbing, the three-way valve I4 connects one of the two activated carbon adsorption towers 30. Connected with the paraffin oil absorption tower 20; when one activated carbon adsorption tower 30 is in a saturated state, the activated carbon adsorption tower 30 in the saturated state stops feeding the gas discharged from the paraffin oil absorption tower 20, and the three-way valve I4 is switched to adsorb another activated carbon. The tower 30 communicates with the paraffin oil absorption tower 20 .

The desorption assembly 31 includes a monitor 310 arranged in the exhaust gas channel 30a of each activated carbon adsorption tower 30 and used for monitoring the flow rate of the exhaust gas, and a desorption mechanism communicated with the monitor 310 and capable of desorbing the activated carbon adsorption tower 30 311, and a PLC controller (not shown in the figure, but not difficult to imagine) communicated with the monitor 310 and the desorption mechanism 311, wherein the monitor 310 has a setting module, when the monitored value is less than or equal to the setting module When the value is fixed, the PLC controller drives the three-way valve I4 to switch, and the desorption mechanism 311 desorbs the activated carbon adsorption tower 30 in a saturated state.

Here, the applicant explains the "set value". It is understood that the "flow safety value" of the activated carbon adsorption tower in a saturated state. As long as it is equal to or exceeds the limit, the exhaust gas supply will be stopped immediately and desorption will be carried out.

The desorption mechanism 311 includes a three-way valve IIa arranged on the gas pipeline, a direct steam heating component b communicated with the three-way valve IIa, a second condenser c communicated with each activated carbon adsorption tower 30, and a second condenser c communicated with a second solvent recovery device d, and an auxiliary component e capable of drying and cooling the activated carbon adsorbent of the activated carbon adsorption tower 30 to restore the adsorption capacity of the activated carbon adsorbent.

In this example, each activated carbon adsorption tower 30 also has a solvent recovery channel 30b, the solvent recovery channel 30b is communicated with the second condenser c, and the exhaust gas channel 30a and the solvent recovery channel 30b are respectively provided with a first control valve f1 and the second control valve f2, wherein when the activated carbon adsorption tower 30 is in the adsorption state, the first control valve f1 is opened, and the second control valve f2 is closed; when it is in the desorption state, the second control valve f2 is opened, and the first control valve f1 is closed.

The auxiliary component e includes an exchanger e1 capable of adding hot or cold medium, and a first fan e2 for feeding the gas (air) heated or cooled by the exchanger e1 into the activated carbon adsorption tower 30 to be desorbed.

Specifically, the heating medium is steam, and the cooling medium is cooling water.

In this example, activated carbon adsorption unit 3 has four processes: adsorption, evaporation, drying, and cooling. When the exhaust gas passes through the activated carbon layer, the solvent is adsorbed, and the exhaust gas can reach the standard at this time (GB16297-1996 "Comprehensive Emission Standard of Air Pollutants" ) into the atmosphere, when the adsorption capacity of the activated carbon in the adsorption tower is reduced to a certain level, the tail gas flow is converted into another adsorption tower, and the activated carbon saturated by the solvent can be heated by direct steam and taken away by water vapor The solvent in the adsorbent is condensed in the second condenser, and then the solvent is recovered by the second solvent recovery device. In this way, a recovery rate of 95% to 99.9% can be achieved.

In addition, the activated carbon adsorption unit 3 further includes a second fan 32 arranged on the communication pipeline between the activated carbon adsorption tower 30 and the paraffin oil absorption tower 20 .

At the same time, the exhaust gas absorption system in this example also includes a flame arrester, a check valve, an explosion vent, and a nitrogen safety protection unit communicated with the paraffin oil absorption unit and the activated carbon adsorption unit.

In this example, the flame arrester, check valve, explosion vent, and nitrogen safety protection device are all connected to the PLC controller, and the ultimate purpose is to form a complete safety control system (although these are not shown in the figure, but for the field For personnel, it is very commonly used and will not be elaborated here).

To sum up, this embodiment can not only achieve a recovery rate of 95% to 99.9% for the solvent in the exhaust gas, but also control the solvent concentration in the gas to be 0.08 to 0.1 g/m ³ during emptying, which is in line with GB16297-1996 "Atmosphere". Integrated Pollutant Emission Standard", at the same time, it is simple to operate and greatly reduces the cost.

Meanwhile, the implementation process of this embodiment is as follows:

1) The tail gas discharged from the grease leaching workshop is filtered by the tail gas pretreatment unit to filter out the particles and water mist in the tail gas, and leads to the paraffin oil absorption unit;

2), the treated tail gas is absorbed by the paraffin oil absorption unit, and the recovery of the solvent is realized through the analytical tower, the first condenser, and the first solvent recovery device, and the discharged gas is directed to the activated carbon adsorption unit, wherein The content of solvent in the discharged gas accounts for 10%~20%;

3) The exhaust gas adsorption treatment is carried out by the working group of the activated carbon adsorption unit, and the treated exhaust gas is discharged from the working group of the activated carbon adsorption unit, and the solvent content in the discharged gas accounts for 0.1%~5%. When the adsorption is saturated, the gas discharged from the paraffin oil absorption unit enters the standby group for adsorption treatment. At the same time, the desorption component automatically desorbs the solvent from the activated carbon adsorption tower in the adsorption saturation state, and recovers the solvent after desorption. The attached activated carbon adsorption tower forms a spare group, which can be used alternately and circularly to achieve continuous exhaust gas absorption.

Meanwhile, the above-mentioned desorption process is as follows:

a), adopt direct steam to pass into the activated carbon adsorption tower, and the solvent on the activated carbon adsorbent is brought out of the activated carbon adsorption tower by steam, and then liquefies to realize the recovery of the solvent;

b) Pass heated hot air into the activated carbon adsorption tower to dry the activated carbon adsorbent quickly;

c), pass the cooled cold air into the activated carbon adsorption tower, so that the activated carbon adsorbent is rapidly cooled to restore the adsorption capacity of the activated carbon adsorbent.

The present invention has been described in detail above, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it, and cannot limit the scope of protection of the present invention by this, and the present invention is not limited to the above-mentioned embodiments, All equivalent changes or modifications made according to the spirit of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. a kind of tail gas absorbing system in oil extraction workshop comprising:

Paraffin oil absorptive unit comprising paraffin oil-absorption tower, the Analytic Tower, first being connected to oil extraction workshop exhaust end Condenser and the first solvent recycler, wherein the Analytic Tower can be by institute in paraffin oil in the paraffin oil-absorption tower The solvent analysis contained comes out, first condenser Analytic Tower is parsed after gas liquefaction, described first is molten Solvent after liquefaction is separated and recovered from by agent recover with paraffin oil；

It is characterized by: the tail gas absorbing system further includes that the paraffin oil-absorption tower and the oil extraction is arranged in Tail gas pretreatment unit, the activated carbon adsorption list that is connected to the paraffin oil-absorption tower exhaust end portion between the exhaust end of workshop Member, wherein the tail gas pretreatment unit can filter out particle in tail gas and water mist, the activated carbon adsorption unit packet Include the activated carbon adsorber being connected to the exhaust end of the paraffin oil-absorption tower, can to the activated carbon adsorber carry out it is molten The desorption component of agent desorption, wherein the activated carbon adsorber at least there are two, and be divided into two groups, one group is working group, another Group is spare group, and when the working group is in adsorption saturation state, described spare group is connected to the paraffin oil-absorption tower, The desorption component is automatically desorbed the working group under in a saturated state.

2. the tail gas absorbing system in oil extraction workshop according to claim 1, it is characterised in that: the active carbon is inhaled There are two attached towers, and one is the working group, and one is described spare group；The tail gas absorbing system further includes for by two The triple valve I that a activated carbon adsorber is connected with the paraffin oil-absorption tower exhaust end portion, when absorption, described three An activated carbon adsorber in two is connected to by port valve I with the paraffin oil-absorption tower；The active carbon described in one When adsorption tower adsorption saturation state, activated carbon adsorber stopping in a saturated state being passed through from the paraffin oil-absorption tower Another described activated carbon adsorber is connected to by the gas of discharge, the switching of triple valve I with the paraffin oil-absorption tower.

3. the tail gas absorbing system in oil extraction workshop according to claim 2, it is characterised in that: the desorption group Part include be arranged in row's exhaust gas channel of each activated carbon adsorber and for monitor be discharged exhaust flow monitor, Be connected to the monitor and can to the desorption mechanism that the activated carbon adsorber is desorbed and with the monitor With the PLC controller that is connected of the desorption mechanism, wherein the monitor has setting module, be less than when institute's monitor value or When equal to definite value set by the setting module, the PLC controller drives the triple valve I to switch, and the desorption The activated carbon adsorber in a saturated state is desorbed in mechanism.

4. the tail gas absorbing system in oil extraction workshop according to claim 3, it is characterised in that: the desorption machine Structure include the triple valve II being arranged on gas piping, the direct steam heating component being connected to the triple valve II, with it is each The second condenser that the activated carbon adsorber is connected, the second solvent recycler being connected to second condenser and The acticarbon of the activated carbon adsorber can be dried and be cooled down with the adsorption energy of activity recovery carbon adsorbent The accessory of power.

5. the tail gas absorbing system in oil extraction workshop according to claim 4, it is characterised in that: each activity Charcoal adsorption tower also has a solvent recovery channel, and the solvent recovery channel is connected with second condenser, and It is respectively equipped with the first control valve and the second control valve on row's exhaust gas channel and the solvent recovery channel, wherein when the work Property charcoal adsorption tower when being in adsorbed state, first control valve is opened, the second control valve closure；When in desorption When, second control valve is opened, the first control valve closure.

6. the tail gas absorbing system in oil extraction workshop according to claim 4, it is characterised in that: the assisted parts Part includes that hot or cold medium exchanger, the gas for the exchanger to be heated or cooled can be added to be sent into de- The first blower in the attached activated carbon adsorber, wherein the thermal medium is steam, the cold medium is cooling water.

7. the tail gas absorbing system in oil extraction workshop according to claim 1, it is characterised in that: the active carbon Absorbing unit further includes the second blower being arranged on the activated carbon adsorber and the paraffin oil-absorption tower connecting pipe.

8. the tail gas absorbing system in oil extraction workshop according to claim 1, it is characterised in that: the tail gas is located in advance Managing unit includes the filter containing filter assemblies；The tail gas absorbing system further include fire arrester, non-return valve, venting of dust explosion mouth, And the nitrogen security protection unit being connected with the paraffin oil absorptive unit and the activated carbon adsorption unit.

9. a kind of tail gas absorption technology in oil extraction workshop, it is characterised in that: the process employs in claim 1 to 8 The tail gas absorbing system in oil extraction workshop described in any one claim, its step are as follows:

1), the tail gas of oil extraction workshop discharge is filtered out particle in tail gas and water mist by the tail gas pretreatment unit, and is led to To the paraffin oil absorptive unit；

2), by the paraffin oil absorptive unit, to treated, tail gas absorbs, and passes through the Analytic Tower, the first condensation Device and the first solvent recycler realize the recycling of solvent, while the gas being discharged is directed to the activated carbon adsorption unit；

3) tail gas adsorption processing, is carried out by the working group of the activated carbon adsorption unit, treated tail gas is from the active carbon The working group of absorbing unit is discharged, when working group is in adsorption saturation state, from the gas of paraffin oil absorptive unit discharge Body enters spare group of carry out adsorption treatment, while the desorption component automatically inhales the active carbon under adsorption saturation state Attached tower carries out solvent desorbing, and after being desorbed solvent recycling, while the activated carbon adsorber after being desorbed formed it is described Spare group.

10. the tail gas absorption technology in oil extraction workshop according to claim 9, it is characterised in that: the desorption Process is as follows:

A), it is passed through in activated carbon adsorber using direct steam, takes the solvent on acticarbon out of active carbon by steam Then adsorption tower liquefies, to realize the recycling of solvent；

B), the hot-air after being passed through heating into activated carbon adsorber, so that acticarbon rapid draing；

C), cold air after cooling is passed through into activated carbon adsorber, so that acticarbon is quickly cooled down, with activity recovery The adsorption capacity of carbon adsorbent.