CN110577850A

CN110577850A - method for preparing bio-oil by performing subcritical/supercritical liquefaction treatment on chicken manure

Info

Publication number: CN110577850A
Application number: CN201910865856.8A
Authority: CN
Inventors: 肖智华; 刘壮壮; 方俊; 栾辉
Original assignee: Hunan Agricultural University
Current assignee: Hunan Agricultural University
Priority date: 2019-09-09
Filing date: 2019-09-09
Publication date: 2019-12-17
Anticipated expiration: 2039-09-09
Also published as: CN110577850B

Abstract

The invention provides a method for preparing bio-oil by performing subcritical/supercritical liquefaction treatment on chicken manure, which comprises the following steps: a. drying fresh chicken manure, crushing and sieving to obtain a powdery mixed material; b. sub/supercritical liquefaction: adding the powdery mixed material and a liquefied solvent into a reaction kettle according to a solid-liquid ratio of 0.05-0.150 g/mL and a solvent filling rate of 10-30%; setting the pressure of a reaction kettle to be 10-15 MPa and the liquefaction temperature to be 220-300 ℃; heating the reaction kettle, keeping the reaction kettle at the preset liquefaction temperature for 30-60 min, stopping heating after the reaction is finished, and cooling to room temperature; c. solid-liquid separation; d. and putting the liquefied product into a rotary evaporator to prepare the bio-oil. According to the invention, the biological oil is prepared by performing sub/supercritical liquefaction treatment on the chicken manure, so that harmless and recycling treatment of the chicken manure can be realized.

Description

method for preparing bio-oil by performing subcritical/supercritical liquefaction treatment on chicken manure

Technical Field

the invention relates to the technical field of livestock and poultry manure treatment, in particular to a method for preparing bio-oil by sub/supercritical liquefaction treatment.

Background

As an important component of the third industry, the breeding industry gradually realizes modernization of production scale and production mode along with the development of economy. The development of the chicken industry is not only increasing in quantity, but also the breeding scale is getting bigger, but the problem of the treatment of the chicken manure is also the key point and the problem to be solved in the chicken industry.

A related survey shows that 1 chicken farm with about 10 ten thousand chickens produces up to 10t of chicken manure per day, and therefore about 3600t of chicken manure is produced in 1 year in the chicken farm. If the huge chicken manure is not treated according to a scientific treatment mode, the nutrient in the chicken manure is lost, and ammonia gas is generated when the chicken manure is not treated properly. Hydrogen sulfide and methane, which further harm the health of the breeders and the surrounding residents. In order to improve the safety coefficient of chicken manure treatment and comply with the requirements of the era of sustainable development and ecological balance protection, the harmless treatment of the chicken manure and the effective utilization of nutrients in the chicken manure are realized by advanced scientific technology, so that the healthy and sustainable development of the breeding industry is promoted.

The biomass liquefaction is a process of generating biomass oil by complex thermochemical reaction of biomass and a liquid medium under the conditions of high temperature and high pressure, and the biomass liquefaction technology is a biomass thermochemical treatment technology which is developed rapidly in recent years and can be widely applied to the fields of automobiles, power generation, engineering machinery and the like as internal combustion engine fuel, and the biomass liquefaction technology comprises two aspects of thermal cracking and direct liquefaction. As for the thermal cracking technology, extensive and intensive research is carried out at home and abroad, and various types of biomass thermal cracking devices are also designed. But the oil bath thermal cracking conditions are harsh, the heating rate is high, and the reaction residence time is short. Compared with thermal cracking, the conditions of direct liquefaction technology are relatively mild, and therefore, in recent years, the conditions become hot spots of biomass liquefaction technology.

because the biomass liquefaction is to degrade macromolecular substances in the biomass into small molecular fragments with high reactivity and instability under certain conditions, and the small molecules with instability and high activity can be polymerized again to form liquid oily compounds with relatively large molecular mass, the chicken manure can be converted into bio-oil products under certain conditions by using a biomass liquefaction technology. Compared with the chicken manure pyrolysis treatment, the direct biomass liquefaction treatment process is generally carried out under high pressure, and the biomass raw material can be directly liquefied without being dried. Just because the biomass can be converted into high-quality liquid fuel under certain conditions by using a biomass direct liquefaction technology, the liquid fuel is also a chemical product with certain value after being analyzed by a GC-MS (Gas Chromatography-Mass Spectrometry). Therefore, the chicken manure with huge discharge in the breeding industry is used as a raw material to prepare a valuable and potential bio-oil product, so that not only can a valuable reference be provided for further researching fossil energy substitutes in the later period, the dependence on fossil energy is reduced, but also the ecological environment problem caused by the chicken manure can be effectively solved. Therefore, the related technologies for treating chicken manure by directly liquefying biomass are also receiving more and more attention, but the requirements of the biomass liquefying technology on equipment and operating conditions are higher, and the biomass liquefying technology is still in the beginning stage at present.

comparison document 1: CN105668968A discloses a method for harmless and resourceful treatment of feces, which comprises the following steps: 1) separating excrement from urine by an excrement-urine separator, and harmlessly collecting the urine for agricultural utilization; 2) after being liquefied by a liquefying device, the excrement is placed in a storage barrel for harmless collection; 3) adding a catalyst into the collected liquid excrement for reaction in a reaction kettle to obtain biomass oil, and discharging water after oil-water separation. The method discloses a method for obtaining biomass oil through catalytic reaction after excrement liquefaction treatment, but excrement and urine separation is needed before the excrement liquefaction, the adopted catalyst is alkali metal salt, and heavy metal is easy to remain in the biomass oil.

comparison document 2: CN102021048A discloses a biomass liquefaction method under the coupling action of subcritical/supercritical cyclohexane and a molecular sieve. The method takes subcritical/supercritical cyclohexane as a medium and a molecular sieve catalyst containing a zeolite component as a catalyst, and biomass, cyclohexane and the molecular sieve catalyst containing the zeolite component react under the conditions that the temperature is 285-330 ℃ and the pressure is 1.7-4.2 Mpa to prepare the biomass oil. The biomass is straw, trees, pasture, rice hull, plant seeds, bagasse, sawdust, wood chips, seaweed, garbage, livestock and poultry manure or any mixture thereof. It discloses a method for realizing high-efficiency conversion of biomass by utilizing the coupling effect of a cyclohexane solvent and a molecular sieve catalyst under a subcritical or supercritical condition.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for preparing bio-oil by performing subcritical/supercritical liquefaction treatment on chicken manure, which can be used for preparing bio-oil by performing subcritical/supercritical liquefaction treatment on the chicken manure, realizing harmless and resource treatment on the chicken manure, and realizing conversion of active heavy metals (Pb, Zn, Cu, Mn, Ni, Cd and Cr) in the chicken manure to relatively stable heavy metals by adding a heavy metal stabilizer, so that pollution harm of the heavy metals is obviously reduced, and the plant absorbability of the heavy metals is reduced.

In order to solve the technical problems, the invention adopts the following technical scheme:

The method for preparing the bio-oil by performing the subcritical/supercritical liquefaction treatment on the chicken manure comprises the following steps:

a. pretreatment: drying fresh chicken manure to a certain water content, crushing and sieving to obtain a powdery mixed material;

b. Sub/supercritical liquefaction: firstly, adding a powdery mixed material and a liquefied solvent into a reaction kettle according to a solid-liquid ratio of 0.05-0.15 g/mL and a solvent filling rate of 10-30%; setting the pressure of a reaction kettle to be 10-15 MPa and the liquefaction temperature to be 220-300 ℃; heating the reaction kettle, keeping the reaction kettle at the preset liquefaction temperature for 30-60 min, stopping heating after the reaction is finished, and cooling to room temperature;

c. solid-liquid separation: c, carrying out solid-liquid separation on the solid-liquid mixture obtained by the reaction kettle treatment in the step b to obtain a solid product and a liquefied product;

d. And c, putting the liquefied product obtained by separation in the step c into a rotary evaporator, and removing the organic solvent and the water phase product in the liquefied product to obtain the bio-oil.

Further, the air conditioner is provided with a fan,

in the step a, after drying, adding a heavy metal stabilizer which is 5-10% of the weight of the chicken manure raw material, and crushing.

Further, the air conditioner is provided with a fan,

the method further comprises the steps of: e. and c, carrying out BCR (BCR) continuous extraction analysis, XRD (X-ray diffraction, X-ray diffractometer technology) analysis and heavy metal environment risk assessment on the solid product obtained by separation in the step c.

Further, the air conditioner is provided with a fan,

And c, performing vacuum filtration by using a circulating water type multipurpose vacuum pump to realize solid-liquid separation.

further, the air conditioner is provided with a fan,

And (b) sieving with a sieve of 60-80 meshes in the step a.

Further, the air conditioner is provided with a fan,

And (b) drying the chicken manure in the step (a) until the water content is below 10%.

Further, the air conditioner is provided with a fan,

In the step a, the addition amount of the heavy metal stabilizer is preferably 10% of the total amount of the chicken manure raw material.

preferably, the first and second electrodes are formed of a metal,

In the step a, the heavy metal stabilizer is palygorskite.

further, the air conditioner is provided with a fan,

In the step b, the reaction kettle is an intermittent reaction kettle or a continuous reaction kettle.

further, the air conditioner is provided with a fan,

In the step b, after the reaction kettle stops heating, when the temperature of the reaction kettle is about 100 ℃, the reaction kettle is cooled to room temperature by using condensed water.

further, the air conditioner is provided with a fan,

In the step b, the liquefied solvent is absolute ethyl alcohol or ethyl acetate.

further, the air conditioner is provided with a fan,

in the step b, a magnetic stirrer is arranged in the reaction kettle, and the stirring speed is 60-80 r/min.

Preferably, the first and second electrodes are formed of a metal,

In step b, the solvent filling rate is preferably 15%.

preferably, the first and second electrodes are formed of a metal,

in the step b, the solid-liquid ratio of the chicken manure raw material to the liquefying solvent is preferably 0.05 g/mL.

Preferably, the first and second electrodes are formed of a metal,

In step b, the liquefaction temperature is preferably 220 ℃.

Further, the air conditioner is provided with a fan,

In the step d, the rotating speed of the rotary evaporator is 60-110 rpm.

The invention has the beneficial effects that:

1. According to the invention, the biological oil is prepared by directly liquefying the chicken manure with huge discharge as a raw material, so that on one hand, valuable reference can be provided for further researching fossil energy substitutes in the later period, and the dependence on fossil energy can be reduced to a certain extent; on the other hand, the chicken manure liquefaction treatment method provided by the invention can effectively solve the ecological environment problems of odor, water body pollution and the like caused by chicken manure, and all pathogen germs and pathogenic microorganisms carried in the chicken manure can be killed in the high-temperature high-pressure liquefaction process; in addition, the heavy metal stabilizer is added to realize the conversion of the active heavy metals (Pb, Zn, Cu, Mn, Ni, Cd and Cr) in the chicken manure to the heavy metals with relatively stable forms, so that the pollution hazard of the heavy metals is obviously reduced, and the plant absorbability of the heavy metals is reduced. Therefore, the method can realize the recycling and harmless treatment of the chicken manure.

2. The invention has wide raw material source, lower energy consumption, convenient large-scale preparation of the bio-oil and strong industrial potential.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a graph showing the effect of reaction temperature on the yield of liquefied bio-oil under certain solid-to-liquid ratio (0.1g/mL) and solvent fill ratio (20%) according to the present invention;

FIG. 2 is a graph showing the effect of solid-liquid ratio on the yield of liquefied bio-oil under certain reaction temperature (300 ℃) and solvent filling rate (20%) according to the present invention;

FIG. 3 is a graph showing the effect of solvent filling rate on the yield of liquefied bio-oil under certain reaction temperature (300 ℃) and solid-to-liquid ratio (0.1g/mL) according to the present invention.

Detailed Description

In order to better illustrate the content of the invention, the invention is further verified by the following specific examples. It should be noted that the examples are given for the purpose of describing the invention more directly and are only a part of the present invention, which should not be construed as limiting the invention in any way.

The materials and equipment used in the following examples are commercially available.

Example 1

a method for preparing bio-oil by performing sub/supercritical liquefaction treatment on chicken manure specifically comprises the following steps:

a. pretreatment: drying fresh chicken manure until the water content is 10%, and then crushing the chicken manure and sieving the crushed chicken manure with a 80-mesh sieve;

b. Sub/supercritical liquefaction: mixing the treated chicken manure with absolute ethyl alcohol according to a solid-to-liquid ratio of 0.1g/mL and a filling rate of solvent absolute ethyl alcohol of 20 percent, and pouring the mixture into a reaction kettle; sealing the reaction kettle, wherein the design pressure is 12.5MPa, the heating voltage is 250V, and the liquefaction temperature is set to be 220 ℃; heating the reaction kettle, keeping the reaction kettle at the preset liquefaction temperature for 30-60 min, stopping heating after the reaction is finished, and cooling the reaction kettle to room temperature by using condensate water when the temperature of the reaction kettle is about 100 ℃;

c. Solid-liquid separation: directly discharging gas-phase products generated by the reaction without further analysis, opening a reaction kettle cover, taking out a solid-liquid mixture in a kettle body of the reaction kettle, cleaning the kettle wall for a plurality of times by using ethyl acetate, transferring the kettle wall into a vessel, and performing vacuum filtration by using a circulating water type multipurpose vacuum pump to obtain solid products and liquefied products;

d. and c, putting the liquefied product obtained by separation in the step c into a rotary evaporator, setting the rotating speed to be 80rpm for rotary evaporation, firstly removing ethanol and ethyl acetate in the solution, and then removing a small amount of water phase products in the solution to obtain the bio-oil, wherein the bio-oil is recorded as a sample S1.

Example 2

This example differs from example 1 in that the liquefaction temperature was set at 260 ℃ and the sample of bio-oil obtained was designated as S2.

Example 3

this example differs from example 1 in that the liquefaction temperature was set at 300 ℃ and the resulting bio-oil sample was designated as S3.

Example 4

The difference between the present example and example 3 is that the solid-to-liquid ratio of the chicken manure to the absolute ethyl alcohol is 0.05g/mL, and the obtained bio-oil sample is designated as S4.

example 5

The difference between the present example and example 3 is that the solid-to-liquid ratio of the chicken manure to the absolute ethyl alcohol is 0.075g/mL, and the prepared bio-oil sample is marked as S5.

Example 6

The difference between this example and example 3 is that the solid-to-liquid ratio of chicken manure to absolute ethyl alcohol is 0.125g/mL, and the obtained bio-oil sample is designated as S6.

Example 7

The difference between the present example and example 3 is that the solid-to-liquid ratio of the chicken manure to the absolute ethyl alcohol is 0.15g/mL, and the obtained bio-oil sample is designated as S7.

example 8

This example is different from example 3 in that the filling rate of the solvent absolute ethyl alcohol was 10%, and the obtained bio-oil sample was designated as S8.

Example 9

This example is different from example 3 in that the filling rate of the solvent absolute ethyl alcohol was 15%, and the obtained bio-oil sample was designated as S9.

Example 10

This example differs from example 3 in that the filling rate of the solvent absolute ethanol was 25%, and the obtained bio-oil sample was designated as S10.

example 11

This example is different from example 3 in that the filling rate of the solvent absolute ethyl alcohol was 30%, and the obtained bio-oil sample was designated as S11.

example 12

the difference between this example and example 11 is that in step a, after the chicken manure is dried, 5% of palygorskite is added as a heavy metal stabilizer, and the prepared bio-oil sample is recorded as S12.

example 13

the difference between this example and example 12 is that in step a, 7% of palygorskite is added as a heavy metal stabilizer after the chicken manure is dried, and the prepared bio-oil sample is recorded as S13.

example 14

the difference between this example and example 12 is that in step a, 10% of palygorskite is added as a heavy metal stabilizer after the chicken manure is dried, and the prepared bio-oil sample is recorded as S14.

The above examples were subjected to comparative analysis:

1. The results of measuring the yields of bio-oil obtained in examples 1 to 14 are shown in the following table 1:

TABLE 1 Process parameters and yields for examples 1-14

The results were further analyzed in groups for the effect of liquefaction reaction temperature, solid-to-liquid ratio of chicken manure to liquefaction solvent, and packing rate on bio-oil yield:

1) Taking examples 1-3 as a group, it can be seen from the data in table 1 above, with reference to fig. 1: under the condition that the solid-liquid ratio (0.1g/mL) and the solvent filling rate (20%) are constant, the yield of the liquefied bio-oil with the liquefaction temperature of 220 ℃ is the highest within the preferable solid-liquid ratio range (220-300 ℃).

2) Taking examples 4-7 as a group, it can be seen from the data in table 1 above, with reference to fig. 2: under the condition that the filling rate of the solvent (20%) and the liquefaction temperature (300 ℃) are constant, the yield of the liquefied bio-oil is reduced along with the increase of the solid-liquid ratio in a preferable solid-liquid ratio range (0.05-0.15 g/mL), and the yield of the liquefied bio-oil with the solid-liquid ratio of 5% is the highest.

3) Taking examples 8-11 as a group, it can be seen from the data in table 1 above, with reference to fig. 3: under the condition that the solid-liquid ratio (0.1g/mL) and the liquefaction temperature (300 ℃) are constant, the yield of the liquefied bio-oil with the solvent filling rate of 15% is the highest within the preferable solvent filling rate range (10-30%).

2. Taking the solid product obtained by solid-liquid separation in the step c of the example 11-14, and adopting ICP-OES (inductively coupled plasma emission spectrometer) (Optima 8300, USA) to determine and analyze the content of heavy metals in the solid product, wherein the determination results are shown in the following table 2:

TABLE 2 heavy Metal content in samples S11-S14 (unit: mg/kg)

from the comparison of the data in table 2 above, it can be seen that:

1) The content of each heavy metal in the solid-phase product obtained by adding the heavy metal stabilizer (5%, 7% and 10%) is higher than that of each heavy metal in the solid-phase product obtained without adding the heavy metal stabilizer, which indicates that the heavy metal in the liquefied product is transferred to the solid-phase product, so that the content of each heavy metal in the liquefied product is reduced;

2) Through data comparison, the effect of adding 10% of heavy metal stabilizer of chicken manure raw material on stabilizing heavy metal is optimal.

3. taking the solid product obtained by solid-liquid separation in the step c of the embodiment 11-14, and determining the chemical forms of the heavy metals by using a continuous extraction method (BCR heavy metal continuous extraction method), wherein the contents of the heavy metals in different chemical forms of the heavy metals are shown in the following tables 3 and 4:

TABLE 3F 1 (exchangeable/carbonate bound) content of heavy metals in solid product

TABLE 4 content of heavy metals in the solid product in the F2 (reducible state)

from the comparison of the data in tables 3 and 4, it can be seen that:

1) The comparison of the chicken manure raw material, the stabilizer without heavy metal and the stabilizer with heavy metal proves that: the heavy metal stabilizer is added, so that the conversion of the active heavy metals (Pb, Zn, Cu, Mn, Ni, Cd and Cr) in the chicken manure to the heavy metals with relatively stable forms can be realized, the pollution hazard of the heavy metals is obviously reduced, and the plant absorbability of the heavy metals is reduced.

2) The heavy metal stabilizer with the mass of 10% of the chicken manure raw material is added, so that the stabilizing effect is optimal.

Claims

1. A method for preparing bio-oil by performing sub/supercritical liquefaction treatment on chicken manure is characterized by comprising the following steps:

b. sub/supercritical liquefaction: adding the powdery mixed material and a liquefied solvent into a reaction kettle according to a solid-liquid ratio of 0.05-0.150 g/mL and a solvent filling rate of 10-30%; setting the pressure of a reaction kettle to be 10-15 MPa and the liquefaction temperature to be 220-300 ℃; heating the reaction kettle, keeping the reaction kettle at the preset liquefaction temperature for 30-60 min, stopping heating after the reaction is finished, and cooling to room temperature;

2. The method for preparing bio-oil by sub/supercritical liquefaction processing of chicken manure according to claim 1,

3. The method for preparing bio-oil by sub/supercritical liquefaction processing of chicken manure according to claim 2,

The method further comprises the steps of: e. and c, carrying out BCR continuous extraction analysis, XRD analysis and heavy metal environment risk assessment on the solid product obtained by separation in the step c.

4. the method for preparing bio-oil by sub/supercritical liquefaction processing of chicken manure according to any one of claims 1 to 3,

5. the method for preparing bio-oil by performing sub/supercritical liquefaction on chicken manure according to any one of claims 1 to 3, wherein in the step b, the liquefaction solvent is absolute ethyl alcohol and/or ethyl acetate.

6. the method for preparing bio-oil by performing sub/supercritical liquefaction on chicken manure according to any one of claims 1 to 3, wherein in the step b, a magnetic stirrer is arranged in the reaction kettle, and the stirring speed is 60 to 80 r/min.

7. the method for preparing bio-oil by performing sub/supercritical liquefaction on chicken manure according to any one of claims 1 to 3, wherein in the step b, the addition amount of the heavy metal stabilizer is 10% of the total amount of the chicken manure raw material.

8. The method for preparing bio-oil by performing sub/supercritical liquefaction on chicken manure according to any one of claims 1 to 3, wherein in the step d, the rotating speed of a rotary evaporator is 60-110 rpm.

9. The method for preparing bio-oil by performing sub/supercritical liquefaction on chicken manure according to any one of claims 1 to 3, wherein in the step b, the filling rate of the solvent is 15%; the solid-liquid ratio of the chicken manure raw material to the liquefying solvent is 0.05 g/mL.

10. The method for preparing bio-oil by performing sub/supercritical liquefaction on chicken manure according to any one of claims 1 to 3, wherein the liquefaction temperature in the step b is 220 ℃.