A method for preparing a modified solution for coal surface

Abstract

The invention discloses a method for preparing a modified solution on the surface of coal, and relates to the technical field of coalbed methane extraction. The method comprises the following steps: Step 1: preparing a PDA culture medium, inoculating an appropriate amount of solid inclined chrysosporium chlorosporum into the culture medium, culturing on a constant temperature shaker for four days, and obtaining a white rot fungus liquid; Step 2: preparing a soy protein isolate aqueous solution, adding protease for hydrolysis reaction, controlling the pH value, sterilizing by heating in a water bath, adding glucan after cooling, stirring and dissolving, and cooling to room temperature after heating in a water bath. The modifier prepared by the invention is composed of a microbial liquid and a biomass active agent, can effectively degrade organic matter in coal, significantly improve the physical and chemical properties of coal, and create ideal conditions for efficient desorption and migration of coalbed methane. Compared with some existing modifiers prepared by traditional preparation methods, the modifier has stronger degradability, is more environmentally friendly, and is safer to use.

Description

Technical Field

[0001] The invention relates to the technical field of coalbed methane extraction, and in particular to a method for preparing a modified solution on the surface of coal. Background Art

[0002] Coalbed methane, also known as coal mine methane, is an important clean energy source. Its mining efficiency is directly related to the development and utilization of resources and economic benefits.

[0003] In the process of coalbed methane extraction, the physical and chemical properties of coal can be effectively improved by analyzing the storage characteristics of methane in coal and selecting suitable modifiers to treat coal reservoirs.

[0004] The modifiers prepared by traditional preparation methods are mainly chemical reagents, which are usually not biodegradable and may cause environmental pollution and ecological hazards after use, increasing the environmental cost and social burden of coalbed methane extraction. Since existing chemical modifiers have certain defects in environmental protection, degradability and safety, their widespread application in actual coalbed methane extraction is limited.

[0005] Based on this, a method for preparing a modified solution for the surface of coal is now provided, which can eliminate the disadvantages of existing chemical reagents. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing a modified solution for coal surface, so as to solve the shortcomings of the current products in the background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing a modified solution for coal surface comprises the following steps:

[0009] Step 1: prepare PDA culture medium, inoculate an appropriate amount of solid inclined chrysosporium Phanerochaete into the culture medium, and culture on a constant temperature shaker for four days to obtain a white rot fungus culture liquid;

[0010] Step 2: preparing a soy protein isolate aqueous solution, adding protease to carry out a hydrolysis reaction, controlling the pH value, sterilizing by heating in a water bath, adding dextran after cooling and stirring to dissolve, heating in a water bath and cooling to room temperature to obtain a soy protein-based biomass active agent, and freeze-drying;

[0011] Step 3: The soy protein-based biomass active agent obtained in step 2 is prepared with distilled water, and a 1wt% potassium chloride solution is used as a base liquid, and a rhamnolipid active agent is added in proportion to prepare a composite biomass active agent solution;

[0012] Step 4: fully mix the white rot fungus solution in step 1 and 0.05% of the compound biomass active agent solution obtained in step 3 to prepare a modified solution.

[0013] On the basis of the above technical solution, the present invention also provides the following optional technical solution:

[0014] In an optional scheme: in the step 1, the culture temperature is 35°C and the rotation speed of the shaking table is 150r / min.

[0015] In an optional scheme: in the step 2, a 4% soy protein isolate aqueous solution is used, the hydrolysis temperature is 55° C., 0.85% (w / w) of glucan is added after the hydrolysis reaction, and heated in a 90° C. water bath for 1 hour.

[0016] In an optional scheme: in the step three, the compounding ratio of the rhamnolipid active agent to the soy protein-based biomass active agent is 3:7.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The modifier prepared by the present invention is composed of microbial liquid and biomass activator, which can effectively degrade organic matter in coal, significantly improve the physical and chemical properties of coal, and create ideal conditions for efficient desorption and migration of coalbed methane. Compared with some existing modifiers prepared by traditional preparation methods, it is more degradable, more environmentally friendly and safer to use.

[0019] 2. The modified solution prepared by the present invention can effectively change the organic matter structure of the coal body, thereby reducing and reducing its intermolecular pores, reducing the total micropore volume of the coal, and achieving the purpose of significantly improving the permeability of the coal seam and increasing the coalbed methane recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FTIR diffraction diagrams of the coal samples before and after modification according to the present invention.

[0021] Figure 2 It is the distribution diagram of the change of hydroxyl group content of the coal sample before and after modification of the present invention.

[0022] Figure 3 It is the distribution diagram of the change of the aliphatic hydrocarbon group content of the coal sample before and after modification of the present invention.

[0023] Figure 4 It is a distribution diagram of the change in the vibration content of oxygen-containing functional groups and aromatic ring skeletons before and after the coal sample is modified according to the present invention.

[0024] Figure 5 It is the distribution diagram of the change of aromatic hydrocarbon group content before and after the coal sample is modified according to the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0026] In one embodiment, Figure 1-Figure 5 As shown, a method for preparing a modified solution for coal surface comprises the following steps:

[0027] Step 1: prepare PDA culture medium, inoculate an appropriate amount of solid inclined chrysosporium Phanerochaete into the culture medium, and culture on a constant temperature shaker for four days to obtain a white rot fungus culture liquid;

[0028] Step 2: preparing a soy protein isolate aqueous solution, adding protease to carry out a hydrolysis reaction, controlling the pH value, sterilizing by heating in a water bath, adding dextran after cooling and stirring to dissolve, heating in a water bath and cooling to room temperature to obtain a soy protein-based biomass active agent, and freeze-drying;

[0029] Step 3: The soy protein-based biomass active agent obtained in step 2 is prepared with distilled water, and a 1wt% potassium chloride solution is used as a base liquid, and a rhamnolipid active agent is added in proportion to prepare a composite biomass active agent solution;

[0030] Step 4: fully mix the white rot fungus solution in step 1 and 0.05% of the compound biomass active agent solution obtained in step 3 to prepare a modified solution.

[0031] In one embodiment, in step 1, the culture temperature is 35° C. and the shaking speed is 150 r / min.

[0032] In one embodiment, in step 2, a 4% soy protein isolate aqueous solution is used, the hydrolysis temperature is 55° C., 0.85% (w / w) dextran is added after the hydrolysis reaction, and the mixture is heated in a 90° C. water bath for 1 hour.

[0033] In one embodiment, in step three, the compounding ratio of the rhamnolipid active agent to the soy protein-based biomass active agent is 3:7.

[0034] The above embodiment discloses a method for preparing a modified solution for the surface of coal. The prepared modified solution is subjected to a comparative experiment. The process and results of the comparative experiment are as follows:

[0035] Embodiment 1:

[0036] S1: Prepare PAD medium in a triangular flask, sterilize and cool, inoculate solid slant white rot fungus strains, plug the mouth of the triangular flask with a sterilized cotton plug, shake and mix on a fast mixer for 2 minutes, and culture in a shaker at 35°C and 150 r / min for 4 days to obtain a white rot fungus culture liquid;

[0037] S2: Prepare a 4% soy protein isolate aqueous solution, add alcalase protease (0.15%, w / w), react at 55°C for 30 minutes, maintain pH 8.0 during the reaction, heat in a water bath at 90°C for 10 minutes, add 0.85% dextran after cooling, mix and stir for 10 minutes, heat in a water bath at 90°C for 0.5h, cool in an ice water bath after the reaction, and freeze-dry to obtain a soy protein-based active agent;

[0038] S3: Prepare a 1 wt % potassium chloride solution as a base liquid, add three parts of a soybean protein-based active agent and seven parts of a rhamnolipid active agent, fully dissolve them, and obtain a 2 g / L composite biomass active agent solution;

[0039] S4: Take 10g of 60-80 mesh coal powder, add a modified solution mixed with 10ml of white rot fungus solution and 5ul of a composite biomass active agent solution, adjust the pH value to about 7.0, and treat it at a constant temperature of 28°C and 120r / min for 7 days, wash and filter, and finally dry to constant weight.

[0040] Embodiment 2:

[0041] S1: Prepare PAD medium in a triangular flask, sterilize and cool, inoculate solid slant white rot fungus strains, plug the mouth of the triangular flask with a sterilized cotton plug, shake and mix on a fast mixer for 2 minutes, and culture in a shaker at 35°C and 150 r / min for 4 days to obtain a white rot fungus culture liquid;

[0042] S2: Prepare a 4% soy protein isolate aqueous solution, add alcalase protease (0.15%, w / w), react at 55°C for 30 minutes, maintain pH 8.0 during the reaction, heat in a water bath at 90°C for 10 minutes, add 0.85% dextran after cooling, mix and stir for 10 minutes, heat in a water bath at 90°C for 0.5h, cool in an ice water bath after the reaction, and freeze-dry to obtain a soy protein-based active agent;

[0043] S3: Prepare a 1 wt % potassium chloride solution as a base liquid, add three parts of a soybean protein-based active agent and seven parts of a rhamnolipid active agent, fully dissolve them, and obtain a 2 g / L composite biomass active agent solution;

[0044] S4: Take 10g of 60-80 mesh coal powder, add a modified solution mixed with 15ml of white rot fungus solution and 7.5ul of a composite biomass active agent solution, adjust the pH value to about 7.0, and treat it at a constant temperature of 28°C and 120r / min for 7 days, wash and filter, and finally dry to constant weight.

[0045] Embodiment 3:

[0046] S1: Prepare PAD medium in a triangular flask, sterilize and cool, inoculate solid slant white rot fungus strains, plug the mouth of the triangular flask with a sterilized cotton plug, shake and mix on a fast mixer for 2 minutes, and culture in a shaker at 35°C and 150 r / min for 4 days to obtain a white rot fungus culture liquid;

[0047] S2: Prepare a 4% soy protein isolate aqueous solution, add alcalase protease (0.15%, w / w), react at 55°C for 30 minutes, maintain pH 8.0 during the reaction, heat in a water bath at 90°C for 10 minutes, add 0.85% dextran after cooling, mix and stir for 10 minutes, heat in a water bath at 90°C for 0.5h, cool in an ice water bath after the reaction, and freeze-dry to obtain a soy protein-based active agent;

[0048] S3: Prepare a 1 wt % potassium chloride solution as a base liquid, add three parts of a soybean protein-based active agent and seven parts of a rhamnolipid active agent, fully dissolve them, and obtain a 2 g / L composite biomass active agent solution;

[0049] S4: Take 10g of 60-80 mesh coal powder, add a modified solution mixed with 10ml of white rot fungus solution and 5ul of a composite biomass active agent solution, adjust the pH value to about 7.0, and treat it at a constant temperature of 28°C and 120r / min for 10d, wash and filter, and finally dry to constant weight.

[0050] Comparative Example:

[0051] Take 10g of 60-80 mesh coal powder without modification, dry it to constant weight, and obtain a blank control group sample.

[0052] Comparison of microstructure changes before and after modification:

[0053] Figure 1 The infrared spectra of the coal samples before and after modification are shown in Figure 2. It can be seen that the peak position and intensity of the modified coal have changed compared with the original coal. The spectrum shows that the modified solution can significantly break the chemical bonds or functional groups of the coal.

[0054] Figure 2 The distribution diagram of the hydroxyl group content of the coal sample before and after modification. -1 There is an absorption peak at 3500-3200cm. The peak intensity of the coal sample treated with the modified solution decreases slightly. -1 In the range of , the coal sample shows an absorption peak with a large intensity and a wide peak shape, which is mainly caused by the out-of-plane stretching vibration of the hydroxyl group or the hydrogen bond formed by the association between water molecules. This shows that there is a network system mainly composed of polyhydroxyl groups formed by the condensation of internal water in the coal sample. The absorption peak still exists in the modified coal sample, but its intensity is significantly reduced, reflecting that the structure of the modified coal becomes looser.

[0055] Figure 3 This is the distribution diagram of the change of aliphatic hydrocarbon group content before and after the coal sample is modified. -1 and 2850cm -1 There are two significant absorption peaks nearby, corresponding to the antisymmetric and symmetric stretching vibrations of methyl (CH2). -1 With 2880cm -1 At 2890 cm -1 A secondary peak was detected at , which was attributed to the stretching vibration of CH. After the coal sample was modified, the total content of aliphatic hydrocarbon groups in the coal was significantly lower than that in the original coal, indicating that the amount of dissolved organic matter increased, resulting in a significant reduction in the total content of aliphatic hydrocarbon groups.

[0056] Figure 4 The distribution diagram of the change of oxygen-containing functional groups and aromatic ring skeleton vibration content before and after the coal sample is modified. -1 The main functional groups in the region are oxygen-containing functional groups, while in the range of 1450-1350cm -1 In this region, the main vibrations are asymmetric and symmetric deformation vibrations of alkanes. -1 The peaks on the left and right are mainly the vibrations of aromatic hydrocarbons and polycyclic aromatic layers, reflecting the degree of aromatization of coal. Compared with the original coal, the absorption peak area of ​​oxygen-containing functional groups in the coal sample treated with the modified solution is significantly reduced, and the absorption peak intensity of the C=C skeleton is significantly reduced, indicating that the oxygen-containing functional groups of the modified coal have cracked and fallen off, and the COC stretching vibration has been greatly broken, condensing with the aromatic ring to form aromatic ethers, the aromatic ring has been destroyed, and its condensation degree has been significantly reduced.

[0057] Figure 5 This is the distribution diagram of the change of aromatic hydrocarbon group content before and after the coal sample modification. -1 、800cm -1 、750cm -1 and 700cm -1Strong characteristic absorption peaks appear at , representing different substitution positions of H on the benzene ring, mainly including pentasubstituted benzene ring (1H), trisubstituted ortho aromatics (3H), disubstituted ortho aromatics (4H) and monosubstituted (5H). The number of ortho substitutions reflects the degree of aromatic substitution and polycondensation during coal modification. Compared with the original coal, the absorption peak area of ​​aromatic hydrocarbons in the coal samples treated with the modified solution is significantly reduced, and the overall strength of the aromatic structure of the coal samples is significantly reduced, indicating that the modification enhances the dissolution of aromatic rings in the coal samples. The aromatic structure is closely related to the gas adsorption performance of coal. The reduction in the content of aromatic structure of the modified coal indicates that it is not conducive to gas adsorption, but more conducive to gas desorption and release. After the coal samples are modified, the content of hydroxyl groups is greatly reduced, the length of the aliphatic side chain is significantly shortened, the aromatic structure is reduced, the absorption peak intensity of the C=C skeleton is reduced, the condensation degree of the aromatic ring is reduced, the small molecular compounds of the coal samples are dissolved, and extraction and swelling reactions occur inside the coal. At the same time, the pore components of the coal are degraded by the modified solution. The combined effect of the two causes the fat structure and oxygen-containing functional groups to fall off. Through aromatization, the active agent involved in the reaction prompts the fat structure to form small-sized aromatic rings, which causes the micropore morphology to change, more macropores to increase, and the coal methane desorption performance to be improved.

[0058] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing a modified solution for coal surface, characterized in that: The following steps are involved: Step 1: prepare PDA culture medium, inoculate an appropriate amount of solid inclined chrysosporium Phanerochaete into the culture medium, and culture on a constant temperature shaker for four days to obtain a white rot fungus culture liquid; Step 2: preparing a soy protein isolate aqueous solution, adding protease to carry out a hydrolysis reaction, controlling the pH value, sterilizing by heating in a water bath, adding dextran after cooling and stirring to dissolve, heating in a water bath and cooling to room temperature to obtain a soy protein-based biomass active agent, and freeze-drying; Step 3: The soy protein-based biomass active agent obtained in step 2 is prepared with distilled water, and a 1wt% potassium chloride solution is used as a base liquid, and a rhamnolipid active agent is added in proportion to prepare a composite biomass active agent solution; Step 4: fully mix the white rot fungus solution in step 1 and 0.05% of the compound biomass active agent solution obtained in step 3 to prepare a modified solution.

2. The method for preparing a modified solution for coal surface according to claim 1, characterized in that: In the step 1, the culture temperature is 35° C. and the rotation speed of the shaking table is 150 r / min.

3. The method for preparing a modified solution for coal surface according to claim 1, characterized in that: In the step 2, a 4% soy protein isolate aqueous solution is used, the hydrolysis temperature is 55° C., 0.85% (w / w) of glucan is added after the hydrolysis reaction, and the mixture is heated in a water bath at 90° C. for 1 hour.

4. The method for preparing a modified solution for coal surface according to claim 1, characterized in that: In the step three, the compounding ratio of the rhamnolipid active agent to the soy protein-based biomass active agent is 3:7.

Images