High energy density methanol gel fuel and its preparation method and application

Abstract

The application discloses a high-energy-density methanol gel fuel as well as a preparation method and application thereof. The methanol gel fuel comprises methanol, a gelling agent and adamantane; the mass fraction of the methanol is 43.8-97.5%, the mass fraction of the gelling agent is 0.6-1.2%, and the mass fraction of the adamantane is 1.3-55.6% based on the total mass of the methanol gel fuel. The methanol gel can be formed only by adding calcium acetate powder and through ultrasonic oscillation; further adding micron-grade adamantane into the methanol gel can obviously improve the energy density of the methanol and avoid the problems of agglomeration and sedimentation of high-energy-density additives in the methanol; and the methanol gel fuel has high calorific value, high viscosity, excellent mechanical strength and low volatilization rate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of methanol fuel, and particularly relates to a high-energy-density methanol gel fuel, a preparation method and application thereof, and more particularly to the application of the methanol gel fuel as a special fuel in a low-oxygen area such as a plateau mountain or an environment with limited transportation space. BACKGROUND

[0002] Compared with ethanol and natural gas, methanol has a higher oxygen content and is more inexpensive. Many factories, hotels, canteens, even rural households and field operations have begun to consider methanol as a fuel to meet the demand for heating and warming.

[0003] However, as a fuel, the heat value (volume energy density) of methanol is lower than that of ethanol and natural gas, which means that the energy delivery and release efficiency of methanol is limited in an environment with limited storage or transportation space such as a fuel tank or a boiler. To increase the energy density of methanol, an effective method is to add high-volume-energy-density fuels such as high-tension cyclic hydrocarbons and high-energy nanoparticles. However, the cost of high-tension cyclic hydrocarbons is high, and although the energy of nanoparticles is high, the nanoparticles are prone to agglomeration and lose high energy density, which limits their application in increasing the energy density of methanol. Micron-sized particles are not prone to agglomeration compared with nanoparticles, but their energy density is relatively low, and they are also prone to sedimentation in methanol.

[0004] Therefore, it is desirable to select inexpensive and readily available additives, prepare methanol gel fuel by a simple method, and avoid the problems of agglomeration and sedimentation of the additives in methanol.

[0005] The present application aims to solve the above problems. SUMMARY

[0006] The present application only needs to add calcium acetate powder and form methanol gel through ultrasonic oscillation. Further adding micron-sized adamantane to the methanol gel can significantly increase the energy density of methanol, and avoid the problems of agglomeration and sedimentation of high-energy-density additives in methanol. The methanol gel fuel of the present application has high heat value, high viscosity, excellent mechanical strength and low volatilization rate.

[0007] The present application provides a high-energy-density methanol gel fuel, which comprises methanol, a gelling agent and adamantane; the mass fraction of the methanol is 43.8-97.5%, the mass fraction of the gelling agent is 0.6%-1.2%, and the mass fraction of the adamantane is 1.3-55.6% based on the total mass of the methanol gel fuel; and the heat value of the methanol gel fuel is 18-37 MJ·L -1 .

[0008] Preferably, the gelling agent comprises calcium acetate powder, half crown ether-bis carbonyl small molecule organic HCE, sorbitol-based small molecule organic DBS (1,3:2,4-dibenzyl sorbitol). More preferably, the gelling agent is selected from calcium acetate powder.

[0009] Preferably, the calcium acetate powder is anhydrous calcium acetate powder, and the particle size is 4-120 μm.

[0010] Preferably, the adamantane is in powder form, and the particle size is 500 nm-50 μm.

[0011] Preferably, at room temperature, the shear rate of the methanol gel fuel is 0.01 s -1 The viscosity of the methanol gel fuel is 10-500 kPa·s at a shear rate; and the storage modulus of the methanol gel fuel is 10-4000 kPa at room temperature in the linear elastic region.

[0012] The second aspect of the present application provides a preparation method of the methanol gel fuel as described in the first aspect of the present application. First, a gelling agent is added to methanol to prepare a methanol gel, and then adamantane is added to the methanol gel to prepare the methanol gel fuel by ultrasonic oscillation.

[0013] Preferably, the preparation method of the methanol gel fuel comprises the following steps:

[0014] (1) adding methanol and a gelling agent into a container to obtain a methanol-gelling agent mixture;

[0015] (2) adding adamantane powder into the methanol-gelling agent mixture, and placing it in an ultrasonic environment to oscillate for 30 s-5 min to obtain the methanol gel fuel.

[0016] Preferably, when the gelling agent is calcium acetate powder, there is further a step between step (1) and step (2), i.e. placing the container containing the methanol-gelling agent mixture in an ultrasonic environment to oscillate for 5-10 s, and the ultrasonic frequency and ultrasonic power density of the ultrasonic source are 20-80 kHz and 10-50 W·L -1 ;

[0017] When the gelling agent is half crown ether-bis carbonyl small molecule organic HCE or sorbitol-based small molecule organic DBS, there is further a step between step (1) and step (2), i.e. heating and stirring the methanol-gelling agent mixture.

[0018] Preferably, in step (3), the ultrasonic frequency of the ultrasonic source is 20-80 kHz; and the ultrasonic power density is 10-50 W·L -1 .

[0019] The third aspect of the present application provides the application of the methanol gel fuel as the first aspect of the present application as a special fuel in the low-oxygen area such as highland or the environment with limited transportation space.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] 1、The present application can prepare the methanol gel by adding the gelling agent into the methanol, and further adding the micron diamond into the methanol gel to improve the energy density of the methanol fuel, and the methanol gel fuel has high calorific value, high viscosity, excellent mechanical strength and low volatilization rate. -1 The viscosity of the methanol gel is 10-500 kPa·s under the shear rate at room temperature, the storage modulus of the methanol gel is 10-4000 kPa in the linear elastic region at room temperature, and the calorific value of the methanol gel fuel is 18-37 MJ·L -1 .

[0022] 2、The present application can prepare the methanol into the methanol gel fuel, reduce the volatilization rate of the methanol, and the volatilization rate of 10 mL pure methanol is 50% after standing for 25 h, and the volatilization rate of the same volume of methanol gel fuel is only 30%, which improves the safety of the methanol fuel and reduces the storage and transportation difficulty.

[0023] 3、In order to improve the energy density of the methanol, the present application firstly proposes to add diamond into the methanol, and the diamond has low cost (at least 12 yuan·kg-1) and high volumetric energy density (since the diamond is a pure substance, it has a certain energy density of 47.794 MJ·L -1 at room temperature and normal pressure), which makes the micron diamond have high energy density even if it is not ground into nanoscale, and the micron diamond can obviously improve the energy density of the methanol and avoid the problem of easy agglomeration of high energy density nanoparticles.

[0024] However, the solubility of diamond in methanol is low, and it will quickly settle in methanol, and the present application further thinks that the methanol is prepared into methanol gel, so that the diamond is fixed in the solid methanol gel, avoiding the settlement of the diamond, reducing the volatilization of the methanol, being easy to store, increasing the flash point of the fuel, and improving the safety.

[0025] Further, the gelling agent is currently divided into three categories: inorganic small molecule gelling agent, high molecular gelling agent and organic small molecule gelling agent. According to the above three kinds of gelling agents, there are also the following three methods for preparing the methanol gel: first, the high molecular polymer can be added with emulsifier, water and other auxiliary materials, mixed with methanol, stirred and heated, and then cooled to form a methanol gel. However, the methanol gel prepared by using the high molecular gelling agent will have the problem of incomplete combustion of the high molecular gelling agent, which will cause a small amount of odor and smoke. Second, the inorganic gelling agent is dissolved in water, and then added into methanol to form a methanol gel after stirring. The preparation process of the methanol gel prepared by using the inorganic small molecule gelling agent needs to add more than 10% of water by volume of methanol to dissolve and disperse the inorganic small molecule gelling agent, and the addition of water will cause the reduction of the heat value of the methanol gel. Third, the organic small molecule is added into methanol, heated and cooled to form a methanol gel. The preparation process of the methanol gel prepared by using the organic small molecule gelling agent needs to be heated, and the synthesis of the organic small molecule gelling agent is difficult and the cost is high. The present application further proposes that only by adding calcium acetate powder and through ultrasonic oscillation, a gel can be formed. The calcium acetate powder used as the gelling agent is cheap and easy to obtain, and the preparation process is simple, without the need for stirring, heating and other links, greatly simplifying the process. In addition, the preparation process does not need to add high molecular polymer, and the combustion is pollution-free and odor-free. The gelling agent used in the present application is calcium acetate powder, which is cheap and easy to obtain, and the amount is small, only a small amount of calcium acetate powder is needed to stably form a methanol gel. Specifically, compared with the methanol gel prepared by using the high molecular gelling agent, the present application does not need to add emulsifier, water and other auxiliary materials, and there is no odor and smoke after combustion. Compared with the methanol gel prepared by using the inorganic small molecule gelling agent, the present application does not need to add water and does not need to stir, and the combustion heat value is high. Compared with the methanol gel prepared by using the organic small molecule gelling agent, the gelling agent of the present application is inorganic small molecule calcium acetate powder, and the cost is low.

[0026] 4, The present application is not expected that the combination of calcium acetate powder and methanol can form a gel by ultrasonic oscillation. Correspondingly, the calcium acetate powder is replaced by other inorganic gelling agent such as fumed silica, or the methanol is replaced by other alcohol such as ethanol, which cannot form a stable gel. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The flow chart for preparing the methanol gel fuel of the present application.

[0028] Figure 2 The flow chart for preparing the methanol gel fuel of Example 6. DETAILED DESCRIPTION

[0029] The present application is further described by the following examples, which are not intended to limit the present application. The experimental methods in the examples, unless otherwise specified, are generally performed according to conventional conditions and procedures described in the manuals, or by using general equipment, materials, reagents, etc. suggested by the manufacturers, which are commercially available.

[0030] Example 1

[0031] This example is the preparation of methanol gel sample 1. The methanol gel sample 1 comprises methanol and calcium acetate, and it does not comprise water; the mass fraction of methanol is 98.1%, and the mass fraction of calcium acetate powder is 1.9% based on the total mass of the methanol gel. The calcium acetate powder is anhydrous calcium acetate powder. The particle size of the calcium acetate powder is 4-120 μm.

[0032] The preparation method is: adding methanol and calcium acetate powder into a container; placing the container containing methanol and calcium acetate powder in an ultrasonic environment, and oscillating for 3 min to obtain a methanol gel. The ultrasonic frequency and ultrasonic power density of the ultrasonic source are 40 kHz and 28 W·L -1 .

[0033] Comparative Example 1

[0034] This comparative example is the preparation of methanol mixture comparative sample 1. The preparation method is the same as that of the methanol gel sample 1 in Example 1, except that the gelling agent is fumed silica. The mass fraction of methanol in the methanol mixture comparative sample 1 is 98.6%, and the mass fraction of fumed silica powder is 1.4%.

[0035] Comparative Example 2

[0036] This comparative example is the preparation of ethanol mixture comparative sample 2. The preparation method is the same as that of the methanol gel sample 1 in Example 1, except that methanol is replaced by ethanol. The mass fraction of ethanol in the ethanol mixture comparative sample 2 is 98.2%, and the mass fraction of calcium acetate powder is 1.8%.

[0037] From Comparative Examples 1 and 2, it can be seen that the combination of calcium acetate powder and methanol can form a gel by ultrasonic oscillation. Correspondingly, replacing the calcium acetate powder with other inorganic gelling agent fumed silica, or replacing the methanol with ethanol and other alcohols, cannot form a stable gel.

[0038] Example 2

[0039] This example is the preparation of methanol gel fuel sample 1. The methanol gel fuel sample 1 comprises methanol, calcium acetate and adamantane, the mass fraction of methanol is 63.7%, the mass fraction of calcium acetate is 1.6%, and the mass fraction of adamantane is 34.7% based on the total mass of the methanol gel fuel. The adamantane is in powder form with a particle size of 500 nm to 50 μm.

[0040] The preparation method is as follows: the methanol gel is prepared according to the method of Example 1, then the adamantane powder is added to the methanol gel, and the mixture is placed in an ultrasonic environment and oscillated for 3 min to obtain the methanol gel fuel.

[0041] The viscosity, mechanical strength, heat value and volatilization degree data of the methanol gel fuel sample 1 are shown in Table 1. The viscosity refers to the viscosity of the sample at room temperature, 0.01 s -1 under shear rate. The mechanical strength refers to the storage modulus of the sample in the linear elastic region at room temperature. The volatilization degree refers to the percentage of the volatilization volume to the initial volume after standing for 25 h.

[0042] Example 3

[0043] This example is the preparation of methanol gel fuel sample 2. The preparation method is the same as that of methanol gel fuel sample 1 in Example 2, except that the mass fraction of methanol in the methanol gel fuel sample 2 is 96.9%, the mass fraction of calcium acetate powder is 1.8%, and the mass fraction of adamantane is 1.3%. The adamantane is in powder form with a particle size of 500 nm to 50 μm.

[0044] The viscosity, mechanical strength, heat value and volatilization degree data of the methanol gel fuel sample 2 are shown in Table 1.

[0045] Example 4

[0046] This example is the preparation of methanol gel fuel sample 3. The preparation method is the same as that of methanol gel fuel sample 1 in Example 2, except that the mass fraction of methanol in the methanol gel fuel sample 3 is 43.6%, the mass fraction of calcium acetate powder is 0.9%, and the mass fraction of adamantane is 55.5%. The adamantane is in powder form with a particle size of 500 nm to 50 μm.

[0047] The viscosity, mechanical strength, heat value and volatilization degree data of the methanol gel fuel sample 3 are shown in Table 1.

[0048] Example 5

[0049] This embodiment is the preparation of methanol gel fuel sample 4. With hemi-crown ether-bis-ketone small molecule organic HCE as the gelling agent, the methanol gel fuel with high energy density prepared by ultrasonic oscillation contains the following equipment, raw materials and their mass fractions: 40L ultrasonic cleaner, methanol 63.6%, adamantane 34.7%, HCE 1.7%.

[0050] Among them, the ultrasonic frequency and ultrasonic power of the ultrasonic cleaner are 40 kHz and 840 W respectively.

[0051] Among them, the particle size of the adamantane powder is in the range of 500 nm to 50 μm.

[0052] The preparation method includes the following steps:

[0053] S1): The first step is to add methanol and HCE into the container, stir at 600 r·min-1 at 60°C for 5 min, and prepare the aforementioned methanol-gelling agent mixture.

[0054] S2): The second step is to add adamantane powder into the container.

[0055] S3): The third step is to place the container in an ultrasonic environment and oscillate for 3 min until the system is completely converted to a solid state to obtain the methanol gel fuel.

[0056] The viscosity, mechanical strength, heat value and volatility data of methanol gel fuel sample 4 are shown in Table 1.

[0057] Example 6

[0058] This embodiment is the preparation of methanol gel fuel sample 5. With small molecule organic 1,3:2,4-dibenzyl sorbitol (DBS) as the gelling agent, the methanol gel fuel with high energy density prepared by ultrasonic oscillation contains the following equipment, raw materials and their mass fractions: 40L ultrasonic cleaner, methanol 63.6%, adamantane 34.7%, DBS 1.7%.

[0059] Among them, the ultrasonic frequency and ultrasonic power of the ultrasonic cleaner are 40 kHz and 28 W respectively.

[0060] Among them, the particle size of the adamantane powder is in the range of 500 nm to 50 μm.

[0061] The preparation method includes the following steps:

[0062] S1): The first step is to add methanol and DBS into the container, stir at 600 r·min-1 at 60°C for 5 min, and prepare the aforementioned methanol-gelling agent mixture. -1

[0063] ​S2): the second step, adding adamantane powder into the container.

[0064] S3): the third step, placing the container into the ultrasonic environment, oscillating for 3 minutes, oscillating until the system is completely converted into solid state, obtaining the methanol gel fuel.

[0065] The viscosity, mechanical strength, heat value and volatility degree data of the methanol gel fuel sample 5 are shown in Table 1.

[0066] It can be known by comparing Examples 1-6 that, although the calcium acetate powder which is cheap and easy to obtain is selected as the gelling agent in Examples 1-4, the methanol gel fuel is prepared by the simple ultrasonic method, but compared with Examples 5-6, the viscosity, mechanical strength, heat value and volatility resistance of the methanol gel fuel sample in Examples 1-4 are all excellent.

[0067] Example 7

[0068] This example is the preparation of the methanol gel fuel sample 6. The methanol gel fuel sample 1 comprises methanol, calcium acetate and carbon black, the mass fraction of the methanol is 50.1%, the mass fraction of the calcium acetate is 1.0%, and the mass fraction of the carbon black is 48.9% based on the total mass of the methanol gel fuel. The carbon black is in powder form, and the particle size is 20-50 μm.

[0069] The preparation method is that the methanol gel is prepared according to the method of Example 1, then the carbon black powder is added into the methanol gel, and the methanol gel is placed into the ultrasonic environment and oscillated for 3 minutes, obtaining the methanol gel fuel.

[0070] The viscosity, mechanical strength, heat value and volatility degree data of the methanol gel fuel sample 6 are shown in Table 1.

[0071] It can be known by comparing Examples 1 and 7 that, compared with Example 7 in which the carbon black is added into the methanol gel, the energy density of the methanol fuel can be improved to a greater extent in Example 1 in which the micron-sized adamantane is added into the methanol gel.

[0072] Table 1 Properties of different methanol gel fuel samples

[0073]

[0074]

[0075] The above has exemplarily described the present application, and it should be indicated that, without departing from the core of the present application, any simple modification, change or other equivalent replacement which can not cost the creative labor of the person skilled in the art falls into the protection scope of the present application.

Claims

1. A high-energy-density methanol gel fuel, characterized in that, It comprises methanol, a gelling agent, and adamantane; based on the total mass of the methanol gel fuel, the mass fraction of methanol is 43.8-97.5%, the mass fraction of the gelling agent is 0.6%-1.2%, and the mass fraction of adamantane is 1.3-55.6%; the calorific value of the methanol gel fuel is 18-37 MJ·L. -1 ; The gelling agent includes anhydrous calcium acetate powder; The method for preparing methanol gel fuel is as follows: first, a gelling agent is added to methanol to prepare methanol gel, and then adamantane is added to the methanol gel and methanol gel fuel is prepared by ultrasonic oscillation. The method for preparing the methanol gel fuel includes the following steps: (1) Add methanol and gelling agent into the container to obtain methanol-gelling agent mixture. Place the container containing methanol-gelling agent mixture in an ultrasonic environment and vibrate for 5-10 seconds. (2) Add adamantane powder to the methanol-gelling agent mixture and place it in an ultrasonic environment and vibrate for 30s-5min to obtain methanol gel fuel; In step (1), the ultrasonic frequency and ultrasonic power density of the ultrasonic source are 20-80 kHz and 10-50 W·L, respectively. -1 ; In step (2), the ultrasonic frequency of the ultrasonic source is 20-80 kHz; the ultrasonic power density is 10-50 W·L. -1 .

2. The methanol gel fuel according to claim 1, characterized in that, The anhydrous calcium acetate powder has a particle size of 4-120 μm.

3. The methanol gel fuel according to claim 1, characterized in that, The adamantane is in powder form with a particle size of 500 nm to 50 μm.

4. The methanol gel fuel according to claim 1, characterized in that, At room temperature, 0.01s -1 At the shear rate, the viscosity of the methanol gel fuel is 10-500 kPa·s; at room temperature, in the linear elastic region, the energy storage modulus of the methanol gel fuel is 10-4000 kPa.

5. The application of the methanol gel fuel as described in any one of claims 1-4 as a special fuel in high-altitude, low-oxygen areas or environments with limited transport space.

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