A methanol gel, its preparation method and use

Abstract

The application discloses a kind of methanol gel and its preparation method and application, methanol gel includes methanol and calcium acetate, and it does not include water;The mass fraction of methanol is 90.00-99.50%, and the mass fraction of calcium acetate powder is 0.50-10.00% based on the total mass of methanol gel.The application only by adding calcium acetate powder, and by ultrasonic oscillation can form at room temperature with high viscosity, high mechanical strength and low volatile rate of methanol gel, using calcium acetate powder as gelling agent, cheap and easy to obtain, and preparation process is simple, without stirring, heating and other links, greatly simplifies the process.In addition, the preparation process does not need to add high molecular polymer, combustion is pollution-free, odor generation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of methanol fuel, and particularly relates to a methanol gel and a preparation method and application thereof, and more particularly to the application of the methanol gel as fuel. BACKGROUND

[0002] Compared with ethanol, natural gas and other fuels, methanol has a higher oxygen content and is more inexpensive. Many factories, hotels, canteens, even rural household heating and field operations have begun to consider methanol as fuel to meet the demand for heating. However, liquid methanol is volatile and toxic, which will increase the transportation cost and have certain risk. A specific gelling agent can change the corresponding solvent into a gel, and the principle is to use the various intermolecular forces between the gelling agent molecules and the solvent to make the system into a solid state. Making methanol into a gel can reduce methanol evaporation, improve safety, and reduce transportation costs, which is what people hope for.

[0003] At present, gelling agents are divided into three categories: inorganic small molecule gelling agents, high molecular weight gelling agents and organic small molecule gelling agents. According to the above three types of gelling agents, there are the following three methods for preparing methanol gel: first, a high molecular weight polymer can be added with emulsifiers, 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 a high molecular weight gelling agent will have the problem of incomplete combustion of the high molecular weight gelling agent, which will cause a small amount of odor and smoke. Second, the inorganic gelling agent is dissolved in water, and then added to methanol to form a methanol gel after stirring. The preparation of methanol gel by using inorganic small molecule gelling agent requires the addition of more than 10% of water by volume of methanol to dissolve and disperse the inorganic small molecule gelling agent, which will cause the heat value of the methanol gel to decrease. Third, the organic small molecule is added to methanol, heated and cooled to form a methanol gel. The preparation of methanol gel by using organic small molecule gelling agent requires heating, and the synthesis of organic small molecule gelling agent is difficult and has high cost.

[0004] Therefore, it is desirable to select a cheap and readily available gelling agent to prepare a methanol gel by a simple method, and to avoid the problems of odor and heat value reduction of the methanol gel during combustion.

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

[0006] The present application only adds calcium acetate powder and forms a methanol gel with high viscosity, high mechanical strength and low evaporation rate at room temperature by ultrasonic oscillation. The use of calcium acetate powder as a gelling agent is cheap and readily available, and the preparation process is simple without the need for stirring, heating and other steps, greatly simplifying the process. In addition, the preparation process does not require the addition of high molecular weight polymers, and the combustion is pollution-free and odor-free.

[0007] The first aspect of the present application provides a methanol gel, which comprises methanol and calcium acetate, and which does not comprise water; the mass fraction of the methanol is 90.00-99.50%, and the mass fraction of the calcium acetate powder is 0.50-10.00%, based on the total mass of the methanol gel.

[0008] Preferably, the calcium acetate powder is anhydrous calcium acetate powder.

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

[0010] Preferably, the mass fraction of the methanol is 98.1%, and the mass fraction of the calcium acetate powder is 1.9%.

[0011] Preferably, at room temperature, the viscosity of the methanol gel is 5-15 kPa·s at a shear rate of 0.01 s -1 Preferably, at room temperature, the storage modulus of the methanol gel is 5-100 kPa in the linear elastic region.

[0012] The second aspect of the present application provides a preparation method of the methanol gel of the first aspect of the present application, which uses calcium acetate powder as a gelling agent and uses ultrasonic oscillation to prepare the methanol gel.

[0013] Preferably, the method comprises the following steps:

[0014] (1) adding methanol and calcium acetate powder into a container;

[0015] (2) placing the container containing the methanol and the calcium acetate powder into an ultrasonic environment, oscillating for 30 s-5 min to obtain the methanol gel.

[0016] More preferably, the oscillation time is 3 min.

[0017] Preferably, the ultrasonic frequency of the ultrasonic source is 20-80 kHz, and the ultrasonic power density is 10-50 W·L -1 .

[0018] More preferably, the ultrasonic frequency and the ultrasonic power density of the ultrasonic source are 40 kHz and 28 W·L -1 .

[0019] The ultrasonic source is any device that can provide ultrasonic waves in the specified range, including but not limited to ultrasonic cleaning machines, ultrasonic dispersion machines, and ultrasonic cell pulverizers.

[0020] The third aspect of the present application provides the use of the methanol gel of the first aspect of the present application as a fuel.

[0021] Preferably, the heat value of the methanol gel fuel is 15-20 MJ·L -1 .

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] 1、The gelling agent used in the present application is calcium acetate powder, which is cheap and easy to obtain, and the amount used is small. Only 0.5% of the methanol gel is needed to form a stable methanol gel. The gel is transparent or translucent, has high viscosity (5-15 kPa·s) at shear rate, and high mechanical strength (storage modulus in the linear elastic region is 5-100 kPa). -1

[0024] 2、The present application prepares methanol into methanol gel, which reduces the volatilization rate of methanol. After standing for 25 h, 10 mL of pure methanol volatilizes by 50%, while the same volume of methanol gel volatilizes by only 30%, which improves the safety of methanol fuel and reduces the difficulty of storage and transportation.

[0025] 3、The present application only needs to add calcium acetate powder and ultrasonic oscillation to form a gel. The use of calcium acetate powder as a 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 require the addition of high molecular polymers, and the combustion is pollution-free and odor-free.

[0026] Specifically, compared with methanol gel prepared by selecting 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 methanol gel prepared by selecting 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 methanol gel prepared by selecting organic small molecule gelling agent, the gelling agent of the present application is inorganic small molecule calcium acetate powder, which has low cost.

[0027] 4、Unexpectedly, the combination of calcium acetate powder and methanol can form a gel after ultrasonic oscillation. Correspondingly, replacing calcium acetate powder with other inorganic gelling agent, such as silicon dioxide, or replacing methanol with ethanol or other alcohols, cannot form a stable gel. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Flow chart for preparing methanol gel. DETAILED DESCRIPTION

[0029] The present application will be further described by the following examples, which are not limited to the present embodiment. The experimental methods not specified in the examples are generally carried out according to the conventional conditions and the conditions described in the manual, or using the general equipment, materials, reagents, etc. suggested by the manufacturer, unless otherwise specified, which can be obtained from commercial channels.

[0030] Example 1

[0031] ​This example is the preparation of methanol gel sample 1. 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 as follows: methanol and calcium acetate powder are added into a container; the container containing methanol and calcium acetate powder is placed in an ultrasonic environment, and oscillated 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] The viscosity, mechanical strength, heat value and volatilization degree data of methanol gel sample 1 are shown in Table 1. The viscosity refers to the viscosity of the sample at room temperature, 0.01 s -1 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.

[0034] Comparative Example 1

[0035] This comparative example is the preparation of methanol mixture comparative sample 1. The preparation method is the same as that of methanol gel sample 1 in Example 1, except that the gelling agent is fumed silica. The mass fraction of methanol in methanol mixture comparative sample 1 is 98.6% and the mass fraction of fumed silica powder is 1.4%.

[0036] Comparative Example 2

[0037] This comparative example is the preparation of ethanol mixture comparative sample 2. The preparation method is the same as that of methanol gel sample 1 in Example 1, except that methanol is replaced by ethanol. The mass fraction of ethanol in ethanol mixture comparative sample 2 is 98.2% and the mass fraction of calcium acetate powder is 1.8%.

[0038] From Comparative Examples 1 and 2, it can be seen that the combination of calcium acetate powder and methanol can form a gel after ultrasonic oscillation. Correspondingly, replacing calcium acetate powder with other inorganic gelling agent fumed silica or replacing methanol with ethanol or other alcohols cannot form a stable gel.

[0039] Example 2

[0040] This example is the preparation of methanol gel sample 2. The preparation method is the same as that of methanol gel sample 1 in Example 1, except that the mass fraction of methanol in methanol gel sample 2 is 99.5% and the mass fraction of calcium acetate powder is 0.5%.

[0041] The viscosity, mechanical strength, heat value and volatilization degree data of the methanol gel sample 2 are shown in Table 1.

[0042] Example 3

[0043] This example is the preparation of methanol gel sample 3. The preparation method is the same as that of methanol gel sample 1 in Example 1, except that the mass fraction of methanol in the methanol gel sample 3 is 90% and the mass fraction of calcium acetate powder is 10%.

[0044] The viscosity, mechanical strength, heat value and volatilization degree data of the methanol gel sample 3 are shown in Table 1.

[0045] Example 4

[0046] This example is the preparation of methanol gel fuel sample 4. The methanol gel is prepared by using the semi-crown ether-dicarbonyl small molecule organic HCE as the gelling agent and ultrasonic oscillation. Based on the total mass of the methanol gel, the mass fraction of methanol in the methanol gel sample 4 is 98.8% and the mass fraction of HCE is 1.2%. Among them, the ultrasonic frequency and ultrasonic power of the ultrasonic cleaning machine are 40 kHz and 840 W respectively.

[0047] The preparation method is: methanol and HCE are added into a container, stirred at 600 r·min-1 and 60 ℃ for 5 min, and then a methanol gel is prepared. -1

[0048] The viscosity, mechanical strength, heat value and volatilization degree data of the methanol gel sample 4 are shown in Table 1.

[0049] Example 5

[0050] This example is the preparation of methanol gel fuel sample 5. The methanol gel fuel is prepared by using the small molecule organic 1,3:2,4-dibenzal sorbitol (DBS) as the gelling agent and ultrasonic oscillation. Based on the total mass of the methanol gel, the mass fraction of methanol in the methanol gel sample 5 is 98.8% and the mass fraction of DBS is 1.2%. Among them, the ultrasonic frequency and ultrasonic power of the ultrasonic cleaning machine are 40 kHz and 840 W respectively.

[0051] The preparation method is: methanol and DBS are added into a container, stirred at 600 r·min-1 and 60 ℃ for 5 min, and then a methanol gel is prepared. -1

[0052] The viscosity, mechanical strength, heat value and volatilization degree data of the methanol gel sample 5 are shown in Table 1.

[0053] ​​As can be seen from the comparison of Examples 1-5, although the calcium acetate powder, which is cheap and easy to obtain, is used as the gelling agent in Examples 1-3, the methanol gels are prepared by a simple ultrasonic method, but the viscosity, mechanical strength, heat value and volatile resistance of the methanol gel samples in Examples 1-3 are all very excellent compared with Examples 4-5.

[0054] Table 1 Properties of different methanol gel samples

[0055]

[0056] The above has made an exemplary description of the present application, it should be explained that, without departing from the core of the present application, any simple transformation, modification 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 methanol gel, characterized in that, It includes methanol and calcium acetate, but does not include water; based on the total mass of the methanol gel, the mass fraction of methanol is 90.00-99.50%, and the mass fraction of calcium acetate powder is 0.50-10.00%. The calcium acetate powder is anhydrous calcium acetate powder. The method for preparing the methanol gel is as follows: using calcium acetate powder as a gelling agent, methanol gel is prepared by ultrasonic oscillation. The method for preparing the methanol gel includes the following steps: (1) Add methanol and calcium acetate powder to the container; (2) Place the container containing methanol and calcium acetate powder in an ultrasonic environment and vibrate for 30s-5min to obtain methanol gel; The ultrasonic source has an ultrasonic frequency of 20-80 kHz and an ultrasonic power density of 10-50 W·L, respectively. -1 .

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

3. The methanol gel according to claim 1, characterized in that, The methanol has a mass fraction of 98.48%; the calcium acetate powder has a mass fraction of 1.52%.

4. The methanol gel according to claim 1, characterized in that, At room temperature, 0.01s -1 At the shear rate, the viscosity of the methanol gel is 5-15 kPa·s; at room temperature, in the linear elastic region, the storage modulus of the methanol gel is 50-100 kPa.

5. An application of the methanol gel as described in any one of claims 1-4 as a fuel.

6. The application according to claim 5, characterized in that, The calorific value of methanol gel fuel is 14-20 MJ·L. -1 .

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