Method for synthesizing methanol by using methane

Abstract

The invention discloses a method for synthesizing methanol by using methane, which comprises the following steps: placing water in a discharge area, ionizing the water to generate water free radical cation clusters, simultaneously introducing methane gas into a discharge reaction cavity, activating methane gas molecules by water free radical cations, converting the methane gas molecules into methanol, dissolving the generated target product methanol in the water, and discharging to obtain the methanol. A methanol aqueous solution is obtained in a product collection area. By simulating an atmospheric discharge experiment, methane and water fully act to prepare methanol, and a new method is provided for solving the problems that in the prior art, when methanol is prepared from methane, the reaction condition is harsh, and a catalyst is needed.

Description

Technical Field

[0001] The present invention relates to the fields of chemical basis and green chemistry, and in particular to a synthesis method for preparing methanol by reacting methane with water. Background Art

[0002] Methane (CH4) is the simplest and most inert hydrocarbon, widely distributed on Earth in the form of natural gas, shale gas, or biogas, and is highly available. Given its abundant reserves in the form of natural gas, shale gas, and combustible ice, as well as its clean-burning properties, methane shows great potential to surpass coal and oil as the dominant energy source. Currently, methane is mainly utilized through indirect pathways, first converting it into synthesis gas under high temperature and pressure, and then reacting to form methanol or hydrocarbons. There is a great need to directly convert methane into liquid chemicals suitable for transportation and storage. Methanol, as a clean and renewable fuel source, contains a large amount of useful energy and is an intermediate source of green energy, and its demand is very high. Therefore, the ideal solution is to convert methane into the liquid oxygen compound methanol, but significant obstacles remain in this research process, especially in terms of how to improve methanol selectivity and achieve target conversion rates.

[0003] Because the C-H bond in methane (104 kcal / mol) is the most inert of all hydrocarbons, with a low electron affinity and high ionization potential, the high temperatures required to activate the C-H bond often lead to over-oxidation of methane to CO2. Therefore, the direct conversion of methane into liquid oxygen compounds (methanol) suitable for transportation and storage remains a major challenge. In recent years, research on water radical cations has also been increasingly in-depth. Water radical cations play an important role in promoting research in related fields such as the origin of life, cell damage, proton transfer, and hydrogen bond formation. In addition, water radical cations are active substances that can serve as effective working media for ultraviolet radiation sources and as oxidants in droplet chemistry. Therefore, research related to water radical cations has also shown a gradual increase worldwide.

[0004] So far, there has been no report on how to use water radical cations to prepare methanol. Summary of the Invention

[0005] The present invention aims to provide a novel reaction for the rapid synthesis of methanol based on the reaction of water radical cations with methane. This invention can provide new ideas for the research of green, environmentally friendly, and low-energy methanol synthesis. The technical solutions of the present invention are as follows:

[0006] A method for synthesizing methanol from methane comprises: ionizing water by discharge in a reaction device to prepare water radical cation clusters; simultaneously, methane gas is introduced into the reaction device; the water radical cations activate methane gas molecules; and under normal temperature and pressure conditions, the water radical cations interact with methane in the reaction device to convert the methane into methanol and hydrogen.

[0007] Furthermore, the reaction device includes a reaction chamber, an array plate and a stainless steel reaction tank located in the reaction chamber, and a gas output port and a gas source inlet connected to the reaction chamber. The array plate is connected to the positive electrode of the high-voltage source, the stainless steel tank is connected to the negative electrode of the high-voltage source, and a water input channel and a product output channel are provided on the stainless steel tank.

[0008] Furthermore, the reaction device also includes a distance adjustment device capable of adjusting the up and down movement of the array plate.

[0009] Furthermore, the methane gas content in the reaction chamber is 8-12L.

[0010] Furthermore, the discharge voltage in the reaction chamber is 4-8 kV.

[0011] Furthermore, the product output channel is connected to a detection device.

[0012] Furthermore, the detection equipment is one of a chromatograph, an ultraviolet detector and a mass spectrometer.

[0013] Furthermore, the array plate is provided with tungsten needles arranged in a grid array, the distance between the tips of the tungsten needles and the water level in the stainless steel tank is between 10-30 mm, and the curvature radius of the tips of the needles is between 0.01-0.1 mm.

[0014] Furthermore, during detection, the methanol detection color developing agent is basic fuchsin.

[0015] Furthermore, the reaction device also includes a hydrogen detector, which is used to detect whether hydrogen is generated in the reaction chamber.

[0016] The present invention has the following beneficial effects: It utilizes a reaction chamber to convert water molecules into water radical cation clusters. The resulting water radical cation clusters react with methane gas molecules to produce methane radical cations, which then rapidly reach a stainless steel tank to produce methanol. This method avoids the traditional, tedious and lengthy reaction processes of high temperature, high pressure, acid and alkali dissolution, and the use of catalysts. The entire reaction time is extremely short, with the product signal clearly visible via mass spectrometry the moment methane gas is injected. The present invention aims to provide a novel reaction for the rapid synthesis of methanol based on the reaction of water radical cations with methane, offering new insights into environmentally friendly, low-energy methanol synthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above advantages of the present invention will become apparent and easily understood in conjunction with the following drawings, wherein;

[0018] Figure 1 Schematic diagram of the methanol synthesis device structure of the present invention: 1-gas output port, 2-gas source inlet, 3-water input channel, 4-distance adjustment device, 5-high-voltage source positive electrode, 6-high-voltage source negative electrode; 7-product output channel, 8-adjustment scale, 9-sealing slide rod, 10-reaction chamber, 11-stainless steel tank, 12-array plate;

[0019] Figure 2 The mass spectrum of methanol produced by the reaction of water radical cations with methane gas is compared with that of standard methanol;

[0020] Figure 3 This is a gas chromatogram comparing the methanol produced by the reaction of water radical cations with methane gas and the standard methanol. DETAILED DESCRIPTION

[0021] To make the objectives, features, and advantages of the present invention more readily apparent, the following detailed description of specific embodiments of the methane-to-methanol invention is provided with reference to the accompanying drawings. The accompanying drawings illustrate several reaction examples of the present invention. However, the present invention can be implemented in many different forms and is not limited to the examples described herein. Rather, these reaction examples are provided to enhance the openness and transparency of the present invention.

[0022] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0023] In this document, unless otherwise specified or limited, the terms "connect," "fixed," and "connected" are to be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or non-mechanical connections; direct, through an intermediate medium, or internal communication between components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0024] See also Figure 1-Figure 3 , a methanol preparation device used in a methanol synthesis method proposed in one embodiment of the present invention ( Figure 1), the shell of which is made of acrylic material, and specifically includes a gas output port 1, a gas source inlet 2, a water input channel 3, a distance adjustment device 4, a high-voltage source positive electrode 5 and a product output channel 7.

[0025] The gas outlet 1 is connected to a mechanical pump, which is used to extract the air in the reaction chamber 10 and to output and collect the reaction product H2 from the reaction chamber 10.

[0026] The gas source inlet 2 is used to fill the reaction chamber 10 with methane gas.

[0027] The water input channel 3 is connected to the product collection channel 7. After water is input into the reaction chamber 10 through the water input channel 3, it reacts in the stainless steel tank 11 to generate product methanol, which is output through the product output channel 7 and collected.

[0028] The stainless steel tank 11 is connected to the high voltage source negative electrode 6 and has a size of 32.4×32.4×1.5 cm.

[0029] The distance adjustment device 4 is connected to the array plate 12 in the reaction chamber 10, and the distance between the needle tip and the water level in the stainless steel tank 11 can be adjusted by adjusting the height of the array plate 12. Preferably, the distance between the needle tip and the water level is optimized to be between 10-30 mm.

[0030] The array plate 12 and the stainless steel tank 11 are respectively connected to the positive electrode and the negative electrode of a high voltage source. Preferably, the voltage of the high voltage source is 6 kV.

[0031] A reaction space is defined between the array plate 12 and the stainless steel tank 11 . The methane gas is introduced into the reaction space. 900 mL of water is placed in the stainless steel tank. In another embodiment, during detection, the methanol detection developer is basic fuchsin.

[0032] The array plate 12 is composed of 841 tungsten needles (with a tip diameter of 60 μm) arranged in a 29×29 grid configuration and connected to the positive electrode 5 of the high voltage source.

[0033] The distance between the tip of the tungsten needle and the water level in the stainless steel tank is between 10-30 mm, and the curvature radius of the tip of the needle is between 0.01-0.1 mm.

[0034] Based on the above device, the methanol preparation method includes:

[0035] The air in the reaction chamber 10 is pumped out by a mechanical pump through the gas outlet 1, and then methane gas is input into the reaction chamber 10 through the gas source inlet 2. Water is injected into the stainless steel tank 11 in the reaction chamber 10 through the water input channel 3. Then, the height of the array plate 12 is adjusted. The height adjustment can be intuitively adjusted by adjusting the scale.

[0036] The high voltage source is turned on and voltage is applied to the array plate 12, so that the needle tip of the discharge array needle generates a spark discharge and ionizes the surrounding water vapor to form water radical cation clusters. The formed water radical cation clusters react with methane gas to produce methanol molecules, which condense into liquid and are further collected through the product output channel 7. In specific implementation, the product output channel 7 can be connected to a detection device, which can be a chromatograph, an ultraviolet detector or a mass spectrometer, but is not limited thereto.

[0037] The methanol-water solution formed in the stainless steel tank 11 in the sample collection area is removed and collected by opening a valve. Specifically, a high voltage (6 kV) is applied to the array plate 12, generating a spark discharge at the tip of the discharge needle. At room temperature and pressure (e.g., 25°C, 1 atmosphere) with methane as the carbon source, this high-voltage spark discharge generates water radical cation clusters. These water radical cation clusters fully contact the methane gas and react to produce methanol molecules. The resulting methanol molecules condense into a liquid state, are stored in the stainless steel tank 11, and are collected through the product output channel 7.

[0038] This invention designs a novel reaction device that simulates the ionization of water into water radical cation clusters under the action of a discharge. Methane gas is then introduced, and the water radical cations activate methane molecules, producing the target product, methanol. This enables a low-energy methane conversion process that is efficient, rapid, green, and environmentally friendly. The reaction conditions are flexible and can be carried out at room temperature and pressure, using water as the solvent, resulting in a pure product.

[0039] The following are several examples to verify the preparation results of the above-mentioned methanol preparation method:

[0040] Example 1

[0041] At room temperature and pressure, the air in the reaction chamber was evacuated and methane (10 L) gas was introduced. Water was injected into the stainless steel tank of the negative electrode plate. The height of the array plate was adjusted (the distance between the needle tip and the water liquid surface was 20 mm). A high voltage (6 kV) was applied to the array plate and the reaction was allowed to proceed for 10 minutes. The generated methanol molecules condensed into a liquid and were discharged to the sample collection area through the product output channel to produce methanol.

[0042] Example 2

[0043] At room temperature and pressure, the air in the reaction chamber was evacuated and methane (10 L) gas was introduced. Water was injected into the stainless steel tank of the negative electrode plate. The height of the array plate was adjusted (the distance between the needle tip and the water liquid surface was 20 mm). A high voltage (6 kV) was applied to the array plate and the reaction was allowed to proceed for 20 minutes. The generated methanol molecules condensed into a liquid and were discharged to the sample collection area through the product output channel to produce methanol.

[0044] Example 3

[0045] At room temperature and pressure, the air in the reaction chamber was evacuated and methane (10 L) gas was introduced. Water was injected into the stainless steel tank of the negative electrode plate. The height of the array plate was adjusted (the distance between the needle tip and the water liquid surface was 20 mm). A high voltage (6 kV) was applied to the array plate and the reaction was allowed to proceed for 30 minutes. The generated methanol molecules condensed into a liquid and were discharged to the sample collection area through the product output channel to produce methanol.

[0046] Test 1: The product of Example 1 was subjected to mass spectrometry and chromatography analysis. From the results of mass spectrometry data, the collected methanol product was characterized by high resolution ionization mass spectrometry positive ion mode, such as Figure 2 In a, the product methanol signals m / z 33.0334 and m / z 51.0435 can be clearly observed, corresponding to [CH3OH+H] + and [CH3OH+H3O] + , consistent with the standard methanol ( Figure 2 b). These newly generated methanol product ions m / z 33, m / z 51 and m / z 52 were further screened by tandem mass spectrometry analysis as shown in FIG. Figure 2 Middle C and Figure 2 In d, these signals can be identified as protonated methanol [CH3OH+H] + , stable intermediate [CH3OH+·+H·] and water cluster compound [CH3OH2+H2O] + The tandem mass spectrometry data of these product ions all showed typical loss of H2O and (CH3·) characteristic ions, which are typical loss fragment ion characteristics of methanol water cluster compounds, indicating that methanol was formed in the reaction solution.

[0047] Test 2: Identification of methanol produced from CH4 oxidation by gas chromatography (GC) equipped with a flame ionization detector. Figure 3 The reaction sample a in the middle showed a peak at 1.3 min, and the retention time was consistent with that of the standard methanol. The reaction sample was detected by the fuchsin-sulfite method, and the product was further verified by using ultraviolet-visible (UV-VIS) spectroscopy and compared with the corresponding standards, such as Figure 3 As shown in Figure b, the peak positions of the reaction sample and the standard are the same, which is consistent with the experimental data from mass spectrometry.

[0048] In summary, according to the methanol synthesis method proposed in this embodiment, the entire synthesis process can be carried out at room temperature and pressure (referring to pressure), without the need for chemical catalysts, saving energy, and being green and pollution-free.

[0049] In the description of this specification, reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples.

[0050] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for synthesizing methanol from methane, characterized in that: In the reaction device, water is ionized by discharge to prepare water radical cation clusters. At the same time, methane gas is introduced into the reaction device. The water radical cations activate the methane gas molecules. Under normal temperature and pressure conditions, the water radical cations interact with methane in the reaction device to convert methane into methanol and hydrogen.

2. The method for synthesizing methanol from methane according to claim 1, wherein: The reaction device includes a reaction chamber, an array plate and a stainless steel reaction tank located in the reaction chamber, and a gas output port and a gas source inlet connected to the reaction chamber, wherein the array plate is connected to the positive electrode of the high-voltage source, the stainless steel tank is connected to the negative electrode of the high-voltage source, and the stainless steel tank is provided with a water input channel and a product output channel.

3. The method for synthesizing methanol from methane according to claim 2, wherein: The reaction device also includes a distance adjustment device capable of adjusting the up and down movement of the array plate.

4. The method for synthesizing methanol from methane according to claim 1, wherein: The methane gas content in the reaction chamber is 8-12L.

5. The method for synthesizing methanol from methane according to claim 1, characterized in that: The discharge voltage in the reaction chamber is 4-8 kV.

6. The method for synthesizing methanol from methane according to claim 2, wherein: The product output channel is connected to a detection device.

7. The method for synthesizing methanol from methane according to claim 6, characterized in that: The detection equipment is one of a chromatograph, an ultraviolet detector and a mass spectrometer.

8. The method for synthesizing methanol from methane according to claim 2, wherein: The array plate is provided with tungsten needles arranged in a grid array, the distance between the needle tips and the water level in the stainless steel tank is between 10-30 mm, and the curvature radius of the needle tips is between 0.01-0.1 mm.

9. The method for synthesizing methanol from methane according to claim 6, characterized in that: During the detection, the color developing agent for methanol detection is basic fuchsin.

10. The method for synthesizing methanol from methane according to claim 2, characterized in that: The reaction device also includes a hydrogen detector, which is used to detect whether hydrogen is generated in the reaction chamber.

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