CN107523274B

CN107523274B - Method for producing high latent heat phase change material

Info

Publication number: CN107523274B
Application number: CN201710444662.1A
Authority: CN
Inventors: 孙剑锋; 赵彬; 陈保莲; 陈明; 刘纾言; 张志银
Original assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Current assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Priority date: 2016-06-17
Filing date: 2017-06-13
Publication date: 2020-04-14
Anticipated expiration: 2037-06-13
Also published as: CN107523274A

Abstract

The invention discloses a method for producing a high latent heat phase change material. The method takes an F-T synthetic product as a hydrogenation raw material, and carries out hydrogenation conversion under the action of a catalyst; distilling the hydrogenation product to prepare a component with a proper distillation range as a sweating raw material; then producing the target product through sweating. The method of the invention is based on the common sweating process, a high-temperature constant-temperature stage is added in the temperature reduction process, liquid components are carried by airflow through a wax layer in the sweating process to forcibly separate solid components and liquid components, and simultaneously, the method preferentially emulsifies aqueous solutions of more than two substances which can react to generate gas respectively and then sweats, and is also beneficial to the rapid discharge of the liquid components. The method has the advantages of low equipment investment, simple preparation process, low operation cost, safety, no solvent pollution, high latent heat of the obtained product and the like.

Description

Method for producing high latent heat phase change material

Technical Field

The invention belongs to the technical field of special wax production, and particularly relates to a method for producing a high latent heat phase change material.

Background

The world energy supply is mainly mineral fuels such as petroleum, natural gas, coal and the like, and with the reduction of reserves and the rise of prices of the non-renewable resources, the research on various alternative energy sources such as F-T synthesis and the like is continuously strengthened; further, environmental problems caused by the use of these fossil fuels have become serious, and attention has been paid to energy saving, utilization of solar energy, and the like. Meanwhile, with the development of society, the requirement of people on living comfort level is higher and higher, and more energy is required to be consumed.

Phase Change Materials (PCM) have little temperature Change during melting or solidification, but absorb or release latent heat in a small temperature range rather greatly, and the characteristic makes the PCM widely applied to constant temperature, energy storage and the like. Generally, a phase change material is required to have a proper phase change temperature and a large latent heat of phase change. Researches on the aspect of storing solar energy and low-price electric energy by utilizing phase-change materials at home and abroad are very active fields at present.

Generally, phase change materials can be classified into high-temperature phase change materials, medium-temperature phase change materials and low-temperature phase change materials according to the difference of phase change temperatures. Generally, phase change materials can be classified into inorganic phase change materials and organic phase change materials according to their chemical compositions. Phase-change materials are generally classified into solid-gas phase-change materials, liquid-gas phase-change materials, solid-liquid phase-change materials, and solid-solid phase-change materials according to the phase change of the materials during the energy storage process. Two phase-change materials of solid-liquid and solid-solid are commonly used in the constant temperature and energy storage processes. The wax phase-change material is a common organic medium and low temperature solid-liquid phase-change material.

Petroleum wax is a generic name for various wax products prepared from distillate oil containing wax after crude oil refining, and comprises liquid paraffin, soap wax, paraffin wax and microcrystalline wax. The paraffin wax generally contains C₂₀～C₅₀Normal paraffin, isoalkane, a small amount of cyclane and other components, and the melting point is usually 50-74 ℃; the microcrystalline wax is generally composed of C₃₀～C₆₀The isoparaffin and a small amount of normal paraffin and cycloparaffin, the drop melting point is usually 65-92 ℃, and the isoparaffin has a needle-shaped crystal structure which is finer than paraffin in a solid state. Petroleum wax is a hydrocarbon mixture of n-paraffins, iso-paraffins, cyclo-paraffins, etc. with various carbon numbers, and has a wide carbon number distribution and a low n-paraffin content.

The latent heat of phase change of normal paraffins is large compared to isoparaffins and cycloalkanes. With the increase of the chain length of the n-alkane, the melting point of the n-alkane is increased, and the melting point of the common n-alkane is-20-100 ℃. The melting point of the wax is the comprehensive reflection of various components of the wax, so that the melting point of the wax can be adjusted within the range of-20-100 ℃, and the wax is the most advantage of being used as a phase change material. Meanwhile, the temperature region is the most frequently contacted range in daily life of people, and the wax has stable chemical property, no corrosiveness and no environmental pollution, so that the wax has incomparable advantages when being used as a phase change material. However, the common petroleum wax contains components such as isoparaffin and cyclane, and has wider carbon number distribution, smaller latent heat and wider phase change interval when being directly used as a phase change material.

Petroleum waxes must be purified to increase the n-alkane content and reduce the carbon number distribution breadth for use as phase change materials. The purification processes are complex in process, not only are the production cost high, but also a certain amount of non-suitable components such as oil and the like exist in the phase-change material, and the existence of the non-suitable components influences the service performance of the phase-change material.

The Fischer-Tropsch (F-T) synthesis technology was invented in 1923 and was industrialized in 1936 in Germany. The F-T synthesis technology mainly comprises a high-temperature synthesis technology and a low-temperature synthesis technology. Since the nineties of the twentieth century, F-T synthesis processes and catalysts have made breakthrough progress, and F-T synthesis products are increasingly abundant. The fischer-tropsch synthesis product contains olefins and oxygenates and has a very broad carbon number distribution and cannot be used directly as a phase change material.

In the production process, the separation means of wax substances commonly used include distillation, solvent separation, sweating separation and the like.

Distillation is used for separating and purifying different hydrocarbons by utilizing different boiling points, and the reduction of the boiling range of distillation can effectively reduce the width of the carbon distribution of the product, for example, CN201410217632.3 (a method for increasing the freezing point of Fischer-Tropsch wax) introduces that raw materials are subjected to high temperature and high vacuum to remove low boiling point substances, and then are further subjected to distillation refining under extremely high vacuum to prepare high melting point wax products. The raw materials need to be heated to a boiling point above in the distillation process, a large amount of energy is consumed, the boiling point of the hydrocarbon with the melting point above 70 ℃ is above 500 ℃ (normal pressure), and the efficiency is greatly reduced when the distillation is adopted for separation.

The solvent separation is to utilize the different solubility of alkanes with different structures and molecular weights in the solvent to achieve the separation, such as CN200410043806.5 (a method for separating polyethylene wax) and CN201110351185.7 (a method for separating polyethylene byproduct polyethylene wax). The investment of production equipment of the solvent separation process is large; a large amount of solvent is needed in the production process, and a large amount of energy is consumed for recovering the solvent; the solvent usually contains benzene series substances, which can affect the environment; the solvent is inflammable and is easy to cause production accidents.

The sweating separation method is to separate and purify by utilizing the properties of different melting points of various components in the raw materials. The difference in molecular weight and structure of the various components will cause them to have different melting points. When the normal paraffin is the same as the normal paraffin, the melting point of the normal paraffin with larger molecular weight is higher, and the melting point of the normal paraffin with smaller molecular weight is lower; the same molecular weight, isoparaffins and naphthenes have lower melting points than normal paraffins, and the higher the degree of isomerization, the lower the melting point. Therefore, the sweating separation method can reduce the width of the carbon distribution of the product and can also improve the content of the normal alkane.

Compared with a distillation method, the energy consumption of the sweating process is far lower than that of distillation because the melting point temperature of various hydrocarbons is far lower than the boiling point temperature; compared with solvent separation, the solvent is not used in the sweating process, so that the sweating process is safe and energy-saving and has no influence on the environment. And the sweating method can reduce the width of the carbon distribution of the product and improve the content of the normal alkane, so that the sweating separation process has advantages in the production process and the product performance for producing the phase-change material.

The common sweating process mainly comprises the following steps: (1) preparation work: filling water (filling the space under the dish plate of the sweating device with water), and then loading the materials (loading the materials into the sweating device when the materials are heated to be liquid above the melting point); (2) and (3) crystallization: the raw material is slowly cooled to 10-20 ℃ below the melting point thereof at a cooling rate of not more than 4 ℃/h. In the cooling process, the components are crystallized sequentially from high to low according to the melting points to form solids; (3) sweating: when the temperature of the wax layer reaches the preset temperature reduction termination temperature, draining the padding water; the material is then slowly heated to a predetermined sweating termination temperature. During sweating, the components are sequentially melted into liquid state according to the sequence of melting point from low to high and flow out (under wax), and finally the wax layer residue (on wax) is the wax with high melting point and low oil content; (4) refining: collecting the crude product (raising the temperature continuously after the sweating process is finished to melt and take out the wax to obtain the crude product), performing clay refining (heating the crude product to a preset temperature after melting, adding clay, stirring at a constant temperature for a preset time, and filtering), and then molding and packaging to obtain the target product.

The common sweating process can produce soap wax and low-melting-point paraffin with the melting point of 40-60 ℃, and is not suitable for producing wax products with the melting point of more than 70 ℃. When the common sweating process is used for producing the soap wax and the low-melting-point paraffin wax at 40-60 ℃, the solid component (the wax with a higher melting point) and the liquid component (the oil and the wax with a lower melting point) are respectively in two phases of solid and liquid in the sweating process, but are difficult to be completely separated. In order to make the final product meet the requirements, a method of prolonging the sweating time (reducing the temperature rise speed) and increasing the sweating termination temperature is generally adopted, but the method has the disadvantages of long production period and low product yield; tests show that when a wax product with the melting point of more than 70 ℃ is produced by a common sweating process, the carbon distribution width and the n-alkane content on the wax at the sweating later stage are irrelevant to the yield, namely the carbon distribution width on the wax is not reduced along with the reduction of the yield, and the n-alkane content is not improved along with the reduction of the yield, so that no report is found for producing the wax phase-change material with the melting point of more than 70 ℃ by the sweating process.

Compared with solvent separation, the sweating process is intermittent operation, the product yield is low, the production period is long, but the sweating process has the advantages of low investment, simple production process, low operation cost, safe production process, energy conservation, no pollution to the environment and the like, and at present, partial manufacturers still use the method to produce the wax products for the soap.

For many years, the sweating separation method is developed in the aspects of production equipment and processes, such as CN89214332 (vertical square multi-section partition sweating tank), CN94223980.6 (dish type sweating device), CN98233254.8 (paraffin sweating tank), CN200920033500.X (novel paraffin sweating tank), CN201210508905.0 (high-efficiency paraffin sweating device), CN201320127680.4 (tubular paraffin deoiling device) and the like, and is improved on the sweating separation production equipment; CN91206202 (a high-efficiency paraffin sweating pot) is improved on the sweating separation process, but the improvements still cannot produce wax phase-change materials with the melting point of more than 70 ℃.

The sweating process is the only solvent-free separation method for producing petroleum wax products on an industrial scale, and the demand for producing wax phase-change materials with the melting point of more than 70 ℃ by adopting the sweating process is more urgent at present when green, low-carbon, environmental-friendly and energy-saving production is advocated.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for producing a high latent heat phase-change material, which comprises four parts of hydrogenation, distillation, emulsification and sweating. Specifically, a proper F-T synthetic product is used as a raw material, and hydrogenation is carried out under the action of a catalyst; distilling the hydrogenation product to prepare a component with a proper distillation range as a sweating raw material; then, on the basis of a common sweating process, a sweating device is adopted, preferably, the sweating raw material and aqueous solutions of more than two substances capable of reacting to generate gas are respectively emulsified and then sweating is carried out, and the aqueous solutions and the gas generated by the reaction form tiny spaces in a wax layer, so that the liquid components in the sweating stage are favorably discharged; in the sweating process, the liquid components are carried by the airflow through the wax layer to forcibly separate the solid components from the liquid components, so that the separation effect is enhanced and the separation speed is increased; and the constant temperature stages of the crystallization process and the sweating process are increased, so that the solvent-free separation method can produce a high latent heat phase-change material product with the melting point of more than 70 ℃ and the latent heat of more than 210J/g. The method has the advantages of low investment of production equipment, simple production process, low operation cost, safety, energy conservation, no solvent pollution and the like.

The invention relates to a method for producing a high latent heat phase-change material, which comprises the following steps:

hydrogenation: hydrogenating the F-T synthetic product under the action of a hydrogenation catalyst to convert olefin and oxygen-containing compounds in the F-T synthetic product into normal alkane;

(II) distillation: preparing a fraction with an initial boiling point of 490-520 ℃ and an end boiling point of 520-550 ℃ from the product obtained by the hydroconversion in a distillation device, and taking the fraction as a sweating raw material;

(III) emulsification: the method comprises the following steps:

(A1) preparing an oil phase material: heating and melting the sweating raw material prepared in the step (II); adding an oil-soluble emulsifier, and uniformly stirring to form an oil material phase;

(A2) preparing a water-phase material: respectively dissolving the component (I) and the component (II) in water, and forming a water phase material of the component (I) and a water phase material of the component (II) with or without heating;

(A3) preparing an emulsion: respectively adding the water phase material of the component (I) and the water phase material of the component (II) into the oil phase material under the stirring condition, and continuously stirring for 5-60 minutes to form an emulsion of the component (I) and an emulsion of the component (II);

(IV) sweating: the method comprises the following steps:

(B1) preparation work: mixing the emulsion of the component (I) prepared in the step (A3) and the emulsion of the component (II) uniformly under the pressure condition, and filling the mixed emulsion into a sweating device;

(B2) and (3) crystallization: under the pressure condition, cooling the mixed emulsion to the melting point of the sweating raw material plus 4 ℃ to plus 15 ℃ at the speed of 2.0 ℃/h to 30.0 ℃/h, then cooling the wax layer to a proper temperature at the speed of 1.0 ℃/h to 3.0 ℃/h, and keeping the temperature at the high temperature for a period of time; then cooling to the termination temperature of 5-20 ℃ below the melting point of the sweating raw material at the speed of 0.5-2.5 ℃/h;

(B3) and (3) low-temperature constant temperature: keeping the temperature constant for a period of time at the crystallization termination temperature, and simultaneously reducing the pressure to the normal pressure;

(B4) sweating: heating to a first preset temperature at the speed of 0.5-3.0 ℃/h, keeping the temperature for a period of time, heating to a second preset temperature at the speed of 0.5-2.5 ℃/h, keeping the temperature for a period of time, and stopping sweating; forcing an air stream through the wax layer during sweating;

(B5) refining: and refining the target product to obtain the phase-change material.

In the method of the present invention, the F-T synthesized product has a normal paraffin content of 85% by weight or more, preferably 95% by weight or more, as a hydrogenation raw material.

In the method of the present invention, the hydrogenation process described in the process (a) adopts the conventional technology in the field, and the operation conditions are as follows: the reaction pressure is 3-10 MPa, the reaction temperature is 150-300 ℃, and the liquid hourly space velocity is 0.2-2.0 h^-1And the volume ratio of the hydrogen to the liquid is 100-1000: 1, the volume ratio of hydrogen liquid is preferably 300-800: 1. the hydrogenation catalyst can be selected from Ni/Al₂O₃、W-Ni/Al₂O₃、Mo-Ni/Al₂O₃Or W-Mo-Ni/Al₂O₃Catalysts, and the like. The weight content of active metal component in the catalyst is 20-70% calculated by oxide. The hydrogenation catalyst may be prepared according to methods conventional in the art. The catalyst may be used by reducing or sulfiding the active metal oxide as required to enhance catalyst activity according to methods conventional in the art.

In the method of the present invention, a sweating raw material is emulsified with an aqueous solution of component (I) and an aqueous solution of component (II) in the presence of an oil-soluble emulsifier to prepare an emulsion of component (I) and an emulsion of component (II), and the two are mixed under pressure to serve as a sweating raw material. The oil-soluble emulsifier is selected from one or more of nonionic surfactant, anionic surfactant, cationic surfactant and amphoteric surfactant. The HLB value of the oil-soluble emulsifier is 1-10, preferably 3-8. The freezing point or melting point of the surfactant is below the first predetermined temperature for sweating in step (B4).

Wherein the nonionic surfactant is selected from the group consisting of sorbitan monooleate, sorbitan monostearate, diethylene glycol fatty acid ester, diethylene glycol monolaurate, sorbitan monopalmitate, tetraethylene glycol monostearate, polyoxypropylene stearate, sorbitan monolaurate and polyoxyethylene fatty acid ester; the anionic surfactant is selected from fatty alcohol sulfate ester monoethanol amine salt, alkyl polyoxyethylene ether sodium sulfate, oleamido carboxylic acid sodium, sodium alkyl benzene sulfonate, N-methyl oleoyl taurate, butyl naphthalene sodium sulfonate, succinate sodium sulfonate, and maleic acid monoester sodium sulfonate. The cationic surfactant is selected from a group of substances consisting of benzyl quaternary ammonium salt, dodecyl dimethyl benzyl ammonium chloride, dodecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride and triethylamine oleate; the amphoteric surfactant is selected from the group consisting of dodecyl betaine, dodecyl dimethyl ammonium oxide, fatty alkyl imidazoline derivatives, fatty acid derivatives, and amphoteric modified ethylene oxide adduct.

In the present invention, the oil-soluble emulsifier is preferably a composite emulsifier composed of two or more surfactants.

In the method of the present invention, the component (I) and the component (II) in the step (A2) are a group of corresponding substances which are soluble in water and react with each other to form a gas. For example, component (I) may be selected from at least one of water-soluble acids, and component (II) may be selected from at least one of carbonates, bicarbonates, sulfites, bisulfites, metal sulfides; alternatively, the component (I) can be selected from at least one of inorganic bases, and the component (II) can be selected from at least one of inorganic ammonium salts; or the component (I) is selected from hydrochloric acid, and the component (II) is selected from at least one of perchlorate, chlorate and hypochlorite; alternatively, component (I) is also selected from hydrochloric acid and component (II) is selected from urea.

Wherein the water-soluble acid comprises an inorganic acid and/or an organic acid. The inorganic acid is selected from perchloric acid, hydroiodic acid, sulfuric acid, hydrobromic acid, hydrochloric acid, nitric acid, iodic acid, sulfurous acid, phosphoric acid, nitrous acid and hydrofluoric acid; the organic acid is selected from the group consisting of methanesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, trifluoromethanesulfonic acid, sulfamic acid, methanesulfinic acid, benzenesulfonic acid, thioacetic acid, methanethiol, thiophenol, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, n-heptanoic acid, n-octanoic acid, oxalic acid, malonic acid, tartaric acid, succinic acid, adipic acid, citric acid, acrylic acid, crotonic acid, oleic acid, fumaric acid, maleic acid, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid, salicylic acid, caffeic acid, glycolic acid, lactic acid, malic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, perfluorobutyric acid, perfluorooctanoic acid.

In the present invention, the mass concentration of the component (I) and the component (II) in the aqueous solution of the component (I) and the component (II) is 0.1 to 10.0%, preferably 0.5 to 4.0%. The components (I) and (II) are preferably acid and carbonate (bicarbonate) which are cheap, have wide sources, are non-toxic and have no pungent smell per se and reaction products. If component (I) is preferably hydrochloric acid and/or sulfuric acid, and component (II) is preferably at least one of sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate.

In the method of the present invention, the composition of the emulsion obtained in step (a 3) is: the mass percentage of the sweating raw material is 60.0-90.0%, the sum of the mass percentages of the water solutions of the component (I) and the component (II) is 9.9-30.0%, and the mass percentage of the oil-soluble emulsifier is 0.1-10.0%. The preferred composition of the emulsion is: 65.0-84.0 percent of sweating raw material, 15.0-30.0 percent of the sum of the mass percent of the aqueous solution of the component (I) and the mass percent of the aqueous solution of the component (II), and 1.0-5.0 percent of oil-soluble emulsifier.

The emulsification is a routine operation in the art. The emulsification conditions were: mixing at 75-98 ℃ for 5-60 minutes at a stirring speed of 50-1500 rpm; preferably, the mixture is mixed for 10 to 30 minutes at a stirring speed of 100 to 1000 revolutions per minute at a temperature of 80 to 95 ℃. In the step (A1) and the step (A2), the oil-phase material and the water-phase material are generally heated to 75 ℃ to 95 ℃ and 80 ℃ to 98 ℃, respectively.

In the method of the present invention, the sweating device is generally a sweating dish, and a detachable sealing system and a pressurizing device are added above the wax layer for applying air pressure above the wax layer during steps (B1) and (B2) to inhibit the gas generated by the reaction from escaping the wax layer during the preparation and crystallization. The pressure (gauge pressure) is 0.5 to 50.0 atm, preferably 10.0 to 30.0 atm.

In the method of the invention, in the step (B2), the temperature is preferably reduced to the range of the melting point of the sweating raw material plus 4 ℃ to the melting point plus 10 ℃ at the speed of 5.0 ℃/h to 25.0 ℃/h, and then the temperature reduction speed before the high-temperature constant-temperature section is preferably 1.5 ℃/h to 2.5 ℃/h. The proper temperature of the high-temperature constant-temperature section in the temperature reduction process is-1.0-4.0 ℃ of the melting point of the sweating raw material, and the melting point of the sweating raw material is preferably-3.0 ℃. The time of the high-temperature constant-temperature section in the cooling process is 0.1-6.0 hours, preferably 0.5-5.0 hours, and more preferably 1.0-4.0 hours.

In the method, the cooling rate of the crystallization in the step (B2) after the high-temperature constant-temperature section is preferably 1.0-2.0 ℃/h. The temperature reduction termination temperature is preferably 8-15 ℃ below the melting point of the sweating raw material.

In the method, the constant temperature in the step (B3) is kept for 0.1-5.0 h, preferably 0.5-3.0 h; while gradually reducing the pressure to atmospheric pressure. The rate of pressure reduction is generally 0.1 to 150.0 atm/hr, preferably 5.0 to 50.0 atm/hr.

In the method, a pressure device is added above the wax layer of the sweating dish and/or a vacuum device is added below the wax layer, so that a pressure difference is formed between the upper part and the lower part of the wax layer. And (B4) forcing the air flow through the wax layer by increasing the pressure (air pressure) above the wax layer and/or decreasing the pressure (air pressure) below the wax layer to form a pressure difference between the upper and lower sides of the wax layer. The pressure differential is generally between 0.1 and 5.0 atmospheres, preferably between 0.2 and 2.0 atmospheres, to force the air flow through the wax layer.

In the method of the present invention, in the step (B4), the temperature increase rate before the first predetermined temperature is preferably 1.0 ℃/h to 2.5 ℃/h, and the temperature increase rate after the first predetermined temperature is preferably 0.5 ℃/h to 2.0 ℃/h; the first preset temperature is the melting point of a target product minus 5 ℃ to the melting point of the target product, and the second preset temperature is the melting point of the target product minus 5 ℃ to the melting point of the target product; after the temperature is raised to the preset temperature, the constant temperature stage is added to enable the solid component and the liquid component to be separated more fully, and the time of the constant temperature stage is 0.1-10.0 hours, preferably 1.0-8.0 hours, and most preferably 2.0-5.0 hours.

In the method of the present invention, the temperature increasing rate and the temperature decreasing rate of the wax layer may be controlled by an air bath, a water bath, an oil bath, or other feasible means, and preferably, a water bath or an oil bath is used. When the temperature rise rate and the temperature reduction rate of the wax layer are controlled by adopting a water bath or oil bath mode, a jacket can be added outside the sweating dish, the jacket is connected with a movable coil and a circulating system, the circulating system has a programmed cooling/heating function, and substances such as water or heat conduction oil and the like are added into the circulating system to serve as circulating media; after loading, the coil pipe is immersed and fixed in the wax layer, so that the temperature rising/reducing process of the wax layer is quicker and the temperature of the wax layer is more uniform.

In the method of the present invention, the forced flow of air through the wax layer in step (B4) may be carried out at any stage of the sweating process, preferably during the initial stage of sweating.

In the method of the present invention, the forced airflow through the wax layer in the step (B4) is achieved by increasing the pressure above the wax layer, for example, a gauge pressure of 0.2 to 2.0 atm can be applied above the wax layer, and the pressure below the wax layer is kept at a normal pressure.

In the method of the present invention, the forced flow of gas through the wax layer in step (B4) is achieved by reducing the pressure of the gas below the wax layer, for example, by maintaining atmospheric pressure above the wax layer and a gauge pressure of-0.2 to-0.8 atm below the wax layer.

In the method of the present invention, the target product in the step (B5) is wax-separated, i.e., the wax-separated product collected from the end of the first constant temperature to the end of the second constant temperature in the process (B4).

As the phase change material, an appropriate phase transition temperature and a large latent heat of phase transition are required from the viewpoint of the use properties, and an appropriate average carbon number, a high n-alkane content and a narrow carbon number distribution are required from the viewpoint of the chemical composition. The phase-change material produced by using petroleum as a raw material has high production cost, and the use performance of the phase-change material is influenced because the phase-change material contains a certain amount of non-suitable components. The heavy components of the low-temperature F-T synthetic product are mainly normal alkanes, but also contain a certain amount of olefins and oxygen-containing compounds, and the distribution of carbon number is very wide, so the product is not suitable for serving as a phase-change material.

The common sweating method is used for separating and producing wax products by utilizing different properties of wax and oil melting points, but for the wax products with the melting point of about 70 ℃, the chemical composition of the raw materials is complex, so that the crystal structure is finer and more compact during crystallization, and huge filtration flow resistance is formed for discharging liquid components, so that the solid components and the liquid components are difficult to completely separate in the common sweating process which naturally separates by only gravity. Thus, conventional sweating processes cannot produce phase change material products having melting points above 70 ℃.

In order to produce a high-performance phase-change material, through deep research on the relationship between the performance of the phase-change material and the chemical composition of the phase-change material and the composition of an F-T synthetic product, aiming at the reason that a low-temperature F-T synthetic product contains a certain amount of olefin and oxygen-containing compounds and the very wide carbon number distribution causes that the low-temperature F-T synthetic product cannot meet the technical requirements of the phase-change material product, the invention converts the unsuitable components such as the olefin, the oxygen-containing compounds and the like in the low-temperature F-T synthetic product into normal alkane by selecting a proper catalyst and reaction conditions; and enriching the target components by reduced pressure distillation, and reducing the distribution width of carbon number by sweating to produce the phase-change material.

In order to enable the solvent-free separation method for sweating to produce a phase-change material product with a melting point of more than 70 ℃, the invention aims at the reason that the wider carbon number distribution in the chemical composition of the F-T synthetic component prepared by hydrogenation and distillation cannot meet the technical requirements of the phase-change material through deeply researching the relation between the performance of the phase-change material and the chemical composition of the phase-change material and the ordinary sweating process, and the carbon number distribution width is reduced by sweating; aiming at the reason that solid components and liquid components are difficult to separate in the common sweating process, the method of carrying the liquid components out by forced airflow through a wax layer is adopted in the sweating process, and meanwhile, the sweating raw materials and two components capable of reacting to generate gas are preferably emulsified respectively to form W/O type emulsion for sweating, and the processes of a high-temperature constant-temperature stage, a low-temperature constant-temperature stage, a constant-temperature stage after the temperature is raised to a preset temperature and the like in the cooling process are added. The measures effectively reduce the width of the carbon distribution of the product, so that the performance of the product can meet the technical requirements of the phase-change material.

Aiming at the reason that the solid component and the liquid component are difficult to separate in the sweating process, the solid component and the liquid component are forced to be separated by adopting a method that the liquid component is carried out by air flow through a wax layer in the sweating process, so that the separation effect is enhanced and the separation speed is accelerated; the wax can be more greatly crystallized by increasing the high-temperature constant-temperature stage in the cooling process, and the liquid components can be discharged in the sweating process. Studies on wax crystallization processes have shown that the chemical composition of wax is the most important factor in determining the crystal morphology, and the conditions of the cooling process also affect the crystal morphology, especially the cooling conditions at temperatures around the melting point have the most significant effect on the crystal morphology. When the wax is cooled to the vicinity of the melting point, the n-alkane with larger molecular weight is crystallized and separated, and the part of the crystal can be used as the crystal nucleus for the subsequent crystallization, and the high-temperature constant-temperature stage is increased, so that the crystal nucleus can be fully grown to form crystals with larger size, and the crystals with larger size are not as coarse as the crystals of the paraffin with low melting point, but the enlarged crystal structure is also very favorable for discharging the liquid component in the sweating stage. Meanwhile, the raw material wax and two components capable of reacting to generate gas are respectively emulsified to form W/O type emulsion, and then are mixed under pressure to perform sweating. The water solution in the mixed emulsion is uniformly distributed in the raw material wax layer in a micro particle form; because of the W/O type emulsion, the two components which can react do not react or react at a slower speed due to the isolation effect of the oil film; the emulsion is cooled to 5 to 20 ℃ below the melting point under pressure, and pressure is applied to the wax layer during the steps (B1) and (B2), whereby the gas generated by the reaction during the preparation, crystallization, and the like can be inhibited from escaping from the wax layer. The wax layer is in a softer solid state after the sweating raw material is cooled to be below the melting point and the sweating process is ended, and in the process, two reactive components gradually undergo chemical reaction to release gas, so that uniformly distributed micro bubbles are formed in the raw material wax layer; in the sweating process, the air flow passes through the wax layer, on one hand, the water solution of a reactive substance can be carried out to form tiny spaces in the wax layer, and the tiny spaces generated by the bubbles are easy to form a plurality of tiny channels in the wax layer in the sweating process, so that the liquid components in the sweating process can be discharged; on the other hand, the gas flow can carry the liquid component to forcibly separate the solid component from the liquid component, thereby enhancing the separation effect and accelerating the separation speed. The surfactant is selected to have a melting or freezing point below the first predetermined temperature of the sweating process and to contain functional groups that are poorly compatible with the sweating material and which are capable of being expelled with the liquid component during the sweating process. And then assisting with a low-temperature constant-temperature stage of a crystallization process to ensure that solid crystallization is more sufficient, and a constant-temperature stage of a sweating process to ensure that solid components and liquid components are more sufficiently separated, so that the sweating process can produce a high latent heat phase-change material product with narrow carbon number distribution range and high n-alkane content.

The method of the invention has the advantages that: olefins and oxygen-containing compounds in the F-T synthetic product are converted into proper components (normal alkane) through a hydrogenation process by selecting proper catalysts and reaction conditions, and other impurities are not generated; concentrating the sweating raw material by distillation; in the sweating process, the method that the liquid component is carried out by the airflow through the wax layer enhances the separation effect of the solid component and the liquid component and accelerates the separation speed; the crystal size is increased by adopting high-temperature crystallization, and meanwhile, a micro space formed by micro bubbles generated by a reactable substance and a water solution are discharged to generate a micro space to form a plurality of fine channels in the sweating process, so that the quick discharge of liquid components is facilitated; and the processes of a low-temperature constant-temperature stage of a crystallization process, a constant-temperature stage of a sweating process and the like are added, so that the sweating process can produce the high latent heat phase-change material. The method has the advantages of low device investment, simple production process, low operation cost, safety, no solvent pollution to the environment and the like.

Detailed Description

The invention selects a proper low-temperature F-T synthetic product as a hydrogenation raw material, and produces the phase-change material with the melting point of more than 70 ℃ and the phase-change latent heat of more than 220J/g through the technical processes of hydrogenation, distillation, emulsification, sweating and the like. Specifically, hydrogenation is carried out on a low-temperature F-T synthetic product under the action of a catalyst; preparing 500-540 ℃ fraction as a sweating raw material from the hydrogenation product in a distillation device; heating and melting the sweating raw material, respectively emulsifying the sweating raw material and aqueous solution of two components capable of reacting to generate gas under the condition of an emulsifier, uniformly mixing the sweating raw material and the aqueous solution under the condition of pressure, and then filling the sweating raw material into a sweating dish; controlling the temperature rising and reducing speed of the wax layer by water bath; the temperature of the wax layer is reduced to be near the melting point temperature of the raw materials under the pressure condition, and the temperature is kept at a high temperature for a period of time; continuously cooling to a preset temperature and keeping the temperature constant for a period of time; during sweating, the compressor is activated to create a positive pressure above the wax layer and/or the vacuum pump is activated to create a negative pressure below the wax layer to force an airflow through the wax layer; the temperature of the wax layer reaches a first preset temperature and is kept constant for a period of time, the temperature is continuously increased to a second preset temperature and is kept constant for a period of time, and then the sweating process is stopped; the target product is refined to obtain the high latent heat phase change material product.

The method for producing a high latent heat phase change material of the present invention is specifically described below by examples 1 to 4. Unless otherwise noted, the following references to% are mass percentages and the pressures are gauge pressures.

Example 1

The embodiment comprises the following steps: hydrogenation, (II) distillation, (III) emulsification, and (IV) sweating.

(I) hydrogenation

Wax oil product (with n-alkane content of 95.50 wt%) of low-temperature F-T synthesis experimental device of China petrochemical industry Co., Ltd is used as raw material in FHJ-2 catalyst (Ni/Al)₂O₃Commercial catalyst developed and produced by the research institute of petrochemical industry, the content of active metal nickel is 40 percent in terms of oxide, and the catalyst is subjected to conventional reduction treatment before use) under the action of reaction pressure of 5.0MPa, reaction temperature of 200 ℃ and volume space velocity of 1.0h^-1And hydrogen liquid volume ratio 500: 1 to convert olefins and oxygenates therein.

The weight content of the normal paraffin of the hydrogenation product is 97.36 percent; and (4) analyzing by chromatography-mass spectrometry, detecting no substances such as alkene, alcohol, acid and the like, and showing that the alkene and the oxygen-containing compound in the raw material are removed.

(II) distillation

And (3) preparing a fraction at 500-540 ℃ from the product obtained by the hydroconversion in a reduced pressure distillation device which is close to 2 theoretical plates under the pressure condition of 13.3-133 Pa.

The melting point of the distillate at 500-540 ℃ is 77.3 ℃, the yield is 4.82% (relative to the hydrogenated product), and the latent heat of phase change is 185.36J/g.

(III) emulsification: comprises three steps of (A1) preparation of oil phase materials, (A2) preparation of water phase materials, and (A3) preparation of emulsion.

(A1) Preparing an oil phase material:

heating 78.0Kg of fraction prepared in part (II) to 85 deg.C to melt, adding 1.5Kg of sorbitan monostearate, 0.6Kg of diethylene glycol monolaurate and 0.3Kg of sodium alkyl benzene sulfonate, stirring well, and dividing into two parts.

(A2) Preparation of aqueous phase Material

Preparing a water-phase material of a component (I): h with the concentration of 2.2% is prepared₂SO₄Taking 9.8Kg of solution and heating to 89 ℃;

preparing a water-phase material of a component (II): k with the preparation concentration of 3.0%₂CO₃9.8Kg of solution are taken and heated to 89 ℃.

(A3) Preparation of emulsions

Preparing an emulsion of a component (I): stirring one part of the oil phase materials at the speed of 500/min, slowly adding the water phase materials of the component (I) into the oil phase materials, and continuously stirring for 20min to form the water-in-oil type emulsion of the component (I).

Preparing an emulsion of a component (II): stirring the other part of the oil phase material at a speed of 750r/min, slowly adding the water phase material of the component (II) into the oil phase material, and continuously stirring for 15min to form a water-in-oil type emulsion of the component (II).

(IV) sweating: comprises five steps of (B1) preparation work, (B2) temperature reduction-high temperature and constant temperature-temperature reduction crystallization, (B3) low temperature and constant temperature, (B4) temperature rise-constant temperature-temperature rise-constant temperature sweating, and (B5) refining.

(B1) Preparation work

Connecting a sealing system of the sweating dish with a pressurizing buffer tank and a compressor; a decompression buffer tank is arranged at the lower part of the sweating dish and is connected with a vacuum pump; connecting the sweating dish jacket and the movable coil pipe with a circulating system, and fixing the coil pipe on the sweating dish; water is used as a heating medium; starting the heating function of the circulating system to heat the circulating water to 82 ℃. And water is filled below the sweating dish plate. Installing a sealing system at the upper part of the sweating dish and pressurizing to 21.2-21.4 atmospheric pressure; and (3) uniformly mixing the emulsion of the component (I) prepared in the step (A3) and the emulsion of the component (II) under 21.2-21.4 atmospheric pressure, and adding the mixture into a sweating dish.

(B2) Cooling-high temperature constant temperature-cooling crystallization

Standing the emulsion for 1.0h under 21.2-21.4 atmospheric pressures. Starting the refrigeration function of the circulating system, controlling the temperature of the wax layer to be reduced to 79.0 ℃ at the cooling rate of 2.0 ℃/h, keeping the temperature for 3.0 hours, and carrying out high-temperature constant temperature so as to fully increase the crystal; and then the temperature of the wax layer is reduced to 67.0 ℃ at the temperature reduction rate of 1.5 ℃/h so that the wax layer is crystallized to form a solid.

(B3) Constant temperature at low temperature

The temperature is kept constant at 67.0 ℃ for 1.0h to make the wax layer crystallize more fully, and simultaneously the pressure in the pressurized buffer tank is controlled by an evacuation system to gradually decrease to the normal pressure at the rate of 30 atmospheres/h. The refrigeration function of the circulation system is closed.

(B4) Heating-constant temperature-heating-constant temperature sweating

Draining the pad water of the sweating dish. The outlet of the sweating dish is connected with the intermediate storage tank (I) to receive wax; starting a compressor, keeping the pressure in a pressurizing buffer tank stable at 1.3-1.5 atmospheric pressures, and keeping the normal pressure below a sweating dish plate; starting a heating function of a circulating system, raising the temperature of the wax layer to 77.0 ℃ at a heating rate of 1.5 ℃/h, and keeping the temperature for 4.0 hours; the compressor is stopped.

The outlet of the sweating dish is connected with a crude product storage tank (I) in a switching mode to receive the crude product (I). Starting a vacuum pump and keeping the pressure in the decompression buffer tank stable at-0.5 to-0.7 atmospheric pressure, and keeping the atmospheric pressure above the wax layer at normal pressure; raising the temperature of the wax layer to 80.0 ℃ at a heating rate of 1.0 ℃/h and keeping the temperature for 4.0 hours; stopping the vacuum pump and stopping the sweating process.

The outlet of the sweating dish is connected with an intermediate storage tank (II) in a switching way to receive wax; the temperature of the circulating water was further raised to 95 ℃ to melt and remove the wax and clear the perspiration device.

(B5) Refining

And (4) refining the crude product (I) by using clay to obtain the phase-change material product (I).

The phase change material product (I) has the following properties: melting point 79.2 ℃; melting point (DSC method): 80.85 ℃; latent heat of phase change: 228.47J/g. The yield of phase change material product (i) was 28.5% (relative to the antiperspirant starting material).

Example 2

(I) hydrogenation

The same as in example 1.

(II) distillation

The same as in example 1.

(A1) Preparing an oil phase material:

83.0Kg of fraction (same as example 1) prepared in the second step is heated to 90 ℃ to melt, and then 1.4Kg of diethylene glycol fatty acid ester, 0.4Kg of sorbitan monooleate and 0.2Kg of polyoxyethylene fatty acid ester are added, and after stirring uniformly, the mixture is divided into two parts on average.

(A2) Preparation of aqueous phase Material

Preparing a water-phase material of a component (I): h with the concentration of 1.2% is prepared₂SO₄Taking 7.5Kg of solution and heating to 94 ℃;

preparing a water-phase material of a component (II): NaHCO with the preparation concentration of 2.0 percent₃7.5Kg of solution are taken and heated to 94 ℃.

(A3) Preparation of emulsions

Preparing an emulsion of a component (I): stirring one part of the oil phase materials at 300/min, slowly adding the water phase materials of the component (I) into the oil phase materials, and continuously stirring for 30min to form the water-in-oil type emulsion of the component (I).

Preparing an emulsion of a component (II): stirring the other part of the oil phase material at 900r/min, slowly adding the water phase material of the component (II) into the oil phase material, and continuously stirring for 10min to form the water-in-oil type emulsion of the component (II).

(B1) The pressure during the preparation and the (B2) crystallization was 27.1 to 27.3 atmospheres, and the rest was the same as in example 1.

The phase change material product produced in this example has the following properties (II): melting point 79.4 ℃; melting point (DSC method): 81.26 deg.C; latent heat of phase change: 230.52J/g. The yield of phase change material product (ii) was 29.6% (relative to the sweating material).

Example 3

(I) hydrogenation

The same as in example 1.

(II) distillation

The same as in example 1.

(A1) Preparing an oil phase material:

75.0Kg of fraction (same as example 1) prepared in the second part is heated to 82 ℃ to melt, and then 1.9Kg of sorbitan monostearate, 0.7Kg of tetraethylene glycol monostearate and 0.4Kg of triethylamine oleate are added, and after uniform stirring, the mixture is divided into two parts on average.

(A2) Preparation of aqueous phase Material

Preparing a water-phase material of a component (I): h with the concentration of 3.3 percent is prepared₂SO₄Taking 11.0Kg of solution and heating to 88 ℃;

preparing a water-phase material of a component (II): na with the concentration of 3.5% is prepared₂CO₃11.0Kg of solution was taken and heated to 88 ℃.

(A3) Preparation of emulsions

Preparing an emulsion of a component (I): stirring one part of the oil phase materials at the speed of 1000/min, slowly adding the water phase materials of the component (I) into the oil phase materials, and continuously stirring for 10min to form the water-in-oil type emulsion of the component (I).

Preparing an emulsion of a component (II): stirring the other part of the oil phase material at 350r/min, slowly adding the water phase material of the component (II) into the oil phase material, and continuously stirring for 30min to form the water-in-oil type emulsion of the component (II).

(B1) The pressure during the preparation and the (B2) crystallization was 18.5 to 18.7 atmospheres, and the rest was the same as in example 1.

The phase change material product produced in this example (iii) had the following properties: melting point 79.2 ℃; melting point (DSC method): 81.15 deg.C; latent heat of phase change: 227.19J/g. The yield of phase change material product (iii) was 30.2% (relative to the sweating material).

Example 4

(I) hydrogenation

The same as in example 1.

(II) distillation

The same as in example 1.

(A1) Preparing an oil phase material:

taking 70.0Kg of fraction (same as example 1) prepared in part (II), heating to 87 deg.C to melt, adding 2.5Kg of diethylene glycol fatty acid ester, 0.8Kg of sorbitan monolaurate and 0.3Kg of dodecyl betaine, stirring well, and dividing into two parts on average.

(A2) Preparation of aqueous phase Material

Preparing a water-phase material of a component (I): preparing 1.8 percent HCl solution, taking 13.2Kg and heating to 92 ℃;

preparing a water-phase material of a component (II): na with the concentration of 2.6% is prepared₂CO₃13.2Kg of solution are taken and heated to 92 ℃.

(A3) Preparation of emulsions

Preparing an emulsion of a component (I): stirring one part of the oil phase materials at 800/min, slowly adding the water phase materials of the component (I) into the oil phase materials, and continuously stirring for 15min to form the water-in-oil type emulsion of the component (I).

Preparing an emulsion of a component (II): stirring the other part of the oil phase material at a speed of 450r/min, slowly adding the water phase material of the component (II) into the oil phase material, and continuously stirring for 25min to form the water-in-oil type emulsion of the component (II).

(B1) The pressure during the preparation and the (B2) crystallization was 24.2 to 24.6 atmospheres, and the rest was the same as in example 1.

The phase change material product produced in this example (iv) had properties: melting point 79.0 ℃; melting point (DSC method): 80.83 deg.C; latent heat of phase change: 229.05J/g. The yield of the phase change material product (IV) was 29.6% (relative to the sweating material).

As can be seen from examples 1-4, the method for producing the phase change material with high latent heat of the invention converts the olefin and the oxygen-containing compound in the raw material into the proper components of the phase change material by selecting the proper catalyst and reaction conditions; concentrating the sweating raw material by distillation; improvements to the sweating device by adding pressure and/or vacuum means, etc.; the sweating process is improved by respectively emulsifying the sweating raw material and two reactive components, forming micro bubbles in a wax layer by utilizing gas generated by reaction and forming a micro space after discharging an aqueous solution, forcing airflow to pass through the wax layer in the sweating process, increasing the constant temperature stage of crystallization and the sweating process and the like; the separation effect of the solid component and the liquid component is enhanced and the separation speed is accelerated, so that the phase-change material product with the phase-change temperature of more than 70 ℃ and the phase-change latent heat of more than 220J/g can be produced by the sweating process.

Claims

1. A method of producing a high latent heat phase change material comprising:

(III) emulsification: the method comprises the following steps:

(A1) preparing an oil phase material: heating and melting the sweating raw material prepared in the step (II); adding an oil-soluble emulsifier, and uniformly stirring to form an oil phase material;

(A2) preparing a water-phase material: respectively dissolving the component (I) and the component (II) in water to form a water phase material of the component (I) and a water phase material of the component (II);

(IV) sweating: the method comprises the following steps:

(B2) and (3) crystallization: under the pressure condition, cooling the mixed emulsion to the melting point of the sweating raw material plus 4-15 ℃ at the speed of 2.0-30.0 ℃/h, then cooling the wax layer to a proper temperature at the speed of 1.0-3.0 ℃/h, and keeping the temperature at the high temperature for 0.1-6.0 hours; then cooling to the crystallization termination temperature of 5-20 ℃ below the melting point of the sweating raw material at the speed of 0.5-2.5 ℃/h; the proper temperature is the melting point of the sweating raw material minus 1.0 ℃ to the melting point plus 4.0 ℃;

(B3) and (3) low-temperature constant temperature: keeping the temperature constant at the crystallization termination temperature for 0.1-5.0 hours, and simultaneously reducing the pressure to the normal pressure;

(B4) sweating: heating to a first preset temperature at the speed of 0.5-3.0 ℃/h, keeping the temperature for 0.1-10.0 hours, heating to a second preset temperature at the speed of 0.5-2.5 ℃/h, keeping the temperature for 0.1-10.0 hours, and stopping sweating; forcing an air stream through the wax layer during sweating; the first preset temperature is the melting point of a target product minus 5 ℃ to the melting point of the target product, and the second preset temperature is the melting point of the target product minus 5 ℃ to the melting point of the target product;

2. The method of claim 1, wherein the oil-soluble emulsifier is selected from the group consisting of nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants; the HLB value of the oil-soluble emulsifier is 1-10, and the melting point or the freezing point of the oil-soluble emulsifier is lower than the first preset temperature for sweating in the step (B4).

3. The method of claim 2, wherein the nonionic surfactant is selected from the group consisting of sorbitan monooleate, sorbitan monostearate, diethylene glycol fatty acid ester, sorbitan monopalmitate, tetraethylene glycol monostearate, polyoxypropylene stearate, sorbitan monolaurate, polyoxyethylene fatty acid ester; the anionic surfactant is selected from a group of substances consisting of fatty alcohol sulfate ester monoethanolamine salt, alkyl polyoxyethylene ether sodium sulfate, oleamido carboxylic acid sodium, sodium alkyl benzene sulfonate, N-methyl oleoyl taurate, butyl naphthalene sodium sulfonate, succinate sodium sulfonate and maleic acid monoester sodium sulfonate; the cationic surfactant is selected from a group of substances consisting of benzyl quaternary ammonium salt, dodecyl dimethyl benzyl ammonium chloride, dodecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride and triethylamine oleate; the amphoteric surfactant is selected from a group consisting of dodecyl betaine, dodecyl dimethyl ammonium oxide, fatty alkyl imidazoline derivatives, fatty acid derivatives and amphoteric modified ethylene oxide adducts.

4. The method according to claim 2, wherein the oil-soluble emulsifier is a complex emulsifier comprising two or more surfactants.

5. The method of claim 1, wherein said components (i) and (ii) are a group of corresponding substances soluble in water and capable of reacting with each other to form a gas.

6. The method according to claim 5, wherein the component (I) is at least one selected from the group consisting of water-soluble acids, and the component (II) is at least one selected from the group consisting of carbonates, bicarbonates, sulfites, bisulfites, metal sulfides; or, the component (I) is at least one of inorganic alkali, and the component (II) is at least one of inorganic ammonium salt; or the component (I) is selected from hydrochloric acid, and the component (II) is selected from at least one of perchlorate, chlorate and hypochlorite; alternatively, component (I) is selected from hydrochloric acid and component (II) is selected from urea.

7. The method of claim 6, wherein the water-soluble acid comprises an inorganic acid and/or an organic acid.

8. The method of claim 7, wherein the inorganic acid is selected from the group consisting of perchloric acid, hydroiodic acid, sulfuric acid, hydrobromic acid, hydrochloric acid, nitric acid, iodic acid, sulfurous acid, phosphoric acid, nitrous acid, and hydrofluoric acid; the organic acid is selected from a group consisting of methanesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, trifluoromethanesulfonic acid, sulfamic acid, methanesulfinic acid, benzenesulfonic acid, thioacetic acid, methanethiol, thiophenol, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, n-heptanoic acid, n-octanoic acid, oxalic acid, malonic acid, tartaric acid, succinic acid, adipic acid, citric acid, acrylic acid, crotonic acid, oleic acid, fumaric acid, maleic acid, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid, salicylic acid, caffeic acid, glycolic acid, lactic acid, malic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, perfluorobutyric acid and perfluorooctanoic acid.

9. The method of claim 8, wherein component (I) is at least one of hydrochloric acid and sulfuric acid, and component (II) is at least one selected from sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate.

10. The method according to claim 1, wherein the aqueous solution of the component (I) and the component (II) has a mass concentration of the component (I) and the component (II) of 0.1 to 10.0%.

11. The method according to claim 1, wherein the stirring speed in the step (A3) is 50 to 5000 rpm, and the temperature for preparing the emulsion is 75 to 98 ℃.

12. The method of claim 1, wherein the composition of the mixed emulsion obtained in step (B1) is: the mass percentage of the sweating raw material is 60.0-90.0%, the sum of the mass percentage of the water solution of the component (I) and the mass percentage of the water solution of the component (II) is 9.9-30.0%, and the mass percentage of the oil-soluble emulsifier is 0.1-10.0%.

13. The method of claim 12, wherein the composition of the blended emulsion resulting from step (B1) is: 65.0-84.0 percent of sweating raw material, 15.0-30.0 percent of the sum of the mass percent of the aqueous solution of the component (I) and the mass percent of the aqueous solution of the component (II), and 1.0-5.0 percent of oil-soluble emulsifier.

14. The method of claim 1, wherein a pressure of 0.5 to 50.0 atmospheres gauge is applied above the wax layer during steps (B1) and (B2) to inhibit gases formed during the preparatory work and the crystallization from escaping the wax layer.

15. The method of claim 1, wherein the suitable temperature in step (B2) is from the melting point of the antiperspirant material to the melting point +3.0 ℃.

16. The process of claim 1 wherein said crystallization termination temperature in step (B2) is from 8 ℃ to 15 ℃ below the melting point of the antiperspirant material.

17. The method of claim 1, wherein the depressurization in step (B3) is at a rate of 0.1 to 150.0 atm/hr.

18. The method of claim 1, wherein said forcing of said air stream through said wax layer during an initial sweating session in step (B4).

19. The method of claim 1, wherein said forcing air flow through the wax layer in step (B4) is accomplished by increasing the pressure of air above the wax layer and/or decreasing the pressure of air below the wax layer to create a pressure differential between the upper and lower sides of the wax layer, said pressure differential being between 0.1 and 5.0 atmospheres.

20. A method according to claim 19, wherein said forcing of the gas through the wax layer is accomplished by increasing the pressure of the gas above the wax layer by applying a gauge pressure of 0.2 to 2.0 atmospheres above the wax layer while maintaining a constant pressure below the wax layer.

21. A method according to claim 19, wherein said forced gas flow through the wax layer is achieved by reducing the gas pressure below the wax layer, maintaining a constant pressure above the wax layer and a gauge pressure of-0.2 to-0.8 atmospheres below the wax layer.

22. The process of claim 1 wherein the F-T synthesis product has a normal alkane content of greater than 85% by weight.

23. The process of claim 1, wherein the hydrogenation in process (one) is carried out under the following conditions: the reaction pressure is 3-10 MPa, the reaction temperature is 150-300 ℃, and the liquid hourly space velocity is 0.2-2.0 h^-1And the volume ratio of the hydrogen to the liquid is 100-1000: 1.

24. the process of claim 1 wherein the hydrogenation catalyst of process (one) is Ni/Al₂O₃、W-Ni/Al₂O₃、Mo-Ni/Al₂O₃Or W-Mo-Ni/Al₂O₃The catalyst comprises 20-70 wt% of active metal components in terms of oxide.

25. The method of claim 1, wherein the desired product of step (B5) is a wax-free product collected from the end of the first constant temperature period to the end of the second constant temperature period of step (B4).

26. The method of claim 1 wherein said sweating device is a sweating dish.

27. The method according to claim 10, wherein the aqueous solution of component (i) and component (ii) has a mass concentration of component (i) and component (ii) of 0.5% to 4.0%.

28. The method of claim 14, wherein said gage pressure is from 10.0 to 30.0 atmospheres.

29. The method of claim 17, wherein the depressurization in step (B3) is at a rate of 5.0 to 50.0 atm/hr.

30. The method of claim 19, wherein the pressure differential is between 0.2 and 2.0 atmospheres.