A process for producing insoluble sulfur with high thermal stability by gasification

Abstract

The present application relates to the field of technology for producing high thermal stability insoluble sulfur by gasification, and specifically to a technology for producing high thermal stability insoluble sulfur by gasification, which technology includes: selecting ordinary sulfur with a purity of above 1000 ℃ as raw material, screening and drying; heating and stirring the dried sulfur; and sending it into a tubular gasifier for gasification to obtain high-temperature sulfur vapor; passing the high-temperature sulfur vapor into a polymerization furnace for polymerization reaction, and controlling the temperature during the polymerization process; using carbon disulfide as an extractant, passing the sulfur vapor after the polymerization reaction into an extraction tower, and obtaining a mixture of insoluble sulfur and a small amount of residual extractant from the bottom of the extraction tower; using a centrifuge to separate the mixture into solid and liquid, drying and crushing, and obtaining insoluble sulfur. The present application aims to avoid the problem of reduced yield due to too low or too high temperature by controlling the temperature during the polymerization reaction.

Description

Technical Field

[0001] The present application relates to the field of technology for producing insoluble sulfur with high thermal stability by gasification, and in particular to a technology for producing insoluble sulfur with high thermal stability by gasification. Background Art

[0002] Insoluble sulfur, referred to as IS, is a polymer of sulfur, also called polymerized sulfur. It is a non-toxic high-molecular modified variety of ordinary sulfur. It is named because it is insoluble in carbon disulfide and rubber hydrocarbons. At room temperature, insoluble sulfur is a light yellow powder with a relative molecular mass of tens of thousands and a density of about , with certain plasticity and stability. Insoluble sulfur, due to its linear polymer characteristics, is insoluble in rubber and will not migrate to the surface of the rubber, so it will not produce sulfur spraying. It is one of the necessary vulcanizers in the production process of radial tires.

[0003] The production methods of insoluble sulfur mainly include melting method and gasification method. Among them, gasification method is the main production process of insoluble sulfur at home and abroad. Gasification method is also called high temperature method. It is to heat ordinary sulfur and melt it in a It starts to vaporize and continues to heat up to At this time, the sulfur is high-temperature and high-pressure sulfur vapor, and then The polymerization reaction lasts for 10 minutes, and then the sulfur vapor after the reaction is passed into a cooling medium for quenching, and then solidified and extracted to obtain insoluble sulfur with a yield of about.

[0004] The traditional gasification production process sets a fixed polymerization reaction temperature based on empirical values. However, there may be slight differences between different batches of raw materials, which may lead to an inappropriate polymerization temperature and a decrease in yield. During the polymerization process, as the polymerization temperature increases, the yield of insoluble sulfur increases. However, the polymerization reaction of sulfur is a reversible reaction. Excessively high temperatures will cause the insoluble sulfur to crack, resulting in a decrease in yield. When using the gasification method to produce insoluble sulfur, controlling the appropriate polymerization reaction temperature is also beneficial to improving thermal stability. Therefore, it is necessary to optimize temperature control during the polymerization process to increase the yield of insoluble sulfur. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a process for producing insoluble sulfur with high thermal stability by gasification to solve the existing problems.

[0006] The process of producing high thermal stability insoluble sulfur by gasification method of the present application adopts the following technical scheme:

[0007] One embodiment of the present application provides a process for producing high thermal stability insoluble sulfur by gasification, the process comprising the following steps:

[0008] A1, Raw material preparation: Select the purity of The above common sulfur is used as raw material, and is screened and dried;

[0009] A2, pre-melting: use an electric heating pre-melting kettle to heat and stir the dried sulfur;

[0010] A3, gasification: the pre-melted liquid sulfur is sent to a tubular gasifier through a pipeline to be gasified to obtain high-temperature sulfur vapor;

[0011] A4, polymerization reaction: high temperature sulfur vapor is introduced into the polymerization furnace for polymerization reaction, and a halide stabilizer is added at the same time; and the temperature is controlled during the polymerization process, including:

[0012] S1: Collect infrared spectra during the polymerization process;

[0013] S2: Calculate the impurity interference of each absorption peak based on the half-peak width difference between the absorption peaks in the infrared spectrum;

[0014] S3: Calculate the overlap of infrared spectra by combining the impurity interference of all absorption peaks and the symmetry of the intensity on both sides of the absorption peaks;

[0015] S4: Based on the degree of overlap, the derivative spectroscopy method is used to solve the overlapping absorption peaks in the infrared spectrum, and the content of various sulfur molecules in the polymerization reaction is obtained to calculate the degree of polymerization at the current acquisition moment;

[0016] S5: determining how to adjust the temperature of the polymerization reaction at the current collection time according to the polymerization degrees at a plurality of consecutive adjacent collection time points;

[0017] A5, quenching: using carbon disulfide as an extractant, passing the sulfur vapor after the polymerization reaction into an extraction tower, and obtaining a mixture of insoluble sulfur and a small amount of residual extractant from the bottom of the extraction tower;

[0018] A6, solid-liquid separation: use a centrifuge to separate the mixture into solid and liquid;

[0019] A7, drying and crushing: drying and crushing the separated insoluble sulfur to obtain insoluble sulfur;

[0020] The calculation method of the polymerization degree is as follows: the polymerization degree at time t is recorded as , ; In the formula, Indicates time t The content of , and Respectively represent time t , and The content.

[0021] Preferably, in step A1, the mesh size of the screening operation is controlled at Head.

[0022] Preferably, after the drying in step A1, the water content of the raw material is reduced to the following.

[0023] Preferably, in step A3, the flow rate of liquid sulfur introduced into the tubular gasifier is .

[0024] Preferably, the halide stabilizer is one of ferric chloride, zinc chloride or potassium bromide.

[0025] Preferably, the impurity interference degree is calculated as follows:

[0026] Calculate the average half-peak width of all absorption peaks in the infrared spectrum;

[0027] For any absorption peak, the difference between the half-peak width of any absorption peak and the average half-peak width is forwardly fused with the number of all absorption peaks in the infrared spectrum to obtain the impurity interference degree of any absorption peak.

[0028] Preferably, the overlap degree is calculated as follows:

[0029] For both sides of any absorption peak, select two points with equal wavelengths from the center of the absorption peak, and calculate the slope of the line between the center of the absorption peak and the two points;

[0030] Calculate the absolute value of the sum of the two slopes and the product of the impurity interference of the corresponding absorption peak;

[0031] The cumulative sum of the product results of all absorption peaks in the infrared spectrum is taken as the overlap degree of the infrared spectrum.

[0032] Preferably, the de-overlapping process comprises:

[0033] When the normalized value of the overlap is greater than or equal to a preset overlap threshold, a second-order derivative is performed in the process of using the derivative spectroscopy method; otherwise, a first-order derivative is performed.

[0034] Preferably, the step of determining how to adjust the temperature of the polymerization reaction at the current collection moment according to the polymerization degrees at a plurality of consecutive adjacent collection moments comprises:

[0035] For a preset number of collection moments adjacent to the current collection moment, when the difference in the degree of polymerization of a preset number of consecutive collection moments is greater than 0, the temperature of the polymerization reaction process is increased at the current collection moment; when the difference in the degree of polymerization of a preset number of consecutive collection moments is less than 0, the temperature of the polymerization reaction process is reduced at the current collection moment; when the sum of the difference in the degree of polymerization of a preset number of consecutive collection moments is 0, the temperature of the polymerization reaction process is kept unchanged at the current collection moment;

[0036] The difference is the difference in aggregation degree between the adjacent subsequent collection moment and the adjacent previous collection moment.

[0037] In the above scheme, its beneficial effect is that the temperature of the polymerization reaction is adjusted based on the degree of polymerization at two sampling moments. Compared with the traditional gasification method for producing insoluble sulfur with a fixed polymerization temperature, this application focuses on analyzing the effect of temperature on the polymerization reaction to avoid low yields due to too low temperature, or reverse reactions due to too high temperature, which leads to reduced yields. The temperature control of the polymerization reaction in the process of producing insoluble sulfur by gasification is optimized, and the yield is improved. In addition, when the temperature is controlled within a suitable range, the sulfur molecules can be polymerized in a relatively orderly manner. This ordered polymerization structure is more stable than the disordered small molecule structure, because there are strong covalent bonds between the molecules after polymerization, and higher energy is required to break them. Therefore, the insoluble sulfur produced by the process described in this application has the characteristics of high thermal stability. After heating, the remaining insoluble sulfur content , After heating, the remaining insoluble sulfur content . BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A flow chart of the steps of a process for producing high thermal stability insoluble sulfur by gasification provided in one embodiment of the present application;

[0040] Figure 2 A flow chart of temperature control during polymerization provided for one embodiment of the present application;

[0041] Figure 3 A curve diagram of the change in degree of polymerization during a polymerization reaction provided in one embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation method, structure, characteristics and effects of a process for producing high thermal stability insoluble sulfur by gasification according to the present application in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0044] The specific scheme of a process for producing high thermal stability insoluble sulfur by gasification provided by the present application is described in detail below with reference to the accompanying drawings.

[0045] An embodiment of the present application provides a process for producing high thermal stability insoluble sulfur by gasification. For the preparation flow chart, please refer to Figure 1 , the specific preparation process is as follows:

[0046] Embodiment 1:

[0047] A1, Raw material preparation

[0048] Select purity in The above common sulfur is used as raw material and screened using a vibrating screen with the mesh size set at The mesh size is kept between each other to ensure that the sulfur particles are of uniform size and to avoid impurities from mixing in during the screening process.

[0049] In this embodiment 1, the screened sulfur raw material is placed The drying time is , the vacuum degree is maintained at It accelerates the removal of moisture while preventing sulfur oxidation, reducing its water content to The following is to avoid moisture from having adverse effects in subsequent reactions and causing sulfur hydrolysis.

[0050] In Example 2 of the present application, while other conditions in step A1 of Example 1 remain unchanged, the screened sulfur raw material is placed in The drying time is .

[0051] In Example 3 of the present application, while other conditions in step A1 of Example 1 remain unchanged, the screened sulfur raw material is placed in The drying time is .

[0052] A2, pre-melt

[0053] Use an electric heating pre-melting kettle to heat the dried sulfur to In this temperature range, sulfur is in a fluid state with low viscosity, which is convenient for transportation and subsequent gasification operations. A stirring paddle is installed in the kettle, and the speed is rpm to ensure that the sulfur can be heated evenly and the heating rate is controlled within .

[0054] A3, Gasification

[0055] The pre-melted liquid sulfur is sent into the tubular gasifier through a pipeline at a flow rate of The temperature in the gasifier is controlled at The liquid sulfur is converted into gas to obtain high-temperature sulfur vapor. The pressure in the furnace is maintained at a constant level by adjusting the inert gas (such as nitrogen) flow rate at the air inlet and the scheduled flow rate at the air outlet. The nitrogen flow rate at the air inlet is controlled between Its function is to dilute the sulfur vapor, prevent the sulfur from oxidizing at high temperature, and maintain the pressure in the furnace stable.

[0056] A4, Polymerization

[0057] High-temperature sulfur vapor is introduced into the polymerization furnace for polymerization reaction, and halide stabilizers such as ferric chloride, zinc chloride or potassium bromide are added to improve the stability of insoluble sulfur. The polymerization reaction time is set to minutes, the initial temperature is set to .

[0058] The polymerization reaction refers to The eight-membered ring sulfur molecule breaks under heat to form monomers with different molecular weights and double-terminal free radicals. The monomers polymerize with each other to form insoluble sulfur. However, the polymerization reaction is a reversible process. If the temperature is too low, the conversion rate of the polymerization reaction is low. If the temperature is too high, the chain will depolymerize during the growth process, which will also reduce the yield of insoluble sulfur. Therefore, it is necessary to control the temperature according to the degree of polymerization during the polymerization reaction to increase the conversion rate of insoluble sulfur. The specific temperature control flow chart of the polymerization process is shown in the attached figure. Figure 2 As shown, specifically:

[0059] S1: Collect infrared spectra during the polymerization reaction.

[0060] In order to optimize the temperature control in the polymerization reaction of producing high thermal stability insoluble sulfur by gasification, this application uses an infrared spectrometer with an external high temperature resistant probe, and sets the measurement wavelength range of the infrared spectrometer to , the resolution is set to The infrared spectrum was obtained by scanning once every 1 minute.

[0061] An observation window made of quartz glass is provided on the polymerization furnace to transmit infrared light source, and an interface is provided to connect the light probe of infrared spectrometer. In order to ensure good sealing at the interface and prevent leakage of reactants, polytetrafluoroethylene gaskets can be used.

[0062] S2: Calculate the impurity interference degree of each absorption peak based on the difference in half-peak width between absorption peaks in the infrared spectrum.

[0063] The formation mechanism of insoluble sulfur is as follows: ordinary sulfur is a yellow solid at room temperature, in the form of an eight-membered ring. exist, The following is an orthorhombic crystal. The above is a monoclinic crystal, heated to When heated to more than After that, the color of sulfur gradually darkens, the viscosity increases rapidly, and the eight-membered ring is stimulated by heat and breaks, forming sulfur chain free radical monomers with electrons at both ends. These monomers participate in the reversible polymerization reaction to generate chain sulfur molecules of different lengths, that is, insoluble sulfur with the structure of Chain. Continue heating to obtain the long sulfur chain that begins to break. When the liquid sulfur is vaporized, the insoluble sulfur molecules are almost completely broken, and the vapor sulfur is mainly , also contains , and structure.

[0064] Continue heating and enter the polymerization reaction of gasification to produce insoluble sulfur. Ring-opening decomposition, free radical monomers polymerize to form insoluble sulfur. As the temperature increases, the yield (that is, the conversion rate) of insoluble sulfur increases, because as the temperature of sulfur vapor increases, its composition gradually changes to small molecular sulfur. , and The bond length of small molecule sulfur is shorter, and the insoluble sulfur structure obtained by polymerization is more stable and not easy to produce reverse reaction. However, as the temperature continues to increase, the polymer molecules produced during the chain increase are still double-terminal free radicals, which will break under heat and form reverse reaction, which will reduce the yield.

[0065] To improve The conversion rate can be measured by collecting infrared spectra during the polymerization reaction to measure the content of each component. When the content is high, it means that the critical temperature has not been reached, and the temperature can be increased to increase the conversion rate. When the content of small molecular sulfur increases, it means that the temperature is too high and a reverse reaction occurs. At this time, the temperature needs to be lowered to avoid a decrease in yield. Because the raw materials produced each time may be slightly different, there is no fixed critical temperature, which needs to be regulated during the polymerization reaction.

[0066] Infrared spectroscopy is an absorption spectrum based on the vibration and rotation energy level transitions of molecules. When infrared light is irradiated on sample molecules, the molecules absorb infrared light of a specific frequency, causing the vibration and rotation energy levels of the molecules to transition. When the frequency of infrared light matches the vibration frequency of the molecules, the molecules absorb infrared light to produce absorption peaks, and then the content of different components is determined through the absorption peaks.

[0067] During the polymerization reaction, as the temperature rises, the number of atoms that make up the sulfur molecule decreases. ,besides and and polymerized into long insoluble sulfur chains , which consists of The number of sulfur atoms in each molecule is uncertain, and due to differences in chemical bonds and molecular structures, they have different absorption peaks.

[0068] However, in the polymerization process, there are not only sulfur molecules, but also impurities that are difficult to remove, by-products generated during the reaction, and stabilizers added. These substances have their own absorption peaks in the infrared spectrum region, which may overlap with the absorption peaks of different sulfur molecules, thus interfering with the spectral analysis of the components in the polymerization process.

[0069] First, the position and intensity of each absorption peak are determined by the spectrum automatic peak search algorithm, and then the impurity interference degree can be calculated according to the shape of the absorption peak to characterize the degree to which the current infrared spectrum is interfered by impurities. Among them, the spectrum automatic peak search algorithm is a well-known technology and will not be described in detail.

[0070] Among them, for any absorption peak in the infrared spectrum, the calculation method of the impurity interference degree of any absorption peak is: calculate the average half-peak width of all absorption peaks in the infrared spectrum; for any absorption peak, the difference between the half-peak width of any absorption peak and the average half-peak width is forward fused with the number of all absorption peaks in the infrared spectrum to obtain the impurity interference degree of any absorption peak.

[0071] It can be understood that forward fusion is a fusion method such as addition and multiplication between data. The specific forward fusion method is determined by the implementer according to the actual situation, and this application does not impose any special restrictions.

[0072] As an implementation method, taking time t as an example, one calculation method is:

[0073]

[0074] In the formula, It represents the impurity interference degree of the i-th absorption peak in the infrared spectrum collected at time t, norm[] represents the normalization function, represents the number of absorption peaks detected in the infrared spectrum, It represents the average half-width of all absorption peaks in the infrared spectrum. represents the half-peak width of the i-th absorption peak.

[0075] It should be understood that, in the absence of impurity interference, the number of absorption peaks within this range should be the number of absorption peaks of each component of sulfur, and the average half-peak width of the absorption peak reflects the sharpness of the absorption peak. When impurities are present, the absorption peak will be widened or additional small peaks will be generated, which will lead to an increase in the number of absorption peaks and the average half-peak width in this area. Therefore, the greater the difference between the half-peak width of the current peak and the average half-peak width, the more serious the interference. Therefore, when the degree of impurity interference is greater, it means that the baseline drift in the infrared spectrum collected at time t is more serious, that is, the greater the interference from impurities, and vice versa, it means that the impurity interference is less serious.

[0076] S3: Calculate the overlap of infrared spectra by combining the impurity interference of all absorption peaks and the symmetry of the intensity on both sides of the absorption peaks.

[0077] Further, , , , and Both contain sulfur-sulfur bonds, and the basic vibration modes of these chemical bonds are similar. Although their molecular structures are different, the absorption peaks corresponding to these similar vibration modes may be close in the infrared spectrum, resulting in overlapping absorption peaks.

[0078] Overlapping absorption peaks are not conducive to the accurate calculation of the content of sulfur molecules in each component, so the overlapping absorption peaks need to be separated first. Derivative spectroscopy can be used to differentiate the original spectrum to highlight the detailed information of the absorption peak, especially for overlapping absorption peaks. The higher the order of the derivative, the more details of the absorption peak, but the amount of calculated data is also larger, which will bring more noise.

[0079] Therefore, it is necessary to analyze the degree of overlap of the absorption peaks and select the appropriate derivative order according to the degree of overlap. For spectra with a small degree of overlap, the first-order derivative can be used, while for spectra with a large degree of overlap, higher-order derivatives are required.

[0080] Based on the above analysis, the overlap of infrared spectra is calculated. Taking the infrared spectrum collected at time t as an example, one of the calculation methods of the overlap is:

[0081]

[0082] In the formula, represents the overlap of the infrared spectra collected at time t, It represents the impurity interference degree of the i-th absorption peak in the infrared spectrum collected at time t, Determine the center position of the i-th absorption peak, then select two points of equal wavelength on both sides of the center position, and calculate the slope of the line connecting the center position and these two points, where , Respectively represent the slopes of the lines connecting the center of the i-th absorption peak and the right point and the left point. In this embodiment, the distance value is 10 If it cannot be obtained, move to the center until it is obtained.

[0083] In other embodiments, the overlap of infrared spectra can be analyzed based on the difference in intensities at all corresponding equidistant wavelengths on both sides of the absorption peak and the impurity interference of the absorption peak.

[0084] S4: Based on the degree of overlap, the derivative spectroscopy method is used to de-overlap the overlapping absorption peaks in the infrared spectrum, and finally the content of each component is obtained, and the degree of polymerization at the current moment is calculated.

[0085] In the overlapping region, the spectral intensity is the sum of the absorption contributions of each component. Due to the overlap of the absorption peaks of each component, the intensity change is no longer determined by a single component, but is the result of the interaction of the components. The degree of overlap can be quantified by analyzing this intensity change. When a symmetrical absorption peak overlaps with other peaks, its asymmetry may increase, and the direction and degree of asymmetry depend on the position and intensity of the overlapping peaks. For example, an originally symmetrical absorption peak may become steeper on the right side after overlapping with a weaker absorption peak located on its right side.

[0086] When the overlap is greater, it means that the overlap of the absorption peaks in the infrared spectrum collected at time t is more serious, and a higher-order derivative is needed to resolve the overlapping peaks, because the higher-order derivative can highlight the details and change points of the absorption peaks. For severely overlapping peaks, these details are critical for separating and identifying each component. On the contrary, it means that the overlap is less severe, and the first-order derivative may be sufficient to provide enough information to resolve the overlapping peaks, while reducing the noise amplification problem caused by the higher-order derivative.

[0087] In this embodiment, the overlap is normalized. When the second-order derivative is used, the first-order derivative is used. The infrared spectrum is derived according to the determined order, and then the peak is resolved to distinguish the overlapping peaks. The derivative spectroscopy belongs to the known technology, and the specific steps are not repeated. Wherein, T is a preset overlap threshold value, which is 0.5 in this embodiment and can be set by the implementer.

[0088] The contents of various sulfur molecules in the polymerization reaction can be calculated using the de-overlapped infrared spectrum, which can be calculated using a multiple linear regression method. The multiple linear regression method is a well-known technique, and the specific steps are not described in detail.

[0089] Since the molecular structure of insoluble sulfur is a long chain of sulfur atoms, which contains a variety of structures, it is difficult to directly measure its content. and below There are few small molecular sulfur species that can be directly measured. Combined with the above-mentioned formation mechanism of insoluble sulfur, the polymerization degree is calculated using the content of different types of sulfur molecules to characterize the effect of temperature on the yield of insoluble sulfur.

[0090] Taking the collected data at time t as an example, one of the calculation methods of the aggregation degree at time t is:

[0091]

[0092] In the formula, represents the degree of aggregation at time t, Indicates time t The content of , and Respectively represent time t , and The content.

[0093] It should be understood that at the beginning of the polymerization reaction, The highest content, , and The content of is less, and the degree of polymerization is low. As the temperature increases, The content of cyclic kinetics is continuously reduced, and , and The content of increases, the degree of polymerization increases. When the critical temperature is reached, The content reaches the lowest, and the degree of polymerization is the highest. When the temperature is too high, the reverse reaction occurs, and the insoluble sulfur is cracked. The content will increase and the degree of polymerization will decrease. When the degree of polymerization is higher, it means that the content of insoluble sulfur is higher. In order to increase the yield, the temperature can be further increased. On the contrary, it means that the content of insoluble sulfur is lower.

[0094] S5: Determine how to adjust the temperature of the polymerization reaction at the current collection time according to the polymerization degrees at a plurality of consecutive adjacent collection time points.

[0095] The degree of polymerization per minute is obtained according to the acquisition frequency of the infrared spectrum, and the difference between the degree of polymerization at time t and the degree of polymerization at time t-1 is calculated. If the difference between two consecutive adjacent moments is greater than 0, it means that the critical temperature has not been reached. At this time, The temperature is raised at a heating rate of ; if the sum of the difference between two consecutive moments is equal to 0, the temperature is kept unchanged; if the difference between two consecutive moments is less than 0, it means that the temperature is too high, then The temperature is controlled during the polymerization reaction until the polymerization reaction is completed.

[0096] A5, quenching

[0097] Carbon disulfide was used as the extractant with a purity of Above, water content below The sulfur vapor after the polymerization reaction is passed into the extraction tower to quickly cool the high-temperature sulfur vapor to , in order to inhibit the occurrence of reverse reaction. After multi-stage extraction, the carbon disulfide solution containing soluble sulfur impurities is discharged from the top of the extraction tower, and a mixture of higher purity insoluble sulfur and a small amount of residual extractant is obtained from the bottom.

[0098] A6, solid-liquid separation

[0099] Use a centrifuge to separate the solid and liquid in the mixture at a speed of rpm, and the centrifugation time is 20 minutes, causing the insoluble sulfur to precipitate at the bottom of the centrifuge tube, and the extractant containing impurities and a small amount of residual quenching liquid are on the upper layer.

[0100] A7, dry crushing

[0101] The separated insoluble sulfur is dried in a hot air circulation drying oven. The drying oven is equipped with a multi-layer stainless steel tray for placing the insoluble sulfur. A hot air blower is installed on the top of the drying oven to evenly blow the heated air to the surface of the insoluble sulfur to accelerate the drying process. The drying temperature is , drying time When the water content drops to When the dried insoluble sulfur is crushed by a jet mill, insoluble sulfur with high thermal stability can be obtained.

[0102] Comparison of Examples

[0103] In order to verify the validity of the parameters of this application, this application sets up a number of comparative examples, specifically:

[0104] Comparative Example 1: The polymerization temperature is set to , and no temperature adjustment is performed during the polymerization reaction;

[0105] Comparative Example 2: The polymerization temperature is set to , and no temperature adjustment is performed during the polymerization reaction;

[0106] Comparative Example 3: The polymerization temperature is set to , and no temperature adjustment is performed during the polymerization reaction;

[0107] Except for the explanation, the process flow and parameters of Comparative Examples 1, 2 and 3 are consistent with those of this embodiment.

[0108] The final insoluble sulfur yield is shown in Table 1 below:

[0109]

[0110] From the comparison in Table 1, it can be seen that if the polymerization temperature is not controlled during the polymerization reaction, it is not conducive to the polymerization reaction if the polymerization temperature is set too low or too high, resulting in a decrease in the final yield of insoluble sulfur. If the temperature is adjusted during the polymerization reaction, the final yield and thermal stability of insoluble sulfur are significantly improved.

[0111] And the effectiveness of the temperature adjustment of the present application has been verified by the change curve of the degree of polymerization during the polymerization reaction, as shown in the following figure: Figure 3 shown.

[0112] Depend on Figure 3 It can be seen that as the polymerization reaction temperature increases, the final yield increases accordingly. However, when the temperature is too high, a reverse reaction will occur, thereby reducing the yield. In the temperature adjustment process of the present application, the temperature of the polymerization reaction is adjusted in real time to keep it near the critical temperature, thereby ultimately increasing the yield of insoluble sulfur.

[0113] The various embodiments in the present application are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0114] It should be noted that, unless otherwise specified and limited, terms such as "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, an element defined by the sentence "including one..." does not exclude the existence of other identical elements in the article or device including the element. In addition, the term "and\or" used herein includes any and all combinations of one or more related listed items.

[0115] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not invented by the present application.

[0116] It should be understood that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A process for producing high thermal stability insoluble sulfur by gasification, characterized in that: The process The following steps are involved: A1, Raw material preparation: Select the purity of The above common sulfur is used as raw material, and is screened and dried; A2, pre-melting: use an electric heating pre-melting kettle to heat and stir the dried sulfur; A3, gasification: the pre-melted liquid sulfur is sent to a tubular gasifier through a pipeline to be gasified to obtain high-temperature sulfur vapor; A4, polymerization reaction: high temperature sulfur vapor is introduced into the polymerization furnace for polymerization reaction, and a halide stabilizer is added at the same time; And control the temperature during the polymerization process, including: S1: Collect infrared spectra during the polymerization process; S2: Calculate the impurity interference of each absorption peak based on the half-peak width difference between the absorption peaks in the infrared spectrum; S3: Calculate the overlap of infrared spectra by combining the impurity interference of all absorption peaks and the symmetry of the intensity on both sides of the absorption peaks; S4: Based on the degree of overlap, the derivative spectroscopy method is used to solve the overlapping absorption peaks in the infrared spectrum, and the content of various sulfur molecules in the polymerization reaction is obtained to calculate the degree of polymerization at the current acquisition moment; S5: determining how to adjust the temperature of the polymerization reaction at the current collection time according to the polymerization degrees at a plurality of consecutive adjacent collection time points; A5, quenching: using carbon disulfide as an extractant, passing the sulfur vapor after the polymerization reaction into an extraction tower, and obtaining a mixture of insoluble sulfur and a small amount of residual extractant from the bottom of the extraction tower; A6, solid-liquid separation: use a centrifuge to separate the mixture into solid and liquid; A7, drying and crushing: drying and crushing the separated insoluble sulfur to obtain insoluble sulfur; The calculation method of the polymerization degree is as follows: the polymerization degree at time t is recorded as , ; In the formula, Indicates time t The content of , and Respectively represent time t , and The content.

2. A process for producing insoluble sulfur with high thermal stability by gasification as claimed in claim 1, characterized in that: In step A1, the mesh size of the screening operation is controlled at Head.

3. A process for producing insoluble sulfur with high thermal stability by gasification as claimed in claim 1, characterized in that: After drying in step A1, the moisture content of the raw material is reduced to the following.

4. A process for producing insoluble sulfur with high thermal stability by gasification as claimed in claim 1, characterized in that: In step A3, the flow rate of liquid sulfur introduced into the tubular gasifier is .

5. The process for producing insoluble sulfur with high thermal stability by gasification as claimed in claim 1, characterized in that: The halide stabilizer is one of ferric chloride, zinc chloride or potassium bromide.

6. A process for producing insoluble sulfur with high thermal stability by gasification as claimed in claim 1, characterized in that: The calculation method of the impurity interference degree is: Calculate the average half-peak width of all absorption peaks in the infrared spectrum; For any absorption peak, the difference between the half-peak width of any absorption peak and the average half-peak width is forwardly fused with the number of all absorption peaks in the infrared spectrum to obtain the impurity interference degree of any absorption peak.

7. A process for producing insoluble sulfur with high thermal stability by gasification as claimed in claim 1, characterized in that: The calculation method of the overlap is: For both sides of any absorption peak, select two points with equal wavelengths from the center of the absorption peak, and calculate the slope of the line between the center of the absorption peak and the two points; Calculate the absolute value of the sum of the two slopes and the product of the impurity interference of the corresponding absorption peak; The cumulative sum of the product results of all absorption peaks in the infrared spectrum is taken as the overlap degree of the infrared spectrum.

8. A process for producing insoluble sulfur with high thermal stability by gasification as claimed in claim 1, characterized in that: The process of de-overlapping includes: When the normalized value of the overlap is greater than or equal to a preset overlap threshold, a second-order derivative is performed in the process of using the derivative spectroscopy method; otherwise, a first-order derivative is performed.

9. A process for producing insoluble sulfur with high thermal stability by gasification as claimed in claim 1, characterized in that: The method of determining how to adjust the temperature of the polymerization reaction at the current collection time according to the polymerization degrees at a plurality of consecutive adjacent collection time moments comprises: For a preset number of collection moments adjacent to the current collection moment, when the difference in the degree of polymerization of a preset number of consecutive collection moments is greater than 0, the temperature of the polymerization reaction process is increased at the current collection moment; when the difference in the degree of polymerization of a preset number of consecutive collection moments is less than 0, the temperature of the polymerization reaction process is reduced at the current collection moment; when the sum of the difference in the degree of polymerization of a preset number of consecutive collection moments is 0, the temperature of the polymerization reaction process is kept unchanged at the current collection moment; The difference is the difference in aggregation degree between the adjacent subsequent collection moment and the adjacent previous collection moment.

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