JP2014508846A - Desulfurization method for petroleum oil - Google Patents

Abstract

Disclosed is a method for desulfurization of petroleum oils, including a step of diluting a feedstock with a suitable organic solvent before the desulfurization reaction. The organic solvent is selected from alkanes, alkenes, cyclic alkenes and alkynes, in particular n-hexane, cyclohexane, heptane, pentene, hexene, heptene, octene, toluene and xylene. The solvent concentration in the feedstock and solvent mixture is in the range of 0.1-70%.
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Description

  The present invention relates to a desulfurization method. In particular, the present disclosure relates to a method for desulfurizing petroleum heavy oil and petroleum residues, more specifically carbon black feedstock.

Petroleum oil is a complex mixture of mainly hydrocarbons and other carbon containing compounds. It is known that the overall composition of a petroleum-based oil or crude oil varies greatly from its source or the geographical location of the refinery. The elemental composition of these oils is roughly composed of carbon (84-87%) and hydrogen (12-14%) along with oxygen, nitrogen, sulfur, moisture and ash. The sulfur content can vary significantly from 0.2 to 8%. In addition to these major components, there are trace metal impurities that may be present initially or associated with the oil during various refinery processing steps. Crude oil may also contain hydrocarbons, paraffin, asphaltenes, resins, and ash. Crude oil compositions can be differentiated into various individual fractions at different boiling ranges. The low boiling fraction (<170 ° C.) is typically naphtha, the boiling fraction of 180-250 ° C. is kerosene, and the boiling fraction in the range of 250-350 ° C. is called light oil. . The boiling fraction above 350 ° C. is commonly referred to as residue and is obtained after all or most of the distillation product has been removed from the petroleum. These residue fractions can be further distinguished as light vacuum gas oil, heavy vacuum gas oil, and vacuum residue. Each of these different fractions has a different molecular weight distribution of various hydrocarbon species and related compounds. In particular, one of the important aspects is the distribution of sulfur-containing species in these fractions. The use of petroleum residues includes heating (as fuel) and use as a feedstock for producing carbon black. The presence of sulfur contained in petroleum residues has a number of drawbacks. During complete or partial combustion of petroleum residues, sulfur is converted to SO ₂ and SO ₃ . These are a major cause of environmental problems in the form of acid rain and have a negative health impact. In addition, sulfur species cause poisoning of catalyst systems used in refineries. They are also known to be a major cause of equipment and exhaust corrosion. The presence of sulfur in the residue fraction has a further influence when it is used as a raw material for the production of carbon black. Apart from significant air pollution, these species remain associated with the final carbon black product which is harmful to various applications. Furthermore, the high sulfur content affects the throughput of the production process.

Carbon black raw material oil (CBFO) is a raw material used for carbon black production, and is an important material used in the tire industry. The carbon black used as a raw material, rich high component C ₁₂ and in naphthalene, methyl indene, anthracene, fluorene, mixtures of other polyaromatic component. CBFO is basically procured from either refineries or coal tar distillation. There are two types of CBFO: high BMCI types and general types. “BMCI” (Mine Bureau Correlation Index) effectively measures the degree of carbon black yield. The higher the BMCI, the better the yield of carbon black. High BMCI CBFO is used as raw material by carbon black manufacturers, while other grades are used by various consumers to produce rubber process oils, incense sticks and the like.

  The sulfur content in CBFO reduces the effective BMCI value. Furthermore, this sulfur is carried as impurities to the final carbon black product. It is therefore interesting to reduce the sulfur content of CBFO. It would therefore be interesting to find a method for reducing the sulfur content of petroleum residues used as CBFO.

The desulfurization method is usually performed to remove sulfur (S) from petroleum products such as natural gas, gasoline, gasoline, jet fuel, kerosene, diesel fuel, and fuel oil. Essential oil feedstocks (naphtha, kerosene, light oil and heavy oil) contain a wide range of organic sulfur compounds, including thiols, thiophenes, organic sulfides, disulfides and many others. These organic sulfur compounds are sulfur degradation products containing biological components that are present during natural formation in fossil fuels, petroleum feedstocks. The purpose of removing sulfur is in automobile vehicles, aircraft, railway locomotives, ships, gas or oil burning power plants, residential and industrial furnaces, and other forms of equipment that use fuel for combustion. Reducing sulfur dioxide (SO ₂ ) emissions as a result of using these fuels.

Many technologies, including catalytic conversion methods such as hydrodesulfurization, and physicochemical methods such as solvent extraction, alkylation, oxidation, precipitation, adsorption, etc., reduce sulfur content from various fractions of petroleum oils. Has been functioning. Hydrodesulfurization is generally used for this purpose. This method is based on the catalytic hydrogenation of sulfur species to convert to H ₂ S. However, hydrodesulfurization is known to work efficiently in low-boiling fractions such as gasoline, naphtha and kerosene. The catalyst system generally includes a transition metal such as Ni, Co, Mo, etc. supported on Al ₂ O ₃ . Several efforts have been made in the past to provide hydrodesulfurization technology. Some typical conventional examples are U.S. Pat. No. 2,516,877, U.S. Pat. No. 2,604,436, U.S. Pat. No. 2,697,682, U.S. Pat. No. 2,866,751, and U.S. Pat. No. 2,866,752. , U.S. Pat.No. 2,911,359, U.S. Pat.No. 2,921,182, U.S. Pat.No. 3,620,968, U.S. Pat.No. 3,668,116, U.S. Pat. No. 4,193,864, U.S. Pat. This is disclosed in Japanese Patent No. 4960506 and US Pat. No. 5,677,259. Most of these methods are very suitable for the treatment of low boiling fractions or crude oil. However, the efficiency decreases when processing high boiling fractions or vacuum residues. This is relatively easy to desulfurize due to the fact that the lower boiling petroleum fraction contains sulfur primarily in the form of mercaptans or lower member cyclic compounds. However, the high boiling fraction or residue is part of a more stable cyclic compound, such as substituted benzothiophene, and a higher order derivative or macromolecular cyclic compound that is extremely difficult to desulfurize, Contains sulfur species. Some prior art examples for treating the residue by hydrodesulfurization include US Pat. No. 2,604,011, US Pat. No. 2,929,182, US Pat. No. 4,328,127 and US Pat. No. 4,576,710. Including the specification of the issue. In most cases, the processing parameters are extreme, i.e. the use of high temperatures above 400 ° C. and pressures above 1000 psig. Furthermore, the desulfurization efficiency is low. Furthermore, because of these different processing conditions, hydrodesulfurization leads to coke formation, leading to deactivation of the catalyst system. Furthermore, the hydrodesulfurization process results in the formation of H ₂ S, which cannot be repositioned due to environmental concerns. In order to convert this H ₂ S into elemental sulfur, it is necessary to treat it by the Claus method at a high temperature of about 800 ° C. in the presence of an Al ₂ O ₃ catalyst.

In addition to hydrodesulfurization, there are several other technologies that are being considered for the desulfurization of petroleum oils. These include oxidation, adsorption, solvent extraction and bioenzymatic methods. Some typical conventional examples of oxidative desulfurization processes are described in US Pat. No. 3,816,301, US Pat. No. 3,163,593, US Pat. No. 3,413,307, US Pat. No. 3,505,210, US Pat. US Pat. No. 3,816,301, US Pat. No. 3,847,800, US Pat. No. 6,274,785, US Pat. No. 6,277,271, US Pat. No. 7,144,499, US Pat. This specification is disclosed in US Pat. No. 7,314,545, US Pat. No. 2,050,189261, US Pat. No. 200600226049, and US Pat. No. 2,090,148374. Common oxidizing agents used, H ₂ O ₂ or, acetate and combinations, and a H ₂ O ₂ in the presence of an oxidation catalyst system. Furthermore, tert-butyl hydroperoxide can also be used as an oxidizing agent because it tends to be soluble in oil. Adsorption methods generally use adsorbents such as viscosity, Al ₂ O ₃ , bauxite, silica or transition metal oxide systems supported on alumina, zeolite, activated carbon and the like. Some typical examples of these methods are US Pat. No. 2,436,550, US Pat. No. 2,537,756, US Pat. No. 2,988,499, US Pat. No. 3,620,969, US Pat. No. 4,419,224. US Pat. No. 4,695,366, US Pat. No. 5,219,542, US Pat. No. 5,310,717, US Pat. No. 6,655,533, US Pat. No. 6,650,209, US Pat. No. 7,291,259 U.S. Pat. No. US20030029777, U.S. Pat. No. US20030188993, U.S. Pat. No. US200602283780, and U.S. Pat. No. US2009090000990. Solvent extraction methods use various solvent systems such as dimethylformamide, dimethyl sulfoxide, phenol, dichloroether, nitrobenzene and the like. Some typical prior art methods are disclosed in US Pat. No. 2,486,519, US Pat. No. 2,262,004, US Pat. No. 2,634,230, and US Pat. No. 3,779,895. . However, most of the methods described above are aimed at desulfurization of crude oil or low boiling fractions. Similarly, most of the methods described above (except for bioenzymatic methods) are aimed at targeting and removing the entire sulfur-containing molecule, rather than specifically removing sulfur atoms. While pure sulfur content is low and sulfur is dispersed over a small number of low molecular weight compounds, while considering desulfurization of crude oil or low boiling fractions, this may not have a significant impact. However, in the case of residues where the sulfur content can be as high as 4-5%, the sulfur is essentially dispersed over the majority of the molecules contained in the oil. appear. Thus, by removing all of the sulfur-containing molecules, a significant amount of material in the oil portion will be lost.

Another such desulfurization process is based on the use of alkali metals, in particular sodium metal as a desulfurizing agent. In this process, sulfur is removed primarily as a metal sulfide rather than as a total removal of sulfur-containing molecules. Some typical prior art examples of this method are U.S. Pat. No. 1,938,672, U.S. Pat.No. 1,952,616, U.S. Pat.No. 2,902,441, U.S. Pat. No. 3093575, US Pat. No. 3,617,530, US Pat. No. 3,755,149, US Pat. No. 3,787,315, US Pat. No. 4,0038,242, US Pat. No. 4,120,795, US Pat. No. 4,123,350 Specification, US Pat. No. 4,147,612, US Pat. No. 4,248,695, US Pat. No. 4,437,980, US Pat. No. 6,620,564, US Pat. No. 7,192,516, US Pat. No. 7,507,327 , It disclosed in national Patent No. US7588680. These documents therefore describe the desulfurization of crude oil and residual oil with metallic sodium. Sodium metal can be used as a pure metal, an alloy supported on an inert species, or dissolved in a solvent such as ammonia. These methods also use hydrogen at high pressure in combination with sodium metal for desulfurization. In some methods, sodium-based compounds such as NaHS, NaNH ₂ are used for desulfurization. The main product formed as a reaction of sodium metal and sulfur in the feedstock is sodium sulfide (Na ₂ S). Some of the prior art documents mentioned above also describe the regeneration of sodium from Na ₂ S. These methods report the effects of refractory sulfur desulfurization, particularly the desulfurization effect of high boiling residue from refractory sulfur. However, these sodium-based desulfurization processes are associated with limitations such as low yields of desulfurized feedstock, the formation of large amounts of insoluble sludge, hydrogen requirements and safety concerns. Due to the high inherent viscosities of heavy oil and petroleum residue, processing and separation operations before and after the desulfurization process are difficult. A large amount of valuable residual feedstock remains associated with precipitated sodium sulfide residues or unreacted sodium in the form of viscous sludge. Sludge is also extremely difficult to filter and separate due to its inherent viscosity and sticky nature. There is therefore a substantial loss of raw material during the process, especially during filtration or separation. Furthermore, due to the lower density of metallic sodium compared to the residual oil, sodium metal tends to float on the surface of the oil, which can lead to dangerous situations during failed reactions or incomplete mixing. There is.

  Thus, known desulfurization processes are associated with a number of limitations, such as low yields of desulfurized feedstock, the formation of large amounts of insoluble sludge, hydrogen requirements and safety issues. Due to the high inherent viscosity of heavy oil and petroleum residues, processing and separation operations before and after the desulfurization process are difficult. A large amount of valuable residual feedstock remains associated with precipitated sulfur residues or unreacted sodium in the form of high viscosity sludge. Sludge is also extremely difficult to filter and separate due to its inherent viscosity and sticky nature. The substantial loss of raw material during the process is in particular during filtration or separation. Furthermore, it has been observed that the sodium-based desulfurization process results in the retention of sodium metal in the oil. In the presence of metallic sodium, even a low concentration of <100 ppm results in a change in carbon black morphology during the manufacturing process. Accordingly, there is a need to develop a method for minimizing the loss of feedstock during petroleum oil desulfurization. The present invention is an improved process for the desulfurization of petroleum oils, particularly carbon black feedstock (CBFO), which reduces the sulfur content in the oil.

Objective The objective of the present disclosure is to provide a method for desulfurizing a carbon black feedstock that provides improved yield and high quality of the desulfurized oil.

  Another object of the present disclosure is to provide a method for desulfurizing a carbon black feedstock that includes improved processing and handling operations.

  Still another object of the present disclosure is to provide a method for desulfurizing a carbon black raw material without using hydrogen.

  Another object of the present disclosure is to provide a method for further processing of desulfurized oil to remove residual sodium content.

SUMMARY According to the present disclosure, a method is provided for the desulfurization of petroleum-based oils, said method comprising the following steps:
Diluting a petroleum-based oil with a hydrocarbon organic solvent selected from the group consisting of alkanes, alkenes, cyclic alkenes and alkynes to obtain a petroleum solvent mixture, wherein the organic solvent in the oil solvent mixture A step wherein the concentration is in the range of 0.1 to 70%;
Transferring the oil solvent mixture to a reactor;
Adding solid sodium metal to the oil solvent mixture in the reactor, wherein the sodium metal concentration is 0.1-20% of the petroleum oil concentration;
Reacting the oil-solvent mixture with sodium while mixing at a temperature in the range of 240-350 ° C. and a pressure in the range of 0-500 psig for 15 minutes to 4 hours to obtain the resulting mixture;
Cooling and precipitating the resulting mixture;
Decanting the cooled mixture and filtering the decanted solution of the desulfurized petroleum oil.

  Typically, according to the present disclosure, the hydrocarbon organic solvent is selected from the group consisting of n-hexane, cyclohexane, heptane, pentene, hexene, heptene, octene, toluene and xylene.

  Preferably, according to the present disclosure, the method comprises purging the reactor with hydrogen gas at a pressure in the range of 0-500 psig.

  Typically, according to the present disclosure, the method includes the step of separating the organic solvent from the petroleum oil desulfurized by distillation.

  Preferably, according to the present disclosure, the method uses high shear mixing with a mixer selected from an in-line mixer, a mechanical mixer, a pump around loop, and an ultrasonic mixer, and the oil in the reactor. Mixing the solvent mixture with sodium.

  According to the present disclosure, a method is provided for removing residual sodium metal, said method comprising: 0. 0 ° C. in an organic solvent at a temperature in the range of 50-150 ° C. for 30 minutes to 90 minutes with vigorous stirring. Treating the desulfurized petroleum oil with 1-10% carboxylic acid; and filtering the resulting mixture to obtain a desulfurized petroleum oil having a sodium content of 10-50 ppm Including.

  Typically, according to the present disclosure, the carboxylic acid is selected from acetic acid, formic acid and propionic acid.

  Preferably, according to the present disclosure, the organic solvent is selected from alkanes, alkenes, cyclic alkenes, alkynes and alcohols. More preferably, the organic solvent is xylene.

  According to the present disclosure, a method is provided for removing residual sodium metal by purging desulfurized petroleum-based oils with air at a temperature in the range of 30-150 ° C.

DETAILED DESCRIPTION OF THE DISCLOSURE The present disclosure relates to a method for desulfurizing carbon black feedstock (CBFO). Stock oil (CBFO) has a high viscosity at ambient temperature. The method includes diluting the feedstock with a suitable solvent prior to the desulfurization reaction. The organic solvent can be selected from the hydrocarbon solvent group consisting of alkanes, alkenes, cyclic alkenes and alkynes. Similarly, other oils such as gasoline, kerosene, and crude oil can be used to dilute the feedstock. The organic solvent is in particular selected from the group consisting of n-hexane, cyclohexane, heptane, pentene, hexene, heptene, octene, toluene and xylene, preferably the solvent is xylene. The solvent concentration used is a mixture of CBFO and solvent and is in the range of 0.1-70%, preferably in the range of 0.1-50%, more preferably in the range of 1-30%.

  The feedstock for the method of the present disclosure is a carbon black feedstock having a sulfur content in the range of 0.1% to 20%. The method of the present disclosure can also be used for petroleum-based oils of various boiling fractions. Further, the disclosed method can be used to remove sulfur from coal tar, shale oil, or other organic sulfur-containing compounds. The organic solvent is removed after the desulfurization process. The process results in a desulfurization stream (after removing xylene) with a significant viscosity drop. The formation of insoluble sludge (unusable material) due to the polymerization reaction of the desulfurized species is reduced by improving the viscosity of the feedstock. Furthermore, improving the viscosity of the feedstock promotes the processing of the feedstock required in applications such as the production of carbon black products.

  The method results in improved feedstock quality by reducing the asphaltene content in the feedstock. Asphaltenes are considered insoluble n-heptane, a soluble component of carbonaceous materials such as crude oil, bitumen or lime. Asphaltenes are a high molecular weight heteroatom species that is generally considered harmful to the quality of the treated carbon black product.

  The method of the present disclosure is performed in the absence of hydrogen at pressures ranging from 0 to 500 psig, which is a higher C of the processed oil compared to the method performed in the presence of high pressure hydrogen. : Results in an H ratio. This is useful to convert most of the treated oil to carbon black because hydrogen leaves the process in the form of water vapor without contributing to product formation. The method removes moisture present in the CBFO. CBFO typically contains about <1% moisture. Sodium metal is known to have a strong affinity for water and thereby react with water. The method uses sodium metal at a concentration of 0, 1-20% of the CBFO oil concentration. Therefore, the water present in the CBFO is completely removed.

  In one aspect of the present disclosure, the method is performed in the presence of hydrogen. The added hydrogen can be in the range of 0-500 psig, preferably in the range of 0-300 psig, more preferably in the range of 0-100 psig. Furthermore, hydrogen will not be present in the form of a closed system, i.e., without hydrogen pressure or under a pressureless system. It can therefore be added in a continuous or semi-continuous flow of hydrogen gas.

  The desulfurization process of the present disclosure provides crystalline sodium sulfide as a by-product. The by-product so formed is easy to separate and filter, thus providing good recovery of the desulfurized oil and good separation and processing efficiency of the desulfurized oil.

  An important aspect of the present disclosure is to provide a method for reducing the size of dispersed sodium, either as solid particles or as a molten form as droplets. The fine dispersion of sodium metal increases the efficiency of the desulfurization process. In conventional methods, the by-product, sodium sulfide, is orally coating the surface of the sodium metal, thereby reducing the efficiency of the method. Accordingly, mixing, preferably high shear mixing, is provided, for example, mixing that lasts at a temperature in the range of 240-350 ° C. for 15 minutes to 4 hours, whereby the high sulfide mixing destroys the sodium sulfide, thereby Provide a new sodium surface to promote the reaction. Any form of mixing may be used, such as an in-line mixer, pump around loop, mechanical mixer or ultrasonic mixer, which provides the required amount of dispersion to sodium metal.

  In the absence of hydrogen, there is the formation of insoluble sludge (unusable material) due to the polymerization reaction among the desulfurized species.

  Furthermore, pure CBFO has a high viscosity of over 1500 cP at ambient conditions. The method of the present disclosure results in a desulfurized stream (after xylene / solvent removal) having a substantial viscosity drop to the range of 100-150 cP at ambient conditions. Thus, the overall effect is that the desulfurization process is performed in the absence of hydrogen, not only reducing the loss of feedstock caused by the formation of insoluble sludge, but also improving the properties of the treated carbon black product. It is expected to improve the viscosity of the feedstock. Furthermore, if the process is carried out in the presence of hydrogen, there may be a reduction in the aromatic content of the feed due to hydrogenation (decreased C: H ratio), which is a measure of the carbon black product yield. Bring about a decline. Thus, when the process is carried out in the absence of hydrogen, the C: H ratio of the treated feed increases, thereby increasing the yield of carbon black product. It should be noted that the method of the present disclosure can also be extended by means of proceeding with desulfurization using Na and organic solvents with hydrogen. The results in the presence of organic solvent and hydrogen before desulfurization also show advantages in terms of product quality and yield, the yield of the desulfurized feedstock being 15 to 15 compared to known methods. It is 20% bigger. The scope of our method thus includes the simultaneous use of organic solvent and hydrogen, however, with each optimized combination of reactants (or in the absence), expanded as a much improved desulfurization method can do.

Another aspect of the disclosed method is the formation and processing of by-products after the desulfurization reaction. Desulfurization of feedstock using sodium metal results in the formation of Na ₂ S as a by-product. However, a large amount of valuable residual CBFO is lost because it remains associated with this Na ₂ S residue or unreacted sodium in high viscosity sludge form. The presence of the organic solvent in the feedstock prior to the desulfurization reaction results in the formation of crystals and pure by-products. This product is easier to separate and filter due to less substantial CBFO loss. This results in good recovery of the desulfurized oil and good separation and processing efficiency after the desulfurization reaction.

  The present disclosure uses a high shear mixing device aimed at reducing the size of dispersed sodium, either as solid particles or as a molten form as droplets. This provides a fine dispersion of sodium metal in the feedstock that increases the desulfurization efficiency of the process. Second, during the desulfurization process, the by-products formed tend to coat the surface of the sodium metal, thereby reducing efficiency. High shear mixing helps break these surfaces and provide a new sodium surface to enhance the reaction. Any form of mixing can be used, such as an in-line mixer, pump around loop, mechanical mixer, or ultrasonic mixer, which provides the required amount of dispersion to sodium metal.

Carbon black feedstock oil has a high viscosity of 1500 cP or more at ambient conditions. By adding an organic solvent prior to desulfurization, its viscosity is reduced to a significant degree (less than 50 cP at ambient conditions, depending on the amount of solvent added), facilitating better mixing as well as transport and processing. Making it easier to contact with other reactants. Apart from viscosity, the density of CBFO is also high, typically 1.01-1.08 g / cm ³ . The density of sodium solid at 30 ° C. is about 0.96 g / cm ³ and the density of molten sodium is about 0.927 g / cm ³ . Therefore, sodium tends to remain suspended above the surface of the CBFO. Therefore, in order to carry out the reaction, it should be ensured that the sodium remains sufficiently immersed in the liquid, mainly by a continuous stirring mechanism. This can lead to serious safety concerns if the agitation fails or if the reaction fails. The result will be that all of the sodium (due to its low density) may come into contact with atmospheric moisture as it rises to the top of the feed. By adding an appropriate amount of organic solvent (referred to as xylene having a density of about 0.86 g / cm ³ ), the density of CBFO is reduced compared to the density of sodium, so that all sodium is always in the liquid circle. Make sure it stays soaked well.

  Also disclosed is a process for removing residual metallic sodium from desulfurized oil. During the desulfurization process, sodium metal is finely dispersed in the oil. After completion of the desulfurization process, some sodium metal always remains in the system, either as a suspension or as bound to molecular chains in the oil. The separation or removal of sodium from the oil system is quite difficult depending on the pure mechanical method. The presence of this residual sodium, even in trace amounts, has significant implications for the overall quality of the product for the carbon black industry. The disclosed method uses acetic acid in an organic solvent mixture. The role of acetic acid is that sodium metal and organic solvent scavenging promotes better mixing between the feedstock and acetic acid. Alternatively, apart from acetic acid, various carboxylic acids such as formic acid, propionic acid and mixtures thereof can be used. In addition, ethanol and such alcohols can also be used for sodium scavenging. Furthermore, removal of residual sodium can also be achieved by purging the oil with air at a temperature raised to 30-150 ° C. Such treatment includes not only air but also other gaseous agents such as oxygen and ozone.

  The present disclosure is described with reference to the following examples, which are not intended to limit the scope and boundaries of the present disclosure. The description provided is for illustration only.

Example 1
Experiments were performed on CBFO and xylene mixtures with varying ratios to evaluate the effect of xylene content on CBFO yield. All three examples below (described in Table 1) were performed in the presence of a hydrogen atmosphere. In Example 1, 150 g CBFO was mixed with 150 mL xylene. This resulted in a mixture of CBFS: xylene = 50: 50 (weight: volume basis). The solution was mixed well and then transferred to a high pressure reactor. 9 gm of sodium metal was weighed separately. The sodium metal was then cut into 0.5-1.0 cm pieces and added to the CBFS / xylene solution in the reactor. The reaction vessel was first purged with nitrogen to remove air, and then the vessel was purged with hydrogen. The reactor was then pressurized to 300 psi with hydrogen. The reactor was subsequently heated to a temperature of 290 ° C. The reaction was carried out at this temperature for 4 hours. After cooling the entire solution to room temperature, CBFO was decanted. The decanted solution was filtered and analyzed for sulfur content by XRF (X-ray fluorescence spectroscopy). Similarly, the desulfurization process was carried out for various other CBFO: xylene ratios, ie 70:30, 80:20 (shown in Examples 2 and 3 in Table 1). The results for these different compositions are summarized in Table 1. The CBFO, xylene and sodium contents used, along with the desulfurization efficiency for each of the different CBFS: xylene ratios, are also expressed below.

  It was observed that more than 70% desulfurization was obtained in all cases.

Viscosity The sample from Example 2 after desulfurization and xylene distillation was analyzed for viscosity as a function of temperature. Samples were initially heated to about 175 ° C. and viscosity measurements were recorded at different temperatures when the samples were cooled. Similarly, measurements were recorded for a second sample of CBFO that was untreated or raw. The results are shown in Table 2.

  Therefore, a significant reduction in the viscosity of the desulfurized sample was observed, especially at low temperatures below 50 ° C. The fundamental benefits of viscosity reduction can include easier processing of the oil, thereby reducing energy costs and improving the quality of the carbon black product by forming fine droplets during the spraying process. It is to improve.

Asphaltene content Samples were further tested for oil asphaltene content. Asphaltenes have been found to be harmful not only in the quality of carbon black but also in the manufacturing process during carbon black formation. Therefore, the asphaltene content for the treated and untreated oils was determined by measuring the n-heptane insoluble content in both oils. It was observed that the asphaltene content of the untreated oil was 10.59%. However, the asphaltene content of the treated oil was substantially reduced to 4.65%. This suggested that our method can reduce asphaltene content by 50% or more.

Example 2
The following experiments were conducted to optimize time, temperature and pressure parameters for the desulfurization process. These studies were decided on a CBFO: xylene ratio of 70:30. These optimization studies are illustrated in Examples 4-11 listed in Table 3.

Table 3 below illustrates the effect of temperature on the desulfurization effect. Therefore, in each case, the CBFO: xylene ratio is kept constant at 70:30. The batch contained 210 g CBFO and 90 mL xylene. 13.5 g of sodium metal was added to each sample. All reagents were placed in a high pressure reactor and then pressurized with hydrogen (about 300 psi). The reactions were carried out at temperatures of 290 ° C. for Examples 4-8, respectively, with different residence time intervals of 3 hours, 1 hour, 45 minutes, 30 minutes, and 10 minutes. The reactor was then cooled and the CBFO was decanted and analyzed in each case by XRF. These desulfurization results are summarized in Table 3. It was observed that the desulfurization efficiency remained substantially the same for residence times of 3 hours, 1 hour and 45 minutes, respectively, with an overall desulfurization efficiency of 70%. However, the desulfurization efficiency decreased dramatically to 59 and 50% for reduced residence times of 30 and 10 minutes, respectively.

  In addition, desulfurization was performed at a reduced temperature of 240 ° C. in order to understand the effect of temperature on desulfurization efficiency. Therefore, in Example 9, an appropriate amount of CBFO: xylene (70:30) mixture was removed to the high pressure reactor. 13.5 g of sodium metal was added and the reactor was pressurized with hydrogen to a pressure of about 300 psi. The reactor was then heated to a temperature of 240 ° C. using a 1 hour residence time. The reactor was cooled, CBFO was decanted and analyzed for sulfur content. In this case, a desulfurization efficiency of 10% is obtained, and the minimum temperature at which effective desulfurization can be performed is 240 ° C.

  These studies were further expanded to understand the effect of hydrogen partial pressure on desulfurization efficiency.

  In Examples 10 and 11, different hydrogen thicknesses of 500 psi and 100 psi were maintained. The temperature was raised to 290 ° C. using a residence time of about 1 hour. The reactor was cooled, the sample was decanted and the sulfur content was analyzed. It has been observed that there is only a slight improvement in the overall desulfurization efficiency at high hydrogen partial pressures.

  Therefore, it was observed that the minimum temperature required for the desulfurization reaction was 250 ° C. Furthermore, it has been found that a residence time of 1 hour is sufficient for optimal desulfurization to occur. It was also observed that the residence time could be further reduced by increasing the sodium content above stoichiometry or by raising the reaction temperature above 300 ° C. It was not recognized that the effect of hydrogen partial pressure significantly affects desulfurization efficiency.

Example 3
Desulfurization experiments were conducted in the presence and absence of hydrogen and xylene. The presence of xylene was observed to have a significant impact not only on processing but also on by-product formation. Similarly, it was important to understand the impact of hydrogen on the overall desulfurization process. Therefore, in order to study the effect of individually and combined hydrogen and xylene were studied following scheme: a presence of Example 12 xylene, and desulfurization in the absence of H _2; Example Desulfurization in the presence of 13-xylene and in the presence of H 2; Example 14 Desulfurization in the absence of xylene and in the absence of H ₂ .

In the case of Example 12, 210 g CBFO and 90 mL xylene were removed from the high pressure reactor. Hydrogen was not added to the reactor. For Example 13, 210 g CBFO and 90 mL xylene were removed from the high pressure reactor and approximately 300 psig hydrogen was added to the reactor. For Example 14, 210 g of CBFO was removed and no xylene or hydrogen was added. In all of Examples 12-14, a stoichiometric amount of sodium metal was added. The reaction temperature was maintained at 290 ° C. for a 1 hour residence time. Therefore, after the reaction time, the sample was cooled and decanted in each case. All schemes yielded free CBFO and sludge (Na ₂ S + CBFO) in various proportions. Decanted CBFO was weighed and the yield is shown in Table 4.

  When xylene was used, it was observed that the CBFO yield was higher than when xylene was not added. In addition, a 5% mixture of acetic acid in xylene was prepared to reduce the sodium content from the desulfurized oil. The acetic acid solution was added to the treated or desulfurized oil. The mixture was then heated at 100 ° C. for 1 hour with vigorous stirring. The mixture was then cooled and filtered. Treatment resulted in a significant reduction in sodium content from 2000 ppm to <50 ppm. Alternatively, treatment of the desulfurized oil can also be accomplished by purging the oil with air at high temperatures. For this, 100 mL of desulfurized CBFO was taken into a glass air treatment tube, and compressed air was continuously purged into the tube over a period of 30 minutes. This air reacts with the excess Na present in the oil to form a precipitated mass that can be filtered off. This treatment was found to result in a reduction of Na content on the order of 50% (from 2000 ppm to 900 ppm). In order to further optimize the process, the same reaction was carried out at a temperature increased to 50 ° C. The treatment was found to result in a significant reduction in Na content of about 96% (2200 ppm to 90 ppm).

Using a stirrer with a dull blade (Teflon / plastic), the sample is mixed with low agitation mixing (200-300 rpm) and the sample in a parr reactor with a metal blade with a relatively sharp blade Experiments were conducted to confirm the effect of heavy shear mixing, mixing under higher stirring speed (700-800 rpm) mixing. It was observed that if the agitator was able to break the formed Na ₂ S particles, a higher desulfurization was obtained, bringing the sodium metal surface into contact with CBFO for further reaction.

Technical Advantages As described in the present disclosure, the method for desulfurization of carbon black feed oil is a method that does not require hydrogen; a method that does not require high pressure conditions; a method that reduces the loss of feedstock; > Methods to reduce the asphaltene content of> 50% petroleum oil; <Methods to increase the viscosity of oil desulfurized to 200 cP; <Methods to reduce residual sodium content to 10 ppm; Accelerate CBFO treatment and handling conditions A method that provides easy filtration and separation of desulfurized oil and its by-products; a method that is safer to reduce the density of the oil compared to sodium metal; and compared to sodium metal Has technical advantages, including but not limited to the realization of methods that are safe for reducing the density of oils.

  Throughout this specification the word “comprise” or variations such as “comprises” or “comprising” may be used to describe an element, whole or process, or element, whole or It will be understood that it refers to a group of steps, but is not meant to exclude any other element, whole or process, or group of elements, whole or steps.

  The use of the expression “at least” or “at least one” is more than one element, as its use may be in embodiments of the invention to achieve one or more desired purposes or results. Or suggest the use of ingredients or amounts.

  Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. Any or all of these matters may form part of the prior art base, or as they existed anywhere before the priority date of this application, Should not be taken as an admission when in the knowledge field.

  Numeric values referring to various physical parameters, dimensions or quantities are only approximations and are higher than those assigned to parameters such as dimensions or quantities unless there is a condition in the specific specification that contradicts it. Low values are envisioned to fall within the scope of this disclosure. Where a range of values is specified, the disclosed range includes values up to 10% and above of the specified range, with the lowest and highest values, respectively.

  Although considerable emphasis is placed herein on the specific steps of the preferred method, additional steps can be made and many changes can be made in the preferred steps without departing from the principles of the present disclosure. It will be understood that it can be made. These and other changes in preferred process steps of the present disclosure will be apparent to those skilled in the art from the disclosure herein, so that the above description should be construed as illustrative only of the present disclosure, It should not be construed as limiting in any way.

Claims (10)

A method for desulfurizing petroleum oil, comprising the following steps:
1. Diluting a petroleum-based oil with a hydrocarbon organic solvent selected from the group consisting of alkanes, alkenes, cyclic alkenes and alkynes to obtain an oil solvent mixture, the organic solvent in the oil solvent mixture A step in which the solvent concentration is in the range of 0.1 to 70%;
2. Transferring the oil solvent mixture to a reaction vessel;
3. Adding solid sodium metal to the oil solvent mixture in the reaction vessel, wherein the sodium concentration is 0.1-20% of the petroleum oil concentration;
4). Reacting the oil-solvent mixture with sodium for 15 minutes to 4 hours at a temperature in the range of 240 to 350 ° C. and a pressure in the range of 0 to 500 psig with mixing to obtain a mixture;
5. Cooling and precipitating the obtained mixture;
6). Decanting the cooled mixture and filtering the decanted solution of desulfurized petroleum oil;
A method comprising the steps of:   The method of claim 1, wherein the hydrocarbon organic solvent is selected from the group consisting of n-hexane, cyclohexane, heptane, pentene, hexene, heptene, octene, toluene and xylene.   The method of claim 1, comprising purging the reaction vessel with hydrogen gas at a pressure in the range of 0-500 psig.   The method according to claim 1, comprising a step of separating the organic solvent from petroleum oil desulfurized by distillation.   Mixing sodium and the oil-solvent mixture in the reaction vessel by using high shear mixing by mixer means selected from in-line mixers, mechanical mixers, pump around loops and ultrasonic mixers The method of claim 1.   Treating the desulfurized petroleum oil with 0.1 to 10% carboxylic acid in an organic solvent at a temperature in the range of 50 to 150 ° C. with vigorous stirring for 30 minutes to 90 minutes; and The method of claim 1, comprising removing residual sodium metal by filtering the resulting mixture to obtain a desulfurized petroleum-based oil having a sodium content of 10 to 50 ppm.   7. A process according to claim 6, wherein the carboxylic acid is selected from acetic acid, formic acid and propionic acid.   7. A process according to claim 6, wherein the organic solvent is selected from alkanes, alkenes, cyclic alkenes, alkynes and alcohols.   The method of claim 6, wherein the organic solvent is xylene.   The method of claim 1, comprising removing residual sodium metal by purging the desulfurized petroleum-based oil with air at a temperature in the range of 30-150 ° C.