JPS6118598B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel hydrorefining method for producing petroleum-based waxes with excellent photostability and thermal stability. Conventionally, wax has been purified by sulfuric acid washing and clay treatment, but these purification methods yield satisfactory quality, but they suffer from low yields, high manufacturing costs, and problems. Due to problems such as waste disposal, there has been a recent trend toward converting to hydrorefining methods. However, in the conventional hydrorefining techniques, although it is possible to obtain a good hue by selecting reaction conditions, it is not necessarily possible to obtain a product with stable light stability and thermal stability. In order to improve this, some additives are used, but when wax is used for food or food packaging, it is regulated as a food additive, and additives approved by the Ministry of Health and Welfare are especially effective for photostability. There is currently no. Additionally, regulations on food additives are expected to become increasingly strict in the future. Under these circumstances, there is an urgent need to improve photostability and thermal stability in hydrorefining, and hydrogenation to produce petroleum-based waxes with improved photostability and thermal stability is an urgent task. Establishment of a purification method is desperately needed. As such a hydrorefining method, Japanese Patent Publication No. 45-27339
The publication describes a wax purification method for obtaining wax with good stability against ultraviolet rays.
A wax mixture mixed with hydrogen is first passed over a catalyst made of a hydrogenated metal supported on a refractory inorganic oxide carrier, and then passed over a catalyst made of a hydrogenated metal supported on an activated carbon support to form the wax. Although a purification method has been proposed, this method is still insufficient to produce a wax with good photostability and thermal stability. As a result of intensive studies to establish a hydrorefining method to obtain a petroleum-based wax with excellent photostability and thermal stability, the present inventors found that 5 to 35% by weight of silica was added to the base.
A petroleum wax with excellent photostability and thermal stability can be produced by contacting petroleum-based wax with hydrogen in the presence of a catalyst comprising a noble metal of Group Group of the Periodic Table of Elements supported on a refractory inorganic oxide carrier containing within the range of It has been found that a wax-based wax can be obtained. In addition, after contacting the petroleum wax with a catalyst containing a group metal and/or a group (iron group) metal of the periodic table, a refractory inorganic oxide carrier containing silica in a range of 5 to 38% by weight is prepared. They discovered that it is possible to produce a petroleum-based wax with particularly excellent photostability and thermal stability by bringing it into contact with a catalyst comprising precious metals supported on the wax. That is, in the present invention, the raw material wax is about 40% by weight.
In the presence of a catalyst comprising a group noble metal of the Periodic Table of Elements supported on a refractory inorganic oxide support containing silica, a reaction temperature of about 100 to about 400°C, about
A process for hydrorefining petroleum-based wax, characterized by contacting it with hydrogen of about 10 m ³ /Kl or more under reaction conditions of a reaction pressure of 10 Kg/cm ² or more and a liquid hourly space velocity of about 5 V/H/V or less. It is. Further, the present invention involves contacting the raw material wax with hydrogen in the presence of a catalyst () containing an iron group metal and/or a group metal of the periodic table of the elements, and then adding silica in a range of 5 to 35% by weight. In the presence of a catalyst () comprising a group noble metal of the Periodic Table of Elements supported on ^a refractory inorganic oxide support containing 5V/H/
The present invention includes a hydrorefining method for petroleum-based waxes, which is characterized by contacting with hydrogen of about 10 m ³ /Kl or more under reaction conditions of a liquid hourly space velocity of V or less. As the raw material wax to be subjected to the hydrorefining of the present invention, not only crystalline paraffin wax separated from relatively light lubricating oil distillate oil but also microcrystalline wax obtained from residual oil can be used. , or a mixture of these may be used. These petroleum-based waxes are obtained from petroleum hydrocarbon oils by known solvent dewaxing methods. For example, self-cooling hydrocarbon solvents (ethane,
Dewaxing method using one or more of propane, butane, ethylene, propylene and butylene) or a mixed solvent of a self-cooling hydrocarbon solvent and a ketone solvent (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), and ketone A dewaxing method using a mixed solvent of a solvent and an aromatic hydrocarbon solvent (benzene, toluene) can be employed. The raw material wax suitable for carrying out the present invention has a melting point of 35 to
It is 100℃ and has an oil content of 0 to 20%. Such raw material wax generally does not have sufficient quality in terms of photostability and thermal stability, as shown in the Examples below. In the description of the present invention, "photostability" refers to stability against ultraviolet rays when exposed to direct sunlight, and in the case of paraffin wax, it was measured by the following method. Collect the molten sample at the lowest possible temperature in a 25 x 25 x 100 mm mold, allow it to cool to room temperature, and solidify.
Remove the formwork, place the sample on a horizontal laboratory table approximately 1m from the south window, and place it under direct sunlight.
After continuous exposure to light for 15 days, the sample was dissolved and the hue was measured using a Saybolt hue meter to evaluate stability. Results of photostability test using the above method for commercially available paraffin wax washed with sulfuric acid and treated with white clay (hue,
Seibold +21) was set as the tentative goal. Moreover, "thermal stability" refers to stability against thermal deterioration in a heated and melted state, and in the case of paraffin wax, it was measured by the following method. Pour 100gr into a 200ml beaker that has been thoroughly washed with a small knife.
Scrape off the sample. Preheat this beaker to 160℃±
After heating and deteriorating for 2 hours in a rotary constant temperature bath set at 1°C, the hue was measured using a Saybolt hue meter. The hydrorefining method according to the present invention hydrogenates unstable aromatic hydrocarbons contained in trace amounts in unrefined raw material wax, and simultaneously removes sulfur compounds and nitrogen compounds. To hydrogenate aromatic rings without being affected by sulfur and nitrogen compounds,
Catalysts used in hydrorefining are required to have high hydrogenation activity. In the hydrorefining method of the present invention, a catalyst is used in which a group noble metal of the periodic table of elements is supported on a refractory inorganic oxide carrier containing 5 to 35% by weight of silica. As the refractory inorganic oxide carrier, alumina, magnesia, zirconia, titania, hafnia, boria, etc. can be used. The most preferred carrier is
It is alumina, and about 1 to about 10% of refractory inorganic oxide such as magnesia, zirconia, and hafnia is added to it.
It can also be added in a range of % by weight. The content of silica is in the range of 5 to 35% by weight in the carrier, in particular
It ranges from 5 to 30% by weight. The silica content in the carrier affects the sulfur poisoning resistance of the catalyst and the hydrogenolysis of wax.
By adjusting the amount to 40% by weight or less, the catalyst life can be extended by improving the resistance to sulfur poisoning without reducing wax quality or yield. If it does not contain silica, the resistance to sulfur poisoning of the catalyst will decrease and the hydrogenation activity will decrease.
It is not possible to industrially produce the high quality wax that is the object of the present invention. The noble metals of the Periodic Table of Elements are ruthenium, rhodium, palladium, osmium, iridium and platinum. Preferred metals are platinum and palladium, and a particularly preferred metal is palladium. A catalytically effective amount of the noble metal supporting group is suitable, for example in the range of about 0.1 to about 10% by weight as paldium. The silica-alumina support particularly preferably used in the present invention is obtained by mixing silica gel and alumina gel, immersing silica gel in an aqueous aluminum compound solution, and adding an alkaline substance to this mixture to deposit alumina gel on the silica gel. It can be produced by a conventionally known method, or a method in which an alkaline substance is added to a homogeneous aqueous solution of a silicon compound and an aluminum compound to coprecipitate silica and alumina gel. The noble metal component can be supported on the inorganic oxide by any method. For example, a method can be adopted in which a noble metal compound is added to an aqueous solution of silicon and aluminum compounds and all these components are coprecipitated, or a method in which an aqueous solution of a noble metal compound is added to a gel of a carrier. A preferred method is to impregnate the carrier with the noble metal component by immersing the carrier in an aqueous solution of the noble metal compound. A particularly preferred method is
The method includes the steps of impregnating a carrier with an aqueous solution, acidic solution, or basic solution of a noble metal compound, separating the solution, and then washing, drying, and baking the impregnated carrier. As the noble metal compound, water-soluble compounds such as chlorides, nitrates, sulfates or complex salts can be used. The drying temperature is preferably from room temperature to about 150℃.
The firing temperature is preferably in the range of about 150 to about 500°C. By firing, the noble metal component exists as a metal and/or an oxide. Noble metal supported catalysts may contain other co-catalyst components, e.g.
Thorium, cerium, etc. can also be added. The noble metal catalyst supported by an inorganic oxide containing silica according to the present invention preferably has the following characteristic values. Specific surface area: about 100 to about 500 m ² /g Pore volume: about 0.5 to about 1.2 ml/g Average pore radius: about 30 to about 120 Å Bulk density: about 0.3 to about 0.7 g/ml The shape of the catalyst is spherical or cylindrical. It may be in the form of tablets, etc., and usually has a diameter of 1 to 4 mm.
Preferably, the size is . The reaction conditions for hydrorefining in the present invention are approximately
Reaction temperature in the range of 100 to about 400°C, preferably about 150 to about 300°C, about 10 Kg/cm2 ^or more, preferably about
Reaction pressure in the range of 30 to about 150Kg/ ^cm2 , about 5V/H/
V or less, preferably in the range of about 0.3 to about 5 V/H/V, and the hydrogen gas circulation rate is about 10 Nm ³ or more per 1 Kl of wax, preferably about
It ranges from 50 Nm ³ to about 800 Nm ³ . There is no problem in using hydrogen gas as long as it has a purity of approximately 85% or higher. Although low temperature, high pressure reaction conditions are preferred for converting aromatic rings to naphthenic rings, the hydrorefining process according to the present invention can be carried out at reaction pressures of about 10 Kg/cm ² or higher. Hydrorefining is
In single or multiple reaction zones, also fixed beds,
Either a fluidized bed or a moving bed can be employed. Next, the two-stage hydrorefining method will be explained. In the two-stage hydrotreating method, the raw material wax is brought into contact with hydrogen in the presence of a catalyst () containing a group metal and/or a group (iron group) metal of the periodic table of the elements, and then 5 to 35 % by weight of silica on a refractory inorganic oxide support containing a group noble metal of the Periodic Table of the Elements. By providing the first stage hydrorefining process,
It is possible to obtain wax of even better quality, and as a result of desulfurization, denitrification, and removal of other impurities from the raw material wax in the first step, the activity of the precious metal catalyst in the second step is raised to a high level. It can be assumed that the Group metals of the periodic table of elements as hydrogenation active components in the above catalyst () include molybdenum,
Chromium group metals such as tungsten and chromium
Further, as the group metal, iron, cobalt, nickel, etc. are used. In particular, it is preferred to utilize a combination of group metals and iron group metals. Preferred combinations include molybdenum-nickel, tungsten-nickel, molybdenum-cobalt or molybdenum-cobalt-nickel. These metal components are usually supported on a refractory carrier in the form of oxides, sulfides or mixtures thereof.
Such active metal components are preferably carried in catalytically effective amounts, ie, about 2 to 6% Group metal and about 10 to 18% Group iron group metal, based on the finished catalyst. As the refractory carrier, one or more of alumina, silica, magnesia, hafnia, titania, zirconia, boria, diatomaceous earth, crystalline aluminosilicate, activated carbon, etc. can be used. Particularly preferred refractory carriers are alumina or alumina-silica. Alumina or alumina-silica can be blended with about 1 to 30% by weight of other refractory inorganic oxides, such as magnesia, zirconia, boria or titania,
Further, phosphoric acids can also be blended in the same manner. Suitable alumina-silica contains silica in a range of about 1 to 30% by weight. If the silica content is large, the acidity of the catalyst will be high and the raw material wax will decompose, so it is preferable that the silica content be within the range of about 5 to 35% by weight. The manufacturing method of the carrier as described above is not particularly limited, and it may be manufactured by any known method. The catalyst manufacturing method is as follows:
Although impregnation methods, deposition methods, coprecipitation methods, etc. are known, the impregnation method is most preferred from the operational point of view. According to the impregnation method, the metal component is impregnated into the carrier by immersing the carrier in a solution of an inorganic or organic compound of the active metal component under predetermined conditions, and then,
The impregnated carrier is separated from the solution, washed, dried and fired. As a result, a catalyst mainly supporting an oxide of an active metal is obtained. As the impregnating solution, aqueous solutions of active metal chlorides, nitrates, sulfates, carbonates, formates, acetates, oxalates, etc. can be used. The amount of impregnating solution relative to the amount of carrier can be appropriately determined as long as the carrier can be completely immersed, but usually, the volume of impregnating solution used is about 1 to 20 times the amount of carrier. Cleaning after impregnation is performed using water or an organic solvent such as alcohol. Further, the drying of the catalyst is carried out at about 50 to 200°C in the presence or absence of oxygen, and the calcination is carried out at about 300 to 600°C. The catalyst () obtained as described above can sulfurize the active ingredient by contacting it with a sulfur compound, such as hydrogen sulfide, carbon disulfide and other sulfur compounds, or a sulfur-containing hydrocarbon oil. can. The sulfurization conditions include hydrogen gas containing sulfur compounds at a reaction temperature of about 100 to 400°C, and a reaction temperature of about 10 to about
The contact may be carried out at a reaction pressure of 200 Kg/cm ² and a gas hourly velocity of about 0.2 to about 5 V/H/V. The reaction conditions for the first purification step are approximately 200 to approximately 400°C;
Preferably, the reaction temperature ranges from about 250 to about 350°C,
About 10 to about 200Kg/cm ² , preferably about 40 to 150Kg/cm 2
The reaction pressure is in the range of cm ² and the liquid hourly space velocity is less than or equal to about 5 V/H/V, preferably in the range of about 0.2 to about 2 V/H/V. The hydrogen gas circulation rate is the raw material wax 1
Kl, about 10 m ³ or more, preferably about 50 to about
The area is ^800m3 . If hydrogen gas purity is approximately 85% or higher, impurities such as carbon monoxide, hydrogen sulfide, and
It can be used even if it contains ammonia or the like. The reaction product fed from the first purification step to the second purification step preferably contains about 50 ppm or less of sulfur. A particularly preferred sulfur content for suppressing poisoning of the noble metal catalyst is about 10 ppm or less. For the second purification step, 5 to 35% by weight of the above
The reaction conditions and operations are the same as for hydrorefining using a catalyst comprising a group noble metal of the Periodic Table of Elements supported on a refractory inorganic oxide support containing silica within the range of . The above-mentioned noble metal catalyst using a refractory inorganic oxide as a carrier containing a specific amount of silica exhibits excellent hydrorefining activity and can contribute to improving the light stability and thermal stability of wax in particular. . In addition, such a catalyst has a long life and can be regenerated, so it is economically advantageous and has high industrial value from the operational and equipment standpoints. In the method of using a known cobalt-molybdenum catalyst for the hydrorefining of wax, the light stability and thermal stability cannot be improved as shown in the comparative example described later, and in this case, the addition of additives cannot improve the light stability and thermal stability. However, according to the present invention, a wax with good photostability and thermal stability can be produced only by hydrorefining, and furthermore, the ultraviolet absorption coefficient of polycyclic aromatics can be almost eliminated. Since it is possible to reduce the temperature to zero, it is possible to produce waxes for foods and food packaging that are superior to conventional techniques. In the present invention, wax with good photostability and thermal stability can be produced by directly subjecting such wax to hydrorefining. However, depending on the properties of the wax, Even better waxes can be obtained if pretreated by contacting with hydrogen in the presence of a catalyst containing a group metal and/or a group iron group metal. The wax obtained according to the method of the present invention not only has excellent photostability and thermal stability, but also meets other wax requirements such as odor, penetration, melting point, and suitability for chlorination. also has satisfactory properties. Next, examples of the present invention will be shown. Example 1 Paraffin wax having the following properties was prepared at a reaction temperature of 250°C, a reaction pressure of 45 Kg/cm ² and a liquid hourly space velocity of
Silica containing 24.0% by weight of silica under reaction conditions of 1.0V/H/V and hydrogen gas circulation rate of 180m ³ /Kl.
A catalyst containing 1.0% by weight of palladium supported on an alumina carrier was used for hydrorefining. [Properties of raw paraffin wax] Standards (135F paraffin wax) Saybolt Color 14 30 ⁺ FDA Purity* (121.1156) Ultraviolet absorbance Fail Pass (UV Absorbanca) [-logT/cm] 280-289mμ 2.27 0.15 290-299mμ 1.81 0.12 300-359mμ 1.19 0.08 360-400mμ 0.03 0.02 Oil content 0.08wt% Sulfur content 4ppm *FDA purity test results are shown as Phase 1 results. Example 2 Hydrogen purification was carried out in the same manner as in Example 1 except that the reaction temperature was 180°C. Example 3 Reaction temperature: 250°C, liquid hourly space velocity: 0.5V/H/V
Hydrorefining was carried out in the same manner as in Example 1 except that the reaction pressure was 50 Kg/cm ² . Example 4 Reaction temperature: 250°C, liquid hourly space velocity: 0.8V/H/V
Hydrorefining was carried out in the same manner as in Example 2 except that the reaction pressure was 50 Kg/cm ² . Comparative example 1 Co-
Hydrorefining was carried out in the same manner as in Example 1 except that a Mo-based catalyst was used and the reaction temperature was 300°C. Comparative Example 2 Hydrorefining was carried out in the same manner as in Example 3 except that the reaction temperature was 250°C. Comparative Example 3 All treatments were carried out under the same conditions as Comparative Example 2, except that the reaction temperature was 300°C. Comparative Example 4 The same paraffin wax used in Example 1 was purified by sulfuric acid/clay clay treatment. The properties of the purified paraffin wax obtained through the above purification steps are summarized in the following table together with the reaction conditions described above.

[Table] Example 5 The same raw material paraffin wax as in Example 1 was
Using a cobalt-molybdenum catalyst Note ⁾ , the following pretreated wax was obtained by contacting it with a treat gas at a rate of 180 m ³ per 1 Kl of wax under the following reaction conditions. Reaction conditions Reaction temperature, °C 300 Hydrogen partial pressure, Kg/cm ² 45 Liquid hourly space velocity, V/H/V 2.4 Note Catalyst composition CoO ₂ 3.5% MoO ₃ 12.5% Al ₂ O ₃ remaining amount Pretreatment wax Hue, Seibold Product 22 After thermal stability test 21 After photostability test -1 FDA purity (121.1156) UV absorbance Fail -logT/cm 280-289mμ 0.22 290-299mμ 0.17 300-359mμ 0.11 360-400mμ 0.02 Pretreatment above The wax was placed in a reaction tower filled with palladium catalyst (palladium: 1.0% by weight) using silica-alumina (silica: 24.0% by weight as a carrier).
It was introduced together with a treat gas at a rate of 180 m ³ per 1 Kl of wax under the following reaction conditions and subjected to hydrorefining. Reaction conditions Reaction temperature, °C 250 Hydrogen partial pressure, Kg/cm ² 45 Liquid hourly space velocity, V/H/V 2.0 As a result of hydrorefining, purified paraffin wax having the following properties was obtained. Properties of purified paraffin wax Hue, Saybolt product 30 ⁺ After heat stability test 30 ⁺ After photostability test 30 ⁺ FDA purity (121.1156) Ultraviolet absorbance (UVAbsorbance) Pass −logT/cm 280−289mμ 0.00 290− 299 mμ 0.00 300-359 mμ 0.00 360-400 mμ 0.00 Examples 6 to 8 The same treatment as in Example 5 was carried out except that the reaction temperature and liquid hourly space velocity were changed as shown in the table below. The results are summarized in the table below.

[Table] From the above examples, extremely high quality wax can be easily obtained according to the hydrorefining method of the present invention, and the palladium/silica-alumina catalyst according to the present invention can be regenerated. Therefore, if an appropriate regeneration method is adopted, long-term continuous operation can be performed. Example 9 The following experiment was conducted to determine the effect of silica content on palladium catalysts. (1) Properties of raw material paraffin wax (135〓paraffin wax) Same as Example row 1. (2) Palladium catalyst treatment reaction conditions without pretreatment: Temperature ℃ 250 Pressure Kg/cm ² , H ₂ pp 50 Liquid hourly space velocity V/H/V 0.5 TGR, m ³ /Kl 180

【table】

[Table] From the above results, it is clear that catalysts containing 5 to 35% by weight of silica have a greater effect on product quality.

Claims (1)

[Scope of Claims] 1. Raw material wax is treated in the presence of a catalyst comprising a group noble metal of the periodic table supported on a refractory inorganic oxide carrier containing 5 to 35% by weight of silica.
It is characterized by contacting with about 10 m 3 /Kl or more of hydrogen under reaction conditions of a reaction temperature of 100°C to about 400°C, a reaction pressure of about 10 Kg/cm ^{2 or} more, and a liquid hourly space velocity of about ⁵ V/H/V or less. A hydrorefining method for petroleum-based wax. 2. Contacting the raw material wax with hydrogen at a reaction temperature of about 200 to about 400°C in the presence of a catalyst containing a group metal of the periodic table of elements and/or a group iron group metal,
Next, in the presence of a catalyst comprising a group noble metal of the Periodic Table of Elements supported on a refractory inorganic oxide support containing 5 to 35% by weight of silica, a reaction temperature of about 100 to about 400°C, about 10 Kg/cm ² The reaction pressure is over and approx.
Approximately 10 under the reaction condition of liquid hourly space velocity of 5V/H/V or less
A hydrorefining method for petroleum-based wax, characterized by contacting it with hydrogen of m ³ /Kl or more.