JP5574216B2 - Method for producing sulfonic acid group-containing carbonaceous material - Google Patents

Description

  The present invention relates to a method for producing a sulfonic acid group-containing carbonaceous material by reactivating a sulfonic acid group-containing carbonaceous material whose activity has been reduced by using it as a solid acid catalyst in the reaction.

  Sulfuric acid is an important catalyst used in various chemical processes. However, it generally requires a large amount of sulfuric acid, there is a problem of corrosion of the equipment, separation of sulfuric acid from the product after the reaction, recovery, purification, reuse process, sulfuric acid remaining in the product There are many problems such as the need for neutralization and the removal and disposal of the salt produced thereby, and wastewater treatment, and the fact that these steps require a lot of energy. Use of a solid acid catalyst instead of a mineral acid catalyst such as sulfuric acid is useful as a catalyst for various chemical reactions because there is no corrosion of the equipment and various steps after the reaction such as separation are omitted or greatly simplified. Various solid acids have been developed. Typical solid acids include inorganic compounds such as silica / alumina, crystalline aluminosilicate (zeolite) and heteropolyacid, as well as polymer compounds such as strong acid ion exchange resins.

  Olefin hydration is an industrially important reaction for the production of alcohols and ketones, and an acid catalyst is used for this reaction. 2-Butanol, which is a raw material of isopropyl alcohol or methyl ethyl ketone, is produced by various methods utilizing hydration of propylene or n-butene. Many processes in the hydration reaction process use sulfuric acid as a catalyst, but there are also problems with many by-products in addition to the above problems, and some solid acid catalysts are also used to solve these problems. Has been. In this case, inorganic solid acid catalysts such as silica / alumina and crystalline aluminosilicate (zeolite) are generally not used because their activity decreases in the presence of water, and phosphoric acid is supported on an inorganic carrier. However, there is a problem that phosphoric acid is detached from the support during the reaction. In addition, strong acid ion exchange resins that are polymers having sulfonic acid groups on the cross-linked polystyrene skeleton are also used, but the sulfonic acid groups are detached when used at high temperatures, the resin softens and cannot maintain its shape, and is expensive. The range of use is limited. An ultra-strong solid acid “Nafion” (registered trademark of DuPont) based on a fluorine-substituted olefin polymer having heat resistance has been developed, but it is too expensive for use in industrial applications.

  By the way, from the viewpoint of reducing carbon dioxide emissions, “bioethanol” using biomass material, which is a renewable resource, as a raw material has attracted a great deal of attention. “Bioethanol” is produced by hydrolyzing cellulose, which is the main component of the biomass material, to obtain monosaccharides and fermenting them using yeast or the like. From the viewpoint of effective utilization of biomass materials, hydrolysis of celluloses is an extremely important technology. Conventionally, either a “concentrated sulfuric acid method” or a “dilute sulfuric acid method” using sulfuric acid as a catalyst has been used for this hydrolysis reaction (Non-patent Document 1). In the “concentrated sulfuric acid method”, polysaccharides are hydrolyzed in concentrated sulfuric acid, but enormous energy is required to separate sulfuric acid from products such as monosaccharides and water-soluble hydrolysates produced by the reaction. . On the other hand, in the “dilute sulfuric acid method” using dilute sulfuric acid at 100 ° C. or higher, not only the separation of the produced monosaccharides and water-soluble hydrolyzate and sulfuric acid, but also the reaction itself requires large energy. It is said. In order to solve such problems of the sulfuric acid method, the application of a solid acid catalyst is desired. However, monosaccharides that can be fermented by yeast by hydrolyzing polysaccharides such as cellulose and starch that constitute biomass materials There was no solid acid catalyst capable of efficiently obtaining.

  Under such circumstances, sulfonic acid group-containing carbonaceous materials obtained by carbonizing and sulfonating natural products such as aromatic compounds, petroleum heavy oils, and saccharides have recently been developed (Patent Document 1). As a solid acid catalyst, it has attracted attention because of its high activity in various chemical reactions, excellent heat resistance, and low cost. So far, evaluation as a catalyst for fatty acid esterification reaction, ester hydrolysis reaction, alkylation reaction, olefin hydration reaction, etc. has been attempted, and it has been confirmed that it has an activity comparable to that of sulfuric acid. (Patent Literature 2, Non-Patent Literature 3, Non-Patent Literature 4, Patent Literature 1, Patent Literature 2). In addition, application to hydrolysis of the above-described biomass raw materials has been studied.

However, when a sulfonic acid group-containing carbonaceous material is used as a catalyst at a high temperature for a long time, the acid group content is lowered and the catalytic activity is lowered. The same applies to strongly acidic ion exchange resins. Ion exchange resins with reduced catalytic activity are only disposed of as waste, and their reactivation is a problem. As for the sulfonic acid group-containing carbonaceous material, it is desirable to recycle and use the sulfonic acid group-containing carbonaceous material having a reduced catalytic activity, instead of discarding it. However, at present, there has been no proposal for reusing a sulfonic acid group-containing carbonaceous material having a reduced catalytic activity, and no knowledge has been obtained regarding the method of regenerating. A method has been proposed in which a cation exchange resin having reduced activity is used for the production of ether from alcohol and olefin, for example, methyl tertiary butyl ether or methyl tertiary amyl ether, and is reactivated by treatment with a sulfonation reagent ( For example, Patent Document 3). However, the cation exchange resin has a completely different structure from the sulfonic acid group-containing carbonaceous material, and this proposal cannot be applied to the sulfonic acid group-containing carbonaceous material.
Bionics February 2006, pages 26-33 Domen et al., “Synthesis Conditions and Catalysis of Carbon-Based Solid Strong Acids”, The 85th Annual Meeting of the Chemical Society of Japan (2005), 2B5-43 Hara, M .; et al. Nature, 438 (10), 178, November (2005). Hara et al., PETROTECH, 29 (6), 411 (2006) Japanese Patent Laid-Open No. 2004-238111 International Publication WO 2005/029508 A1 JP-A-10-139919 (Description of Claims)

  An object of the present invention is to provide a sulfonic acid group-containing carbonaceous material method that is used in a reaction as a solid acid catalyst and reactivates a sulfonic acid group-containing carbonaceous material having reduced activity.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have provided a sulfonic acid group-containing carbonaceous material whose activity as a solid acid catalyst has been lowered by using it for the reaction, by subjecting it to a specific treatment. The inventors have found that it can be reactivated, and have completed the present invention.

  That is, the present invention provides a sulfone group having a first step of reactivating a sulfonic acid group-containing carbonaceous material having a reduced activity by being used as a solid acid catalyst in the reaction by heat treatment in the presence of sulfuric acid. A method for producing an acid group-containing carbonaceous material is provided.

  Conventionally, a sulfonic acid group-containing carbonaceous material having a reduced catalytic activity cannot be used as a solid acid catalyst, and an effective utilization method has not been found. On the other hand, according to the present invention, the sulfonic acid group-containing carbonaceous material having reduced activity is reactivated in the first step, so that the sulfonic acid group is sufficiently reusable as a solid acid catalyst. The contained carbonaceous material can be reactivated. In other words, the method for producing a sulfonic acid group-containing carbonaceous material of the present invention can greatly reduce the amount of catalyst discarded due to a decrease in catalytic activity, and the sulfonic acid group-containing carbon that has been conventionally regarded as waste. This is very useful in terms of the effective use of resources, in which a carbonaceous material can be reused, and in that a sulfonic acid group-containing carbonaceous material can be obtained at a lower cost than in the past.

  In the method for producing a sulfonic acid group-containing carbonaceous material of the present invention, the sulfonic acid group-containing carbonaceous material having reduced activity hydrolyzes a polysaccharide insoluble in water in the presence of the sulfonic acid group-containing carbonaceous material, It is obtained by producing monosaccharides and / or water-soluble polysaccharides. In the first step, the sulfonic acid group-containing carbonaceous material having reduced activity is converted into an unreacted and insoluble in water. It is preferable to include a second step of heat treatment in the presence of sulfuric acid in the presence of polysaccharides.

  Further, the method for producing a sulfonic acid group-containing carbonaceous material of the present invention is such that the sulfonic acid group-containing carbonaceous material having reduced activity hydrolyzes a water-insoluble polysaccharide in the presence of the sulfonic acid group-containing carbonaceous material. In the first step, the sulfonic acid group-containing carbonaceous material having a reduced activity is converted into unreacted and water by the production of monosaccharide and / or water-soluble polysaccharide. It is preferable to include a third step of carbonizing in the presence of an insoluble polysaccharide and a fourth step of heat-treating the sulfonic acid group-containing carbonaceous material after carbonization in the third step with sulfuric acid. .

  In the present invention, a sulfonic acid group-containing carbonaceous material having a reduced activity due to being used in an esterification reaction with a carboxylic acid and an alcohol is preferably used as the sulfonic acid group-containing carbonaceous material having a reduced activity. it can.

  In the present invention, a sulfonic acid group-containing carbonaceous material having a reduced activity due to being used in an esterification reaction with a carboxylic acid and an olefin is preferably used as the sulfonic acid group-containing carbonaceous material having a reduced activity. it can.

  In the present invention, as the sulfonic acid group-containing carbonaceous material having a reduced activity, a sulfonic acid group-containing carbonaceous material having a reduced activity due to use in the ester hydrolysis reaction can be preferably used.

  In the present invention, as the sulfonic acid group-containing carbonaceous material having a reduced activity, a sulfonic acid group-containing carbonaceous material having a reduced activity due to use in the hydration reaction of olefins can be preferably used.

  In the present invention, the sulfonic acid group-containing carbonaceous material obtained through the first step preferably has a sulfonic acid group content of 0.5 mmol / g or more.

  In addition, the sulfonic acid group-containing carbonaceous material obtained through the first step preferably exhibits an acid group content of 1 mmol / g or more.

Further, the present invention uses an olefin hydration reaction, an etherification reaction, a carboxylic acid, using the sulfonic acid group-containing carbonaceous material obtained by the method for producing a sulfonic acid group-containing carbonaceous material of the present invention as a solid acid catalyst. There is provided a method of performing at least one reaction selected from the group consisting of an esterification reaction between an alcohol and an alcohol, and a hydrolysis reaction of an organic compound containing an ester bond or an ether bond .

  Since the sulfonic acid group-containing carbonaceous material obtained by the method for producing a sulfonic acid group-containing carbonaceous material of the present invention has been reactivated to such a degree that it can be sufficiently reused as a solid acid catalyst, It can function well as a solid acid catalyst in the reaction. In addition, it is possible to significantly reduce the waste generated by the reaction and to obtain a sulfonic acid group-containing carbonaceous material at a lower cost than in the past.

According to the present invention, since the sulfonic acid group-containing carbonaceous material can be reused, the waste catalyst can be greatly reduced. Furthermore, the raw materials required for producing the sulfonic acid group-containing carbonaceous material are greatly reduced, and it becomes possible to produce a sulfonic acid group-containing carbonaceous material with less environmental burden.
Further, when the reaction raw material is a polysaccharide insoluble in water, such as cellulose, as in the hydrolysis reaction of biomass, it is substantially possible to separate the unreacted biomass solid and the solid acid catalyst from the mixture after the reaction. It is impossible and all conventional solid acid catalysts must be waste. However, when a solid acid catalyst made of a sulfonic acid group-containing carbonaceous material is used as the solid acid catalyst, unreacted biomass can also be a starting material for the sulfonic acid group-containing carbonaceous material, so without separating them, It is extremely reasonable because it can be carbonized and sulfonated into a sulfonic acid group-containing carbonaceous material by heat treatment in sulfuric acid as it is. This is also a great effect of the present invention. When a cation exchange resin, which is a known solid acid catalyst, is used to hydrolyze a polysaccharide insoluble in water such as cellulose, it is not possible to separate a cation exchange resin with reduced activity from an unreacted polysaccharide unnecessary for water. Therefore, the cation exchange resin with reduced activity must be discarded. On the other hand, the sulfonic acid group-containing carbonaceous material used in the present invention can be reactivated in a state where it is mixed with an unreacted, water-insoluble polysaccharide, and the solid acid catalyst can be reused. .

  Hereinafter, preferred embodiments of the present invention will be described in detail.

(Sulfonic acid group-containing carbonaceous material)
The sulfonic acid group-containing carbonaceous material referred to in the present invention means a carbonaceous material having a sulfonic acid group and not having a clear crystal structure such as diamond or graphite. Typical examples of the solid acid described in JP-A No. 2004-238111 and the sulfonic acid group-introduced amorphous carbon described in International Publication No. WO2005 / 029508A1 are “sulfonic acid groups” in the present invention. “Contained carbonaceous material” is defined similarly. The production method is not particularly limited as long as it is suitable for the intended reaction. For example, the method described in International Publication WO 2005 / 029508A1 or Japanese Patent Application Laid-Open No. 2004-238111 is described. It can be manufactured by the method.

As a preferable sulfonic acid group-containing carbonaceous material, for example, in a spectrum by Raman spectroscopy, when both G band and D band are detected, an integrated intensity ratio (I ( D) / I (G)) may be 0.7 or less, preferably 0.65 or less, and more preferably 0.6 or less. Some raw materials for producing the sulfonic acid group-containing carbonaceous material do not show these spectra, but such materials can be preferably used. In the case of a sulfonic acid group-containing carbonaceous material using cellulose as a raw material, this numerical value may be 0.1 to 0.7. In this specification, the D band, the G band, and their integrated intensities are defined as follows.
The D band is vibration of A1g breathing mode in the carbon six-membered ring, and the peak top appears at 1350 cm ^{−1 to} 1360 cm ⁻¹ . G band is a vibration of E2g mode of six-membered carbon ring, the peak top appears at 1580cm ^-1 ~ ± ^{5cm -1.} A Raman spectrum composed of the sum of both peaks is divided into two peaks by Gaussian or Gaussian-Lorentzian, and the obtained integrated intensities of the D band and G band are taken as the integrated intensities.

  The acid group content of the sulfonic acid group-containing carbonaceous material is preferably 1.0 mmol / g or more, more preferably 1.6 mmol / g or more, and still more preferably 3 mmol / g or more. When the content of the acid group is less than the lower limit of the above range, the activity for the hydrolysis reaction tends to be insufficient. In addition, the upper limit of acid group content is not specifically limited.

  The sulfonic acid group content of the sulfonic acid group-containing carbonaceous material is preferably 0.5 mmol / g or more, more preferably 1.0 mmol / g or more, and 1.5 mmol / g or more. Is more preferable. When the sulfonic acid group content is less than the lower limit of the above range, the activity for the hydrolysis reaction tends to be insufficient. In addition, the upper limit of sulfonic acid group content is not specifically limited.

The sulfur / carbon atomic ratio (molar ratio) of the sulfonic acid group-containing carbonaceous material is a measure of the sulfonic acid group content added to and introduced into the sulfonic acid group-containing carbonaceous material. The sulfur / carbon element ratio (molar ratio) of the sulfonic acid group-containing carbonaceous material of the present invention is preferably 1.5 × 10 ⁻² or more. If it is less than the lower limit of this range, the activity for the hydrolysis reaction tends to be insufficient.

  Further, the sulfonic acid group-containing carbonaceous material of the present invention cannot be confirmed from any structure from the X-ray diffraction pattern, and is substantially amorphous.

The sulfonic acid group-containing carbonaceous material can be produced by subjecting an organic compound to heat treatment in concentrated sulfuric acid or fuming sulfuric acid, as described in International Publication WO 2005/029508.
Heat treatment of an organic compound in concentrated sulfuric acid or fuming sulfuric acid is performed in an inert gas stream such as nitrogen or argon, or in dry air to produce a sulfonic acid group-containing carbonaceous material having a high sulfonic acid density. is necessary. A more preferable treatment is to perform heating while blowing an inert gas such as nitrogen or argon or dry air into concentrated sulfuric acid or fuming sulfuric acid to which an organic compound is added. Aromatic sulfonic acid and water are produced by the reaction of concentrated sulfuric acid and an aromatic compound, and this reaction is an equilibrium reaction. Therefore, when the amount of water in the reaction system increases, the reverse reaction proceeds faster, so that the amount of sulfonic acid introduced into the carbonaceous material is significantly reduced. Amorphous carbon with a high sulfonic acid density is synthesized by reacting in an inert gas or in a dry air stream, or reacting while blowing these gases into the reaction system, and actively removing water from the reaction system. can do.

In the heat treatment, partial carbonization, cyclization, condensation and the like of the organic compound are allowed to proceed, and sulfonation is caused. Accordingly, the heat treatment temperature is not particularly limited as long as the reaction is allowed to proceed, but industrially, it is 50 ° C to 450 ° C, preferably 60 ° C to 350 ° C, and more preferably 80 ° C to 200 ° C. When the treatment temperature is less than 50 ° C., condensation and carbonization of the organic compound is not sufficient, carbon formation is insufficient, sulfonic acid groups may not be sufficiently introduced, and the treatment temperature is 350 ° C. If it exceeds, thermal decomposition of the sulfonic acid group may occur. When the starting material is a polycyclic aromatic hydrocarbon, it is preferable to perform carbonization and sulfonation in one step at the same time.
Although heat processing time can be suitably selected according to the organic compound to be used, processing temperature, etc., it is 1-50 hours normally, Preferably it is 5-20 hours.
Although the quantity of the concentrated sulfuric acid or fuming sulfuric acid to be used is not specifically limited, It is 2.6-50.0 mol normally with respect to 1 mol of organic compounds, Preferably it is 6.0-36.0 mol.

  Aromatic hydrocarbons can be used as the organic compound, but other organic compounds such as natural products such as glucose, sugar (sucrose), and cellulose can also be suitably used. Synthetic polymer compounds such as polyethylene and polyacrylamide, and synthetic resins such as phenol resins and resorcinol resins may be used. These woody materials such as cellulose, hemicellulose, lignin and lignocellulose are preferred because the resulting sulfonic acid group-containing carbonaceous material has high thermal stability. In addition, non-refined fiber materials such as herbs and woods can be used as raw materials.

  The aromatic hydrocarbons may be polycyclic aromatic hydrocarbons or monocyclic aromatic hydrocarbons, and for example, benzene, naphthalene, anthracene, perylene, coronene, etc. can be used, preferably Naphthalene or the like can be used. Moreover, a phenol resin etc. can also be used suitably. Synthetic polymer materials such as phenol resins are preferred because the resulting sulfonic acid group-containing carbonaceous material has a high acid group content. Only one type of organic compound may be used, but two or more types may be used in combination. Further, it is not always necessary to use a purified organic compound, and for example, heavy oil containing aromatic hydrocarbons, pitch, tar, asphalt and the like may be used.

  When using natural products such as glucose and cellulose or synthetic polymer compounds as raw materials, these materials are heated in an inert gas stream and partially carbonized before heat treatment in concentrated sulfuric acid or fuming sulfuric acid. It is preferable to keep it. The heating temperature at this time is usually 100 to 600 ° C., and the treatment time is usually 1 minute to 100 hours, preferably 2 to 30 hours. When the temperature of the carbonization treatment is less than the lower limit of the above range, the heat resistance of the sulfonic acid group-containing carbonaceous material obtained by sulfonation treatment is inferior, or there are many components dissolved in water or organic matter. It tends to cause problems. When the temperature is higher than the upper limit of the above range, a sufficient amount of sulfonic acid groups cannot be imparted when sulfonating this, and various reactions of the resulting sulfonic acid group-containing carbonaceous material It tends to be insufficient in catalytic activity. When the carbonization time is less than the lower limit of the above range, the heat resistance of the sulfonic acid group-containing carbonaceous material obtained by sulfonating the carbonized material is inferior, or the amount dissolved in water or organic matter is large. Tend to cause problems. On the other hand, the necessary carbonization proceeds sufficiently in the upper limit of the above range, and it is not necessary to spend more time than that, and at the same time, excess energy is consumed, which is not preferable.

  After the carbonization and sulfonation treatment steps, excess sulfuric acid is preferably removed by washing with hot water and further dried to obtain the sulfonic acid group-containing carbonaceous material used in the present invention. Washing with hot water is conveniently performed under reflux at about 100 ° C., for example, by a Soxhlet extraction method. It is also possible to shorten the washing time by washing at a higher temperature under pressure.

  When using aromatic hydrocarbons or heavy oil containing the same, pitch, tar, asphalt, etc. as raw materials, it is preferable to heat the product in vacuum after heat treatment in concentrated sulfuric acid or fuming sulfuric acid. This removes excess sulfuric acid, promotes carbonization and solidification of the product, and increases the yield of the product. For evacuation, it is preferable to use an evacuation apparatus having an evacuation speed of 10 L / min or more and an ultimate pressure of 100 torr or less. A preferable heating temperature is 140 to 300 ° C, and a more preferable temperature is 200 to 280 ° C. The evacuation time at this temperature is usually 2 to 20 hours.

(Reaction using sulfonic acid group-containing carbonaceous material as solid acid)
The sulfonic acid group-containing carbonaceous material obtained as described above has an acid strength and an acid group content that are useful for various chemical reactions as a solid acid catalyst. The sulfonic acid group-containing carbonaceous material used in the present invention includes an olefin hydration reaction and an etherification reaction, an esterification reaction between a carboxylic acid and an alcohol, and a hydrolysis reaction of an organic compound containing an ester bond or an ether bond. It is particularly useful as a catalyst for reactions under various polar conditions. That is, in a reaction using a polar substance such as alcohol, carboxylic acid, water, etc. as a reaction substrate, it exhibits excellent activity and resistance and is useful as a catalyst for these polar reactions.

In addition, since the sulfonic acid group-containing carbonaceous material can hydrolyze the polysaccharide, it can also be used as a catalyst for producing monosaccharides and / or other polysaccharides from the polysaccharide.
The polysaccharide to be used is not particularly limited as long as it generates a water-soluble low-polymerized sugar, such as a monosaccharide or other polysaccharide that can be hydrolyzed and used for ethanol fermentation, and is a molecule having a β1-4 glycoside bond. For example, water-insoluble natural polymer materials such as cellulose, hemicellulose, lignocellulose, and cellobiose can be suitably used. A material containing a molecule having a water-soluble β1-4 glycosidic bond such as cellobiose or cellotriose can also be used.
Examples include starch (amylose, amylopectin), dextrin, maltose and the like. Further, the polysaccharide may not be purified, and for example, a natural organic material containing a polysaccharide such as a plant may be used. For example, wood (including waste), waste paper, rice straw, wheat straw, rice husk, bamboo, bagasse (sugar cane press residue), corn cobs, sago palm (starch starch), linter, cotton, pulp, etc. are also used as raw materials. It is possible.
The low polymer sugar which is a hydrolyzate here refers to a water-soluble polysaccharide or a polysaccharide actually dissolved in water. For example, if it is a glucose multimer couple | bonded by (beta) 1-4 glycosidic bond, the glucose skeleton will show the polysaccharide which consists of a repeating structure about 2-10.

  The sulfonic acid group-containing carbonaceous material produced as described above is excellent as a solid acid catalyst, but if used continuously in the acid catalyst reaction as described above, contamination by impurities and other substances in the reaction feed, or The activity decreases due to elimination of the sulfonic acid group. When the user determines that it is not preferable in terms of workability and economy to continue the production operation using the sulfonic acid group-containing carbonaceous material in use, the reactivation operation is performed. The state of the activity decrease is judged by a decrease in the reaction rate in the actual reaction or a decrease in the acid group content.

(Reactivation)
The reactivation is performed by heat-treating the sulfonic acid group-containing carbonaceous material having a reduced activity used in the reaction in the presence of sulfuric acid. As the sulfuric acid used, either concentrated sulfuric acid or fuming sulfuric acid can be used. Preferably, concentrated sulfuric acid having a concentration of 85% by mass or more or fuming sulfuric acid having a sulfur trioxide content of 0 to 40% by mass can be used. When a solid acid catalyst comprising a sulfonic acid group-containing carbonaceous material is used for the hydrolysis reaction of a water-insoluble polysaccharide such as cellulose, the produced monosaccharide and water-soluble polysaccharide are separated from the reaction system as an aqueous solution. However, since polysaccharides such as raw material cellulose are solid and insoluble in water, used sulfonic acid group-containing carbonaceous materials having reduced activity and polysaccharides such as unreacted cellulose cannot be separated. In this case, the sulfonic acid group-containing carbonaceous material having reduced activity can be reactivated by heat treatment in sulfuric acid while coexisting insoluble polysaccharides such as unreacted cellulose in water.

  The amount of concentrated sulfuric acid or fuming sulfuric acid to be used is not particularly limited, but is 1 to 500 times (mass ratio), preferably 2 to 100 times, the amount of used sulfonic acid group-containing carbonaceous material subjected to sulfuric acid treatment. When the lower limit of this range is not reached, the reactivation is not sufficiently performed, and the resulting reactivated sulfonic acid group-containing carbonaceous material has insufficient catalytic activity for various chemical reactions. On the other hand, if the upper limit of this range is exceeded, excessive concentrated sulfuric acid or fuming sulfuric acid will be used, resulting in an increase in cost including the treatment of used sulfuric acid.

  The temperature of the sulfuric acid treatment is 40 to 250 ° C, preferably 80 to 200 ° C. When the treatment temperature is less than the lower limit of this range, reactivation is not sufficiently performed, and the resulting activated sulfonic acid group-containing carbonaceous material tends to have insufficient catalytic activity for various chemical reactions. It is in. When the temperature exceeds the upper limit of this range, the sulfonic acid group added to the used sulfonic acid group-containing carbonaceous material tends to decompose. In addition, the newly added sulfonic acid group may be decomposed by the sulfuric acid treatment. Furthermore, the sulfuric acid treatment operation becomes difficult.

  The time for the sulfuric acid treatment can be selected as appropriate, but it is preferably over 5 minutes and not longer than 10 hours. When the sulfuric acid treatment time is less than the lower limit of this range, the reactivation does not proceed sufficiently, and the resulting reactivated sulfonic acid group-containing carbonaceous material has insufficient activity as a solid acid catalyst. It will be something. On the other hand, the necessary reactivation is sufficiently advanced in the upper limit of this range, and it is not necessary to spend more time.

After the sulfuric acid treatment step, excess sulfuric acid is preferably removed by washing with hot water, and further dried to obtain a completed reactivated sulfonic acid group-containing carbonaceous material. For washing with hot water, a general washing technique can be adopted, but it is easy to carry out the washing under reflux at about 100 ° C. by, for example, a Soxhlet extraction method. It is also possible to shorten the washing time by washing at a higher temperature under pressure.
It should be noted that if the sulfonic acid group-containing carbonaceous material having a decreased activity before the sulfuric acid treatment or a mixture of the sulfonic acid group-containing carbonaceous material and the unreacted water-insoluble polysaccharide is dried in advance, residual moisture or alcohol This is preferable for effective sulfuric acid treatment because it prevents dilution of sulfuric acid by the like.

  As described above, when a solid acid catalyst composed of a sulfonic acid group-containing carbonaceous material is used for the hydrolysis reaction of a water-insoluble polysaccharide such as cellulose, the raw material is solid and insoluble in water. The water-insoluble polysaccharide such as unreacted cellulose cannot be separated from the sulfonic acid group-containing carbonaceous material having reduced activity. Also in this case, it can be reactivated by heat treatment in sulfuric acid while mixing the sulfonic acid group-containing carbonaceous material having reduced activity and a non-water-soluble polysaccharide such as unreacted cellulose. However, when the ratio of water-insoluble polysaccharides such as raw material cellulose to the sulfonic acid group-containing carbonaceous material used as the solid acid catalyst is large, unreacted cellulose to the sulfonic acid group-containing carbonaceous material having reduced activity, etc. The ratio of the water-insoluble polysaccharide increases. In such a case, it is possible to carbonize the mixture of the sulfonic acid group-containing carbonaceous material and the water-insoluble polysaccharide such as unreacted cellulose before the sulfuric acid treatment.

  The conditions for the carbonization treatment are basically the same as when producing a novel sulfonic acid group-containing carbonaceous material. Specifically, carbonization can be performed in a nitrogen atmosphere at 250 to 600 ° C. and 1 to 50 hours. When the temperature of the carbonization treatment is less than the lower limit of the above range, the carbonization of the water-insoluble polysaccharide such as cellulose coexisting with the sulfonic acid group-containing carbonaceous material does not proceed sufficiently, and even if this is treated with sulfuric acid, it is regenerated. The sulfonic acid group-containing carbonaceous material obtained by activation tends to have problems such as inferior heat resistance or a large amount dissolved in water or organic matter. On the other hand, when the temperature exceeds the upper limit of the above range, a sufficient amount of the sulfonic acid group cannot be imparted even if this is treated with sulfuric acid. The catalytic activity for the chemical reaction tends to be insufficient. Also, when the carbonization time is less than the lower limit of the above range, the heat resistance of the sulfonic acid group-containing carbonaceous material obtained by insufficient reactivation even if this is treated with sulfuric acid is inferior, or water or This causes problems such as a large amount dissolved in organic matter. On the other hand, the necessary carbonization proceeds sufficiently in the upper limit of the range, and it is not necessary to spend more time.

(About acid group content)
The acid group content (acid group content before being subjected to the reaction) of the sulfonic acid group-containing carbonaceous material used as the solid acid catalyst is preferably 1.0 mmol / g or more, more preferably 1.6 mmol / g or more. is there. If it is less than 1.0 mmol / g, the performance as a solid acid catalyst tends to be insufficient.
Therefore, in the present invention, the acid group content of the sulfonic acid group-containing carbonaceous material obtained after reactivation is preferably 1.0 mmol / g or more, more preferably 1.6 mmol / g or more. When the acid group content is less than 1.0 mmol / g, the obtained regenerated sulfonic acid group-containing carbonaceous material tends to have insufficient activity as a solid acid catalyst for various chemical reactions.
In addition, acid group content here is what is measured by neutralization titration method (for example, back titration method) with respect to sulfonic acid group containing carbonaceous material, and sulfonic acid group produced | generated by sulfonation treatment and The content of the carboxylic acid group and the phenolic hydroxyl group formed during carbonization and / or sulfonation.

(About sulfonic acid group content)
The sulfonic acid group content of the sulfonic acid group-containing carbonaceous material used as the solid acid catalyst (acid group content before being subjected to the reaction) is preferably 0.5 mmol / g or more, more preferably 1.0 mmol / g or more. It is. If it is less than 0.5 mmol / g, the performance as a solid acid catalyst tends to be insufficient.
Therefore, in the present invention, the sulfonic acid group content of the sulfonic acid group-containing carbonaceous material obtained by reactivation is preferably 0.5 mmol / g or more, more preferably 1.0 mmol / g or more. When the sulfonic acid group content is less than 0.5 mmol / g, the activity of the resulting regenerated sulfonic acid group-containing carbonaceous material as a solid acid catalyst for various chemical reactions tends to be insufficient.
In addition, sulfonic acid group content here is calculated | required by the ion exchange capacity | capacitance measurement using a sodium chloride solution so that it may mention later.

(X-ray diffraction analysis)
As with the new sulfonic acid group-containing carbonaceous material before use in the reaction, the sulfonic acid group-containing carbonaceous material after the reactivation cannot substantially confirm any structure from the X-ray diffraction pattern. It is amorphous.

  The sulfonic acid group-containing carbonaceous material obtained by reactivation as described above can not only effectively use the discarded catalyst, but also obtain a sulfonic acid group-containing carbonaceous material at a low cost because the regeneration method is simple. In addition, it has an acid strength and an acid group content comparable to or higher than those of the new sulfonic acid group-containing carbonaceous material.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

(Method for analyzing sulfonic acid group-containing carbonaceous material)
The following analysis was performed about each sulfonic acid group containing carbonaceous material obtained by the Example and the comparative example.
1. Powder X-ray diffraction analysis An X-ray diffractometer (MXP18VAHF) manufactured by Mac Science was used for the analysis.
2. Measurement of acid group content The acid group content was measured by a back titration method.
3. Elemental analysis Elementary Vario EL was used for the analysis. The results were expressed as the ratio of sulfur atoms to carbon atoms (S / C ratio). This value is a measure of the sulfonic acid group content added to and introduced into the sulfonic acid group-containing carbonaceous material.
4). Measurement of sulfonic acid group content As described above, the sulfonic acid group content was determined by ion exchange capacity measurement using a sodium chloride solution. A predetermined amount of the sulfonic acid group-containing carbonaceous material was added to the sodium chloride solution and stirred for a certain period of time to exchange sulfonic acid group protons and sodium ions. The amount of HCl produced by ion exchange was quantified by neutralization titration to determine the sulfonic acid group content.
The ion exchange reaction is represented by the following formula (1).
R—SO ₃ H + NaCl → R—SO ₃ Na + HCl (1)
(In the formula, R represents a residue obtained by removing a sulfonic acid group from a sulfonic acid group-containing carbonaceous material).

[Comparative Example 1]
(Preparation of sulfonic acid group-containing carbonaceous material)
40 g of glucose was placed in a 1000 ml eggplant type flask and heated at 400 ° C. for 5 hr under a nitrogen stream to obtain 10.7 g of carbide. 278 g of 97% by mass concentrated sulfuric acid was added to 3.0 g of this black powdered carbide, and sulfonation was carried out by heating at 150 ° C. for 2 hours in a nitrogen atmosphere. After sulfonation, the black solid was filtered through a glass filter, and the washing was repeated by refluxing hot water at about 100 ° C. using a Soxhlet extractor, and it was confirmed that sulfuric acid was not detected in the washing solution. This was dried to obtain a black powdery sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material α-1”).

  The various analyzes described above were performed on the sulfonic acid group-containing carbonaceous material α-1. Table 1 shows the measurement results of various physical properties. From the diffraction pattern of the powder X-ray diffraction analysis, a peak capable of specifying the structure was not detected, and it was found to be substantially amorphous.

(Esterification reaction of alcohol using sulfonic acid group-containing carbonaceous material α-1)
Into an eggplant-shaped flask having an internal volume of 100 ml, 30 ml of ethanol was added, acetic acid was added at a molar ratio of 1/50 with respect to alcohol, and 0.20 g of sulfonic acid group-containing carbonaceous material α-1 was added. Heated. The mixture was reacted at reflux temperature (80 ° C.) for 2 hours with stirring, and then quenched in a water bath to stop the reaction. After completion of the reaction, the sulfonic acid group-containing carbonaceous material after the reaction (hereinafter referred to as “sulfonic acid group-containing carbonaceous material α-2”) is separated from the reaction solution, and the product is quantified by gas chromatography with a TCD detector. Analysis was carried out. Further, the esterification reaction was performed again under the same conditions using the separated sulfonic acid group-containing carbonaceous material α-2 as a catalyst. Table 2 shows the unit catalyst amount of each reaction, the amount of ethyl acetate converted per unit time, and the properties of the sulfonic acid group-containing carbonaceous material α-2. From this result, it was confirmed that the sulfonic acid group-containing carbonaceous material α-2 was deteriorated in both activity and physical properties as compared with the sulfonic acid group-containing hydrocarbon material α-1.

[Example 1]
(Reactivation of sulfonic acid group-containing carbonaceous material α-2)
To the sulfonic acid group-containing carbonaceous material α-2, 10 g of concentrated sulfuric acid having a concentration of 97% by mass was added and heat-treated at 150 ° C. for 2 hours for reactivation. The heat-treated sulfonic acid group-containing carbonaceous material is filtered through a glass filter and repeatedly washed with hot water under reflux (about 100 ° C.) using a Soxhlet extractor, so that sulfuric acid is not detected in the washing solution. It was confirmed. This was dried to obtain a reactivated sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material A”).

(Analysis of sulfonic acid group-containing carbonaceous material A)
Various analyzes were performed on the sulfonic acid group-containing carbonaceous material A. The results are shown in Table 2.
From this result, in the sulfonic acid group containing carbonaceous material A obtained by reactivation, it was confirmed that the physical properties were recovered to the same level as the sulfonic acid group containing carbonaceous material α-1.

(Esterification reaction of alcohol using sulfonic acid group-containing carbonaceous material A)
The esterification reaction was carried out under the same conditions as the alcohol esterification reaction using the sulfonic acid group-containing carbonaceous material α-1 of Comparative Example 1 except that the sulfonic acid group-containing carbonaceous material A was used. Table 2 shows the unit catalyst amount and the amount of ethyl acetate produced per unit time. From this result, it was confirmed that the activity of the sulfonic acid group-containing carbonaceous material for the esterification reaction was significantly recovered by reactivation.

[Comparative Example 2]
(Ester hydrolysis reaction using sulfonic acid group-containing carbonaceous material α-1)
2.6 g (0.030 mol) of ethyl acetate is charged into an eggplant-shaped flask having an internal volume of 100 ml, and 27 g of water (molar ratio with respect to ethyl acetate is 50 times) is added to the sulfonic acid group-containing carbonaceous material α. 0.2 g of -1 was added and heated. The mixture was reacted at reflux temperature (80 ° C.) for 2 hours with stirring, and then quenched in an ice bath to stop the reaction. After completion of the reaction, the sulfonic acid group-containing carbonaceous material after the reaction (hereinafter referred to as “sulfonic acid group-containing carbonaceous material α-3”) is separated from the reaction solution, and the product is quantified by gas chromatography with a TCD detector. Analysis was carried out. The ester hydrolysis reaction was again carried out under the same conditions using the sulfonic acid group-containing carbonaceous material α-3 as a catalyst. Table 3 shows the conversion ratio of ethyl acetate to acetic acid in each reaction (produced acetic acid / charged ethyl acetate, molar basis) and the properties of the sulfonic acid group-containing carbonaceous material α-3. From these results, it was confirmed that the sulfonic acid group-containing carbonaceous material α-3 was deteriorated in both activity and physical properties as compared with the sulfonic acid group-containing carbonaceous material α-1.

[Example 2]
(Reactivation of sulfonic acid group-containing carbonaceous material α-3)
10 g of 97 mass% concentrated sulfuric acid was added to the sulfonic acid group-containing carbonaceous material α-3, and the mixture was reactivated by heat treatment at 150 ° C. for 2 hours. After the heat treatment, the sulfonic acid group-containing carbonaceous material is filtered through a glass filter and repeatedly washed with hot water under reflux (about 100 ° C.) using a Soxhlet extractor, so that sulfuric acid is not detected in the washing solution. It was confirmed. This was dried to obtain a reactivated sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material B”).

(Analysis of sulfonic acid group-containing carbonaceous material B)
Various analyzes were performed on the sulfonic acid group-containing carbonaceous material B. The results are shown in Table 3. From this result, it was confirmed that the physical properties of the sulfonic acid group-containing carbonaceous material B obtained by reactivation recovered to the same level as the sulfonic acid group-containing carbonaceous material α-1.

(Hydrolysis reaction of ester using sulfonic acid group-containing carbonaceous material B)
The ester hydrolysis reaction was carried out under the same conditions as the ester hydrolysis reaction using the sulfonic acid group-containing carbonaceous material α-1 of Comparative Example 2 except that the sulfonic acid group-containing carbonaceous material B was used. Table 3 shows the conversion rate of ethyl acetate to acetic acid. From this result, it was confirmed that the activity of the sulfonic acid group-containing carbonaceous material for the hydrolysis reaction of the ester was significantly recovered by the reactivation.

[Comparative Example 3]
(Preparation of sulfonic acid group-containing carbonaceous material)
A sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material β”) was prepared in the same manner as the preparation of the sulfonic acid group-containing carbonaceous material α-1 except that 40 g of cellulose (Aldrich 310697) was used. -1 ").

  The various analyzes described above were performed on the sulfonic acid group-containing carbonaceous material β-1. Various analysis results for the sulfonic acid group-containing carbonaceous material β-1 are shown in Table 1. From the diffraction pattern of the powder X-ray diffraction analysis, a peak capable of specifying the structure was not detected, and it was found to be substantially amorphous.

(Hydrolysis reaction of cellulose using sulfonic acid group-containing carbonaceous material β-1)
To an eggplant flask having an internal volume of 10 ml, charged with 1000 μl of distilled water and 0.025 g of cellulose powder, added 0.30 g of sulfonic acid group-containing carbonaceous material β-1 and sealed, and stirred at 700 rpm up to 120 ° C. in an oil bath. The temperature was raised and a 2 hr hydrolysis reaction was carried out. After completion of the reaction, the reaction solution was cooled and then subjected to solid-liquid separation by centrifugation, followed by filtration with a microfilter, and the amount of glucose in the obtained liquid was quantitatively analyzed with a liquid chromatograph. Table 4 shows the amount of glucose produced per unit catalyst amount and unit time.

  1000 μl of distilled water was added to the separated solid (hereinafter referred to as “sulfonic acid group-containing carbonaceous material β-2”), and the hydrolysis reaction of cellulose was performed again under the same conditions. Table 4 shows the amount of glucose produced by this reaction. From the results of Table 4, it can be seen that the hydrolysis activity of cellulose in the sulfonic acid group-containing carbonaceous material β-2 is lower than that of the sulfonic acid group-containing carbonaceous material β-1.

[Example 3]
(Reactivation of sulfonic acid group-containing carbonaceous material β-2)
16 g of 97% by mass concentrated sulfuric acid was added to the sulfonic acid group-containing carbonaceous material β-2 (about 0.32 g as a solid content), and the mixture was reactivated by heating at 150 ° C. for 2 hours. After the heat treatment, the sulfonic acid group-containing carbonaceous material is filtered through a glass filter and repeatedly washed with hot water under reflux (about 100 ° C.) using a Soxhlet extractor, so that sulfuric acid is not detected in the washing solution. It was confirmed. This was dried to obtain a reactivated sulfonic acid group-containing carbonaceous material (hereinafter referred to as sulfonic acid group-containing carbonaceous material C).
(Analysis of sulfonic acid group-containing carbonaceous material C)
Various analyzes were performed on the sulfonic acid group-containing carbonaceous material C. From this result, it was confirmed that the physical properties were almost the same as those of the sulfonic acid group-containing carbonaceous material β by reactivation.

(Hydrolysis reaction of cellulose using reactivated sulfonic acid group-containing carbonaceous material C)
The cellulose hydrolysis reaction was carried out under the same conditions as the cellulose hydrolysis reaction using the sulfonic acid group-containing carbonaceous material β-1 except that the reactivated sulfonic acid group-containing carbonaceous material C was used. . Table 4 shows the amount of glucose produced per unit catalyst amount and unit time. From this result, in the sulfonic acid group-containing carbonaceous material C obtained by reactivation, it was confirmed that the hydrolysis activity was recovered to almost the same level as that of the sulfonic acid group-containing carbonaceous material β-1.

[Comparative Example 4]
(Preparation of sulfonic acid group-containing carbonaceous material)
50 g of novolak type phenolic resin (TD-739A, manufactured by Dainippon Ink & Chemicals, Inc.) was placed in a 1000 ml eggplant type flask and heat-treated at 450 ° C. for 5 hours under nitrogen flow to obtain 39 g of carbide. 150 g of fuming sulfuric acid containing 10% by mass of sulfur trioxide was added to 5.0 g of this black powdered carbide, and sulfonation was performed by heating at 140 ° C. for 2 hours in a nitrogen atmosphere. After sulfonation, the black solid was filtered through a glass filter, and the washing was repeated by refluxing hot water at about 100 ° C. using a Soxhlet extractor, and it was confirmed that sulfuric acid was not detected in the washing solution. This was dried to obtain a black powdery sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material γ-1”). Table 1 shows the sulfonic acid group content of the sulfonic acid group-containing carbonaceous material γ-1.

(Olefin esterification reaction using sulfonic acid group-containing carbonaceous material γ-1)
Olefin esterification reaction was performed using sulfonic acid group-containing carbonaceous material γ-1 as a catalyst. To a 100 cc autoclave equipped with a stirrer, 36.1 g (0.6 mol) of acetic acid was added, 0.5 g of sulfonic acid group-containing carbonaceous material γ-1 was added and sealed, and 16.7 g (0.4 mol) of propylene was added. ) Enclosed. After adjusting the pressure to 2.0 MPa with nitrogen, the temperature was raised to 80 ° C. while stirring at 500 rpm, and an esterification reaction was performed for 4 hours. After completion of the reaction, the reaction solution was cooled, the sulfonic acid group-containing carbonaceous material and the reaction solution were separated, and quantitative analysis was performed by FID-GC to confirm the amount of isopropyl acetate produced.
Using the separated used sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material γ-2”), the olefin esterification reaction was performed again under the same conditions, and isopropyl acetate The production amount of was confirmed. Table 5 shows the amount of isopropyl acetate produced in each reaction and the sulfonic acid group content of the sulfonic acid group-containing carbonaceous material γ-2 used. From this result, it was confirmed that the sulfonic acid group-containing carbonaceous material γ-2 was deteriorated in both activity and physical properties as compared with the new sulfonic acid group-containing carbonaceous material γ-1.

[Example 4]
(Reactivation of sulfonic acid group-containing carbonaceous material γ-2)
5 g of fuming sulfuric acid containing 10% by mass of sulfur trioxide was added to the sulfonic acid group-containing carbonaceous material γ-2, and the mixture was reactivated by heat treatment at 150 ° C. for 2 hours. After the heat treatment, the sulfonic acid group-containing carbonaceous material is filtered through a glass filter and repeatedly washed with hot water under reflux (about 100 ° C.) using a Soxhlet extractor, so that sulfuric acid is not detected in the washing solution. It was confirmed. This was dried to obtain a reactivated sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material D”).

  The sulfonic acid group content of the sulfonic acid group-containing carbonaceous material D was measured. The results are shown in Table 5. From this result, it was confirmed that the physical properties were almost the same as those of the sulfonic acid group-containing carbonaceous material γ-1 by reactivation.

(Olefin esterification reaction using sulfonic acid group-containing carbonaceous material D)
Except for using the sulfonic acid group-containing carbonaceous material D, an olefin esterification reaction was carried out under the same conditions as the olefin esterification reaction using the sulfonic acid group-containing carbonaceous material γ-1. Table 5 shows the amount of isopropyl acetate produced. From this result, it was confirmed that the activity of the sulfonic acid group-containing carbonaceous material D was recovered to almost the same level as the new sulfonic acid group-containing carbonaceous material γ-1.

[Comparative Example 5]
(Olefin hydration reaction using sulfonic acid group-containing carbonaceous material γ-1)
Into an autoclave reactor equipped with a stirrer with an internal volume of 100 cc, 18.0 g (1.0 mol) of distilled water and 15.0 g of dioxane (solvent) were added, and 0.2 g of a sulfonic acid group-containing carbonaceous material γ-1 was added. After sealing and purging with nitrogen, 10.5 g (0.25 mol) of propylene was sealed. Thereafter, the pressure was increased to 2.5 Mpa with nitrogen, the temperature was raised to 120 ° C. while stirring at 500 rpm, and the hydration reaction was performed for 1.5 hr while maintaining the temperature at 120 ° C. After completion of the reaction, the reaction solution was cooled, and the product was quantitatively analyzed by FID-GC. As a result, the amount of 2-propanol converted per unit catalyst amount per unit time was 0.54 mmol / g-cat. / Hr. The results are shown in Table 6.
Using the separated used sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material γ-3”), the olefin hydration reaction was performed again under the same conditions, and 2-propanol The production amount of was confirmed. Table 6 shows the unit catalyst amount, the amount of 2-propanol produced per unit time, and the sulfonic acid group content of the sulfonic acid group-containing carbonaceous material γ-3. From these results, it was confirmed that the sulfonic acid group-containing carbonaceous material γ-3 was deteriorated in both activity and physical properties as compared with the sulfonic acid group-containing carbonaceous material γ-1.

[Example 5]
(Reactivation of sulfonic acid group-containing carbonaceous material γ-3)
5 g of fuming sulfuric acid containing 10% by mass of sulfur trioxide was added to the sulfonic acid group-containing carbonaceous material γ-3, and the mixture was reactivated by heat treatment at 150 ° C. for 2 hours. After the heat treatment, the sulfonic acid group-containing carbonaceous material is filtered through a glass filter and repeatedly washed with hot water under reflux (about 100 ° C.) using a Soxhlet extractor, so that sulfuric acid is not detected in the washing solution. It was confirmed. This was dried to obtain a reactivated sulfonic acid group-containing carbonaceous material (hereinafter referred to as “sulfonic acid group-containing carbonaceous material E”).

  The sulfonic acid group content of the sulfonic acid group-containing carbonaceous material E was measured. The results are shown in Table 6. From this result, it was confirmed that the physical properties were almost the same as those of the sulfonic acid group-containing carbonaceous material γ-1 by reactivation.

(Olefin hydration reaction using sulfonic acid group-containing carbonaceous material E)
Except for using the sulfonic acid group-containing carbonaceous material E, the olefin hydration reaction was carried out under the same conditions as the olefin hydration reaction using the sulfonic acid group-containing carbonaceous material γ-1. Table 6 shows the unit catalyst amount and the amount of 2-propanol produced per unit time. From this result, it was confirmed that the sulfonic acid group-containing carbonaceous material E has substantially the same activity as the sulfonic acid group-containing carbonaceous material γ-1.

  By the above examples, the activity as a solid acid catalyst can be sufficiently improved by subjecting the sulfonic acid group-containing carbonaceous material, which has been used in various reactions, to have reduced activity, to the predetermined heat treatment according to the present invention. It turns out that it becomes possible to use again like a new catalyst.

  According to the present invention, it becomes possible to reactivate a solid acid catalyst comprising a sulfonic acid group-containing carbonaceous material having reduced activity, and the sulfonic acid group-containing carbonaceous material can be used repeatedly. As a result, it is possible to reduce the cost of the catalyst, and thus the manufacturing cost of the product obtained using the solid acid catalyst can be reduced. Further, by reducing the waste catalyst, the waste is reduced, and the influence on the environment can be reduced. In particular, when used for hydrolysis of water-insoluble polysaccharides such as cellulose, it can be reactivated in the presence of water-insoluble polysaccharides such as unreacted cellulose, which is advantageous for industrial production of bioethanol.

Claims (10)

  A sulfonic acid group-containing carbonaceous material having a first step of reactivating a sulfonic acid group-containing carbonaceous material having a decreased activity by being used in the reaction as a solid acid catalyst in the presence of sulfuric acid Manufacturing method. The sulfonic acid group-containing carbonaceous material having reduced activity hydrolyzes a water-insoluble polysaccharide in the presence of the sulfonic acid group-containing carbonaceous material to produce a monosaccharide and / or a water-soluble polysaccharide. Is obtained by
The first step includes a second step of heat-treating the sulfonic acid group-containing carbonaceous material having reduced activity in the presence of sulfuric acid in the presence of an unreacted polysaccharide insoluble in water. Item 2. A method for producing a sulfonic acid group-containing carbonaceous material according to Item 1. The sulfonic acid group-containing carbonaceous material having reduced activity hydrolyzes a water-insoluble polysaccharide in the presence of the sulfonic acid group-containing carbonaceous material to produce a monosaccharide and / or a water-soluble polysaccharide. Is obtained by
In the third step, the first step includes carbonizing the sulfonic acid group-containing carbonaceous material having reduced activity in the presence of a polysaccharide that is unreacted and insoluble in water; and A method for producing a sulfonic acid group-containing carbonaceous material according to claim 1, comprising a fourth step of heat-treating the sulfonic acid group-containing carbonaceous material after carbonization treatment with sulfuric acid.   2. The sulfonic acid according to claim 1, wherein the sulfonic acid group-containing carbonaceous material having a reduced activity is a sulfonic acid group-containing carbonaceous material having a reduced activity as a result of being used in an esterification reaction with a carboxylic acid and an alcohol. A method for producing a group-containing carbonaceous material.   2. The sulfonic acid according to claim 1, wherein the sulfonic acid group-containing carbonaceous material having reduced activity is a sulfonic acid group-containing carbonaceous material having reduced activity as a result of being used in an esterification reaction with a carboxylic acid and an olefin. A method for producing a group-containing carbonaceous material.   2. The sulfonic acid group-containing carbon material according to claim 1, wherein the sulfonic acid group-containing carbonaceous material having reduced activity is a sulfonic acid group-containing carbonaceous material having reduced activity as a result of being used in an ester hydrolysis reaction. A method for producing quality materials.   2. The sulfonic acid group-containing carbon material according to claim 1, wherein the sulfonic acid group-containing carbonaceous material having reduced activity is a sulfonic acid group-containing carbonaceous material having reduced activity due to being used in an olefin hydration reaction. A method for producing quality materials.   The sulfone according to any one of claims 1 to 7, wherein the sulfonic acid group-containing carbonaceous material obtained through the first step has a sulfonic acid group content of 0.5 mmol / g or more. A method for producing an acid group-containing carbonaceous material.   The sulfonic acid group-containing carbonaceous material obtained through the first step has a sulfonic acid group-containing content according to any one of claims 1 to 8, wherein the sulfonic acid group-containing carbonaceous material exhibits an acid group content of 1 mmol / g or more. A method for producing a carbonaceous material. Use of the sulfonic acid group-containing carbonaceous material obtained by the method according to any one of claims 1 to 9 as a solid acid catalyst, olefin hydration reaction, etherification reaction, esterification of carboxylic acid and alcohol A method of performing at least one reaction selected from the group consisting of a reaction and a hydrolysis reaction of an organic compound containing an ester bond or an ether bond .