JP2014237582A - Hydrated lime, manufacturing method of hydrated lime and acidic gas removing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide hydrated lime having an increased BET specific surface area and an increased efficient quantity of the hydrated lime, and a low COD, and a manufacturing method of the hydrated lime.SOLUTION: There is provided hydrated lime manufactured by a digestion process of reacting caustic lime, water and an additive, and the additive is at least one of organic compound having a hydroxyl group selected from ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, glycerine, glucose, fructose, galactose, mannose, xylitose, sucrose, maltose, lactose, trehalose, sorbitol, xylitol, ethanol amine, diethanol amine and triethanol amine and at least one of inorganic compound containing silicone dioxide selected from silica gel, allophane, imogolite and activated clay. There is also provided hydrated lime with the addition amount of the organic agent having the hydroxyl group of 0.01 to 10 wt.% based on the caustic lime.

Description

  The present invention relates to slaked lime having a high specific surface area, and particularly when applied as an acid gas remover, slaked lime that can reduce chemical oxygen demand (hereinafter referred to as “COD”), a method for producing slaked lime, and acidity It relates to a gas removal agent.

  Quicklime is obtained by baking limestone (the main component is calcium carbonate). Quick lime obtained by firing is converted to slaked lime by reacting with water (reaction of quick lime with water is referred to as “digestion”). Since this slaked lime has strong basicity, it is used as an acid gas removing agent that removes acid gas such as hydrogen chloride gas.

  For example, in a refuse incinerator, acidic gas such as hydrogen chloride gas is generated. In order to remove this acidic gas, an acidic gas remover made from slaked lime may be put into the incinerator. . In particular, powdered slaked lime is often introduced into an exhaust gas flue of an incinerator. At this time, the powdered slaked lime and the acidic gas react on the surface of the slaked lime, and the slaked lime removes the acidic gas through the reaction with the acidic gas. Thus, slaked lime causes a reaction with acidic gas on its surface, so it is preferable that the BET specific surface area is large.

  Based on such a situation, development of slaked lime having a large BET specific surface area has been underway.

  Slaked lime is produced by a digestion reaction between quick lime and water, and various additives are added in this digestion reaction to adjust the BET specific surface area.

  For example, various organic compounds and inorganic compounds are used as additives, and various techniques have been proposed (see, for example, Patent Documents 1, 2, 3, 4, and 5).

  Patent document 1 discloses the technique which adds an organic compound in a digestion process. At this time, Patent Document 1 discloses oxycarboxylic acids, ethanolamines, and ethylene glycols as additives.

  Patent Document 2 discloses a technique using water containing a large amount of ethanol in the digestion process. Patent Documents 1 and 2 disclose a technique of using an organic compound in a digestion process. In particular, Patent Documents 1 and 2 disclose a technique in which an organic compound having a hydroxyl group in a molecule is used in a digestion process.

  Patent document 3 discloses the technique which adds an inorganic compound in a digestion process. Patent Document 3 discloses a substance obtained by mixing a silicon supply substance such as coal ash, silica sand, bentonite, and kaolinite with an alkaline earth metal oxide as an additive in the digestion process. Thus, the slaked lime obtained through the digestion process is used as a desulfurizing agent.

  Patent Document 4 discloses a technique of using alkali silicate, silicate, hydrous silicic acid, anhydrous silicic acid and crystalline silicic acid as additives in the digestion step. The technique which digests quick lime using these additives and obtains slaked lime is disclosed.

  Further, Patent Document 5 discloses a substance obtained by mixing a silicon dioxide-containing substance, which is a silicon supply substance, as an additive.

JP-A-9-278435 JP-A-9-110425 JP-A-5-154335 JP 2003-327427 A JP 2001-276666 A

  As in Patent Documents 1 and 2, various techniques for adding an organic compound have been proposed. Or it is variously proposed that silicon dioxide containing substances, such as coal ash, are used as an additive in a digestion process so that patent document 3 may be disclosed. Patent Document 5 discloses a technique of adding an organic solvent in addition to a silicon dioxide-containing substance.

  When an organic compound is used as an additive, the organic compound remains in the obtained slaked lime. Slaked lime is used as an acid gas remover by being thrown into or blown into an incinerator. However, if an organic compound remains in the slaked lime, there is a problem that COD increases. In addition, there also arises a problem of generating carbon monoxide during acid gas treatment.

  When an inorganic compound is used as an additive, there is a problem that a BET specific surface area cannot be sufficiently secured. If the BET specific surface area is insufficient, naturally, the usefulness as an acid gas removing agent is low. Further, when silicon dioxide, which is an inorganic compound, is used as an additive, there is a problem that a large amount of silicon dioxide is required to reduce the effective component amount of slaked lime in order to sufficiently increase the BET specific surface area.

  Alternatively, Patent Document 5 discloses a technique for adding an organic solvent while using an inorganic compound as an additive. However, Patent Document 5 uses an organic solvent for dispersing quicklime (for example, Examples 7-1 to 7-3) and does not produce an effect of increasing the BET specific surface area. That is, a technique for improving the BET specific surface area when an inorganic compound is used as an additive is not disclosed.

  That is, as disclosed in the prior art, there are merits and demerits in the case where an inorganic compound or an organic compound is used as an additive added in the digestion step. In the prior art, an additive and slaked lime considering the balance between the advantages and disadvantages have not been proposed.

  As described above, the conventional technology balances all of (1) sufficiently increasing the BET specific surface area, (2) keeping COD low, and (3) sufficiently securing the effective component amount of the obtained slaked lime. There was a problem that could not be realized well.

  An object of this invention is to provide the manufacturing method of slaked lime and slaked lime which made the BET specific surface area and the amount of active ingredients of slaked lime fully large, and suppressed COD low in view of the said subject.

In view of the said subject, the slaked lime of this invention is a slaked lime manufactured by the digestion process which makes quicklime and water react,
A predetermined additive used in the digestion process is added,
The additive includes a substance in which an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide are combined,
The organic compound having a hydroxyl group is ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, glycerin, glucose, fructose, galactose, mannose, xylitol, sucrose, maltose, lactose, trehalose, sorbitol, xylitol, ethanol Selected from at least one of the group consisting of amine, diethanolamine and triethanolamine;
The inorganic compound containing silicon dioxide is selected from at least one of the group consisting of silica gel, allophane, imogolite, and activated clay.

  The slaked lime of the present invention can secure a sufficient amount of active ingredients while sufficiently ensuring the BET specific surface area. At the same time, the value of COD can be lowered.

  In particular, by using a substance in which an organic compound and an inorganic compound are combined as an additive in the digestion process, a large BET specific surface area and a low COD value can be made compatible.

  As a result, the acid gas removing agent of the present invention can keep carbon monoxide and COD low, and can reduce the environmental burden.

It is a block diagram which shows the manufacturing process of the slaked lime in Embodiment 1 of this invention. It is a graph which shows the BET specific surface area of slaked lime with respect to the compounding ratio of the inorganic compound in Embodiment 1 of this invention. It is a graph which shows the BET specific surface area of the slaked lime manufactured with the additive by the combination of the organic compound and organic compound in Embodiment 1 of this invention. It is a graph which shows the BET specific surface area of slaked lime in the fluctuation | variation of the addition amount of the inorganic compound in Embodiment 1 of this invention. It is a block diagram which shows the manufacturing process of the slaked lime in Embodiment 2 of this invention.

The slaked lime according to the first invention of the present invention is a slaked lime produced by a digestion process in which quick lime and water are reacted,
Predetermined additives used in the digestion process are added,
The additive includes a material in which an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide are combined,
Organic compounds having a hydroxyl group are ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, glycerin, glucose, fructose, galactose, mannose, xylitol, sucrose, maltose, lactose, trehalose, sorbitol, xylitol, ethanolamine Selected from at least one of the group consisting of: diethanolamine and triethanolamine;
The inorganic compound containing silicon dioxide is selected from at least one of the group consisting of silica gel, allophane, imogolite, and activated clay.

  With this configuration, the slaked lime produced can increase its BET specific surface area and suppress the value of COD.

In the slaked lime according to the second invention of the present invention, in addition to the first invention, the slaked lime has a BET specific surface area of 20 m ² / g or more.

In the slaked lime according to the third invention of the present invention, in addition to the first invention, the slaked lime has a BET specific surface area of 35 m ² / g or more.

  With this configuration, the obtained slaked lime has a sufficient BET specific surface area.

  In the slaked lime according to the fourth invention of the present invention, in addition to any of the first to third inventions, the additives are (1) addition to quick lime, (2) addition to water, and (3) quick lime. In addition to the mixture of water and water, it is added by at least one means of (1) to (3).

  With this configuration, various effects of the additive can be obtained.

  In the slaked lime according to the fifth invention of the present invention, in addition to any one of the first to fourth inventions, at least one addition amount selected from the group of organic compounds having a hydroxyl group, 0.01% by weight to 10% by weight.

  With this configuration, the balance between the BET specific surface area of the slaked lime produced and the COD is optimized.

  In the slaked lime according to the sixth invention of the present invention, in addition to any of the first to fifth inventions, the addition amount of the inorganic compound containing silicon dioxide is 0.01% by weight to 15% with respect to quick lime. % By weight.

  In the slaked lime according to the seventh aspect of the present invention, the addition amount of the inorganic compound containing silicon dioxide is 0.01% by weight to 10% by weight with respect to quicklime.

  With these configurations, the balance between the BET specific surface area of the produced slaked lime and the COD is optimized.

  (Embodiment 1)

Embodiment 1 will be described.
(General manufacturing process of slaked lime)

  First, the manufacturing process of the slaked lime using an additive is demonstrated using FIG. FIG. 1 is a block diagram illustrating a process for producing slaked lime according to Embodiment 1 of the present invention. FIG. 1 schematically shows a production process of slaked lime.

  The digestion step 4 is a step in which quick lime 1 and water 3 are reacted. For this reason, quick lime 1 and water 3 as raw materials are input to the digestion step 4 (for example, to a stirrer that performs the digestion step 4). Furthermore, the additive 2 is also input into the digestion step 4. The additive 2 may be added to the digestion step 4, may be added to the water 3 in advance, or may be added to the quicklime 1 in advance.

  In the digestion step 4, a digestion reaction occurs while the quick lime 1, water 3 and additive 2 that have been added are stirred.

  Following the digestion step 4, in the aging step 5, the mixture that has undergone the digestion reaction is aged. Subsequent to the aging step 5, the slaked lime is produced by drying in the drying step 6.

  Thus, slaked lime is based on the digestion reaction between quick lime and water, and the performance of the produced slaked lime varies depending on the additive.

    (Overview)

  The slaked lime in Embodiment 1 is slaked lime produced by a digestion process in which quick lime reacts with water, and is produced by adding a predetermined additive necessary for the digestion process. The predetermined additive includes a material in which an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide are combined.

Slaked lime only reacted quick lime and water, BET specific surface area of a ^{10m 2 / g~20m 2 / g,} BET specific surface area is not sufficient. A sufficiently large BET specific surface area indicates high acid gas adsorption performance when slaked lime is used as an acid gas remover or the like. Therefore, a sufficiently large BET specific surface area is an important factor in the production of slaked lime.

When a given additive comprises a combined material of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide, this additive contributes to increasing the BET specific surface area, COD To contribute to keeping low. For this reason, the slaked lime in Embodiment 1 has a BET specific surface area of 20 m ² / g or more, preferably 30 m ² / g or more, and more preferably 35 m ² / g or more.

  This is a synergistic effect of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide, and this synergistic effect increases the BET specific surface area. The organic compound is mixed with quick lime in the digestion process to expand its BET specific surface area. At this time, the inorganic compound is widely dispersed in quicklime together with the organic compound while promoting uniform dispersion of the organic compound in quicklime. Moreover, it is thought that the added inorganic compound plays a role of supplementing calcium ions and acts to increase the BET specific surface area. The BET specific surface area in the digestion process is increased by the synergistic effect of the organic compound and the inorganic compound in a plurality of stages. As a result, the BET specific surface area of the slaked lime produced increases.

  Further, many inorganic compounds containing silicon dioxide have a very high BET specific surface area. When the inorganic compound containing silicon dioxide is contained in the additive, the BET specific surface area of the slaked lime produced is increased. When an inorganic compound containing silicon dioxide is mixed after the digestion step is finished, only a BET specific surface area calculated by a weighted average of the inorganic compound mixed with slaked lime is obtained. On the other hand, a BET specific surface area higher than a weighted average can be obtained by adding an inorganic compound in a digestion process like the additive in Embodiment 1.

  In addition, the additive in which the organic compound and the inorganic compound are mixed not only reduces the amount of the organic compound added, but also synergistically contributes to the respective BET specific surface area by the combined use of the organic compound and the inorganic compound. As a result, a high BET specific surface area is obtained.

Here, it is one standard that the BET specific surface area is 20 m ² / g or more, and the BET specific surface area of commercially available slaked lime is about 10 to 20 m ² / g, which exceeds this. This is because slaked lime having a BET specific surface area is required. Of course, it is preferable that the BET specific surface area is larger. When slaked lime is used as an acid gas remover, it is used up, and therefore it is required to have very high adsorption performance after one use. From this point, it is required that the BET specific surface area be higher than the BET specific surface area of the commercial product. From this point, ^{30 m} 2 / g and ^35m 2 / g which is considered to be above sufficiently ^{20 m} 2 / g is more preferred criteria.

  Moreover, an additive can reduce the quantity of the organic compound which occupies for the whole additive by having the substance which combined the organic compound which has a hydroxyl group, and the inorganic compound containing a silicon dioxide. This is because a part of the additive is replaced with an inorganic compound. When the amount of the organic compound contained in the additive is relatively reduced, the remaining amount of the organic compound contained in the produced slaked lime is reduced.

  If the remaining amount of the organic compound is small, the COD value is naturally reduced. If the COD is reduced, the environmental load is small when slaked lime is used as an acid gas remover.

  In particular, when slaked lime is used as an acid gas removing agent, slaked lime is used up, and thus the environmental load is further reduced by the low value of COD.

  In addition, it is not clear about the effect | action of an inorganic compound other than helping the uniform mixing of an organic compound and enlarging a BET specific surface area, reducing the amount of organic compounds. However, it plays a role of capturing calcium ions, and this role seems to form a factor for increasing the BET specific surface area.

  As described above, an additive, which is a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide, is used in the digestion step, so that slaked lime having a large BET specific surface area and a low COD value can be produced. .

  Except for the combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide, the additive includes inevitable mixtures, other mixtures necessary for production, or other mixtures used for improvement. Not what you want.

(Organic compound having a hydroxyl group)
The additive is a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide.

  The organic compound having a hydroxyl group is selected from at least one of the group consisting of glycols, saccharides and ethanolamines. The fact that it is selected from at least one of these groups means that the organic compound having a hydroxyl group may be selected from glycols, saccharides and ethanolamines, or two or more types are selected. Is also good.

  The reason why at least one of glycols, saccharides and ethanolamines is selected is that they are easily available as an organic compound having a hydroxyl group and are easy to handle. In addition, since each of these organic compounds has a wide variety of corresponding compounds, the manufacturing cost (including the acquisition cost) can be suppressed.

  The glycols are selected from at least one of the group consisting of ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol and glycerin.

  This is because these substances are easily available and easy to handle.

  The saccharide is selected from at least one of the group consisting of glucose, fructose, galactose, mannose, xylitolose, sucrose, maltose, lactose, trehalose, sorbitol and xylitol. Here, each of glucose, fructose, galactose, mannose, and xylitol is a monosaccharide. Each of sucrose, maltose, lactose and trehalose is a disaccharide. Each of sorbitol and xylitol is a reducing sugar.

  The ethanolamine is selected from at least one of the group consisting of ethanolamine, diethanolamine and triethanolamine. This is because these are easily available among ethanolamines. These include ethanolamines that can be used generally or as alternatives, including those that are readily available and those that are inconvenient. By using these many kinds of saccharides, slaked lime can be produced flexibly in response to securing an acquisition route and cost fluctuations.

  Each of the above-mentioned substances listed for each of glycols, saccharides, and ethanolamines is different in terms of availability, cost, ease of handling, effects to be produced, etc. It is possible to flexibly respond to performance, necessary procedures, costs, raw material acquisition network in the manufacturing plant, etc. That is, as above-mentioned, as an organic compound which has a hydroxyl group, manufacture of slaked lime can be made easy by including various substances in the category of use.

  Of the substances listed above for each of these glycols, saccharides, and ethanolamines, only a single type may be used as the additive, or a plurality of types may be used as the additive. . In addition, an additive in which these organic compound and inorganic compound are mixed in advance may be mixed in the digestion process of quick lime and water, or after only the organic compound is mixed in quick lime and water (or before that). In addition, an inorganic compound may be mixed with quicklime or water (or quicklime or water mixed with an organic compound).

  As the additive, the organic compounds listed above may be used. In addition, wastes and by-products containing these organic compounds may be used as the organic compounds.

(Inorganic compounds)
An inorganic compound containing silicon dioxide is also used as the additive. This is because the additive has a substance (mixture) in which an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide are mixed.

  By containing an inorganic compound containing silicon dioxide, the amount of organic compound added is reduced, COD is reduced, and the BET specific surface area is increased by a synergistic effect with the organic compound.

  The inorganic compound containing silicon dioxide is selected from at least one of the group consisting of silica gel, diatomaceous earth and zeolite. This is because these types of substances are relatively easily available and easy to handle. Any one of silica gel, diatomaceous earth and zeolite may be mixed with the additive, or two or more substances may be mixed.

  Alternatively, the inorganic compound containing silicon dioxide is selected from at least one of the group consisting of allophane, imogolite, and activated clay. These types of substances are also easy to obtain and handle. Moreover, although allophane, imogolite, and activated clay are not used in the prior art, they are substances that contribute to reduction of COD and increase of BET specific surface area as additives used in the digestion process. Any one of these inorganic compounds may be mixed, or two or more may be mixed.

  Further, as the inorganic compound, at least one selected from the group consisting of silica gel, diatomaceous earth, zeolite, allophane, imogolite, and activated clay may be arbitrarily selected. Alternatively, two or more of this group may be arbitrarily selected. For example, a combination of silica gel and allophane may be selected as the inorganic compound.

  Further, as described above, at least one organic compound is selected from glycols, saccharides, and ethanolamines. For this reason, an inorganic compound may be determined according to the kind of organic compound selected. According to the inventors' findings, at least one organic compound is selected from glycols, saccharides and ethanolamines, and at least one inorganic compound is selected from silica gel, diatomaceous earth, zeolite, allophane, imogolite, and activated clay. If it is a combination of an organic compound and an inorganic compound, the effect of the additive is sufficient. However, when the BET specific surface area and the COD are desired to fall within a specific range or when the cost is taken into consideration, matching between a certain organic compound type and a certain inorganic compound type may be optimal. If there is optimality of such a combination, the additive is obtained by this combination.

  The inorganic compounds listed above differ in availability, cost, ease of handling, effects to be produced, etc., but the intended performance of slaked lime, necessary procedures, costs, and acquisition of raw materials in the manufacturing plant It can respond flexibly according to the network. That is, since many types of inorganic compounds are targeted, it is possible to increase the ease of manufacturing slaked lime and reduce the manufacturing cost. Moreover, the waste and by-product of the catalyst containing these inorganic compounds may be utilized as an inorganic compound.

  The inorganic compound may be mixed with the organic compound in advance to obtain an additive in which the organic compound and the inorganic compound are mixed. In this case, the additive, which is a mixture of a combination of an organic compound and an inorganic compound, is added to quick lime, to water, or to a mixture of quick lime and water.

  In addition, the inorganic compound is not previously mixed with the organic compound, but may be added separately from the organic compound to at least one of quick lime, water, and a mixture of quick lime and water. That is, each of the organic compound and the inorganic compound may be added individually, and as a result, the combination of the organic compound and the inorganic compound may serve as an additive.

  As described above, slaked lime having a large BET specific surface area can be produced easily and at low cost while reducing COD by selecting various substances in the inorganic compound containing silicon dioxide.

(Effects of additives)
The effect of using an additive comprising a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide will be described from experimental results.

  The inventor actually manufactured an additive based on a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide, and manufactured slaked lime using this additive in the digestion process.

  The comparative examples and examples described below are slaked lime produced by the following production process.

(Manufacturing process)
In 400 g of water at 60 ° C., an additive (when the additive is added) is added in advance and dispersed. 60 g of quicklime is put into the water in which the additive is dispersed and stirred. Through this stirring, digestion is performed for 15 minutes.

  After the digestion step, the particles are classified with a 150 μm sieve, and only the particles that have passed through the sieve are filtered under reduced pressure with a Buchner funnel. Note that almost no residue was observed on the 150 μm sieve.

  Further, the filtered particles are dried overnight at 110 ° C. to obtain slaked lime. Each of the comparative examples and examples described below is different in the content of addition of the additive, and the manufacturing process is as described herein.

  Table 1 shows the BET specific surface area, the water content, etc. of the inorganic compounds themselves used in the examples and comparative examples. As shown in Table 1, each inorganic compound selected as an inorganic compound has a difference in its BET specific surface area and moisture. In producing slaked lime, an inorganic compound may be selected according to the required BET specific surface area, moisture, and the like.

(Comparative Example 1-1)
Comparative Example 1-1 is slaked lime produced by reacting only 400 g of water used in the digestion process with 60 g of quicklime and using no additive.

(Comparative Example 1-2)
Comparative Example 1-2 is slaked lime produced using an additive consisting of 60 g quicklime, 400 g water, and an organic compound only. Here, the additive contains 1.0% by weight of ethylene glycol which is an organic compound with respect to quicklime.

Example 1
Example 1 is slaked lime produced using 60 g of slaked lime, 400 g of water, and an additive based on a combination of an organic compound and an inorganic compound. Here, the additive contains 0.5% by weight of ethylene glycol (organic compound) with respect to quick lime and 1.0% by weight of zeolite (inorganic compound) with respect to quick lime.

  Table 2 shows each of the slaked lime of Comparative Example 1-1, Comparative Example 1-2, and Example 1.

As is apparent from Table 2, Comparative Example 1-1 (slaked lime without using any additive) has a BET specific surface area of 11.8 m ² / g. Similar to commercially available slaked lime, the BET specific surface area is small. Comparative Example 1-2 (slaked lime using an additive containing only an organic compound) has a BET specific surface area of 31.5 m ² / g, which seems to be sufficient, but the COD value is as high as 220 ppm, and the BET specific surface area is high. The balance between COD and COD is poor.

In these comparative examples, in Example 1 using an additive which is a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide, the BET specific surface area is as large as 34.5 m ² / g, COD is as small as 120 ppm. Moreover, both balance is also excellent. As described above, the slaked lime produced using the additive that is a combination of the organic compound having a hydroxyl group and the inorganic compound containing silicon dioxide described in Embodiment 1 achieves both a high BET specific surface area and a small COD. Can be made.

  In addition, even when the type of organic compound is changed, the additive based on the combination of the organic compound and the inorganic compound is more BET specific surface area of the slaked lime produced than the case of the additive containing only the organic compound. And has a positive effect on COD.

(Comparative Example 2-1)
Comparative Example 2-1 is slaked lime produced using an additive consisting of 60 g of quick lime, 400 g of water, and an organic compound only. Here, the additive contains 1.0% by weight of propylene glycol, which is an organic compound, based on quick lime.

(Example 2-1)
Example 2-1 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 0.5 wt% propylene glycol and 1.0 wt% zeolite with respect to quicklime. Example 2-1 corresponds to Comparative example 2-1.

(Comparative Example 2-2)
Comparative Example 2-2 is slaked lime produced using an additive consisting of 60 g of quick lime, 400 g of water, and an organic compound only. Here, the additive contains 1.0% by weight of dipropylene glycol with respect to quicklime.

(Example 2-2)
Example 2-2 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 0.5% by weight of dipropylene glycol with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime. Example 2-2 corresponds to Comparative example 2-2.

(Comparative Example 2-3)
Comparative Example 2-3 is slaked lime produced using an additive consisting of 60 g of quick lime, 400 g of water, and an organic compound only. Here, the additive contains 1.0% by weight of glycerin with respect to slaked lime.

(Example 2-3)
Example 2-3 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 0.5% by weight of glycerin with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime. Example 2-3 corresponds to Comparative example 2-3.

  Table 3 shows the results of the slaked lime produced in Comparative Examples 2-1 to 2-3.

As is clear from Table 3, the slaked lime obtained in Comparative Example 2-1 has a BET specific surface area of 33.1 m ² / g and a COD of 190 ppm. In the slaked lime obtained in Example 2-1 corresponding to Comparative Example 2-1, the BET specific surface area is 36.9 m ² / g, and the COD is 90 ppm. As can be seen from the comparison between Comparative Example 2-1 and Example 2-1, the BET specific surface area is increased by the additive by the combination of the organic compound and the inorganic compound, as compared with the case of the additive containing only the organic compound. Is decreasing. By adding an inorganic compound to the additive, the amount of the organic compound is relatively reduced to reduce COD, and the BET specific surface area of slaked lime is increased by the uniform mixing of the organic compound and the calcium capturing ability of the inorganic compound. Because.

  Thus, even when propylene glycol is selected as the organic compound, the additive comprising a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide can increase the BET specific surface area and reduce COD. Realized.

Moreover, as is clear from Table 3, the slaked lime obtained in Comparative Example 2-2 has a BET specific surface area of 32.1 m ² / g and a COD of 180 ppm. In the slaked lime obtained in Example 2-2 corresponding to Comparative Example 2-2, the BET specific surface area is 34.5 m ² / g, and the COD is 100 ppm. As can be seen from the comparison between Comparative Example 2-2 and Example 2-2, the BET specific surface area is increased by the additive by the combination of the organic compound and the inorganic compound, compared with the case of the additive containing only the organic compound. Is decreasing. This is the same as in the case of Example 2-1.

  As described above, even when dipropylene glycol is selected as the organic compound, an additive comprising a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide increases the BET specific surface area and reduces COD. Is realized.

Moreover, as apparent from Table 3, the slaked lime obtained in Comparative Example 2-3 has a BET specific surface area of 30.3 m ² / g and a COD of 190 ppm. In the slaked lime obtained in Example 2-3 corresponding to Comparative Example 2-3, the BET specific surface area is 34.0 m ² / g, and the COD is 110 ppm. As can be seen from the comparison between Comparative Example 2-3 and Example 2-3, the BET specific surface area is increased by the additive by the combination of the organic compound and the inorganic compound, as compared with the case of the additive containing only the organic compound. Is decreasing. This is the same as in Examples 2-1 and 2-2.

  In this way, even when glycerin is selected as the organic compound, an additive consisting of a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide realizes an increase in BET specific surface area and a reduction in COD. Is done.

  As can be seen from the results in Table 2 and Table 3, the additive is a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide, so that the BET can be used more than when an additive containing only an organic compound is used. Slaked lime with increased specific surface area and reduced COD can be produced. The same applies to the case where the additive is only an inorganic compound. That is, when the additive is only an inorganic compound containing silicon dioxide, the COD is lower than when the additive is a combination of an organic compound and an inorganic compound, but the effect on expanding the BET specific surface area is low.

(Experimental results of effective combination of organic and inorganic compounds)
An experimental result in the case where a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide is used as an additive will be described.

  The additive is a combination of diethylene glycol (an organic compound having a hydroxyl group) and zeolite (an inorganic compound containing silicon dioxide).

  The inventor measured the BET specific surface area of the manufactured slaked lime after changing the ratio of the zeolite (inorganic compound) to the whole additive with the whole additive as 100% by weight. The measurement results are shown in FIG. FIG. 2 is a graph showing the BET specific surface area of slaked lime with respect to the blending ratio of the inorganic compound in Embodiment 1 of the present invention.

  In the graph of FIG. 2, the horizontal axis shows the ratio of zeolite to the total additive. The vertical axis shows the BET specific surface area of the slaked lime produced. The value “0” at the origin of the graph of FIG. 2 indicates an additive that does not contain any zeolite that is an inorganic compound (additive only of an organic compound), and is a symmetrical position of the origin of the graph of FIG. A value of “100” indicates an additive that does not contain diethylene glycol, which is an organic compound, at all (an additive only for an inorganic compound).

  In addition, 1 weight% is added with respect to quick lime, regardless of the compounding ratio in an additive itself.

  As is apparent from the graph of FIG. 2, even when the additive is only an organic compound (position corresponding to the origin of the graph) or the additive is only an inorganic compound (right end of the graph), BET The specific surface area does not become sufficiently large. From the graph, it can be seen that it is effective for the BET specific surface area that the additive is a combination of an organic compound and an inorganic compound to some extent.

Here, the inorganic compound is preferably contained in the additive in a predetermined amount, but as can be seen from the graph of FIG. 2, the inorganic compound containing silicon dioxide is 10% by weight to 85% by weight with respect to the additive. % Is preferred. It is because the BET specific surface area of the slaked lime manufactured becomes 35 m < ² > / g or more because the inorganic compound containing a silicon dioxide is this range in an additive. This is because, when the BET specific surface area is 35 m ² / g or more, the ability to remove acid gas when slaked lime is used as the acid gas remover is enhanced.

  In addition, in the experiment of FIG. 2, a comparative example, and an Example, BET specific surface area is made into one standard of the result, but BET specific surface area changes also with the compounding ratio of an additive, or a constituent substance, quick lime, It also varies depending on the amount of water and additives. For this reason, the value of the BET specific surface area in the graph of FIG. 2 shows a tendency that the additive preferably contains a combination of an organic compound and an inorganic compound, and this value is an absolute value. Not that.

  Also, when the additive is a combination of an organic compound and an organic compound, unlike the combination of an organic compound and an inorganic compound, the additive has a positive effect on the BET specific surface area of slaked lime produced by the blending ratio of the organic compounds. Not give.

  FIG. 3 is a graph showing the BET specific surface area of slaked lime produced by an additive comprising a combination of an organic compound and an organic compound in Embodiment 1 of the present invention. FIG. 3 is different from FIG. 2 in that the additive contains diethylene glycol and dipropylene glycol, which are organic compounds. In this additive, the amount of dipropylene glycol changes with respect to the additive. In the graph of FIG. 3, as in the graph of FIG. 2, the horizontal axis indicates the amount of dipropylene glycol added, and the vertical axis indicates the BET specific surface area of the slaked lime produced.

  As apparent from FIG. 3, the BET specific surface area does not increase even when the ratio of the amount of dipropylene glycol added to the additive increases. Thus, when the additive is a combination of an organic compound and an organic compound, even if the ratio is changed, the BET specific surface area is not increased.

  Also from the graph of FIG. 3, it is understood that the additive is preferably a combination of an organic compound and an inorganic compound for improving the performance of the slaked lime produced.

(Addition amount of organic compound)
Next, the effect of the organic compound contained in the additive on the BET specific surface area and COD of the slaked lime produced according to the amount of quick lime added will be described. The inventor made objective the influence on the slaked lime by the addition amount of the organic compound by a plurality of experiments. This will be described based on each example in the series of Example 3.

  First, in each example in the series of Example 3, diethylene glycol was selected as the organic compound having a hydroxyl group, and zeolite was selected as the inorganic compound containing silicon dioxide. In each of the examples, the zeolite was fixed as 1.0% by weight with respect to quicklime, and the amount of diethylene glycol was changed little by little.

(Example 3-1)
Example 3-1 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 0.005% by weight of diethylene glycol with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime.

(Example 3-2)
Example 3-2 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 0.01% by weight of diethylene glycol with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime.

(Example 3-3)
Example 3-3 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 0.1% by weight of diethylene glycol with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime.

(Example 3-4)
Example 3-4 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 0.5% by weight of diethylene glycol with respect to quick lime and 1.0% by weight of zeolite with respect to quick lime.

(Example 3-5)
Example 3-5 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 1.0% by weight of diethylene glycol with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime.

(Example 3-6)
Example 3-6 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 5.0% by weight of diethylene glycol with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime.

(Example 3-7)
Example 3-7 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 10% by weight of diethylene glycol with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime.

(Example 3-8)
Example 3-1 is slaked lime produced using 60 g of quicklime, 400 g of water, and an additive composed of a combination of an organic compound and an inorganic compound. Here, the additive contains a combination of 15% by weight of diethylene glycol with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime.

  Table 4 shows the results of the slaked lime produced by Examples 3-1 to 3-8.

  As shown in Table 4, each of Examples 3-1 to 3-8 has a BET specific surface area and a COD value in the manufactured slaked lime.

As shown in Table 4, the slaked lime produced in Example 3-1 has a BET specific surface area of 32.3 m ² / g and a COD of 6.0 ppm. Although the value of COD is quite low, the BET specific surface area is not sufficiently high, and even if COD can be suppressed, the BET specific surface area cannot be sufficiently increased. That is, the ratio of the organic compound in the additive shown in Example 3-1 is not appropriate.

In the slaked lime produced in Example 3-2, the BET specific surface area is 33.6 m ² / g and the COD is 6.7 ppm. The COD value is sufficiently low, and the BET specific surface area is increased as compared with Example 3-1, and it is sufficient if the ratio of the organic compound is about 0.01% by weight with respect to quick lime. A good BET specific surface area and COD can be achieved.

In the slaked lime produced in Example 3-3, the BET specific surface area is 35.4 m ² / g and the COD is 43 ppm. The BET specific surface area is sufficiently large and the COD is also sufficiently small. That is, the desired slaked lime is produced. As can be seen from the results of Example 3-3, when the ratio of the organic compound is 0.1% by weight with respect to quicklime, sufficient BET specific surface area and COD can be achieved.

In the slaked lime produced in Example 3-4, the BET specific surface area is 37.1 m ² / g and the COD is 120 ppm. Both BET specific surface area and COD suppression are compatible. From this, it is suitable for coexistence with sufficient BET specific surface area and COD that the ratio of an organic compound is 0.5 weight% with respect to quick lime.

In the slaked lime produced in Example 3-5, the BET specific surface area is 37.7 m ² / g and the COD is 200 ppm. Both BET specific surface area and COD suppression are compatible. From this, it is suitable for coexistence with sufficient BET specific surface area and COD that the ratio of an organic compound is 1.0 weight% with respect to quicklime.

In the slaked lime produced in Example 3-6, the BET specific surface area is 39.0 m ² / g, and the COD is 820 ppm. The BET specific surface area is sufficient, but the COD is slightly large. From this, it is a level which can respond to coexistence of a BET specific surface area and COD that the ratio of an organic compound is 5.0 weight% with respect to quicklime.

In the slaked lime produced in Example 3-7, the BET specific surface area is as large as 39.4 m ² / g, but the COD value is also very large as 1500 ppm. When COD is as large as 1500 ppm, carbon dioxide emission becomes large when slaked lime is used as an acid gas remover. From this, it can be seen that the organic compound is necessary for a sufficient BET specific surface area and a small COD to be up to about 10% by weight with respect to quicklime.

In Example 3-8, the BET specific surface area is as large as 39.5 m ² / g, but the COD is very large as 1900 ppm. An organic compound content of 15% by weight with respect to quicklime is inappropriate for a sufficient BET specific surface area and a small COD.

  As mentioned above, from the experimental result in the series of Example 3 shown in Table 4, the addition amount of the organic compound having a hydroxyl group used for the additive is 0.01% by weight to 10% by weight with respect to quicklime. It is considered preferable. As can be seen from Table 4, the amount of the organic compound having a hydroxyl group is more preferably 0.1% by weight to 5% by weight with respect to quicklime.

(Amount of inorganic compound added)
Moreover, the inorganic compound contained in the additive is 0.01% by weight to 15% by weight, and more preferably 0.01% by weight to 10% by weight with respect to quicklime. FIG. 4 is a graph showing the BET specific surface area of slaked lime in the variation of the addition amount of the inorganic compound in Embodiment 1 of the present invention.

  In the experiment on which the graph of FIG. 4 is based, diethylene glycol (designated as DEG in FIG. 4) fixed at 1% by weight with respect to quicklime and zeolite changed from 0% to 20% by weight with respect to quicklime. The BET specific surface area of the slaked lime to which was added was measured. The horizontal axis of the graph of FIG. 4 shows the addition ratio of zeolite, which is an inorganic compound, with respect to quicklime in weight%. The vertical axis | shaft of the graph of FIG. 4 has shown the BET specific surface area of the obtained slaked lime. Since the addition ratio of diethylene glycol, which is an organic compound, is fixed, the contribution of the inorganic compound to slaked lime can be seen.

  As apparent from the graph of FIG. 4, the BET specific surface area of the obtained slaked lime increases as the addition ratio of the inorganic compound zeolite increases. However, when the addition ratio of the inorganic compound zeolite exceeds 15% by weight, the increase in the BET specific surface area of the obtained slaked lime reaches a peak. Furthermore, when the addition ratio of the inorganic compound zeolite exceeds 10% by weight, it is difficult to increase the BET specific surface area of the obtained slaked lime.

  Based on these results which can be found from FIG. 4, the inorganic compound contained in the additive is about 0.01% to 15% by weight, more preferably about 0.01% to 10% by weight, based on quick lime. It is preferable.

(Addition of inorganic compounds)
In the slaked lime in Embodiment 1, the additive used for the digestion process includes an inorganic compound containing silicon dioxide. This inorganic compound decreases the addition amount of the organic compound and increases the BET specific surface area by a synergistic effect with the organic compound.

On the other hand, in the case of an additive containing only an inorganic compound without using an organic compound, the COD can be lowered, but the BET specific surface area cannot be increased. For example, in the case of slaked lime produced by 60 g of quick lime, 60 g of water and additives, and the additive contains only silica gel, the COD of the produced slaked lime is as low as 5.9 ppm, but the BET specific surface area Becomes as small as 30.0 m ² / g. This is not enough.

  Thus, as for the slaked lime in Embodiment 1, the additive used at a digestion process contains the combination of an organic compound and an inorganic compound. Here, at least one of silica gel, diatomaceous earth, zeolite, allophane, imogolite, and activated clay is selected as the inorganic compound. Regardless of which inorganic compound is selected, a sufficient BET specific surface area and COD can be obtained with some differences.

In the series of Example 4, it shows that the BET specific surface area and COD of the slaked lime produced are sufficient regardless of the inorganic compound. In addition, in the experiment of the series of Example 4, unlike Examples 1-3, water is 60g with respect to 60g of quicklime, and the temperature of the water in a digestion process is set to 25 degreeC. For this reason, the absolute value of the BET specific surface area is apparently smaller than the experimental results in Examples 1 to 3. However, it does not fall below the standards required for manufactured slaked lime.
In addition, the slaked lime of the series of Example 4 is manufactured by being dried at 110 ° C. without being classified with a sieve and vacuum filtration.

(Example 4-1)
Example 4-1 is slaked lime produced by 60 g of quicklime, 60 g of water (temperature in the digestion step is 25 ° C.), and additives. Additives are 0.2 wt% diethylene glycol (organic compound) with respect to quicklime and 1.0 wt% allophane-containing soil with respect to quicklime.

(Example 4-2)
Example 4-2 is slaked lime produced by 60 g of quicklime, 60 g of water (temperature in the digestion step is 25 ° C.), and additives. The additives are 0.2% by weight of diethylene glycol (organic compound) with respect to quicklime and 1.0% by weight of zeolite with respect to quicklime.

(Example 4-3)
Example 4-3 is slaked lime produced by 60 g of quicklime, 60 g of water (temperature in the digestion step is 25 ° C.), and additives. The additive is 0.2% by weight of diethylene glycol (organic compound) based on quick lime and 1.0% by weight of activated clay A based on quick lime.

(Example 4-4)
Example 4-4 is slaked lime produced by 60 g of quicklime, 60 g of water (temperature in the digestion step is 25 ° C.), and additives. The additive is 0.2% by weight of diethylene glycol (organic compound) with respect to quicklime and 1.0% by weight of activated clay B with respect to quicklime.

(Example 4-5)
Example 4-5 is slaked lime produced by 60 g of quicklime, 60 g of water (temperature in the digestion step is 25 ° C.), and additives. The additives are 0.2% by weight of diethylene glycol (organic compound) with respect to quicklime and 1.0% by weight with respect to quicklime.

(Example 4-6)
Example 4-6 is slaked lime produced by 60 g of quicklime, 60 g of water (temperature in the digestion step is 25 ° C.), and additives. The additives are 0.2% by weight of diethylene glycol (organic compound) with respect to quicklime and 1.0% by weight of diatomaceous earth with respect to quicklime.

(Example 4-7)
Example 4-7 is slaked lime produced by 60 g of quicklime, 60 g of water (temperature in the digestion step is 25 ° C.), and additives. The additives are 0.2% by weight diethylene glycol (organic compound) with respect to quicklime and 1.0% by weight silica gel with respect to quicklime.

  The above Examples 4-1 to 4-7 are shown in Table 5.

As shown in Table 5, the BET specific surface area of the slaked lime produced in Example 4-1 is 28.2 m ² / g, and the COD is 130 ppm. The slaked lime produced in Example 4-2 has a BET specific surface area of 35.8 m ² / g and a COD of 120 ppm. The slaked lime produced in Example 4-3 has a BET specific surface area of 29.1 m ² / g and a COD of 110 ppm. The slaked lime produced in Example 4-4 has a BET specific surface area of 33.5 m ² / g and a COD of 110 ppm. The slaked lime produced in Example 4-5 has a BET specific surface area of 26.3 m ² / g and a COD of 130 ppm. The slaked lime produced in Example 4-6 has a BET specific surface area of 26.6 m ² / g and a COD of 120 ppm. In the slaked lime produced in Example 4-7, the BET specific surface area is 34.1 m ² / g, and the COD is 110 ppm.

  Both show a sufficiently large BET specific surface area and a sufficiently small COD.

  Thus, although there are fine differences in the obtained slaked lime depending on the type of inorganic compound, good results can be confirmed in any case. For this reason, the person who manufactures the slaked lime in Embodiment 1 can arbitrarily select at least one of silica gel, diatomaceous earth, zeolite, allophane, imogolite, and activated clay as an inorganic compound.

  As mentioned above, the slaked lime in Embodiment 1 is manufactured using the additive which consists of a combination of the organic compound which has a hydroxyl group, and the inorganic compound containing silicon dioxide. As a result, a sufficiently large BET specific surface area can be secured and COD can be reduced.

  The COD value described as the experimental result in the first embodiment is a result of measuring the eluate obtained in accordance with Ministry of the Environment Notification No. 46 in accordance with JIS K 0102 17 in order with potassium permanganate.

  (Embodiment 2)

  Next, a second embodiment will be described.

  In the second embodiment, the method for producing slaked lime described in the first embodiment will be described.

  FIG. 5 is a block diagram illustrating a manufacturing process of slaked lime according to Embodiment 2 of the present invention.

  The slaked lime is a first mixing step 7 in which a predetermined additive 2 is mixed with at least one of quick lime 1 and water 3, a second mixing step 8 in which water 3 is mixed with quick lime 1, quick lime 1, water 3, and added. It is manufactured through a digestion step 4 in which the agent is reacted, an aging step 5 and a drying step 6.

  In the digestion step 4, quick lime 1, water 3 and additive 2 cause a digestion reaction. A substance that becomes slaked lime is obtained by this digestion reaction. When this slaked lime substance is aged for a predetermined time and dried, the final slaked lime is obtained.

  As described in Embodiment 1, the additive 2 used in the digestion step 4 is a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide.

  Here, the additive 2 is added by at least one means: (1) added to quicklime 1 (2) added to water 3 (3) added to a mixture of quicklime 1 and water 3 Is done. In FIG. 5, an arrow A in which additive 2 is added to quicklime 1, an arrow B in which additive 2 is added to water 3, and an arrow C in which additive 2 is added to a mixture of quicklime 1 and water 3 are shown. Has been. Additive 2 may be added by any of these methods (1) to (3).

  For example, when the additive is added to the water 3 as in (2), the additive is sufficiently dispersed and stirred, so that a high effect by the additive can be expected. Of course, even when the additive is added by the means (1) or (2), the effect of the additive can be obtained.

  The quick lime 1 and the water 3 may be the same amount or different amounts. When the quick lime 1 and the water 3 are the same amount, according to the quantity of the quick lime 1 thrown into the stirrer which performs the digestion process 4, the amount of the quick water 3 is controlled and added, and quick lime is added. The digestion process of 1 and water 3 is started. The aging step 5 is performed with an aging machine. Moreover, in order to avoid the drying for a long time at high temperature, it is desirable for the drying process 6 to use the spray dryer and airflow type dryer which can contact the hot air for drying and hydrous slaked lime in several seconds to several minutes.

  Alternatively, when quick lime 1 and water 3 are in different amounts, quick lime 1 is charged into water 3 to form a slurry. The slurry is classified with a vibrating sieve or the like and filtered with a filter press or the like. After this digestion step, the slaked lime is dried and classified with an air dryer or the like. Slaked lime may be manufactured by such a wet digestion method. Alternatively, a dry digestion method with the same amount or less of water 3 with respect to quicklime 1 may be used. Although the semi-wet digestion method may be employed from the viewpoint of cost and the like, slaked lime may be produced by any method.

  Slaked lime is manufactured through the manufacturing process as described above. At this time, by using an additive composed of a combination of an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide, the produced slaked lime has a large BET specific surface area and a small COD value. .

  Further, the slaked lime described in the first and second embodiments is used as an acid gas removing agent that is put into a garbage incinerator or the like. In particular, since the BET specific surface area is large, the acid gas adsorption performance is high, and the COD is low, so that it can be used as an acid gas remover with a small environmental load.

  As mentioned above, the manufacturing method of slaked lime and slaked lime demonstrated in Embodiment 1-2 is an example explaining the meaning of this invention, and includes the deformation | transformation and remodeling in the range which does not deviate from the meaning of this invention.

DESCRIPTION OF SYMBOLS 1 Quicklime 2 Additive 3 Water 4 Digestion process 5 Aging process 6 Drying process 7 1st mixing process 8 2nd mixing process

Claims (9)

Slaked lime produced by a digestion process that reacts quicklime with water,
A predetermined additive used in the digestion process is added,
The additive includes a substance in which an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide are combined,
The organic compound having a hydroxyl group is ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, glycerin, glucose, fructose, galactose, mannose, xylitol, sucrose, maltose, lactose, trehalose, sorbitol, xylitol, ethanol Selected from at least one of the group consisting of amine, diethanolamine and triethanolamine;
The inorganic compound containing silicon dioxide is slaked lime selected from at least one of the group consisting of silica gel, allophane, imogolite, and activated clay. The slaked lime according to claim 1, wherein the slaked lime has a BET specific surface area of 20 m ² / g or more. The slaked lime according to claim 1, wherein the slaked lime has a BET specific surface area of 35 m ² / g or more.   The additive is (1) addition to the quicklime, (2) addition to the water, (3) addition to the mixture of quicklime and water, and at least one of (1) to (3) The slaked lime according to any one of claims 1 to 3, which is added by means.   The slaked lime according to any one of claims 1 to 4, wherein at least one addition amount selected from the group of organic compounds having a hydroxyl group is 0.01 wt% to 10 wt% with respect to the quicklime.   The slaked lime according to any one of claims 1 to 5, wherein an addition amount of the inorganic compound containing silicon dioxide is 0.01 wt% to 15 wt% with respect to the quicklime.   The slaked lime according to any one of claims 1 to 5, wherein an addition amount of the inorganic compound containing silicon dioxide is 0.01 wt% to 10 wt% with respect to the quicklime.   The acidic gas removal agent which uses the slaked lime in any one of Claim 1 to 7 as an active ingredient. A first mixing step of mixing a predetermined additive with at least one of quicklime and water;
A second mixing step of mixing the water with the quicklime;
A digestion step of reacting the quicklime, the additive and the water,
The additive includes a substance in which an organic compound having a hydroxyl group and an inorganic compound containing silicon dioxide are combined,
The organic compound having a hydroxyl group is ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, glycerin, glucose, fructose, galactose, mannose, xylitol, sucrose, maltose, lactose, trehalose, sorbitol, xylitol, ethanol Selected from at least one of the group consisting of amine, diethanolamine and triethanolamine;
The inorganic compound containing silicon dioxide is a method for producing slaked lime selected from at least one of the group consisting of silica gel, allophane, imogolite, and activated clay.