JPH0261320B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to an improvement in a method for cleaning sugar solution in a sugar refining process using a magnesia adsorbent. [Prior Art] Conventionally, a method is known in which an aqueous solution containing colored organic impurities is treated with a magnesia adsorbent to adsorb and remove the colored impurities.
For example, it is applied to purifying sugar solutions and wastewater. Currently, the cleaning method widely practiced in sugar factories is a combination of carbonation filling method and activated carbon method. However, with the diversification of thermal energy, the carbon dioxide filling method may not be able to obtain the necessary carbon dioxide gas, so its survival in the future is a problem. Moreover, even if this is not the case, the carbonation filling method is becoming a problem from the perspective of pollution prevention as it generates a large amount of waste. Furthermore, addition of a large amount of milk of lime dilutes the sugar solution, which is not preferable from the standpoint of energy saving. For this reason, a method for purifying sugar liquid using a magnesia adsorbent has been proposed as an alternative to the carbonate filling method, the details of which are shown in JP-A-56-169599. That is, in the purification treatment of sugar solution using this magnesia adsorbent, a mixture of magnesia and fillers such as perlite and diatomaceous earth is added to the sugar solution, and the colored organic impurities in the sugar solution are adsorbed by the magnesia. , a filter cake consisting of magnesia adsorbing colored organic impurities and a filler is obtained by filtration treatment, the filter cake is fired in a baking furnace to regenerate magnesia, and the mixture of the regenerated magnesia and filler is regenerated. Reused for processing sugar solution. By the way, in the case of a cleaning treatment method using such a magnesia adsorbent, as the magnesia adsorbent is recycled by firing and used repeatedly, local crystallization of the magnesia adsorbent progresses, and its adsorption activity gradually decreases. However, in order to prevent this decrease in activity, the firing temperature must be strictly controlled. [Objective] The object of the present invention is to overcome the above-mentioned drawbacks observed in the cleaning treatment of sugar solution in the sugar refining process using the conventional magnesia adsorbent. [Structure] As a result of various studies to achieve the above object, the present inventors surprisingly found that when using a mixture of a magnesia adsorbent and a filler to which activated carbon is added as a cleaning agent. , oxygen concentration 7.5%
The cleaning treatment agent containing the magnesia adsorbent, which has been fired and regenerated in the following atmosphere, not only does not have a decrease in activity, but in fact shows an improvement in activity, and it is easy to filter the cleaning treatment agent after the cleaning treatment. The cleaning treatment agent can be fired and regenerated under low temperature conditions, and when firing a filter cake consisting of magnesia adsorbent, filler, and activated carbon, the activated carbon can be regenerated while the magnesia adsorbent is regenerated. It was discovered that various advantages such as the ability to achieve regeneration can be obtained, and the present invention was completed. That is, according to the present invention, when cleaning the sugar solution in the sugar refining process with magnesia, after the cleaning, the sugar solution is made of magnesia adsorbed with colored organic impurities, an inorganic filler, and activated carbon, and the activated carbon content is at least 5% by weight. %, the oxygen concentration is
A method for cleaning a sugar solution is provided, which comprises baking at a temperature of 400 to 600°C in an atmosphere of 7.5% or less, and bringing the obtained baked product into contact with the sugar solution. The magnesia adsorbent used in the present invention is a conventionally known one, and a magnesium compound capable of forming magnesia, such as magnesium hydroxide, magnesium carbonate, basic magnesium carbonate, etc. It can be obtained by baking at a low temperature for 30 minutes to several hours. This magnesia adsorbent is usually used in powder form (average particle size of about 1 to 10 μm), and generally 98% of it is
or more have a particle size of 100 mesh or less, preferably 300 mesh or less. The filler used in the present invention is a refractory inorganic oxide or clay mineral powder, and conventionally known fillers are used. Specific examples of such fillers include diatomaceous earth, pearlite, zeolite, kaolin, and alumina. , silica, titania, iron oxide, and the like. In the purification treatment of sugar solution, diatomaceous earth and perlite, which are used as filtering agents for food production, are preferably used. This filler is usually
It is used in powder form (average particle size of about 4 to 15 μm), and generally 98% or more of it is 100 mesh or less, preferably 300 mesh or less, but magnesia adsorbent is used with a larger average particle size than the magnesia adsorbent. is common. Various conventionally known activated carbons can be used as the activated carbon used in the present invention, and the raw materials for the activated carbon are not particularly limited. For example, wood, sawdust, coconut shell, lignin, cow bone, blood, lignite, brown coal, peat, A product manufactured by carbonizing and activating pitch etc. is used. The particle size of the activated carbon used in the present invention is not particularly limited, and both powdered activated carbon and granular activated carbon can be used, but preferably powdered activated carbon with a water content of about 50% by weight (average particle size of about 20 to
100 μm) is advantageously used. In the method of the present invention, when starting the first treatment cycle, a mixture of a magnesia adsorbent and a filler (hereinafter simply referred to as a cleaning treatment agent) is added and mixed to the sugar solution in the refined sugar process, which is the raw material to be treated. do. In this case, the proportion of magnesia adsorbent used is usually
0.1 per part by weight of colored organic impurities to be removed
The proportion is at least 0.2 parts by weight, preferably 0.2 to 0.7 parts by weight. When purifying sugar solution, the appropriate amount of magnesia adsorbent varies depending on the purity of the sugar solution, but
For example, in the case of sugar washing liquids used in sugar refineries, the amount is preferably in the range of 0.3 to 0.6% by weight based on the solids. The proportion of the filler added to the magnesia adsorbent is 1 part by weight or more, preferably 2 to 5 parts by weight, per 1 part by weight of the magnesia adsorbent. The cleaning treatment in which the cleaning treatment agent is brought into contact with the sugar solution in the refined sugar process is carried out at room temperature or heating, preferably at 50°C to
This is carried out by stirring at a temperature of 90°C, particularly 75-85°C, for 30-60 minutes, whereby colored organic impurities contained in the sugar solution are adsorbed and removed by the magnesia adsorbent. After the cleaning treatment, the cleaning treatment product is subjected to solid-liquid separation treatment, and the cleaning treatment agent that has adsorbed colored organic impurities is separated from the sugar solution to be treated. This solid-liquid separation is carried out by a filtration method, a centrifugation method, etc., and the filtration method is generally used. The cleaning agent separated from the cleaning product is washed, dehydrated, and fired. In this case, the firing is performed at a relatively low temperature of 400 to 600°C for 30 minutes to 3 hours. , in an atmosphere where complete combustion does not occur, for example, at an oxygen concentration of 7.5
% or less, preferably in an atmosphere with an oxygen concentration of 0.5 to 5%, thereby obtaining a first regenerated cleaning treatment agent. Next, in order to start the second treatment cycle, the first regenerated cleaning treatment agent and activated carbon obtained above are combined.
It is added to the raw material sugar solution to be treated, and furthermore, a replenishing magnesia adsorbent corresponding to the loss eluted as magnesium ions during the treatment is added and mixed. In this case, the addition ratio of activated carbon is in the range of 5 to 60% by weight, preferably 20 to 40% by weight, based on the total amount of the regenerated cleaning treatment agent and activated carbon. When the addition ratio of activated carbon is less than 5% by weight, a sufficient effect of the addition of activated carbon cannot be obtained, and on the other hand, even when it exceeds 60% by weight, no particular improvement in the addition effect is observed. After this cleaning treatment, the cleaning treatment agent is separated from the cleaning treatment product, washed, dehydrated, and calcined in the same manner as described above to obtain a second regenerated cleaning treatment agent. In this case, a temperature of 400 to 500°C is sufficient for the regeneration conditions in the second treatment cycle. This second regenerated cleaning treatment agent contains activated carbon, which is activated and has a decolorizing ability to compensate for the reduced adsorption activity of the regenerated magnesia adsorbent. Generally, the above-mentioned regeneration conditions of 400 to 500°C are insufficient for the regeneration of activated carbon, and a high temperature of 700 to 900°C is usually required.
In the present invention, it is completely unexpected that sufficient activation regeneration of activated carbon is achieved by calcining it as a mixture with a magnesia adsorbent. Next, to start the third and subsequent treatment cycles, in the same manner as in the case of starting the second treatment cycle, the regenerated cleaning treatment agent and activated carbon obtained in the previous treatment cycle are added to the sugar to be treated. Add to the liquid, then add supplementary magnesia and mix. In this case, since the regenerated cleaning treatment agent contains activated carbon, the addition of activated carbon at this stage can be omitted. After the cleaning treatment, the cleaning treatment agent is separated in the same manner as described above, and then washed, dehydrated, and fired to obtain a regenerated cleaning treatment agent. In the present invention, the addition of activated carbon is not limited to the above-mentioned addition method, and it can also be added at the beginning of the first treatment cycle, or at each treatment cycle, or at intervals between treatment cycles. It can also be added at each time. In addition, it is not necessary to use fresh activated carbon as the activated carbon.
Spent activated carbon can be used. For example, in the purification treatment of sugar solution, the purified sugar solution is further decolorized with activated carbon, and used activated carbon after this decolorization treatment can be used. The method of the invention comprises at least 5% by weight of activated carbon.
It is characterized in that the sugar solution in the refining sugar process is purified using the regenerated purifying agent contained therein. In this case, the activated carbon content in the regenerated purifying agent depends on the firing temperature and the oxygen in the furnace. It can be controlled by adjusting the concentration or the amount of air supplied into the furnace, and in the case of the present invention, it is 5 to 60% by weight, preferably 20% by weight.
Keep at ~40% by weight. [Effects] By using the regenerated cleaning treatment agent containing activated carbon according to the present invention, various effects as shown below can be obtained. (1) The reduction in activity seen in recycled cleaning agents is prevented by the addition of activated carbon, and in fact an improvement in activity (increase in decolorization rate) is observed, allowing cleaning treatment to be performed at a high decolorization rate throughout each treatment cycle. Can be done. The reason for this is not clear, but one of the reasons is
For one thing, when magnesia adsorbent is fired at high temperature, its activity decreases, but when activated carbon is added, the regeneration rate of activated carbon improves, and the improvement in regeneration rate compensates for the decrease in activity of magnesia adsorbent. considered to be a thing. Another reason for the improvement in activity is that in the hydration reaction of magnesia, whereas with a magnesia adsorbent alone, the primary particles cause interparticle aggregation and the secondary particles generated cause the hydration reaction. When activated carbon is added, the primary particles of the magnesia adsorbent are attached and dispersed on the surface of the activated carbon particles to advance the hydration reaction, which is thought to improve the activity accordingly. Furthermore, the impurities adsorbed by the magnesia adsorbent and the impurities adsorbed by activated carbon are not the same, and hydrophobic impurities are easily physically adsorbed by activated carbon, so the adsorption area for impurities is expanded accordingly and the purification effect is improved. This is expected to increase. (2) It becomes easier to filter and separate the cleaning treatment agent after cleaning treatment. For example, the clogging of the filter cloth used as the filter material is greatly reduced compared to the conventional case where activated carbon is not added, and the amount of filtration until the filter cloth clogging is removed reaches 2 to 3 times. (3) The clarity of the filtrate is significantly improved, and the added activated carbon, even if minute, does not leak into the initial filtrate. The reason for this is not clear, but it is thought to be due to the high affinity between the magnesia adsorbent and activated carbon, and the fact that activated carbon acts as a filter aid. (4) Calcining regeneration of cleaning agents with activated carbon added can be carried out at lower temperatures than when regenerating conventional cleaning agents without activated carbon, thus reducing the amount of adsorbed colored organic impurities. As a result, local overheating of the magnesia adsorbent is prevented. Local overheating promotes local crystallization of the magnesia adsorbent and causes a decrease in adsorption activity, but this drawback is overcome in the present invention. Therefore,
In the case of the present invention, the temperature control of the firing furnace becomes easy, and the operation of the firing furnace becomes easy. The reason why the cleaning agent is activated and regenerated at a low temperature is considered to be as follows. In other words, the conditions for regeneration and activation of activated carbon are generally 600 to 800℃.
The adsorbed organic matter is calcined at 800-1000°C and activated with water vapor, etc. In contrast, in the present invention, the cleaning treatment agent containing activated carbon is effectively activated and
What is regenerated is that polluted organic matter exists on the surface layer of the adsorbent and is susceptible to thermal decomposition.
This is thought to be due to the fact that magnesium hydroxide produced by hydration of magnesia acts as a solid base and exhibits an effect as a shift catalyst for thermal decomposition of organic matter. (5) In the present invention, powdered activated carbon is also advantageously activated and regenerated. That is, powdered activated carbon is difficult to regenerate by itself, and cannot be recovered or reused in a normal furnace due to scattering. Therefore, wet oxidation and electric furnaces using special rotating crucibles have been proposed, but they are not sufficient.
In reality, activated carbon is inevitably used in the form of granules. On the other hand, in the present invention, since it is used in combination with a magnesia adsorbent, there is no scattering even if a normal furnace is used, and regeneration can be easily performed. [Example] Next, the present invention will be explained in more detail with reference to Examples. Example 1 Australian raw sugar was subjected to sugar washing operation,
Washed sugar with a color value of AI1880 was obtained. Add warm water to 5.0 kg of this washed sugar to make an aqueous solution of Bx°65, heat it to a temperature of 80°C, and add magnesia adsorbent (commercially available magnesium hydroxide reagent) to this while stirring with a stirrer.
Calcined at 500℃ for 30 minutes, average particle size is 1 to 10μm as primary particles, 98% less than 325 mesh.
20g (0.4% per washed sugar), 40g of powdered activated carbon (SW-50, manufactured by Nimura Chemical), and 60g of perlite (manufactured by Daicalite Orient, average particle size 4-15μm)
g (hereinafter referred to as activated carbon-containing magnesia detergent) was added, and stirring was continued for 60 minutes at a temperature of 80°C.
Thereafter, the entire amount was filtered, and the filtrate and activated carbon-containing magnesia detergent cake were recovered. This filtrate has a Bx゜64.9, an AI231, and a decolorization rate of 87.7% [(1881
−231)/1880×100]. Next, the recovered filter cake was suspended in 3 times its weight of hot water, stirred at 80℃ for 30 minutes, filtered with a suction filter, and the cake was collected on a filter paper. Warm water was added over the cake and washing was continued until the sugar concentration of the washed filtrate was below Bx°1. Thereafter, the cake on the filter paper was compressed and thoroughly dehydrated. This dehydrated cake was placed in a crucible, and in a Matsufuru furnace equipped with a device that can control the amount of air fed into the furnace, the dehydrated cake was heated to a temperature of 500 m Calcined at ℃ for 60 minutes, first cycle refired product (MgO 19.5%, activated carbon 19.9%, perlite 59.6%, other 1.0%)94
I got g. Next, using this first cycle refired product, the second cycle
In order to perform the sugar solution cleaning operation in the first cycle,
Washed sugar 3.9Kg (adjusted to Bx゜65 and 80
℃), 80 g of the re-fired product from the first cycle (the amount equivalent to 0.4% of the washed sugar, same as the first cycle, as MgO conversion rate)
was added and stirring was continued at 80°C for 60 minutes. after that,
The entire amount was filtered, and the filtrate and cake were collected.
The filtrate has a Bx゜65.6, AI238, and a decolorization rate of 87.3.
It was %. For this cake, the second cycle's re-baked product was prepared using the same operations as the first cycle.
Obtained 76g. Thereafter, the same operations as in the second cycle were repeated to perform a total of 5 cycles of sugar solution cleaning operation and 4 cycles of reburning operation. The results are shown in Table 1.

[Table] Comparative example 1 Raw sugar from Australia was subjected to sugar washing operation,
A washed sugar of AI1810 was obtained. Add warm water to 5.0 kg of this washed sugar to make an aqueous solution of Bx°65, heat it to a temperature of 80°C, stir it with a stirrer, and add 20 g of the same magnesia adsorbent as in Example 1 (0.4% based on the washed sugar). A mixture of 60 g of perlite (the same as in Example 1) (hereinafter referred to as magnesia detergent) was added, and stirring was continued at a temperature of 80° C. for 60 minutes. Thereafter, the entire amount was filtered, and the filtrate and magnesia detergent cake were collected. This filtrate has Bx゜65.4, AI358
The decolorization rate was 80.2%. The recovered cake was subjected to the same operation as in Example 1 to obtain 75 g of re-fired product for the first cycle. Next, using this first cycle refired product, the second cycle
In order to perform the sugar solution cleaning operation in the first cycle, the same 3.9 kg of sugar as in the first cycle (adjusted to Bx゜65 and 80℃
), the first cycle re-fired
67.5g (MgO equivalent addition rate: 0.4% based on washed sugar)
) and continued stirring at 80°C for 60 minutes. Thereafter, the entire amount was filtered, and the filtrate and cake were collected. This filtrate has Bx゜65.9, AI411,
The decolorization rate was 77.3%. Regarding cake, 1
The same operation as in the second cycle was performed to obtain 64 g of second cycle re-fired product. Thereafter, the same operation as in the second cycle was repeated, resulting in a total of 5 cycles of sugar solution cleaning operation and 4 cycles of rebaking operation. The results are shown in Table 2.

[Table] Example 2 One part of raw sugar produced in Australia and one part of raw sugar produced in Thailand were subjected to a sugar washing operation to obtain washed sugar with a color value of AI1640.
Add warm water to 5.0 kg of this washed sugar to form a solution of Bx゜65 and heat it to a temperature of 80°C. While stirring with a stirrer, add magnesia adsorbent (commercially available magnesium hydroxide reagent) to this by baking at 500°C for 30 minutes. The average particle size is 1 to 10 μm as a primary particle, 325 mesh (98% or less) 30g (0.6% per washed sugar), Perlite (manufactured by Daicalite Orient Co., Ltd., average particle size 4 to
15 μm) (hereinafter referred to as magnesia detergent) was added, and stirring was continued for 60 minutes at a temperature of 80°C. The entire amount was filtered, and the filtrate and magnesia detergent cake were collected. This filtrate has Bx゜65.8,
With AI362, the decolorization rate is 77.9% [(1640−362)/1640
×100]. Next, the recovered filter cake was suspended in 3 times its weight of hot water, stirred at 80℃ for 30 minutes, filtered with a suction filter, and the cake was collected on a filter paper. Warm water was added over the cake and washing was continued until the sugar concentration of the washed filtrate was below Bx°1. Thereafter, the cake on the filter paper was compressed and thoroughly dehydrated. This dehydrated cake was placed in a crucible and fired in a Matsufuru furnace equipped with a device that can control the amount of air fed into the furnace at a temperature of 500°C for 60 minutes. 64.7%, activated carbon (charcoal of adsorbed organic matter) 2.2%, other 2.1%]
Obtained 87g. Next, in order to perform the sugar solution cleaning operation in the second cycle using this first cycle re-baked product, for the same 4.2 kg of washed sugar (adjusted to Bx ° 65) as in the first cycle, 1st cycle fired product 81.3g
(The amount of MgO added is the same as in the first cycle.
0.6% based on washed sugar) and used activated carbon (color value AI110)
26.2g of used activated carbon (used activated carbon that has been desugared after adding 0.2% wet powdered activated carbon to the solid content of the sugar solution)
%) and stirred at 80°C for 60 minutes. The entire amount was filtered, and the filtrate and cake were collected. This filtrate had a Bx of 65.6, an AI of 325, and a decolorization rate of 80.2%. Next, this cake was subjected to the same operation as in the first cycle to obtain 75 g of a second cycle re-baked product. Thereafter, the same operation as in the second cycle was repeated, resulting in a total of 6 cycles of sugar solution cleaning operation and 5 cycles of reburning operation. The results are shown in Table 3.

[Table] Example 3 After carrying out the fifth cycle of sugar solution cleaning operation in the same manner as in Example 2, 133 g of activated carbon-containing magnesia detergent cake was obtained. this cake 40
Pour each g into three crucibles [referred to as (a), (b), and (c)], and fire each crucible at a temperature of 450°C, (b) at 500°C, and (c) at 600°C. 22.2 to the crucible (a).
20.8 g of baked products (a), (b), and (c) were obtained in crucible (b) and 17.4 g in crucible (c), respectively. Add warm water to the same washed sugar as in Example 2 and make Bx゜65.
I made a sugar washing solution. This washing sugar solution was heated to 80°C, and the baked product (a) obtained in the crucible (a) was added in an amount equivalent to 0.6% MgO based on the washing sugar.
After stirring at 80° C. for 1 hour, suction filtration was performed using No. 2 filter paper to obtain a filtrate (a). This filtrate (a)
The color value was measured and the decolorization rate was calculated. Next, the crucible
The same operation was performed for the baked products (b) and (c) obtained in (b) and (c), and the decolorization rate was calculated for each. The results are shown in Table 4. Comparative Example 2 After performing the sugar solution cleaning operation in the fifth cycle under the same operating conditions as in Example 2, except that no used activated carbon was added in each cycle, magnesia cleaning agent was added. Got the cake. This cake was baked under the three conditions of Example 3, and the decolorization rate of the baked product was measured. The results are shown in Table 4.

[Table] Example 4 The sugar solution cleaning and re-baking operations of the 5th cycle were repeated in the same manner as in Example 2, and 36 g of the re-baked product of the 5th cycle was obtained. The ingredients of the refired product are
MgO24.9%, activated carbon 27.2%, perlite 44.6%,
Others accounted for 3.3%. Take 30g of this re-fired product in a beaker, add a small amount of water to make a slurry, gradually add 100ml of dilute hydrochloric acid while stirring, continue stirring for 10 minutes, filter, and wash the residue on the filter paper with water. The filtration residue was collected. This was dried at 105° C. for 6 hours to obtain 21.9 g of a hydrochloric acid-treated dry product. This dried material is thought to be mostly activated carbon and pearlite. Therefore, a small amount of this dried material is heated in a Matsufuru furnace.
Quantitative analysis was performed on the weight loss after heating at 1000℃ for 1 hour as activated carbon and the remainder as pearlite.The dried product was 38.1% activated carbon and 61.9% pearlite.
It was %. Next, the same sugar washing solution as in Example 2 (Bx°65,
AI1640) was placed in a beaker, 200g each, washed with sugar, and the hydrochloric acid-treated dry product consisting of perlite and activated carbon obtained above was added to the activated carbon content of 0.1%, 0.2%,
Add each at a ratio of 0.4% and heat at 80℃.
After continuing stirring for 30 minutes, suction filtration was performed using No. 2 filter paper, and the decolorization rate was calculated from the color value (AI) of the filtrate. The results are shown in Table 5. Comparative Example 3 200g of the same sugar washing solution as in Example 2 was taken into beakers, and the dry matter was 0.1%, 0.2%,
Powdered activated carbon equivalent to 0.4% (manufactured by Futamura Chemical, SW-
50) and perlite of the same weight as each activated carbon, continued stirring at 80℃ for 30 minutes, filtered with suction using No. 2 filter paper, and calculated the decolorization rate from the color value (AI) of the filtrate. Calculated. The results are shown in Table 5.

[Table] * Example of regeneration rate for new activated carbon for decolorizing activated carbon in reburned products 5 Magnesia cleaning containing powdered activated carbon was applied to 300 g of an aqueous solution (Bx゜65) of washed sugar obtained by washing raw sugar from Australia. Add 5.85 g (3.0% based on the solid content of the sugar washing solution) of the baked product (MgO28.2%, activated carbon 24.8%, perlite and others 47.0%) baked at 550°C for 30 minutes, and stir while maintaining the temperature at 80°C. I did this. After 30 minutes, use a Nicholson type filter (diameter 45 mm).
Transfer the entire amount to a filter cloth (height: 250 mm, equipped with heating device, made of polypropylene fiber), and maintain the pressure at 2 kg/cm ² .
Filtration was performed in the first cycle, and the amount of filtrate was measured for 30 minutes after the start of filtration. After filtration, remove the filter cloth from the filter and add a certain amount (approximately 30ml) of warm water (80℃).
The filter was washed with water, reattached to the filter, and subjected to a second cycle of filtration using the same operations as the first cycle. Thereafter, the same operation was repeated, and the filtrate amount (until 30 minutes after the start of filtration) was measured every 10th cycle. The results are shown in Table 6 and Figure 1. Comparative Example 4 To 300 g of the same washing sugar solution as in Example 5, 5.85 g of baked magnesia detergent cake (not containing activated carbon) (calcined at 550°C for 30 minutes, Mg0 36.6%, pearlite and others 63.4%) 3.0 for sugar solution solid content
%) was added, and the filtrate amount was measured every 5th cycle in the same manner as in Example 5. The results are shown in Table 6 and Figure 1.

【table】 [Brief explanation of drawings]

FIG. 1 is a graph showing changes in filtrate amount for each number of treatment cycles.

Claims (1)

[Claims] 1. When cleaning the sugar solution in the refined sugar process with magnesia, after cleaning, a mixture consisting of magnesia that has adsorbed colored organic impurities, an inorganic filler, and activated carbon, and whose activated carbon content is at least 5% by weight, is heated with oxygen. In an atmosphere with a concentration of 7.5% or less
A method for purifying a sugar solution, which is characterized by baking at a temperature of 400 to 600°C and bringing the obtained baked product into contact with a sugar solution.