JP2005509056A - Bulk material oxidative treatment method - Google Patents

Abstract

The present invention relates to oxidative treatment of bulk materials in containers. The bulk material to be treated is placed in a container, in which water or an aqueous solution, the desired final product has a predetermined pH value, a predetermined solubility or a predetermined polarity or a predetermined solubility behavior and / or granules. Moisture is absorbed to be treated with an oxygen-ozone gas mixture until it has this distribution. The method of the present invention allows the bulk material to be oxidized very efficiently with a minimum amount of ozone in the oxygen-ozone gas mixture, such that 70-100% of the ozone portion enters the reaction. To.

Description

The present invention relates to a method for oxidative treatment of bulk material in a container and to a processing station connected to the container and processing oxygen in an oxygen-ozone gas mixture, the mixture flowing into the container being treated The gas mixture mixed with the bulk material and flowing out of the container, if it still contains ozone, is purified and reduced to oxygen in a device downstream from the container to remove solids.

Such a method is known from DE 19512448 C2. According to the known method, contaminated material, in particular soil material, is treated with ozone ions in a batch operation mixer, resulting in the destruction of contaminants present in the soil. Oxidizable contaminants are broken down into environmentally friendly components such as oxygen, water or carbon dioxide. Organic and inorganic pollutants that contaminate soil materials are destroyed by treatment with ozone ions whose oxidative capacity is greater than that of unionized ozone molecules. At the same time, the contaminated soil material in the mixer is vigorously shaken while ozone ions are introduced.

Furthermore, the German publication 432020 discloses a method for the oxidative destruction of substances deposited in soil. For this method, the soil is treated with oxygen containing ozone in a rotary reactor.
DE19512448C2 German Publication No. 4302020

The object of the present invention is to selectively alter the product properties of the bulk material by treatment with an oxygen-ozone gas mixture, so that the pH of the bulk material treated with the oxygen-ozone gas mixture has a specific value. It becomes like this.

According to the invention, this object is achieved by the following facts. That is, the bulk material to be processed in the container is absorbed before and / or during the treatment with the oxygen-ozone gas mixture so that the moisture content of the bulk material is equal to the total weight of the bulk material to be treated. Based on this, it is 40% or less.

In addition, the method of the invention has the characteristic advantage that the degree of reaction between the oxygen-ozone gas mixture and the bulk material to be treated can be selectively controlled by the addition of moisture. Not only is the oxidation of the bulk organic material and / or the cleavage of the chain and / or ring structure controlled by the addition of moisture, it is to be treated and provides a starting point for treatment with the oxygen-ozone gas mixture. The pH of the bulk material that forms is also specified. The moisture absorption of the bulk material causes the individual particles to swell or be coated with a liquid film, which favors the oxidation of the individual element groups, depending on the bulk material to be treated. Moisture introduced into the bulk material to be treated reacts with the oxygen-ozone gas mixture or selectively supports the reaction with the bulk material itself. There is a positive effect on the interfacial reaction and the individual particles of the bulk material become more receptive due to oxidation with the oxygen-ozone gas mixture. The reaction can be selectively performed.

Moisture is added to the bulk material to be processed, at least in batches, to the extent that it maintains flowable and flowable bulk material behavior. As a result of the bulk material to be treated being moved strongly in the mixer, the bulk material particles moistened or having a specific moisture content achieve the most likely contact with the oxygen-ozone gas mixture introduced into the mixer. And the desired reaction is carried out. The bulk material to be treated, such as starch, cocoa pieces, kaolin or mechanical wood pulp, is the degree required to react in the desired manner before and / or during treatment with the oxygen-ozone gas mixture In moistened. With the method of the present invention, changes in pH (e.g. from 5.5 to 3.0 in the case of starch) are very efficient, selective and very high, such as 1 to 60 minutes. Brought in a short time,
Hydrophilicity is increased, solubility behavior as a function of temperature is changed (eg, reduced), and viscosity changes are achieved, such as a decrease in viscosity at a constant solids content in the solution. The bulk material to be processed is moved in the mixer by different mixing elements. And at the same time, the mixing containers are often arranged horizontally, at an angle to the vertical plane, or vertically. The method of the present invention is suitable for batch, semi-continuous and continuous operations.

For other bulk materials, the sensitivity of the product of the bulk material to be treated to the oxygen-ozone gas mixture depends on the degree of moisture prior to and / or during treatment with the oxygen-ozone gas mixture. Strengthened or weakened. Alcohol groups are selectively converted to acid groups and the treated final product is made more polar, if desired, or the compounds that occur in natural materials are oxidized. As a result, bulk merchandise treated with the method of the present invention has a lower color tone and has a lower viscosity even in solutions at higher concentrations.
For example, microorganisms present in the bulk material can be inactivated depending on the moisture content before and / or during treatment with the oxygen-ozone gas mixture. The method of the present invention is distinguished by the fact that the extensive reaction of ozone is ensured by this large gas-solid exchange that is ensured in the container. Depending on the bulk material and the performance of this process, 70-100% of the ozone that passes through the bulk material to be treated reacts, resulting in a ratio of ozone in the waste gas (that the gas pollutes the atmosphere). It must be reduced to oxygen before being released without), but very little.

In a further development of the method of the invention, the bulk material to be treated is cooled or heated before and / or during the treatment with the oxygen-ozone gas mixture.

This has the advantage that the temperature of the bulk material to be processed can be selectively changed during the reaction. As a result, it becomes easier to carry out the process in the desired manner, the efficiency of the reaction is improved, and the selective steps of the reaction are expedient. In the case of an exothermic reaction, the reaction temperature of the bulk material to be treated is kept constant by cooling the bulk material during the treatment with the oxygen-ozone gas mixture.

In a further development of the method of the invention, the bulk material to be treated is wetted with water or an aqueous solution such as a solution of acetic acid or sodium hydroxide.

This has the advantage that significant steps of the reaction can be expedient or delayed during processing with the oxygen-ozone gas mixture. Different product characteristics, for example if the treatment of starch with oxygen-ozone gas mixture is started at pH 5.5 or pH 7, or if starch swelling is altered before treatment with oxygen-ozone gas mixture If
Achieved.

In conjunction with the method of the present invention, the natural material portion of the bulk material to be treated and / or the bulk material itself is oxidized and / or depolymerized. This has the advantage that the bulk material treated with the oxygen-ozone gas mixture has new product properties that do not characterize the untreated bulk material. For example, bulk materials processed by the method of the present invention can be used in application processes that require complete solubility at low temperatures, for example.

Furthermore, in one version of the method of the invention, the bulk material to be processed is mixed in a container with an oxygen-ozone gas mixture under a pressure of 1 bar or more. This has the advantage that a greater conversion of ozone in the bulk material to be processed is made.

Advantageously, the oxidation and / or depolymerization of the bulk material to be treated is controlled such that the proportion of ozone in the gas mixture flowing into or out of the container is determined continuously or at a specific time interval. And / or performed under regulated conditions. This has the advantage that the proportion of ozone in the gas mixture is utilized in the most likely way for reaction with the bulk material to be treated, and at the same time the material to be treated is the specific product desired. The processing time is determined so as to have characteristics.

Advantageously, the product characteristics specified for a bulk material treated with an oxygen-ozone gas mixture are controlled and / or regulated by determining the moisture content of the bulk material. This has the advantage that the treatment of the bulk material with the oxygen-ozone gas mixture is monitored and checked by determining simple process parameters.

Variations in the ozone concentration in the oxygen-ozone gas mixture and / or the residence time of the oxygen-ozone gas mixture in the container (the degree of variation) are further process parameters.

This has the advantage that the product sensitivity of the bulk material to be treated is generally taken into account, and the product sensitivity of the bulk material to ozone is specifically taken into account. Product quality is improved and the amount of ozone required for processing is optimized or minimized.

The advantage is particularly great if the container is operated when it is filled to the extent of 10-80%. This ensures that the positional change of the individual particles required for homogeneous and uniform moisture absorption, as well as contact with the oxygen-ozone gas mixture, is ensured as a result of the bulk material to be treated being moved strongly in the container. Because it is done. As long as the liquid and gas are strongly exchanged with the bulk material to be processed, the amount of liquid and gas used is minimized and the solid-gas reaction time is shortened.

Preferably, the oxidation and / or depolymerization of the bulk material to be processed is carried out in a batch mixer operated batchwise and / or continuously. This has the advantage that the bulk material to be processed is moved in these machines, in blast locks, also in a fluidly generated bed, or in a material field (ring) to be mixed. Have. Within these machines, the bulk material is homogeneously and uniformly absorbed on the one hand and treated with an oxygen-ozone gas mixture on the other hand.

It is particularly efficient if the oxygen-ozone gas mixture and the liquid consisting of water or an aqueous solution are introduced at the same time in the lower part of the container or in the bulk material to be treated with an offset time. This is because the liquid as well as the oxygen-ozone gas mixture has the advantage of providing strong contact with the bulk material to be treated. Local increases in concentration can be reliably avoided and larger agglomerates are also eliminated.

Conveniently, the final product after oxidation and / or depolymerization is dried in the container to the desired final moisture content. This has the advantage that no additional equipment is required to dry the bulk material treated with the oxygen-ozone gas mixture in order to be a specific end product with a specific residual moisture content. Similarly, the intended particle size distribution of the final product can be changed by changing the mixing elements movably mounted in the container and / or by additional mixing, cutting and / or agglomerating elements that rotate at high speed in the container. Because it is adjusted. This has the advantage that a wide range of product variations is achieved in cooperation with the method of the invention and the machinery suitably used therein.

Further advantages and possible applications of the invention emerge from the following description of the drawings, which shows one possible method as an example.

The highly diagrammed flow diagram for the method of the present invention shows the structure of an apparatus labeled 10 and intended for oxidative treatment of bulk material. The bulk material 11 to be processed is brought into the plow mixer 12 in the direction of the arrow 13 from above the product inlet connecting piece 14. A mixing shaft 15 on which a mixing element 16 (in this case, a plow-type blade) is mounted passes through the plow-type mixer 12. The mixing element 16 is mounted on the mixing shaft 15 in such a way that the bulk material 11 to be processed can move completely in the mixing space without any blind spots. The mixing element is rotated in the direction of the arrow 17 by the mixer shaft 15 and is therefore constantly immersed in the bulk material 11 to be processed and in the plow mixer 12.

The bulk material 11 to be processed in the plow mixer 12 is the liquid addition device 1
8 absorbs moisture. A nozzle lance that sprays the liquid to be introduced is often used as the liquid addition device 18. For the device under consideration, liquid is sprayed into the area of the product dispensing element 19. This element 19 is rotated at high speed and ensures that the supplied liquid is homogeneously and uniformly distributed without forming agglomerates in the bulk material to be processed. The product distribution element 19 is a mixer shaft 1
As with 5, it is driven by a motor and, if necessary, an interposed transmission.

The oxygen-ozone gas mixture 20 is introduced in the direction of arrow 21 past the feed pipe 22 into the bulk material 11 to be treated carrying moisture. The oxygen-ozone gas mixture is generated, for example, in an ozone generator 23 supplied from an oxygen cylinder. The ratio of ozone gas in the oxygen-ozone gas mixture is measured in the first gas concentration measuring device 24 so that the bulk material 11 to be processed is selectively processed in the plow mixer 12. Furthermore, the volume flow rate at which the oxygen-ozone gas mixture flows into the plow mixer 12 is determined. The bulk material 11 to be processed is processed in a plow mixer 12 until the desired product properties obtained by processing with an oxygen-ozone gas mixture are achieved. A pressure measuring device 25 is provided in the waste gas pipeline that is directly connected inside the plow mixer 12 so that the process pressure in the plow mixer 12 is determined and controlled. The plow mixer 12 is designed to be movable and in this case to mix strongly the bulk material 11 to be processed at an elevated or reduced pressure relative to atmospheric pressure. Furthermore, the plow mixer 12 is designed so that ozone does not escape into the environment as long as the bulk material 11 to be treated is treated with an oxygen-ozone gas mixture.

The flowing oxygen-ozone gas mixture is passed through a second waste gas pipeline 26 with a device (not shown) such as a cyclone or filter to separate the dust.
It is detected by the gas concentration measuring device 27. The ratio of ozone present in the waste gas is determined by the second gas concentration measuring device 27. The ozone determined in the second gas concentration measuring device 27 is reduced to oxygen in the reduction unit 28. The third gas concentration measuring device 29 is used to check again whether the gas flow is now ozone free. If the gas stream is now ozone free, it is released into the atmosphere in the direction of arrow 30. Several ozone monitoring sensors that can detect increasing ozone values around the plant are arranged around the plant 10. If the maximum specific concentration of ozone in the atmosphere around the plant is exceeded, the ozone generator 23 is switched off,
The trouble signal lights up.

The plow mixer 12 is filled with the bulk material 11 to be processed, leaving a free space 31 in the plow mixer. In it, the bulk material to be processed is moved or thrown up, so that a good movement of the particles in the mixing space of the plow mixer 12 is possible. Such movement ensures a good exchange of material between solid, liquid and gas.
During the entire treatment time with the oxygen-ozone gas mixture 20, the product temperature of the bulk material 11 to be treated is detected using a temperature sensor 32. Jacket heating or cooling 33 is provided in the plow mixer by the way the bulk material 11 is heated or cooled. When the desired oxidation or depolymerization of the bulk material 11 to be processed has been completed, the product is moved from the plow mixer 12 in the direction of the arrow 35 via the product discharge connecting piece 34. Prior to this, the treated bulk material 11 in the plow mixer 12 is dried to a predetermined residual moisture content.

The bulk material 11 to be processed is processed batchwise or continuously according to the method of the present invention. If the bulk material is processed continuously according to the method of the invention, it flows into a plow mixer equipped for this purpose at one end and flows out of the plow mixer at the other end. The bulk material that flows continuously from the plow mixer is
It has the desired product properties and is oxidized or depolymerized to the intended extent. The unit for feeding the product to the squeeze mixer and for discharging the product from the squeeze mixer allows the bulk material to be processed to be fed and discharged without escape of the oxygen-ozone gas mixture from the squeeze mixer. Designed to be.

The bulk material is oxidatively processed in the container due to the following facts. That is,
The bulk material to be treated is transferred into a container where it is treated with an oxygen-ozone gas mixture and the end product of interest has a specific pH or specific solubility or specific polarity or specific solubility It is conditioned with water or an aqueous solution to have a behavior and / or particle size distribution. The bulk material is oxidized very efficiently with the minimum amount of ozone in the oxygen-ozone gas mixture according to the method of the present invention, resulting in the reaction of 70-100% of the effective amount of ozone.

Figure 3 is a flow diagram for the method of the present invention.

Claims (15)

Oxidative treatment of bulk material in a container and a processing station connected to the container and processing oxygen in an oxygen-ozone gas mixture;
Here the gas mixture flows into the container and is mixed with the bulk material to be processed,
And the gas mixture flowing out of the container, if it still contains ozone, is purified to remove solids and reduced to oxygen in the device downstream from the container,
As a result of the bulk material to be treated in the container being absorbed before and / or during treatment with the oxygen-ozone gas mixture, the moisture content of the bulk material is based on the total weight of the bulk material to be treated. 40% or less,
A method for oxidative treatment of bulk materials. 2. A method according to claim 1, characterized in that the bulk material to be treated is cooled or heated before or during treatment with the oxygen-ozone gas mixture. 3. A process according to claim 1 or 2, characterized in that the bulk material to be treated is absorbed with water or an aqueous solution such as a solution of acetic acid or sodium hydroxide. 4. Part of the natural material in the bulk material to be treated and the bulk material itself to be treated are oxidized and / or depolymerised. Method. 5. The method according to claim 1, wherein the bulk material to be treated is mixed with an oxygen-ozone gas mixture in a container under a pressure of 1 bar or more. Oxidation and / or depolymerization of the bulk material to be treated is controlled and / or regulated, with the ratio of ozone in the gas mixture flowing into or out of the container determined continuously or at a predetermined time interval. 6. A method according to any one of the preceding claims. The product properties achieved in the bulk material by treatment with an oxygen-ozone gas mixture are controlled and / or regulated by determining the moisture content of the bulk material. The method described in one. 8. The concentration of ozone in the oxygen-ozone gas mixture flowing into the container and / or the residence time of the oxygen-ozone gas mixture in the container is varied. Method. 9. A method according to any one of the preceding claims, characterized in that the container is filled with a product in the range of 10 to 80%. 10. Process according to any one of the preceding claims, characterized in that the oxidation and / or depolymerization of the bulk material to be treated is carried out batchwise or in a continuous blade-type mixer. 11. An oxygen-ozone gas mixture and a liquid consisting of water or an aqueous solution are brought into the bulk material to be treated at the same time or at different times in the lower part of the container. The method according to one. 12. Process according to any one of claims 1 to 11, characterized in that the final product present after oxidation and / or depolymerization is dried in the container to the desired final moisture content. The desired particle size distribution of the final product is achieved by changing the mixing elements movably mounted in the container and / or by mixing, cutting and / or containing elements that rotate additionally at high speed in the container. 13. A method according to any one of claims 1 to 12, characterized in that A container for the oxidative treatment of bulk material, and
A processing station connected to a container for converting oxygen into an oxygen-ozone gas mixture;
The container is equipped as a mixer to mix the gas mixture flowing into the container with the bulk material to be treated;
The downstream side of the container is equipped with a device for reducing the ozone still contained in the gas mixture flowing out of the container to oxygen after the solids in the gas mixture have been removed,
A device for oxidative treatment of a bulk material having a configuration comprising:
The apparatus consists of means for absorbing the bulk material to be treated in the container before and / or during the treatment with the oxygen-ozone gas mixture, so that the moisture content of the bulk material is treated. Device for oxidative treatment of bulk material, characterized in that it is adjusted to a value of less than 40% based on the total weight of the bulk material to be obtained. 15. A device according to claim 14, characterized in that a means is provided by which the final product present after oxidation and / or depolymerization can be dried in the container to the desired final moisture content.

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