JP3096706U - Dioxin dechlorination treatment using pyroelectric effect of graphite silica - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To perform a dechlorination treatment of dioxins contained in flue gas from a waste incinerator by negative ions generated by the pyroelectric effect of graphite silica. The pyroelectric effect refers to the generation of a potential by applying thermal energy to certain ores. The discovery is old 1756
By Epinus in the year. The most widely used method for removing dioxins in flue gas is a bag filter method using activated carbon and slaked lime. However, although this method is an effective means for preventing the diffusion and contamination of dioxin, a large amount of waste containing dioxins is discharged, and the disposal thereof becomes a problem. The present invention fills a scrubber with graphite silica having a pyroelectric effect and heats it by preheating the flue gas to generate negative ions. Then, a dechlorination reaction is caused to detoxify. Since the pyroelectric effect disappears at 400 ° C. or more due to crystal denaturation, it is necessary to maintain the surface temperature of the ore at around 200 ° C. by spraying water to maintain an appropriate temperature.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a method for decomposing and treating dioxins contained in flue gas from a waste incinerator with a simple apparatus. 2. Description of the Related Art Currently, the most widespread method of removing dioxins in flue gas is a bag filter method using activated carbon and slaked lime. However, although this method is an effective means to prevent dioxin diffusion and contamination, a large amount of waste containing dioxins is discharged, its disposal becomes a problem, and the cost becomes large. [Problems to be Solved by the Invention] Provided is a method capable of decomposing dioxins discharged from a waste incinerator with a simple apparatus and at very low cost to meet the discharge standard. Means for Solving the Problems The present invention aims to decompose dioxins with negative ions generated by a pyroelectric effect by filling graphite silica in a scrubber, heating the graphite silica by heat of flue gas. Is what you do. DESCRIPTION OF THE PREFERRED EMBODIMENTS Graphite silica, which is an essential component of the present invention, has the composition shown in Table 1, and is produced at a fault crushed part in Pre-Tertiary black hard mudstone, and silicon oxide is produced. It is a black ore containing mainly carbon, usually containing several percent of iron, and is produced in the form of powder, flakes, and breccias with an extremely greasy feel. [Table 1] [0007] The structure of the dioxin decomposition apparatus using the present invention is as simple as packing graphite silica in a scrubber (smoke tower). Graphite silica heated by the heat of flue gas generates a large amount of negative ions due to the pyroelectric effect and accelerates the dechlorination reaction. The pyroelectric effect generates the most negative ions at about 200 ° C., and becomes ineffective at 400 ° C. or higher due to a change in the crystal structure of the ore. Therefore, it is necessary to adjust the surface temperature of graphite silica to about 200 ° C by spraying an appropriate amount of water. [0008] As shown in Table 2, the results of measurement of negative ions of graphite silica using the negative ion measuring device ION TESTER KST-900 manufactured by Kobe Denpa Co., Ltd. It has the same or better performance than tourmaline, which is known for this. [Table 2] The scrubber is filled with graphite silica which generates negative ions. Graphite silica heated by the heat of smoke generates negative ions due to the pyroelectric effect. It decomposes dioxins contained in flue gas by the dechlorination reaction of graphite silica with negative ions. Washing the smoke with water also removes soot, hydrogen chloride, nitrogen oxides and sulfur oxides in the flue gas. The generated sewage is treated at a wastewater treatment facility and recycled. [0011] As shown in Fig. 1, the inside of a scrubber is filled with graphite silica to react while filtering smoke exhaust. There is a watering nozzle above the packed bed, and the mechanism is such that the adsorbed soot is washed away while adjusting the temperature of the graphite silica. Therefore, the surface of the graphite silica is always kept clean, and the dechlorination reaction continues without interruption. [Practical Examples] As shown in Tables 3 and 4, the distribution of dioxin isomers greatly changes, and 8-chlorinated dioxins are converted into easily decomposed low chlorinated products. The octachloride is chemically, thermally and microbial stable, and its decomposition is considered very difficult. On the other hand, it has been confirmed that low-chlorinated dioxins are highly toxic, but their degradability is remarkably fast and can be rapidly decomposed by chemical and biological methods. Therefore, the dioxin wastewater discharged from the apparatus using the present invention can be treated by an apparatus using ozone or a catalyst. [Table 3] [Table 4] [Effects of the Invention] A method for removing dioxin with a very simple apparatus has been successfully developed for the above purposes. The construction cost and running cost can be much lower than the conventional one. Result of Toko filtrate 3.9ngTEQ / ^{m 3} of the dioxins in purifying the smoke was determined from the apparatus to which the present invention has been obtained, it is possible to clear the reference 5 ngTEQ / ^{m 3} of small incinerator.

[Brief description of the drawings] FIG. 1 is a schematic explanatory view of the present invention.

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[Procedural amendment] [Date of submission] May 6, 2003 (2003.5.6) [Procedure amendment 2] [Document name to be amended] Description [Item name to be amended] Claims for utility model registration [Amendment] [Method] Change [Contents of amendment] [Registration of utility model registration] [Claim 1] Graphite silica having a pyroelectric effect is filled in the inside of a scrubber (smoke-wash tower) and heated by residual heat of flue gas. A device that detoxifies chlorine atoms of dioxins by negative ions.

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Claims (1)

[Claim 1] A scrubber (smoke tower) is filled with graphite silica having a pyroelectric effect, heated by the residual heat of flue gas, and chlorine of dioxins is generated by negative ions generated. A method of detoxifying and removing atoms.