CN1197685A

CN1197685A - Noxious component removal process and noxious component removal agent therefor

Info

Publication number: CN1197685A
Application number: CN98107704A
Authority: CN
Inventors: 柏木佳行; 石垣治久; 吉冈信行
Original assignee: Meidensha Electric Manufacturing Co Ltd
Current assignee: Meidensha Corp; Meidensha Electric Manufacturing Co Ltd
Priority date: 1997-02-24
Filing date: 1998-02-23
Publication date: 1998-11-04
Anticipated expiration: 2018-02-23
Also published as: EP0860183A2; DE69809310T2; EP0860183A3; EP0860183B1; NO980758L; ES2186931T3; KR100341551B1; AU5632998A; MY121329A; ATE227598T1; CN1095687C; NO316905B1; DK0860183T3; DE69809310D1; AU714634B2; KR19980071609A; NO980758D0

Abstract

A process for removing chlorine and/or sulfur from a waste containing chlorine and/or sulfur which chlorine is a source of dioxin. The process comprises the following steps in the sequence set forth: (a) mixing the waste and a chlorine and sulfur removal agent to form a mixture, the chlorine and sulfur removal agent containing an alkali metal compound; and (b) heating the mixture to thermally decompose the waste to generate chlorine-containing substance and/or a sulfur-containing substance, in which the chlorine-containing substance and/or the sulfur-containing substance allow to contact and react with the chlorine and sulfur removal agent thereby to form harmless chloride and/or sulfite.

Description

Method for removing toxic component and toxic component remover

The present invention relates to an improved method for removing toxic components (such as chlorine and/or sulfur) from materials containing chlorine and/or sulfur (referred to as materials to be treated), such as municipal waste or garbage and industrial waste, and to an improvement of a toxic component remover used in the method, and further to a technique for reacting the toxic component remover with a gas (hydrogen chloride, chlorine gas and/or sulfur oxide gas) containing toxic components generated by heat-treating garbage and waste to generate a non-toxic gas or compound.

In recent years, the amount of waste such as municipal waste or garbage is increasing year by year, making its disposal problematic. Municipal waste includes waste and garbage of ordinary homes and offices, which are mainly composed of combustible waste. These combustible wastes include various chemicals (e.g., plastics) containing large amounts of polyvinyl chloride, and various materials (e.g., office paper) containing large amounts of chlorine components such as chlorine-containing bleaching agents.

Incineration has been commonly used in the past to dispose of these wastes. However, when waste or materials to be treated containing chlorine components are incinerated, chlorine-containing gases such as hydrogen chloride gas and chlorine gas are generated, thereby causing problems of environmental pollution and corrosion of incineration facilities by the chlorine-containing gases. In order to suppress the generation of chlorine-containing gases, incineration has been performed by adding a chlorine removing agent such as slaked lime, calcium carbonate or the like to waste to be incinerated or to a material to be treated, as disclosed in japanese patent publication No. JP 2-10341. Furthermore, it is also known to subject the exhaust gases, after subjecting the material to be treated in the incinerator to incineration treatment, to various purification treatments if necessary, for example introducing them into bag filters to react with slaked lime and thus prevent the emission of toxic gases containing chlorine into the atmosphere.

As described above, when waste or materials to be treated are incinerated, chlorine-containing substances such as chlorine and other chlorine compounds become a problem, in which chlorine-containing gases generated during incineration destroy the incinerator body and corrode the vapor tubes, and further cause a problem of generation of very toxic dioxins. Therefore, chlorine-containing gases are typically reacted with slaked lime or the like in a bag filter to prevent its discharge to the atmosphere. It is expected that these measures will have some effect on the treatment of combustion gases to prevent the emission of chlorine-containing gases into the atmosphere. However, it is difficult to completely remove the chlorine-containing substances by these measures because the chlorine-containing substances remain in the residue formed after incineration of the material to be treated. This is partly responsible for the formation of dioxins. Even if a measure is taken to add slaked lime or calcium carbonate in incineration, the generation of chlorine-containing gases cannot be effectively prevented.

Further, it has been proposed to inject an alkali raw material into an incinerator for incinerating a material to be treated, as disclosed in Japanese patent provisional publication No. JP54-93864, for example. In this proposal, however, the chlorine-containing gases which have been generated and filled in the incinerator are treated, similarly to the above-described measures, and therefore complete removal of the chlorine-containing gases is not possible.

Further, it has also been proposed that incineration of the material to be treated be carried out by adding thereto a calcium-containing alkali material such as lime (CaCO)₃) Slaked lime (Ca (OH)₂) Or the like, or by making SO_xRemoval of SO by filtration through a filter filled with alkaline feedstock_xSuch as disclosed in japanese patent publication No. JP2-10341, japanese patent provisional publication No. JP1-296007, and japanese patent provisional publication No. JP 59-12733. The reactions in these proposals are as follows:

in the case of processing chlorine-containing gases (HCL):

in the treatment of sulfur oxide-containing gases (SO)₂) In the case of (2):

further, it has been proposed to subject the material to be treated to thermal decomposition or dry distillation instead of incineration, thereby reducing the volume of the material to be treated and carbonizing the material to be treated, as disclosed in japanese patent provisional publication No. JP5-33916, japanese patent (Kohyo) publication No. JP8-510789, and japanese patent provisional publication No. JP 9-155326. Further, Japanese patent provisional publication No. JP5-33916 discloses that an alkali raw material such as slaked lime is injected into a furnace; however, the desired beneficial effect of removing chlorine-containing gases cannot be obtained because the alkaline raw material is introduced into contact with chlorine-containing gases that have been generated and charged in the furnace.

In view of the above, there is an urgent need to accelerate the development of a technique for effectively removing chlorine-containing gases, which are known to be fatal to the human body, or sufficiently preventing the generation of chlorine-containing gases, which are a part of the cause of the formation of dioxins, from the material to be treated by heat treatment.

Based on the results of various experiments and investigations for removing toxic chlorine-containing substances or gases such as hydrogen chloride and chlorine gas, which are exhaust gases generated by the heat treatment of waste or materials to be treated containing a large amount of chlorine components or compounds, the inventors of the present invention have found that the toxic chlorine-containing substances or gases can be efficiently reacted with alkali metal compounds, preferably alkali metal carbonates, alkali metal bicarbonates and alkali metal hydroxides, to thereby efficiently convert the toxic chlorine-containing gases into non-toxic chlorides. In addition, the alkali metal component has also proven effective in converting toxic sulfur-containing gases to non-toxic sulfites.

In light of the above knowledge, the present invention focuses on providing an improved method for removing toxic components by using a specific toxic component removing agent containing an alkali metal compound, in which a gas containing toxic components generated in heating a material to be treated is rapidly reacted with the toxic gas removing agent to thereby form a non-toxic compound, and the gas containing toxic components is prevented from being discharged into the atmosphere.

It is an object of the present invention to provide an improved method for removing toxic components which overcomes the disadvantages of the conventional similar methods for removing toxic components, and an improved toxic component remover for use in the method.

It is a further object of the present invention to provide an improved method for removing toxic elements for use in a method for the thermal treatment of waste or material to be treated, typically such that gases containing toxic elements are no longer contained in the exhaust gases and residues formed during the thermal treatment of the material to be treated, thereby substantially completely preventing the generation of toxic substances (containing dioxins) in the thermal treatment process.

It is a further object of the present invention to provide an improved method for removing toxic components in which gases containing toxic components formed during the heat treatment of waste or materials to be treated can be completely removed during the heat treatment, thereby eliminating the possibility of generating toxic substances (containing dioxins) whose residues contain only non-toxic compounds and no substances containing toxic components.

It is a further object of the present invention to provide an improved toxic component removing agent which can effectively remove a substance or gas containing a toxic component and can be used in any step of a method for removing a toxic component by subjecting waste or a material to be treated to a heat treatment.

A first aspect of the invention is a method of removing toxic elements from a material to be treated containing the toxic elements, comprising the following steps in the order indicated: (a) mixing a material to be treated with a toxic component remover to form a mixture, the toxic component remover containing an alkali metal compound; and (b) heating the mixture to thermally decompose the material to be treated to produce a material containing the toxic component, and contacting and reacting the material containing the toxic component with the toxic component remover to produce the non-toxic compound.

A second aspect of the present invention is a method for removing at least one of chlorine and sulfur from a material to be treated containing at least one of chlorine and sulfur, comprising the steps of, in the order shown: (a) mixing the material to be treated with a chlorine and sulfur removal agent to form a mixture, the chlorine and sulfur removal agent comprising an alkali metal compound; and (b) heating the mixture to thermally decompose the material to be treated to produce at least one of a chlorine-containing species and a sulfur-containing species, and contacting and reacting the at least one of a chlorine-containing species and a sulfur-containing species with a chlorine and sulfur removal agent to produce at least one of a non-toxic chloride and a sulfite.

A third aspect of the invention is a method for removing chlorine from a chlorine-containing material to be treated, comprising the following steps in the order indicated: (a) mixing a material to be treated with a chlorine removal agent to form a mixture, the chlorine removal agent containing an alkali metal compound; and (b) heating the mixture to thermally decompose the material to be treated to produce a chlorine-containing material, and contacting and reacting the chlorine-containing material with a chlorine scavenger to produce a non-toxic chloride.

A fourth aspect of the present invention resides in a toxic component remover for use in a method of removing a toxic component from a material to be treated containing the toxic component, the chlorine remover containing an alkali metal compound, the toxic component remover being capable of contacting and reacting with a substance containing the toxic component generated from the material to be treated upon heating the material to be treated to generate a non-toxic compound.

A fifth aspect of the present invention is a chlorine and sulfur remover for use in a method of removing at least one of chlorine and sulfur from a material to be treated containing at least one of chlorine and sulfur, the chlorine and sulfur remover containing an alkali metal compound, the chlorine and sulfur remover being capable of contacting and reacting with at least one of a chlorine-containing substance and a sulfur-containing substance generated from the material to be treated by heating the material to be treated, thereby forming at least one of a chloride and a sulfite that is non-toxic.

A sixth aspect of the present invention resides in a chlorine scavenger for use in a method of removing chlorine from a material to be treated containing chlorine, the scavenger containing an alkali metal compound, the scavenger being capable of contacting and reacting with chlorine-containing substances generated from the material to be treated by heating the material to be treated, thereby forming non-toxic chlorides.

A seventh aspect of the present invention resides in a chlorine remover for use in a method of removing at least one of chlorine and sulfur from a material to be treated containing at least one of chlorine and sulfur, comprising the steps of, in the order shown: mixing the material to be treated with a chlorine and sulfur removal agent to form a mixture, the chlorine and sulfur removal agent comprising an alkali metal compound; heating the mixture to thermally decompose the material to be treated to produce at least one of a chlorine-containing species and a sulfur-containing species, and contacting and reacting the at least one of a chlorine-containing species and a sulfur-containing species with a chlorine and sulfur removal agent to produce at least one of a non-toxic chloride and a sulfite, wherein the chlorine removal agent comprises an alkali metal compound.

An eighth aspect of the present invention is directed to a system for removing at least one of chlorine and sulfur from a material to be treated containing at least one of chlorine and sulfur, comprising: means for mixing the material to be treated with a chlorine and sulfur removal agent to form a mixture, the chlorine and sulfur removal agent comprising an alkali metal compound; feeding a mixture furnace of a material to be treated and chlorine and sulfur removing agents, the furnace being adapted to form a low oxygen concentration atmosphere therein; heating means for heating the mixture in a furnace and in a low oxygen concentration atmosphere to thermally decompose the material to be treated to effect destructive distillation of the material to be treated, which causes the mixture to produce at least one of chlorine-containing species and sulfur-containing species, and causes the at least one of chlorine-containing species and sulfur-containing species to contact and react with the chlorine and sulfur removing agent to produce at least one of non-toxic chloride and sulfite.

According to the method for removing toxic components such as chlorine and/or sulfur of the present invention, gas containing toxic components is not generated in the entire course of the heat treatment method of the material to be treated and in the entire temperature range of the heat treatment method, which has not been achieved by the conventional toxic component removal method using slaked lime or calcium carbonate as a chlorine scavenger. Furthermore, the residue formed by the heat treatment of the material to be treated is free of substances of toxic composition, which contain non-toxic compounds(such as chlorides and/or sulfites). Thus, the toxic component removing method of the present invention exhibits excellent toxic component removing effect, particularly for materials to be treated containing a large amount of substances or compounds containing toxic components, such as municipal waste or garbage.

In the toxic component removing method of the present invention, the toxic component removing agent of the present invention is mixed with a material to be treated so as to be rapidly reacted with a gas containing a toxic component generated by heating the material to be treated, thereby forming a compound having no toxic gas and toxic component. It is to be noted that the toxic component remover may be used in any step other than the heating step, regardless of whether the toxic component remover is used in the heating step during the heat treatment of the material to be processed. In other words, the toxic component remover can be used even after the heating step and in a flue, various kinds of facilities for treating exhaust gas, and other various conventional facilities such as an incinerator or the like. It should be understood that the toxic component (chlorine) removing agent of the present invention can be used in any step of the conventional toxic component (chlorine) removing method and the conventional method of incinerating waste.

Since it is generally possible to completely remove gas containing toxic components in a furnace for heat-treating a material to be treated, corrosion of the furnace body (including an incinerator), steam pipes and the like for heat-treating the furnace can be effectively prevented, thereby extending the service life of the furnace and equipment. Furthermore, it is noteworthy that the residues formed by heating the material to be treated no longer contain dioxins which are highly toxic to the human body, thus greatly increasing the safety from the point of view of the ambient and handling processes.

Further, according to the toxic component removing method of the present invention, the exhaust gas of the furnace is non-toxic and flammable, so that the exhaust gas can be reused as a fuel for gas engines, turbines, boilers, heat sources for water heating devices, and heaters. In addition, the aggregated carbon component in the residue can be used as a fuel, and the inorganic material in the residue can be reused as a raw material for glass or ceramics. It is considered that the toxic component removing method of the present invention is not affected even if the waste or the material to be treated contains water. Toxic chlorine-containing gases are not present in the furnace off-gas, so that the off-gas can be further heated for post-combustion as off-gas if desired.

FIG. 1 is a block diagram of a chlorine and sulfur removal system for implementing a fifth embodiment of the toxic component removal method of the present invention.

According to the invention, a process for removing toxic elements (such as chlorine and/or sulphur) from materials to be treated (such as urban or refuse or industrial waste) containing said elements comprises the following steps in the order indicated: (a) mixing a material to be treated with a toxic component remover (chlorine and/or sulfur) containing an alkali metal compound to form a mixture; and (b) heating the mixture to thermally decompose the material to be treated to produce a material containing toxic components (chlorine and/or sulfur), and contacting and reacting the material containing toxic components with a toxic component remover to produce a non-toxic compound.

Examples of the toxic component (chlorine and/or sulfur) removing agent used in the above-described toxic component removing method are:

(1) alkali metal bicarbonates, alkali metal carbonates and the like, e.g. sodium bicarbonate (NaHCO)₃) Sodium carbonate (Na)₂CO₃) Sodium sesquicarbonate(Na₂CO₃·NaHCO₃·2H₂O) and soda ash (containing Na)₂CO₃·NaHCO₃·2H₂O)；

(2) Alkali metal hydroxides such as sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), rubidium hydroxide (RbOH), and cesium hydroxide (CsOH); and

(3) alkali metal carbonates and bicarbonates, e.g. potassium carbonate (K)₂CO₃) Potassium bicarbonate (KHCO)₃) And sodium potassium carbonate (KNaCO)₃·6H₂O)。

It is to be understood that the above-listed compounds are used alone or in combination as a toxic component remover. In other words, the toxic component remover contains at least one of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide (RbOH) and cesium hydroxide (CsOH), potassium carbonate, potassium bicarbonate, potassium sodium carbonate, and the like.

The toxic component removing agent is used in the form of a mass, a tablet, a porous body, a particle (including powder, amorphous particles or a mixture thereof), a solution (aqueous solution or other solution) or a suspension. These forms may be used alone or in combination.

The toxic component remover is used in an amount generally in the range of 0.05 to 10% by weight based on the material to be treated at the initial time before mixing the material to be treated with the toxic component remover. However, if the material to be treated includes a substance or compound containing a large amount of chlorine component, such as polyvinyl chloride, polyvinylidene chloride, other chlorine-containing synthetic resin and/or chlorine-containing rubber, the toxic component remover is used in an amount within the range of 10 to 17% by weight based on the material to be treated at the initial time. The amount of the toxic component remover to be selected is larger than the stoichiometric amount of chlorine-containing substances or gases (chlorine-containing substances or gases) generated by heating the material to be treated, regardless of the weight of the material to be treated. In addition, the amount of the toxic component remover to be selected is such that the emission value of the chlorine-containing gas is lower than the allowable emission standard. If the material to be treated also contains substances or compounds containing a large amount of sulfur components, the toxic components are selected in amounts similar to those described above.

The toxic component remover is mixed with the material to be treated and heated in a low oxygen concentration atmosphere at a thermal decomposition temperature range of 200-1000 ℃. In other words, the process of mixing the toxic component remover with the material to be treated is performed before heating to thermally decompose the material to be treated, that is, before the temperature of the material to be treated rises to a level where thermal decomposition of the material to be treated occurs. The chlorine compounds, sulfur compounds and chlorine and/or sulfur-containing substances are thermally decomposed at the thermal decomposition temperature. The low oxygen concentration atmosphere means an atmosphere having a very low oxygen concentration and can be accomplished by shutting down the inlet and outlet of a heat treatment furnace or tank such as a heating furnace immediately after a mixture of the material to be treated and the toxic component removing agent is fed into the furnace. It should be understood that the low oxygen concentration atmosphere corresponds to a case where air in the atmosphere is left in the furnace with both the inlet and the outlet closed. In other words, a low oxygen concentration atmosphere corresponds to a situation where the mixture is placed inside a substantially sealed furnace, thereby preventing fresh air from entering the furnace, and the pressure inside the furnace leaks out of the furnace. Therefore, the low oxygen concentration atmosphere does not require the entire furnace to be closed or sealed, and also includes a case where the periphery of the furnace inlet is directly closed with the material to be treated, and a case where the gas pressure in the furnace rises due to heating, so that the air supplied outside the furnace is hardly available. The low oxygen concentration atmosphere may be a thermal decomposition atmosphere in which the material to be treated is thermally decomposed to produce a gas called thermal decomposition of the material to be treated. Thus, the low oxygen concentration atmosphere achieves dry distillation of the material to be treated.

It should be understood that the toxic component remover is substantially mixed with the material to be treated when it is thrown or sprayed onto the material to be treated in the furnace. Alternatively, the toxic component remover may be thrown or sprayed into the mixture of the material to be treated and the toxic component remover in the furnace.

Since the above heating is performed under a low oxygen concentration atmosphere, substantially no gaseous component of the chlorine-containing compound (chlorine-containing compound) and/or the sulfur-containing compound (sulfur-containing compound) is present in the furnace off-gas, and therefore, the post-treatment (such as heat treatment or post-combustion) of the off-gas can be performed as needed. This is why the exhaust gas can be discharged into the atmosphere.

Although it has been described that the toxic component remover is mixed with the material to be treated before heating or thermally decomposing the material to be treated,it should be understood that the toxic component remover is effective for removing chlorine even after heating or thermally decomposing the material to be treated by contacting with the retort gas or exhaust gas discharged from the furnace (gas generated by retort of the material to be treated). It should also be clear that the toxic component-removing agent can be fed or sprayed onto the material to be treated which is undergoing thermal decomposition. Further, it is understood that the toxic component removing agent of the present invention is used in contact with chlorine-containing substances and/or sulfur-containing substances, and they may be added in any step of the toxic component removing method, except the steps specified in the present invention, in order to remove chlorine from toxic gases or chlorine-containing materials.

Here, a first embodiment of the toxic component or chlorine removal method according to the present invention will be discussed. In this embodiment, the toxic component or chlorine remover contains an alkali metal bicarbonate and/orAlkali metal carbonates, e.g. sodium bicarbonate (NaHCO)₃) Sodium carbonate (Na)₂CO₃) Sodium sesquicarbonate (Na)₂CO₃·NaHCO₃·2H₂O), natural soda (containing Na)₂CO₃·NaHCO₃·2H₂O) is used.

In this embodiment, sodium bicarbonate (NaHCO) is used₃) As the chlorine removing agent, sodium bicarbonate is mixed with the material to be treated and heated to react with hydrogen chloride (HCl), which is a main chlorine-containing compound contained in the gas generated by heating the material to be treated, as follows.

According to this reaction, if Na and CO components are present in the reaction system, chlorine reacts with Na to form NaCl, which is a partial residue formed by heating the material to be treated, and in addition, water (H) is formed₂O) and gas (CO)₂). The result is that no chlorine-containing gases are generated and discharged from the furnace, and the exhaust gases and residues are considered to be non-toxic. It should be understood that chlorine-containing compounds or gases are a source of dioxins.

According to the invention, an alkali metal carbonate and/or an alkali metal bicarbonate is added as a chlorine removal agent and mixed with the material to be treated to form a mixture before the material to be treated containing chlorine-containing substances which generate chlorine-containing gases by heating is subjected to a heat treatment. By heating the mixture under a low oxygen concentration atmosphere, the chlorine-containing substance is thermally decomposed at a predetermined temperature to generate a toxic chlorine-containing gas. The chlorine-containing gas immediately reacts with the chlorine removal agent to produce non-toxic chloride.

In the following, experiments of the chlorine removal process carried out according to this embodiment will be discussed, in which the experimental results of the example (according to this embodiment) and the comparative example (not within the scope of the present invention) are compared.

Example 1

The dechlorination method of the present embodiment is carried out by using polyvinylidene chloride containing a large amount of chlorine component as a material to be treated. As shown in Table 1, in example 1-1, 20g of a chlorine scavenger (sodium hydrogencarbonate) was added to 4g of a material to be treated to form a mixture to be heated. In comparative example 1-1, a chlorine scavenger was not added to 4g of the material to be treated. In comparative examples 1-2, a chlorine scavenger (slaked orhydrated lime) outside the scope of the present invention was added in an amount of 20g to 4g of the material to be treated to form a mixture to be heated. In comparative examples 1 to 3, a chlorine scavenger (calcium carbonate) which is not within the scope of the present invention was added in an amount of 20g to 4g of the material to be treated to form a mixture to be heated. In all examples and comparative examples, the chlorine removal agent was in the form of a powder having an average particle size of 100. mu.m.

More specifically, in each experiment of example or comparative example, 4g of the material to be treated was placed in a pot or a furnace, and 20g of the chlorine removing agent was added to the pot and mixed with the material to be treated to form the above mixture, except for comparative example 1-1. Then, the pot is completely sealed to isolate the inside of the pot from the outside air or the atmosphere, thereby subjecting the mixture to dry distillation by heating. The sealed can is heated by heating coil in stages at 250 deg.C, 300 deg.C, 350 deg.C, 400 deg.C, 450 deg.C, 500 deg.C, 550 deg.C, and 600 deg.C. During this heating, the temperature of each of the eight temperature stages was maintained for 5 minutes, wherein the concentration of hydrogen chloride in the tank was measured at each temperature rise time (i.e., the time at which the temperature rose from just one temperature stage to just another temperature stage) and at each temperature hold time (i.e., the time at which the temperature remained at just each temperature stage). The temperature rise time is denoted as "rise time" while the temperature hold time is denoted as "hold time" in table 3. The tank is provided with a gas discharge pipe through which gas and pressure generated by heating in the tank are discharged to the outside of the tank. The measurement of the concentration of hydrogen chloride gas can be carried out in accordance with JIS (Japanese Industrial Standard) -K0804 using a sight glass tube, i.e., a sight glass tube is inserted into a gas discharge pipe to measure the concentration of hydrogen chloride gas. The results of the hydrogen chloride gas concentration measurement are shown in table 3. It is to be noted that the above experiment was repeated ten times to obtain ten actual measured values of the hydrogen gas concentration in each of the examples and comparative examples, wherein the measured value (shown in Table 3) of each example refers to the highest value among the measured values, and the measured value (shown in Table 3) of each comparative example refers to the lowest value among the measured values. Further, "ND" in table 3 indicates a case where no hydrogen chloride gas was observed among ten actual measurement values obtained by any ten hydrogen chloride gas concentration measurements. Further, the mode of post-treatment of the chlorine remover was examined and shown in table 3 as "post-treatment of chlorine remover".

Example 2

In this example, the material to be treated was prepared by mixing polyvinylidene chloride with simulated refuse, so that the material to be treated was similar to standard municipal refuse and so that the experiment was carried out under conditions as stringent as possible. As shown in Table 2, in example 1-2, 5g of sodium bicarbonate was added as a dechlorinating agent to the material to be treated, which was prepared by mixing 1g of polyvinylidene chloride with 20g of a simulated garbage to form a mixture to be heated. In examples 1-3, sodium bicarbonate as a dechlorinating agent was added to the material to be treated in an amount of 2.5g, which was prepared by mixing 0.5g of polyvinylidene chloride with 20g of a simulated garbage to form a mixture to be heated. In examples 1-4, sodium bicarbonate as a dechlorinating agent was added to the material to be treated in an amount of 0.5g, which was prepared by mixing 0.1g of polyvinylidene chloride with 20g ofa simulated garbage to form a mixture to be heated. In examples 1-5, sodium bicarbonate was added as a dechlorinating agent to the material to be treated in an amount of 5g, which was prepared by mixing 20cc of municipal water with 20g of simulated garbage to form a mixture to be heated.

The above simulated refuse similar to the standard municipal refuse was prepared by mixing and crushing the following ingredients:

20% by weight of a plastic comprising polyethylene, polypropylene, polystyrene and polyvinylidene chloride;

50% by weight of paper containing tissue paper, newsprint, wrapping paper, cardboard boxes and drink wrappers;

20% by weight of a cloth containing rags; and

10% by weight of the residue containing tea leaves.

In each embodiment, the predetermined amount of material to be treated is placed in a tank, and the predetermined amount of chlorine scavenger is added to the tank and mixed with the material to be treated to form the mixture. The can is then closed tightly to maintain an airtight seal, thereby isolating the interior of the can from the outside air or atmosphere. Thereafter, an experiment was performed in the same manner as in example 1, and the results (or measured values) obtained are shown in Table 3. The results (or measured values) of the hydrogen chloride gas concentration measurement are shown in table 3.

As mentioned above, it can be concluded that alkali metal-containing bicarbonates or carbonates used as dechlorinating agents convert toxic chlorine-containing gases into non-toxic chlorides in the reaction of alkali metals with chlorine to alkali metal chlorides. A preliminary experiment was conducted using polyvinylidene chloride containing a large amount of chlorine component as a material to be treated (comparative example 1-1). The result of the test was that a large amount of hydrogen chloride gas was indeed produced, as shown in table 3 in the column of comparative example 1-1.

Next, comparative experiments (comparative examples 1-2 and 1-3) were conducted in which slaked lime and calcium carbonate were used as conventional chlorine removing agents, respectively. As a result, the production of hydrogen chloride can be suppressed to some extent; however, it could be confirmed that the conventional chlorine removing agent is insufficient in the inhibiting effect and needs further improvement.

In view of the above, as a result of a large amount of investigation and consideration, the present inventors have paid attention to alkali metal-containing hydrogen carbonates and preferably sodium hydrogen carbonate as a chlorine removing agent, and have conducted experiments (examples 1-1 to 1-5). The results of the experiments are that hydrogen chloride formation can be completely suppressed generally in any temperature range, and that sodium bicarbonate is an excellent dechlorinating agent.

Thus, as shown above, if alkali metal-containing hydrogen carbonate and/or carbonate (which is reactive with chlorine) is added to the material to be treated to form a mixture for heat treatment, chlorine-containing gas generated from the material to be treated can be effectively removed to render it nontoxic.

From this point forward, the discussion will be based on the experimental results shown in Table 3 above.

First, if polyvinylidene chloride is used as a material to be treated containing a large amount of chlorine component and a chlorine scavenger is not used, as shown in comparative example 1-1, a large amount of hydrogen chloride gas is generated during heat treatment or heating and in a wide temperature range. The generation of hydrogen chloride gas can be suppressed to some extent, as compared with comparative example 1-1, and in comparative examples 1-2 and 1-3, slaked lime and calcium carbonate were added as chlorine removal agents to the material to be treated, respectively. However, such inhibition of hydrogen chloride gas has proven to be incomplete.

In contrast, in example 1-1, sodium bicarbonate was added as a chlorine scavenger to the material to be treated, and generation of hydrogen chloride gas was not observed over the entire temperature range during heating, which proved that sodium bicarbonate was a good chlorine scavenger. In addition, in examples 1-3, 1-4 and 1-5, sodium bicarbonate was added as a chlorine scavenger in various amounts to the material to be treated containing the simulated garbage and polyvinylidene chloride, and generation of hydrogen chloride gas was not observed over the entire temperature range during heating.

In the case of examples 1 to 5, sodium bicarbonate was added as a chlorine scavenger to the material to be treated containing the simulated garbage and water, and generation of hydrogen chloride gas was hardly observed in the entire temperature range, although generation of hydrogen chloride gas was observed in a very small amount at the temperature rise and holding time at 450 ℃ and the temperature rise time at 500 ℃. This proves that the effect of sodium hydrogencarbonate as a chlorine scavenger is hardly affected in the presence of water in the material to be treated, and that the effect is considerably more remarkable than in the case of comparative example 1-2 in which slaked lime was used as a chlorine scavenger.

Thus, it was confirmed that the addition of alkali metal-containing hydrogen carbonate and/or alkali metal carbonate (which means that it reacts with chlorine) to the material to be treated during the heat treatment or heating can effectively remove chlorine in the chlorine-containing gas generated from the material to be treated, thus rendering thechlorine-containing gas non-toxic.

It is noted that heating the material to be treated at an elevated temperature above 600 c in a similar experiment as described above may show similar results to the above experiment. The heating of the mixture of the material to be treated and the chlorine removing agent is preferably carried out at a temperature not higher than 1000 c, because if the temperature is raised to 1000 c or higher, the equipment for carrying out the chlorine removing method of the present invention is enlarged.

The reaction history between alkali metal (sodium) containing bicarbonate or carbonate and chlorine-containing gases will be discussed below to understand that both the effluent gas and the residue are non-toxic results.

(1) Case of using sodium bicarbonate as chlorine scavenger:

when adding sodium bicarbonate (NaHCO)₃) Adding sodium bicarbonate and chlorine into the material to be treated capable of generating hydrogen chloride (HCl)The hydrogenation reaction is as follows:

if water is present in the reaction of sodium bicarbonate with the material to be treated which produces hydrogen chloride, the reaction proceeds according to the following equation:

(2) case of using sodium carbonate as chlorine remover:

when mixing sodium carbonate (Na)₂CO₃) Added to the material to be treated which produces hydrogen chloride (HCl), the sodium carbonate reacts with the HCl as follows:

Na₂CO₃+2HCl→2NaCl+H₂O+CO₂

(3) case where sodium sesquicarbonate is used as dechlorinating agent:

by the chemical formula Na₂CO₃NaHCO₃2H₂O represents sodium sesquicarbonate and reacts with hydrogen chloride similarly to the case of (1) and (2), thereby converting toxic hydrogen chloride into non-toxic chloride (NaCl). Sodium sesquicarbonate occurs naturally and is referred to as "sodium sesquicarbonate".

In the above experiment, a residue remained in the reaction tank after the completion of the heating reaction. The residue was examined to determine that the residue no longer contained toxic chlorine-containing gaseous components but contained non-toxic chloride or sodium chloride. The residue was poured into water and stirred for 10 minutes, where sodium chloride dissolved in the water leaving carbide. The carbide was also detected to contain no chlorine-containing gas component.

Therefore, the chlorine-containing compound and chlorine component in the material to be treated can be converted into sodium chloride (NaCl) and water (H)₂O) and carbon dioxide gas (CO)₂) So that it is not possible to generate formableThe dioxins are partly derived from hydrogen chloride, with the result that the exhaust gases and residues are rendered non-toxic.

In this embodiment, an alkali metal carbonate-containing substance, such as sodium carbonate, can be obtainedSodium bicarbonate, sodium sesquicarbonate and soda (Na)₂CO₃NaHCO₃2H₂O) can be used as a dechlorinating agent. Sodium carbonate is capable of forming monohydrate and decahydrate compounds, known as soda. Sodium sesquicarbonate occurs naturally as sodium sesquicarbonate.

As will be appreciated, NaCl is formed during the heating process in carrying out the reaction according to the chemical reaction described above. NaCl is a non-toxic chloride and can be effectively removed by washing or dissolving with water or the like. After the rinsing process, the solid residue or carbide remains in the tank for reuse. Thus, the residue can be separated into different materials according to different characteristics by any separation means. The separated different materials are dried into blocks for use as fuel or the like. In addition, the liquid (e.g., water) used for the above-described rinsing treatment contains almost no toxic substances, and thus can be discharged into rivers and oceans.

More specifically, the residue in the tank contains non-toxic chloride or sodium chloride (NaCl). To extract the carbides, the residue is put into a water tank containing water and stirred for a predetermined time to dissolve sodium chloride. The solids in the tank are then removed from the tank and centrifuged to separate the water from the solids. The dewatered solid material is dried and hardened into a block. The water in the water tank and the separated water are discharged through separate discharging and treating means. The carbon component in the hardened mass can be used as a fuel, while the inorganic component in the hardened mass can be used as a raw material for glass and cement. Further, as described above, the residue may be separated into different materials according to different characteristics by any separation means, wherein the separated different materials are dried into pieces for use as fuel or the like.

Next, a second embodiment of the toxic component or chlorine removal method according to the present invention will be discussed. In this embodiment, the toxic component remover or chlorine remover contains at least one alkali metal hydroxide, for example, at least one of sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), rubidiumhydroxide (RbOH), and cesium hydroxide (CsOH).

As an example, a case where sodium hydroxide (NaOH) is used as a chlorine remover, in which sodium hydroxide is mixed with a material to be treated and heated to react with a chlorine-containing compound mainly contained in a gas generated from the material to be treated during heating, that is, hydrogen chloride (HCl), as follows:

according to this reaction, hydrogen chloride reacts with sodium hydroxide to form sodium chloride (NaCl) and water (H) which may form part of the residue₂O). The result is that no chlorine-containing gases are generated and vented from the furnace, making the vent gases and residues non-toxic. It is understood that chlorine-containing compounds or gases are a source of dioxin that is lethal to humans.

According to the present invention, when a material to be treated containing a chlorine-containing substance which will generate a chlorine-containing gas by heating is heat-treated, an alkali metal hydroxide is added as a chlorine scavenger and mixed with the material to be treated to generate a mixture. By heating this mixture under a low oxygen concentration atmosphere, the chlorine-containing substance is thermally decomposed at a predetermined temperature to generate a toxic chlorine-containing gas. The chlorine-containing gas reacts rapidly with the chlorine removal agent to produce non-toxic chloride.

Next, an experiment of the chlorine removal method performed according to this embodiment will be discussed, in which experimental results of examples (according to this embodiment) and comparative examples (not within the scope of the present invention) are compared.

The dechlorination method of this example was carried out by using polyvinylidene chloride containing a large amount of chlorine component as a material to be treated. As shown in Table 4, in example 2-1, 20g of a chlorine scavenger (powdery sodium hydroxide) was added to 4g of the material to be treated to form a mixture to be heated. In example 2-2, a chlorine scavenger (powdery potassium hydroxide) was added in an amount of 20g to 4g of a material to be treated to form a mixture to be heated. In comparative examples 2-1 and 2-2, no chlorine removing agent was added to 1g and 4g of the material to be treated, respectively. In comparative examples 2 to 3, a chlorine scavenger (slaked or hydrated lime) outside the scope of the present invention was added in an amount of 20g to 4g of the material to be treated to form a mixture to be heated. In comparative examples 2 to 4, a chlorine scavenger (calcium carbonate) out of the scope of the present invention was added in an amount of 20g to 4g of the material to be treated to form a mixture to be heated. In all examples and comparative examples, the chlorine removal agent was in the form of a powder having an average particle size of 100. mu.m.

In each of the experiments of examples or comparative examples, the material to be treated was placed in a tank or a furnace in the above-mentioned amount, and then 20g of a chlorine removing agent was added to the tank and mixed with the material to be treated to form the above-mentioned mixture, except for comparative examples 2-1 and 2-2. Then, the pot is completely sealed to isolate the inside of the pot from the outside air or the atmosphere, thereby subjecting the mixture to dry distillation by heating. The sealed can is heated by heating coil tube in stages at 250 deg.C, 300 deg.C, 350 deg.C, 400 deg.C, 450 deg.C, 500 deg.C, 550 deg.C, 600 deg.C and 1000 deg.C in eight temperature stages. During this heating, the temperature of each of the nine temperature stages was maintained for 5 minutes, wherein the concentration of hydrogen chloride in the tank was measured at each temperature rise time (i.e., the time during which the temperature rose from just one temperature stage to another) and at each temperature hold time (i.e., the time during which the temperature was held at each temperature stage). The temperature rise time is represented as "rise time" in table 4, while the time for which the temperature is maintained is represented as "hold time". The tank is provided with a gas discharge pipe through which gas and pressure generated by heating in the tank are discharged to the outside of the tank. The measurement of hydrogen chloride gas can be carried out in accordance with JIS (Japanese Industrial Standard) -K0804 using a sight glass tube, i.e., a concentration of hydrogen chloride gas is measured by inserting the sight glass tube into a gas discharge pipe. The results of the hydrogen chloride gas concentration measurement are shown in table 4. It is to be noted that the above experiment was repeated ten times to obtain ten actual measured values of the hydrogen chloride gas concentration in each of the examples and comparative examples, wherein the measured value (shown in Table 4) of each example refers to the highest value among the measured values, while the measured value (shown in Table 4) of each comparative example refers to the lowest value among the measured values. Further, "ND" in table 4 indicates a case where no hydrogen chloride gas was observed among ten actual measurement values obtained by any ten hydrogen chloride gas concentration measurements. Further, the mode of post-treatment of the chlorine remover was examined and shown in table 4 as "post-treatment of chlorine remover".

As described above, it can be concluded that the alkali metal hydroxide used as a chlorine scavenger can efficiently convert toxic chlorine-containing gases into non-toxic chlorides in the reaction of alkali metals with chlorine to produce alkali metal chlorides. Preliminary experiments were conducted using polyvinylidene chloride containing a large amount of chlorine component as a material to be treated (comparative examples 2-1 and 2-2). The result of the test was that a large amount of hydrogen chloride gas was indeed produced, as shown in the columns of comparative examples 2-1 and 2-2 in Table 4.

Next, comparative experiments (comparative examples 2-3 and 2-4) were conducted in which slaked lime and calcium carbonate were used as conventional chlorine removing agents, respectively. As a result, the production of hydrogen chloride can be suppressed to some extent; however, it could be confirmed that the conventional chlorine removing agent is insufficient in the inhibiting effect and needs further improvement.

In view of the above, as a result of a large number of investigations and considerations, the present inventors have paid attention to alkali metal hydroxide and potassium hydroxide of choice as a chlorine removal agent, and have conducted experiments (examples 2-1 and 2-2). The results of the experiments were that the generation of hydrogen chloride can be completely suppressed generally in any temperature range, and that potassium hydroxide is an excellent chlorine scavenger. As shown above, if an alkali metal hydroxide is added to a material to be treated to form a mixture for heat treatment, chlorine-containing gas generated from the material to be treated can effectively remove chlorine and become non-toxic.

Here, the discussion will be made based on the experimental results shown in table 4 above.

First, in the case of performing the heat treatment of polyvinylidene chloride (a material to be treated containing a large amount of chlorine component) without using a chlorine scavenger, as shown in comparative examples 2-1 and 2-2, a large amount of hydrogen chloride gas is generated during the heat treatment or heating and in a wide temperature range. Comparative examples 2-3 and 2-4 in which slaked lime and calcium carbonate were added as dechlorinating agents to the materials to be treated, respectively, inhibited the generation of hydrogen chloride gas to some extent, as compared with comparative examples 2-1 and 2-2. However, such inhibition of hydrogen chloride gas has proven to be incomplete.

In contrast, in examples 2-1 and 2-2, 20g of sodium hydroxide and 20g of potassium hydroxide were added as chlorine removal agents, respectively, to the same material to be treated, and very little hydrogen chloride was found to be produced during the temperature rise at 350 ℃ and 450 ℃ in example 2-1 and during the temperature maintenance at 450 ℃ in example 2-2; however, generation of hydrogen chloride gas was not observed over the entire temperature range of the heat treatment or heating process, thereby showing good experimental results compared with those of comparative examples 2-1 to 2-4. Therefore, it was confirmed that the addition of an alkali metal hydroxide (which means a compound capable of reacting with chlorine) to the material to be treated during the heat treatment or heating can effectively remove chlorine in the chlorine-containing gas generated from the material to be treated, thus rendering the chlorine-containing gas non-toxic.

It is noted that heating the material to be treated at a high temperature of more than 600 c, similar to the above experiment, can show results similar to the above experiment. The heating of the mixture of the material to be treated and the chlorine removing agent is preferably carried out in a temperature range of not higher than 1000 c, because if the temperature is raised to 1000 c or higher, the equipment for carrying out the chlorine removing method of the present invention is enlarged.

The reaction history between the alkali metal hydroxide and the chlorine-containing gas will be discussed below to understand that both the effluent gas and the residue are non-toxic and unexpected results.

(1) In the case of using sodium hydroxide (NaOH) as a chlorine remover:

when sodium hydroxide is added to a material to be treated that produces hydrogen chloride (HCl), the sodium hydroxide reacts with the HCl to produce non-toxic sodium chloride and water as follows:

(2) in the case of using potassium hydroxide (KOH) as a chlorine scavenger:

when potassium hydroxide is added to a material to be treated that produces hydrogen chloride (HCl), the potassium hydroxide reacts with the HCl to produce non-toxic potassium chloride and water as follows:

in the above experiment, a residue remained in the reaction tank after the completion of the heating reaction. The residue was examined to find that the residue no longer contained toxic chlorine gas components but contained non-toxic chloride (sodium chloride or potassium chloride). The residue was poured into water and stirred for 10 minutes, where sodium chloride or potassium chloride dissolved in water leaving carbides. The carbide was also detected to contain no chlorine-containing gas component.

Thus, chlorine-containing compounds and chlorine components in the material to be treated can be converted into sodium chloride or potassium chloride and water, so that hydrogen chloride which can form a partial source of dioxins cannot be generated, with the result that the exhaust gases and residues are rendered non-toxic. It is known that the same result can be obtained even if at least one alkali metal hydroxide such as lithium hydroxide (LiOH), rubidium hydroxide (RbOH) and cesium hydroxide (CsOH) is used as the chlorine removing agent.

Thus, it should be understood that in this embodiment, at least one alkali metal hydroxide, such as sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), rubidium hydroxide (RbOH), and/or cesium hydroxide (CsOH), may be used as the chlorine scavenger.

As described above, NaCl and KCl are generated during heating for carrying out the reaction according to the above-mentioned chemical reaction. NaCl and KCl are non-toxic chlorides and can be effectively removed by washing with water or similar dissolving treatment. After the rinsing process, the solid residue or carbide remains in the tank for reuse. Thus, the residue can be separated into different materials according to different characteristics by any separation means. The separated different materials are dried into blocks for use as fuel or the like. In addition, the liquid (e.g., water) used for the above-described rinsing treatment contains almost no toxic substances, and thus can be discharged into rivers and oceans.

More specifically, the residue in the tank contains non-toxic sodium chloride (NaCl) and potassium chloride (KCl). To extract the carbide, the residue was put into a water tank containing water and stirred for a predetermined time to dissolve sodium chloride and potassium chloride. The solid material in the tank is then removed from the tank and then centrifuged to separate the water from the solid material. Drying the dehydrated solid matter into blocks. The water in the water tank and the separated water are discharged through separate discharging and treating means. The carbon component in the hardened mass can be used as a fuel, while the inorganic component in the hardened mass can be used as a raw material for glass and cement. Further, as described above, the residue may be separated into different materials according to different characteristics by any separation means, wherein the separated different materials are dried into pieces for use as fuel or the like.

Next, a third embodiment of the toxic component or chlorine removal method according to the present invention will be discussed. This embodiment is particularly suitable for dechlorination processes of polyvinyl chloride, polyvinylidene chloride, chlorine-containing synthetic resins, chlorine-containing rubbers and/or the like. In this embodiment, the toxic component chlorine remover contains an alkali metal bicarbonate and/or an alkali metal carbonate, such as at least one of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate and natural soda. In addition, polyvinyl chloride, polyvinylidene chloride, was used as the material to be treated in this embodiment.

Mixing sodium bicarbonate (NaCO)₃) The case of using as a chlorine removing agent is, as an example, a case in which sodium hydrogen carbonate is mixed with a material to be treated and heated to react with a chlorine-containing compound, i.e., hydrogen chloride (HCl), which is predominant in a gas generated from the material to be treated when heated, as follows: . According to this reaction, if Na and CO components are present in the reaction system, chlorine reacts with Na to form NaCl, which is a partial residue formed by heating the material to be treated, and water (H) is formed₂O) and gas (CO)₂). The result is that no chlorine-containing gases are generated and vented from the furnace, making the vent gases and residues non-toxic. It is understood that chlorine-containing compounds or gases are a source of dioxin that is lethal to humans.

According to this embodiment, when a material to be treated containing chlorine species which can generate a chlorine-containing gas by heating is subjected to heat treatment, analkali metal carbonate and/or an alkali metal hydrogencarbonate is added as a chlorine scavenger and mixed with the material to be treated to generate a mixture. By heating this mixture under a low oxygen concentration atmosphere, the chlorine-containing substance is thermally decomposed at a predetermined temperature to generate a toxic chlorine-containing gas. The chlorine-containing gas reacts rapidly with the chlorine removal agent to produce non-toxic chloride.

The dechlorination method of the present embodiment is performed by using polyvinyl chloride and polyvinylidene chloride containing a large amount of chlorine components as materials to be treated. As shown in Table 5, in example 3-1, 20g of a chlorine scavenger (sodium hydrogencarbonate) was added to 4g of a material to be treated (polyvinyl chloride) to form a mixture to be heated. In example 3-2, a chlorine scavenger (sodium bicarbonate) was added in an amount of 20g to 4g of a material to be treated (polyvinylidene chloride) to form a mixture to be heated. In comparative example 3-1, no chlorine scavenger was added to 4g of the material to be treated (polyvinylidene chloride). In comparative example 3-2, a chlorine scavenger (calcium carbonate) which is not within the scope of the present invention was added in an amount of 20g to 4g of a material to be treated (polyvinylidene chloride) to form a mixture to be heated. In comparative examples 3 to 3, a chlorine scavenger (slaked lime) which is not within the scope of the present invention was added in an amount of 20g to 4g of the material to be treated to form a mixture to be heated. In all examples and comparative examples, the chlorine removalagent was in the form of a powder having an average particle size of 100. mu.m.

In each experiment of example or comparative example, 4g of the material to be treated was placed in a pot or a furnace, and 20g of the chlorine scavenger was added to the pot and mixed with the material to be treated to form the above mixture, except for comparative example 3-1. Then, the pot is completely sealed to isolate the inside of the pot from the outside air or the atmosphere, thereby subjecting the mixture to dry distillation by heating. The sealed can is heated by heating coil in stages at 250 deg.C, 300 deg.C, 350 deg.C, 400 deg.C, 450 deg.C, 500 deg.C, 550 deg.C, and 600 deg.C. During this heating, the temperature of each of the eight temperature stages was maintained for 5 minutes, wherein the concentration of hydrogen chloride in the tank was measured at each temperature rise time (i.e., the rise time of the temperature from just one temperature stage to just another temperature stage) and at each temperature hold time (i.e., the time at which the temperature was just held at each temperature stage). The temperature rise time is represented as "rise time" in table 5, while the time for which the temperature is maintained is represented as "hold time". The tank is provided with a gas discharge pipe through which gas and pressure generated by heating in the tank are discharged to the outside of the tank. The measurement of hydrogen chloride gas can be carried out in accordance with JIS (Japanese Industrial Standard) -K0804 using a sight glass tube, i.e., a concentration of hydrogen chloride gas is measured by inserting the sight glass tube into a gas discharge pipe. The results of the hydrogen chloride gas concentration measurement are shown in table 5. It is to be noted that the above experiment was repeated ten times to obtain ten actual measured values of the hydrogen chloride gas concentration in each of the examples and comparative examples, wherein the measured value (shown in Table5) of each example refers to the highest value among the measured values, while the measured value (shown in Table 5) of each comparative example refers to the lowest value among the measured values. Further, "ND" in table 5 indicates a case where no hydrogen chloride gas was observed among ten actual measurement values obtained by any ten measurements of the hydrogen chloride gas concentration. Further, the mode of post-treatment of the chlorine remover was examined and shown in table 5 as "post-treatment of chlorine remover".

As described above, it can be concluded that the alkali metal-containing bicarbonate or carbonate used as a chlorine scavenger can efficiently convert toxic chlorine-containing gases into non-toxic chlorides in the reaction of alkali metals with chlorine to form alkali metal chlorides. A preliminary experiment (comparative example 3-1) was conducted in which polyvinylidene chloride having a large chlorine content was used as a material to be treated. The result of the test was that a large amount of hydrogen chloride gas was indeed produced, as shown in the column of comparative example 3-1 in Table 5.

Next, comparative experiments (comparative examples 1-2 and 1-3) were conducted in which calcium carbonate and slaked lime were used as the conventional chlorine removing agents, respectively. As a result, the production of hydrogen chloride can be suppressed to some extent; however, it could be confirmed that the conventional chlorine removing agent is insufficient in the inhibiting effect and needs further improvement.

As a result of the experiment (example 3-1 and example 3-2), it was found that the generation of hydrogen chloride can be completely suppressed generally in any temperature range, and that sodium bicarbonate is an excellent chlorine scavenger.

Thus, as discussed above, it has been shown that if alkali metal-containing bicarbonate and/or carbonate is added to a material to be treated to form a mixture for heat treatment, chlorine-containing gases generated from the material to be treated can be effectively removed to render it non-toxic.

Here, the discussion will be made based on the experimental results shown in table 5 above.

First, if polyvinylidene chloride is used as a material to be treated containing a large amount of chlorine component and a chlorine scavenger is not used, as shown in comparative example 3-1, a large amount of hydrogen chloride gas is generated during heat treatment or heating and in a wide temperature range. In comparison with comparative example 3-1, comparative examples 3-2 and 3-3 in which calcium carbonate and slaked lime were added as dechlorinating agents to the material to be treated, respectively, suppressed the generation of hydrogen chloride gas to some extent. However, such inhibition of hydrogen chloride gas has proven to be incomplete.

In contrast, in example 3-2, sodium bicarbonate was added as a chlorine remover to the material to be treated, and generation of hydrogen chloride gas was not observed over the entire temperature range during heating, which proved that sodium bicarbonate was an excellent chlorine remover. In example 3-1, sodium bicarbonate was added as a chlorine scavenger to the other material to be treated (polyvinyl chloride), and the generation of hydrogen chloride gas was completely suppressed over the entire temperature range during heating.

Thus, it was confirmed that the addition of alkali metal (i.e., a hydrogen carbonate and/or a carbonate capable of reacting with chlorine) to a material to be treated containing polyvinyl chloride or the like during heat treatment or heating is effective for removing chlorine in a chlorine-containing gas generated from the material to be treated, thus rendering the chlorine-containing gas non-toxic. It is to be noted that the experiment of heating the material to be treated at a high temperature of more than 600 ℃ is similar to the above and can show results similar to the above experiment. The heating of the mixture of the material to be treated and the chlorine removing agent is preferably carried out at a temperature not higher than 1000 c, because if the temperature is raised to 1000 c or higher, the equipment for carrying out the chlorine removing method of the present invention is enlarged.

It will be appreciated that when sodium bicarbonate, sodium carbonate or sodium sesquicarbonate is reacted with hydrogen chloride produced from the material to be treated (polyvinyl chloride or polyvinylidene chloride) to produce non-toxic chloride, water and carbon dioxide, the reaction is the same as in the first embodiment.

In the above examples, after the heating reaction was completed, a residue remained in the reaction tank. The residue is detected to know that the residue does not contain toxic chlorine gas components, but contains non-toxic chloride or sodium chloride. The residue was poured into water and stirred for 10 minutes, where sodium chloride dissolved in the water leaving carbide. The carbide was also detected to contain no chlorine-containing gas component.

Therefore, the chlorine-containing compound and chlorine component in the material to be treated can be converted into sodium chloride (NaCl) and water (H)₂O) and carbon dioxide gas (CO)₂) So that hydrogen chloride, which may form part of the source of dioxins, cannot be generated, with the result that the exhaust gases and residues are rendered non-toxic.

In this embodiment, alkali metal carbonate-containing substances such as sodium carbonate, sodium bicarbonate, sodium sesquicarbonate and natural soda (Na) can be obtained₂CO₃NaHCO₃2H₂O) can be used as a dechlorinating agent. Sodium carbonate is capable of forming mono-and decahydrate compounds, such as is known as soda. Sodium sesquicarbonate occurs naturally as sodium sesquicarbonate. As described above, NaCl is generated during heating for performing the reaction according to the above-described chemical reaction. NaCl is a non-toxic chloride and can be effectively removed by washing or dissolving with water or the like. After the rinsing process, the solid residue or carbide remains in the tank for reuse. Thus, the residue can be separated into different materials according to different characteristics by any separation means. The separated different materials are dried into blocks for use as fuel or the like. In addition, the liquid (e.g., water) used for the above-described rinsing treatment contains almost no toxic substances, and thus can be discharged into rivers and oceans.

Next, a fourth embodiment of the toxic component or chlorine removal method according to the present invention will be discussed. In this embodiment, the toxic component or chlorine remover contains an alkali metal bicarbonate and/orAlkali metal carbonates, e.g. potassium bicarbonate (KHCO)₃) And potassium carbonate (K)₂CO₃) And for use in which polyvinyl chloride, polyvinylidene chloride, are mixedIn a dechlorination method using vinyl chloride, chlorine-containing synthetic resin, chlorine-containing rubber and/or the like as a material to be treated.

Mixing potassium bicarbonate (KHCO)₃) The case of using as a chlorine removing agent is, as an example, a case in which potassium hydrogencarbonate is mixed with a material to be treated and heated to react with a main chlorine-containing compound contained in a gas generated by heating the material to be treated, that is, hydrogen chloride (HCl), as follows:

。

according to this reaction, if Na and CO components are present in the reaction system, chlorine reacts with Na to form NaCl, which is a partial residue formed by heating the material to be treated, and water (H) is formed₂O) and gas (CO)₂). The result is that no chlorine-containing gases are generated and vented from the furnace, making the vent gases and residues non-toxic. It should be understood that chlorine-containing compounds or gases are a source of production of dioxins that are lethal to humans.

According to this embodiment, when a material to be treated containing a chlorine-containing substance which can generate a chlorine-containing gas by heating is subjected to heat treatment, an alkali metal carbonate and/or an alkali metal bicarbonate is added as a chlorine scavenger and mixed with the material to be treated to form a mixture. By heating this mixture under a low oxygen concentration atmosphere, the chlorine-containing substance is thermally decomposed at a predetermined temperature to generate a toxic chlorine-containing gas. The chlorine-containing gas reacts rapidly with the chlorine removal agent to produce non-toxic chloride.

The dechlorination method of the present embodiment is carried out by using polyvinylidene chloride or pseudo (normal) garbage containing a large amount of chlorine as a material to be treated. The simulated garbage was the same as that used in the experiment of the first embodiment. As shown in Table 6, in example 4-1, 10g of a chlorine scavenger (powdery potassium hydrogencarbonate) was added to 4g of a material to be treated (polyvinylidene chloride) to form a mixture to be heated. In example 4-2, a chlorine scavenger (powdered potassium bicarbonate) was added in an amount of 10g to 4g of the material to be treated (simulated garbage) to form a mixture to be heated. In comparative example 4-1, no chlorine scavenger was added to 4g of the material to be treated (polyvinylidene chloride). In comparative example 4-2, a chlorine removing agent (slaked lime) which is not within the scope of the present invention was added in an amount of 20g to 4g of the material to be treated to form a mixture to be heated. In comparative examples 4 to 3, a chlorine scavenger (calcium carbonate) which is not within the scope of the present invention was added in an amount of 20g to 4g of a material to be treated (polyvinylidene chloride) to form a mixture to be heated. In all examples and comparative examples, the chlorine removal agent was in the form of a powder having an average particle size of 100. mu.m.

Specifically, in each experiment of example or comparative example, a predetermined amount of the material to be treated was placed in a pot or a furnace, and then 20g of the chlorine removing agent was added to the pot and mixed with the material to be treated to form the above mixture, except for comparative example 4-1. Then, the pot is completely sealed to isolate the inside of the pot from the outside air or the atmosphere, thereby subjecting the mixture to dry distillation by heating. The sealed can is heated by heating coil in stages at 250 deg.C, 300 deg.C, 350 deg.C, 400 deg.C, 450 deg.C, 500 deg.C, 550 deg.C, and 600 deg.C. During this heating, the temperature of each of the eight temperature stages was maintained for 5 minutes, wherein the concentration of hydrogen chloride in the tank was measured at each temperature rise time (i.e., the time at which the temperature rose from just one temperature stage to just another temperature stage) and at each temperature hold time (i.e., the time at which the temperature remained at just each temperature stage). The temperature rise time is represented as "rise time" in table 6, while the time for which the temperature is maintained is represented as "hold time". The tank is provided with a gas discharge pipe through which gas and pressure generated by heating in the tank are discharged to the outside of the tank. The measurement of the concentration of hydrogen chloride gas can be carried out in accordance with JIS (Japanese Industrial Standard) -K0804 using a sight glass tube, i.e., a gas discharge tube into which the concentration of hydrogen chloride gas is inserted to measure. The results of the hydrogen chloride gas concentration measurement are shown in table 6. It is to be noted that the above experiment was repeated ten times to obtain ten actual measured values of the hydrogen chloride gas concentration in each of the examples and comparative examples, wherein the measured value (shown in Table 6) of each example refers to the highest value among the measured values, while the measured value (shown in Table 6) of each comparative example refers to the lowest value among the measured values. Further, "ND" in table 6 indicates a case where no hydrogen chloride gas was observed among ten actual measurement values obtained by any ten measurements of the hydrogen chloride gas concentration. Further, the mode of post-treatment of the chlorine removing agent was examined and shown in table 6 as "post-treatment of the chlorine removing agent".

As described above, it can be concluded that the alkali metal-containing bicarbonate or carbonate used as a chlorine scavenger can efficiently convert toxic chlorine-containing gases into non-toxic chlorides in the reaction of alkali metals with chlorine to form alkali metal chlorides. In which polyvinylidene chloride containing a large amount of chlorine component was used as a material to be treated to conduct a preliminary experiment (comparative example 4-1). The result of the test was that a large amount of hydrogen chloride gas was indeed produced, as shown in the column of comparative example 4-1 in Table 6.

Next, comparative experiments (comparative examples 4-2 and 4-3) were conducted in which slaked lime and calcium carbonate were used as conventional chlorine removing agents, respectively. As a result, the production of hydrogen chloride can be suppressed to some extent; however, it could be confirmed that the conventional chlorine removing agent is insufficient in the inhibiting effect and needs further improvement.

In view of the above, as a result of a large amount of investigation and consideration, attention has been paid to potassium hydrogencarbonate and potassium carbonate and preferably potassium hydrogencarbonate as chlorine scavengers, and experiments have been conducted (examples 4-1 and 4-2). The results of the experiments were that the generation of hydrogen chloride can be completely suppressed generally in any temperature range, and that sodium bicarbonate is an excellent dechlorinating agent. Thus, as indicated above, if potassium bicarbonate and/or potassium carbonate (which means reactive with chlorine) is added to the material to be treated to form a mixture for heat treatment, chlorine-containing gases generated from the material to be treated can be effectively removed from chlorine to become non-toxic.

Next, discussion will be made based on the experimental results shown in Table 6 above.

First, if polyvinylidene chloride is used as a material to be treated containing a large amount of chlorine component and a chlorine scavenger is not used, as shown in comparative example 4-1, a large amount of hydrogen chloride gas is generated during heat treatment or heating and in a wide temperature range. In comparative examples 4-2 and 4-3 in which slaked lime and calcium carbonate wereadded as dechlorinating agents to the material to be treated, respectively, the generation of hydrogen chloride gas was suppressed to some extent, as compared with that in comparative example 4-1. However, such inhibition of hydrogen chloride gas has proven to be incomplete.

In contrast, in example 4-1, potassium hydrogencarbonate was added as a chlorine scavenger to the material to be treated, and generation of hydrogen chloride gas was not observed over the entire temperature range during heating, which proved that potassium hydrogencarbonate was an excellent chlorine scavenger. Further, in example 4-2, potassium hydrogencarbonate was added as a chlorine scavenger to other materials to be treated (simulated garbage), and generation of hydrogen chloride in a very small amount was observed; however, the presence of hydrogen chloride gas was not detectable over the entire temperature range during heating.

It is noted that in the above experiment, potassium bicarbonate (KHCO) was produced at a temperature lower than that at which hydrogen chloride (HCl) could be produced from the material to be treated₃) Decomposition into separated CO₃So as to form an atmosphere in which the remaining KH is liable to react with the HCl formed, as follows:

thus, HCl and KH readily react with each other to form the non-toxic chloride (KCl).

In contrast, calcium carbonate (CaCO) is used₃) Or slaked lime (Ca (OH)₂) In the case of (2), it is assumed that a nontoxic chloride (CaCl) is generated similarly to the above; however, the reaction is less easy than in the case of the above-mentioned chlorine removing agent containing potassium.

Thus, it was confirmed that the addition of potassium hydrogencarbonate and/or potassium carbonate (which means those capable of reacting with chlorine) to the material to be treated during the heat treatment or heating can effectively remove chlorine in the chlorine-containing gas generated from the material to be treated, thus rendering the chlorine-containing gas non-toxic. It is noted that heating the material to be treated at a high temperature of more than 600 c, similar to the above experiment, can show results similar to the above experiment. The heating of the mixture of the material to be treated and the chlorine removing agent is preferably carried out in a temperature range of not higher than 1000 c, because if the temperature is raised to 1000 c or higher, the equipment for carrying out the chlorine removing method of the present invention is enlarged.

The reaction carried out in the chlorine removal method of the present embodiment will be discussed below. Using potassium bicarbonate (KHCO)₃) In the case of chlorine removal, potassium bicarbonate reacts with hydrogen chloride (HCl) as follows:

thus, the potassium bicarbonate reacts with the hydrogen chloride to produce non-toxic potassium chloride and carbon dioxide gas.

Using potassium carbonate (K)₂CO₃) In the case of a chlorine removal agent, potassium carbonate reacts with hydrogen chloride as follows:

thus, potassium carbonate reacts with hydrogen chloride to produce non-toxic potassium chloride, water and carbon dioxide gas.

In the above experiment, a residue remained in the reaction tank after the completion of the heating reaction. The residue is detected to know that the residue does not contain toxic chlorinegas components, but contains non-toxic chloride or sodium chloride. The residue was poured into water and stirred for 10 minutes, where sodium chloride dissolved in the water leaving carbide. The carbide was also detected to contain no chlorine-containing gas component. Therefore, the chlorine-containing compounds and chlorine components in the material to be treated can be converted into sodium chloride (KCl) and water (H)₂O) and carbon dioxide gas (CO)₂) So that hydrogen chloride, which may form part of the source of dioxins, cannot be generated, with the result that the exhaust gases and residues are rendered non-toxic. In this embodiment, it is possible to obtain alkali metal bicarbonates and/or carbonates, such as potassium bicarbonate and/or carbonic acidPotassium is used as a dechlorinating agent.

As described above, KCl is generated during heating for carrying out the reaction according to the above-mentioned chemical reaction. KCl is a nontoxic chloride and can be effectively removed by washing with water or the like or dissolving. After the rinsing process, the solid residue or carbide remains in the tank for reuse. Thus, the residue can be separated into different materials according to different characteristics by any separation means. The separated different materials are dried into blocks for use as fuel or the like. In addition, the liquid (e.g., water) used for the above-described rinsing treatment contains almost no toxic substances, and thus can be discharged into rivers and oceans. More specifically, the residue in the tank contains non-toxic potassium chloride (KCl). To extract the carbides, the residue is put into a water tank containing water and stirred for a predetermined time to dissolve potassium chloride. The result is that the solid matter in the basin is removed from the basin and then centrifuged to separate the water from the solid matter. The dewatered solid material is dried and hardened into a block. The water in the water tank and the separated water are discharged through separate discharging and treating means. The carbon component in the hardened mass can be used as a fuel, while the inorganic component in the hardened mass can be used as a raw material for glass and cement. Further, as described above, the residue may be separated into different materials according to different characteristics by any separation means, wherein the separated different materials are dried into pieces for use as fuel or the like.

Next, a fifth embodiment of the toxic component removing method of the present invention will be discussed. The toxic component removing method is a method of removing toxic components (such as chlorine and/or sulfur) from a material to be treated (such as municipal waste or garbage, or industrial waste) containing the toxic components (such as chlorine and/or sulfur). The material to be treated may contain polyvinyl chloride, polyvinylidene chloride, chlorine-containing synthetic resin, chlorine-containing rubber, so-called shredder dust (dust or garbage generated by a shredder), articles formed of polyvinyl chloride or polyvinylidene chloride, waste tires, and produced polystyrene.

The toxic component removal method of this embodiment comprises the following steps in the order shown: (a) mixing a material to be treated with a toxic component (chlorine and/or sulfur) removing agent containing an alkali metal compound to form a mixture; and (b) heating the mixture to thermally decompose the material to be treated to produce a material containing toxic components (chlorine and/or sulfur), and contacting and reacting the material containing toxic components with a toxic component remover to produce a non-toxic compound.

In this embodiment, the toxic component remover contains at least one of an alkali metal carbonate, an alkali metal bicarbonate and an alkali metal hydroxide, i.e., sodium bicarbonate (NaHCO)₃) Sodium carbonate, sodium carbonate(Na₂CO₃) Sodium sesquicarbonate (Na)₂CO₃·NaHCO₃·2H₂O), natural soda (containing Na)₂CO₃·NaHCO₃·2H₂O), sodium hydroxide (NaOH), potassium hydroxide (KOH), potassium carbonate (K)₂CO₃) Potassium bicarbonate (KHCO)₃) And sodium potassium carbonate (KNaCO)₃·6H₂O) is used.

In this embodiment, sodium bicarbonate, potassium bicarbonate, sodium carbonate, sodium hydroxide, or potassium hydroxide is mixed with the material to be treated containing a large amount of chlorine and sulfur. In this embodiment, prior to heat treating a material to be treated containing chlorine-containing species and sulfur-containing species (sulfur-containing species) which, when heated, will generate chlorine-containing gas and sulfur-containing gas (sulfur-containing gas), respectively, a chlorine scavenger is added and mixed with the material to be treated to form a mixture. By heating the mixture under a low oxygen concentration atmosphere, the chlorine-containing substance is thermally decomposed at a predetermined temperature to generate toxic chlorine-containing gas and sulfur-containing gas. The chlorine-containing gas and the sulfur-containing gas immediately react with the toxic component remover to generate non-toxic chloride (NaCl, KCl) and sulfite (Na)₂SO₃、K₂SO₃)。

This embodiment is discussed below with reference to FIG. 1, which analyzes the chlorine and sulfur removal system in which the method of this embodiment is performed.

The chlorine and sulfur removal system includes a mixing device or apparatus 1 for mixing a material to be treated (e.g., powdered waste or garbage) and a toxic constituent remover (e.g., sodium bicarbonate) to form a mixture. The heat treatment furnace 2 is rotatable in a cylindrical shape. The mixture formed by the mixing device 1 is fed into a furnace 2. The mixture may be formed by other means or devices than mixing device 1. The heat treatment furnace 2 is equipped with a rotary transfer device or apparatus (not shown) for conveying the mixture under stirring. In the melting furnace 2, a mixture of the material to be treated and the toxic component removing agent is heated in a low oxygen concentration atmosphere, thereby performing thermal decomposition of the material to be treated. The furnace 2 is also provided with heating coils for heating the contents of the furnace 2.

A residue treatment device or apparatus 4 is provided to treat the residue (ash) generated by heating the material to be treated in the furnace 2. The residue is discharged from the melting furnace 2 and subjected to solid-liquid separation. In the solid-liquid separation process, the residue is washed with a liquid such as water to separate and remove the produced chloride and/or sulfite, and then discharged at the liquid discharge section 4 a. The remaining solids such as metals and carbides are discharged from the solids discharge section 4 b. The exhaust gas of the heat treatment furnace 2 is introduced into an exhaust gas treatment device or facility 5. The exhaust gas is considered to be harmless because the toxic components in the material to be treated have been removed by the toxic component remover. The introduced exhaust gas is subjected to necessary treatment in the exhaust gas treatment device 5. The treated gas from the gas treatment apparatus 5 is then introduced into a gas recovery device or apparatus 6 for recovering the gas or into a secondary combustion device or apparatus 7 for secondary combustion of the gas and discharged.

In the method for removing toxic components using the above toxic component removing system, a material to be treated containing a toxic component and a toxic component removing agent (such as sodium hydrogencarbonate) is charged into a mixing apparatus 1 and sufficiently mixed, and then fed into a heat treatment furnace 2. The material to be treated may be pulverized before being thrown into the container, or may be pulverized while mixing the material to be treated and the toxic component removing agent. The toxic component remover is used in an amount ranging from 5 to 30% by weight relative to the material to be treated. The heat treatment or heating of the mixture in the heat treatment furnace 2 is carried out at a temperature and for a time range for generating HCl gas and SO from the material to be treated_xThe temperature and time range of the gas is the norm, and the temperature (e.g. 600 ℃) and time (e.g. 1 hour) have been predetermined in the prior survey. These temperatures and times are related to the conditions of the heat treatment furnace (e.g., type and heating coil), the throughput of the material to be treated, the heat treatment time of the material to be treated, and the heat treatment temperature of the material to be treated. Therefore, it is necessary to fully examineThe temperature and time are preset, and the data of the temperature and time are read and accumulated.

The heat treatment of the present process is carried out under conditions of complete retorting (or thermal decomposition) of the material to be treated and therefore combustion or incineration of the material to be treated is not achieved under other heating conditions. Under the heat treatment condition, toxic HCl gas and SO_xThe gas can effectively react by contact, SO that the toxic HCl gas and SO_xThe gas is converted into non-toxic chloride and sulfite, respectively.

In order to maintain the heating condition, the total reaction atmosphere or environment in the heat treatment furnace may satisfy necessary conditions and be stable. For example,a stable low oxygen concentration atmosphere is formed within the heat treatment furnace. In other words, it is necessary to supply fresh air only around the material to be treated during the heating or heat treatment. If fresh air is fed around the material to be treated, it is possible to cause combustion of the material to be treated and to stabilize the reaction. In addition, it has been experimentally confirmed that the heating condition can be maintained even in such a manner that fresh air is filled in the whole of the powdery material to be treated while the material to be treated is not combusted, and the fresh air is fed into the heat-treating furnace.

During the heat treatment of the furnace, HCl-and SO-containing gas may be generated_xDecomposition gas of gas, in which HCl and SO_xThe components rapidly react with toxic component remover or sodium bicarbonate to produce nontoxic chloride (such as NaCl) and sodium sulfite (Na)₂SO₃) Thereby removing toxic HCl and SO in the decomposed gas_x. The residue formed by the thermal treatment of the material to be treated no longer contains toxic HCl and SO_x. Therefore, the decomposed gas and the residue can be simultaneously made harmless.

The treated material is discharged through the residue treatment apparatus 4 and washed with water or a solution, thereby separating chloride and sulfite in the residue to leave a solid residue. The solid residue contains valuable metals that can be effectively recycled.

Next, an experiment of the toxic component removal method according to this embodiment will be discussed,in which the experimental results of the examples (according to this embodiment) and comparative examples (not within the scope of the invention) are compared. This experiment shows that the toxic component remover of the present embodiment can effectively react with HCl gas and SO_xThe gases react to produce non-toxic exhaust gases and residues.

In this experiment, the toxic component removal method of the present embodiment can be performed by using a waste derived fuel (hereinafter referred to as "RDF") as a material to be treated. RDF is formed from scrap or slag and contains the following components:

edible leftovers including waste residues of meat, fish, bones, eggshells, vegetables, fruits and the like;

plastic waste containing polyethylene, polypropylene, polystyrene, polyvinylidene chloride and the like;

paper articles, including tissues, billboards, paper bags, cartons, wrapping paper for beverages, and the like;

combustible materials containing fibrous materials such as fibers, wood, rubber, leather, and the like.

As a result of the analysis, it was confirmed that RDF used in the experiment contained 60.173 wt% of carbon (C), 16.277 wt% of oxygen (O), 10.745 wt% of silicon (Si), 7.045 wt% of calcium (Ca), 3.314 wt% of aluminum (Al), 0.888 wt% of magnesium (Mg), 0.505 wt% of phosphorus (P), 0.466 wt% of chlorine (Cl), 0.331 wt% of sulfur (S), 0.155 wt% of potassium (K), and 0.101 wt% of sodium (Na).

The experiments related to the present invention (examples) used RDF (without being superheated or incinerated) as the material to be treated, while the experiments for comparison (comparative examples) used treated RDF (with being superheated or incinerated). For example, RDF made mainly of plastics generally contains 0.29 to 0.89% by weight of chlorine, and RDF made mainly of paper generally contains 0.2% by weight of chlorine. In addition, typically the treated RDF contains about 1.0 wt% of sulfur components.

As shown in Table 7 concerning the examples section, in example 5-1, 10g of a chlorine scavenger (sodium hydrogencarbonate) was added to 40g of a material to be treated (pulverized RDF) to form a mixture to be heated. In example 5-2, a chlorine scavenger (sodium bicarbonate) was added in an amount of 4g to 40g of a material to be treated (pulverized RDF) to form a mixture to be heated. In example 5-3, a chlorine scavenger (potassium bicarbonate) was added in an amount of 3g to 40g of a material to be treated (pulverized RDF) to form a mixture to be heated. In examples 5 to 4, chlorine scavengers (sodium carbonate and potassium carbonate) were added in an amount of 3g to 20g of the material to be treated (comminuted RDF) to form a mixture to be heated. In examples 5 to 5, a chlorine scavenger (sodium hydroxide) was added in an amount of 3g to 30g of a material to be treated (pulverized RDF) to form a mixture to be heated. In examples 5 to 6, a chlorine scavenger (potassium hydroxide) was added in an amount of 3g to 20g of a material to be treated (pulverized RDF) to form a mixture to be heated. In examples 5 to 7, a chlorine scavenger (sodium bicarbonate) was added in an amount of 10g to 40g of a material to be treated (RDF which was not pulverized and was in the form of a lump) to form a mixture to be heated. In all examples, the chlorine scavenger was in powder form and had an average particle size of 100. mu.m.

For the comparative example not using the toxic component remover, 40g of the treated RDF having been pulverized was used as the material to be treated in comparative example 5-1. The treated RDF having been pulverized was used as the material to be treated in comparative example 5-2 in an amount of 20 g. The treated RDF which had not been pulverized and was in the form of a lump was used in an amount of 20g as the material to be treated in comparative example 5-3.

The experiments for each example were performed as follows: a predetermined amount of the material to be treated is placed in a pot or a furnace, and then 20g of the toxic component remover is added to the pot to be mixed with the material to be treated, thereby forming the above-mentioned mixture. In each of the experiments of the comparative examples, a predetermined amount of the material to be treated was placed in a tank or a furnace. The tank is then completely sealed to isolate the tank from the outside air or atmosphere, thereby subjecting the mixture or only the material to be treated to dry distillation by heating. Using the sealed canThe heating coil is heated in sections, namely, the eight temperature sections are heated at 250 ℃, 300 ℃, 350 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃ and 600 ℃. During this heating, the temperature of each of the eight temperature stages was maintained for 5 minutes with each temperature rise time(i.e., the time during which the temperature rises from just one temperature stage to just another) and the time during which the temperature is maintained at each temperature (i.e., the time during which the temperature is maintained at just each temperature stage), the concentration of HCl gas and the SO in the tank are measured₂The concentration of (c). The temperature rise time is represented as "rise time" in tables 7 and 8, while the time for temperature retention is represented as "retention time". The tank is provided with a gas discharge pipe through which gas and pressure generated by heating in the tank are discharged to the outside of the tank. The measurement of the concentration of hydrogen chloride gas can be carried out in accordance with JIS (Japanese Industrial Standard) -K0804 using a sight glass tube, i.e., a gas discharge tube into which a sight glass tube is inserted to measure HCl gas and SO₂The concentration of the gas. HCl gas and SO₂The results of the gas concentration measurements are shown in tables 7 and 8. It is to be noted that the above experiment was repeated ten times to obtain ten actual measured values of the hydrogen chloride gas concentration in each of the examples and comparative examples, wherein the measured value (shown in Table 7) of each example refers to the highest value among the measured values, while the measured value (shown in Table 8) of each comparative example refers to the lowest value among the measured values. Further, "ND" in tables 7 and 8 represents HCl gas and SO at any ten times₂Of the ten actual measurements obtained by the gas concentration measurement, no hydrogen chloride gas was observed. Further, the mode of the post-treatment of the toxic component remover was examined and shown in tables 7 and 8 as "post-treatment of chlorine remover".

From this point on, the experimental results will be discussed with reference to tables 7 and 8.

For the case of hydrogen chloride gas (HCl):

(a) if the material to be treated is crushed, a small amount of HCl gas is detected in examples 5-4; however, HCl gas was not detected in other examples, so that the toxic component remover was very effective in suppressing the generation of HCl gas. This effect of suppressing the generation of HCl gas was considerably high as compared with comparative examples 5-1 and 5-2.

(b) In example 5-7 and in the temperature stage of 350 ℃ to 450 ℃, a small amount of HCl gas was detected, if the material to be treated was used in bulk without being crushed, as compared with the case where the material to be treated was crushed; however, the experimental results of examples 5 to 7 were quite good compared with the results of comparative example.

For sulfur oxide gas (SO)₂) The case (2) is as follows:

(a) if the material to be treated is comminuted, small amounts of SO are detected in examples 5-1 to 5-6 and in a temperature phase of from 400 ℃ to 450 ℃₂A gas; however,the overall experimental results were good, SO that the toxic component remover was effective in suppressing SO₂The generation of gas is very efficient. This inhibits SO as compared with comparative examples 5-1 and 5-2₂The effect of gas generation is quite good.

(b) In examples 5 to 7 and in the temperature stage of 350 ℃ to 450 ℃ a small amount of SO was detected in comparison with the case where the material to be treated was pulverized, if it was used in a lump without pulverizing the material to be treated₂A gas; however, the experimental results of examples 5 to 7 were quite good compared with those of comparative examples 5 to 3.

As a result of the above-mentioned experiments and studies, it was found that HCl and SO can be generally used_xIs completely converted into non-toxic compounds, which can be effectively mixed with HCl and SO by using_xThe toxic component remover of alkali metal compound which can produce non-toxic chloride and sulfite by reaction. Thus, if the toxic component remover is added to the material to be treated to form a mixture and subjected to heat treatment as described above, chlorine-containing gas and sulfur-containing gas generated from the material to be treated can be efficiently converted into non-toxic compounds.

It is noted that heating the material to be treated at a high temperature of more than 600 c, similar to the above experiment, can show results similar to the above experiment. The temperature at which the mixture of the material to be treated and the chlorine removing agent is heated is selected in accordance with the form in which the heat treatment is easily carried out, the time of the heat treatment, the amount of the material to be treated, and the like.

Next, the reaction history between the toxic component remover and the toxic gases (chlorine-containing gas and sulfur-containing gas) will be discussed, so as to understand that both the exhaust gas and the residue are non-toxic results.

(1) For the case of hydrogen chloride gas (HCl):

sodium bicarbonate (NaHCO) was identified according to the reaction equation discussed above₃) Sodium carbonate (Na)₂CO₃) Sodium sesquicarbonate (Na)₂CO₃·NaHCO₃·2H₂O), natural soda (containing Na)₂CO₃·NaHCO₃·2H₂O), sodium hydroxide (NaOH), potassium hydroxide (KOH), potassium carbonate (K)₂CO₃) Potassium bicarbonate (KHCO)₃) Can react with the toxic HCl to convert the HCl to the non-toxic chlorides (NaCl and KCl). It will be appreciated that sodium potassium carbonate and sodium carbonate hydrate can also react with toxic HCl in a similar manner to that described above.

In particular, in the case of using an alkali metal bicarbonate as a toxic component remover, the following tendency is mainly exhibited: first, CO is separated at a temperature lower than the temperature at which hydrogen chloride (HCl) is generated by decomposition of the material to be treated (not lower than 250 ℃ C.)₂NaOH or KOH is formed. It is assumed that an atmosphere is formed, i.e., so that the reaction between NaOH or KOH and HCl proceeds easily. The following reaction is carried out here:

in the case of sodium bicarbonate, the reaction is,

in the case of potassium bicarbonate, the reaction is carried out,

thus, NaOH or KOH readily reacts with HCl to form non-toxic chlorides (NaCl, KCl).

After the heat treatment, the residue was left in the reaction tank after the completion of the heating reaction. The residue was examined to determine that the residue no longer contained toxic chlorine-containing gas components, but contained non-toxic chlorides (sodium chloride or potassium chloride). The residue was put into water and stirred for 10 minutes, where the chloride dissolved in the water leaving the carbide. The carbide was also detected to contain no chlorine-containing gas component.

Therefore, the chlorine-containing compounds and chlorine components in the material to be treated can be converted into sodium chloride (NaCl), potassium chloride (KCl) and water (H)₂O) and carbon dioxide gas (CO)₂) So that hydrogen chloride, which may form part of the source of dioxins, cannot be generated, with the result that the exhaust gases and residues are rendered non-toxic.

(2) For sulfur oxide gas (SO)_x) The case (2) is as follows:

it was confirmed that the toxic component-removing agent was compatible with the toxic SO_xReacting thereby SO_xConverted to the following non-toxic sulfites:

in the case of using sodium bicarbonate as a toxic component remover,

in the case of using potassium bicarbonate as a toxic component remover,

in the case of using sodium hydroxide as the toxic component remover,

in the case of using potassium hydroxide as a toxic component remover,

in the case of using sodium potassium carbonate as a toxic component remover,

in particular, in the case of using an alkali metal bicarbonate as a toxic component remover, the following tendency is mainly exhibited: first, Sulfur Oxides (SO) are produced below the decomposition of the material to be treated₂) At a temperature of not less than 300 ℃ C, separating out CO₂NaOH or KOH is formed. It is assumed that an atmosphere is formed, i.e. NaOH or KOH and SO are caused to₂The reaction between them is easy to proceed. The following reaction is carried out here:

in the case of sodium bicarbonate, the reaction is,

in the case of potassium bicarbonate, the reaction is carried out,

thus, NaOH or KOH readily reacts with SO₂Reacting to produce nontoxic sulfite (Na)₂SO₃、K₂SO₃)。

According to the reaction formula discussed above, sodium carbonate (Na) was confirmed₂CO₃) Sodium sesquicarbonate (Na)₂CO₃·NaHCO₃·2H₂O), natural soda (containing Na)₂CO₃·NaHCO₃·2H₂O), potassium carbonate (K)₂CO₃) And hydrated sodium carbonate with toxic SO₂Carrying out a reaction to thereby make SO₂Conversion to non-toxic sulphite (Na)₂SO₃、K₂SO₃)。

By examining the residue, it was found that the residue no longer contained toxic sulfur-containing gas (SO)_x) And contains non-toxic sulfite (Na)₂SO₃，K₂SO₃). The residue was put into water and stirred for 10 minutes, where the chloride dissolved in the water leaving the carbide. Also detect theThe carbide does not contain a chlorine-containing gas component.

Thus, the sulfur compounds and sulfur components in the material to be treated can be converted into powdery sodium sulfite (Na)₂SO₃) Powdery potassium sulfite (K)₂SO₃) Water (H)₂O) and carbon dioxide gas (C)O₂) SO that no SO is generated which may form_xThereby obtaining the result of making the exhaust gas and residue non-toxic.

In this embodiment, the toxic component remover contains at least one of an alkali metal carbonate, an alkali metal hydrogencarbonate and an alkali metal hydroxide, for example, at least one of sodium hydrogencarbonate (NaHCO)₃) Sodium carbonate (Na)₂CO₃) Sodium sesquicarbonate (Na)₂CO₃·NaHCO₃·2H₂O), natural soda (containing Na)₂CO₃·NaHCO₃·2H₂O), sodium hydroxide (NaOH), potassium hydroxide (KOH), potassium carbonate (K)₂CO₃) Potassium bicarbonate (KHCO)₃) And sodium potassium carbonate (KNaCO)₃·6H₂O). As described above, during the heating process for carrying out the reaction according to the above-mentioned chemical reaction, toxic hydrogen chloride and/or sulfur oxide is converted into non-toxic chloride (NaCl, KCl) and/or sulfite (Na)₂SO₃、K₂SO₃). Thereby making it possible to remove toxic components (hydrogen chloride and/or sulfur oxide) from the decomposed gas generated from the material to be treated by heating. In this way, the decomposition gas or exhaust gas from the furnace can be effectively made harmless. The chloride and/or sulfite form part of the residue and can be effectively removed by washing with water or the like or by dissolution treatment. After the rinsing process, the solid residue or carbide remains in the tank for reuse. Thus, the residue can be separated into different materials according to different characteristics by any separation means. The separated different materials are dried into blocks for use as fuel or the like. In addition, the liquid (e.g., water) used for the above-described washing treatment contains almost no toxic substances, and thus can be discharged into rivers and oceans.

TABLE 1

Item	Test specimen	Examples 1-1	Comparative examples 1-1	Comparative examples 1-2	Comparative examples 1-3
Item	Test specimen	Examples 1-1	Comparative examples 1-1	Comparative examples 1-2	Comparative examples 1-3	Material to be treated	Polyvinylidene chloride	4g	4g	4g	4g
Dechlorinating agent	Sodium bicarbonate	20g	-	-	-	Material to be treated	Polyvinylidene chloride	4g	4g	4g	4g
	Sodium bicarbonate	20g	-	-	-	Slaked lime	-	-	20g	-
	Calcium carbonate	-	-	-	20g	Slaked lime	-	-	20g	-

TABLE 2

Item	Test specimen	Examples 1-2	Examples 1-3	Examples 1-4	Examples 1-5
Item	Test specimen	Examples 1-2	Examples 1-3	Examples 1-4	Examples 1-5	Material to be treated	Simulation rubbish	20g	20g	20g	20g
Polyvinylidene chloride	1g	0.5g	0.1g	-			Simulation rubbish	20g	20g	20g	20g
Polyvinylidene chloride	1g	0.5g	0.1g	-	Dechlorinating agent		Sodium bicarbonate	5g	2.5g	0.5g	5g
Water content	Urban water	-	-	-	Dechlorinating agent	20cc	Sodium bicarbonate	5g	2.5g	0.5g	5g

TABLE 3

Item		Examples 1 to 1	Examples 1 to 2	Examples 1 to 3	Examples 1 to 4	Examples 1 to 5	Comparative examples 1 to 1	Comparative examples 1 to 2	Comparative examples 1 to 3
Item		Examples 1 to 1	Examples 1 to 2	Examples 1 to 3	Examples 1 to 4	Examples 1 to 5	Comparative examples 1 to 1	Comparative examples 1 to 2	Comparative examples 1 to 3	Item	Material to be treated Material	Polyvinylidene chloride (4g)	Polyvinylidene chloride (1g)	Polyvinylidene chloride (0.5g)	Polyvinylidene chloride (0.1g)	-	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)
-	Simulation rubbish (20g)	Analog garbage (20g)	Simulation rubbish (20g)	Simulation rubbish (20g)	-	-	-					Polyvinylidene chloride (4g)	Polyvinylidene chloride (1g)	Polyvinylidene chloride (0.5g)	Polyvinylidene chloride (0.1g)	-	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)
-	Simulation rubbish (20g)	Analog garbage (20g)	Simulation rubbish (20g)	Simulation rubbish (20g)	-	-	-	-	-			-	-	Water (20cc)	-	-	-
Dechlorinating agent	Sodium bicarbonate (20g)	Sodium bicarbonate (5g)	Sodium bicarbonate (2.5g)	Sodium bicarbonate (0.5g)	Sodium bicarbonate (5g)	-	Slaked lime (20g)	-	-			-	-	Water (20cc)	-	-	-	Calcium carbonate (20g)
Dechlorinating agent	Sodium bicarbonate (20g)	Sodium bicarbonate (5g)	Sodium bicarbonate (2.5g)	Sodium bicarbonate (0.5g)	Sodium bicarbonate (5g)	-	Slaked lime (20g)	Temperature of ℃	Measuring time		HCl concentration (not high) In)	HCl concentration (not high) In)	HCl concentration (not high) In)	HCl concentration (not high) In)	HCl concentration (not) Higher than)	HCl concentration (not low) In)	HCl concentration (not low) In)	Calcium carbonate (20g)	HCl concentration (not low) In)
250	Rise time	ND	ND	ND	ND	ND	ND	Temperature of ℃	Measuring time	ND	HCl concentration (not high) In)	HCl concentration (not high) In)	HCl concentration (not high) In)	HCl concentration (not high) In)	HCl concentration (not) Higher than)	HCl concentration (not low) In)	HCl concentration (not low) In)	ND	HCl concentration (not low) In)
	Rise time	ND	ND	ND	ND	ND	ND	Retention time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
	300	Rise time	ND	ND	ND	ND	ND	Retention time	ND	450ppm	ND	ND	ND	ND	ND	ND	ND	1ppm	15ppm
Retention time		Rise time	ND	ND	ND	ND	ND	ND	ND	450ppm	ND	ND	ND	1000ppm	4ppm	35ppm		1ppm	15ppm
Retention time		350	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	1000ppm	4ppm	35ppm	1000ppm	280ppm	350ppm
Retention time	ND		Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	100ppm	15ppm	50ppm		1000ppm	280ppm	350ppm
Retention time	ND		400	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	100ppm	15ppm	50ppm	ND	1000ppm	8ppm	20ppm
Retention time	ND	ND		Rise time	ND	ND	ND	ND	ND	ND	ND	1000ppm	ND	15ppm		ND	1000ppm	8ppm	20ppm
Retention time	ND	ND		450	Rise time	ND	ND	ND	ND	ND	ND	1000ppm	ND	15ppm	ND	1ppm	650ppm	5ppm	10ppm
Retention time	ND	ND	ND		Rise time	ND	ND	ND	3ppm	ND	400ppm	ND	7ppm		ND	1ppm	650ppm	5ppm	10ppm
Retention time	ND	ND	ND		500	Rise time	ND	ND	3ppm	ND	400ppm	ND	7ppm	ND	ND	20ppm	1000ppm	ND	3ppm
Retention time	ND	ND	ND	ND		Rise time	ND	ND	580ppm	ND	ND	ND		ND	ND	20ppm	1000ppm	ND	3ppm
Retention time	ND	ND	ND	ND		550	Rise time	ND	580ppm	ND	ND	ND	ND	ND	ND	ND	1000ppm	ND	ND
Retention time	ND	ND	ND	ND	ND		Rise time	500ppm	ND	ND	ND		ND	ND	ND	ND	1000ppm	ND	ND
Retention time	ND	ND	ND	ND	ND		600	500ppm	ND	Rise time	ND	ND	ND	ND	ND	ND	600ppm	ND	ND
Retention time	ND	ND	ND	ND	ND	50ppm		ND	ND	Rise time		ND	ND	ND	ND	ND	600ppm	ND	ND
Retention time	ND	ND	ND	ND	ND	50ppm		ND	ND	Post-treatment of chlorine removal agent		Is soluble in water	Is soluble in water	Is soluble in water	Is soluble in water	Is soluble in water	-	Slightly soluble in water	Slightly soluble in water

TABLE 4

Item		Example 2-1	Examples 2 to 2	Comparative example 2-1	Comparative examples 2 to 2	Comparative examples 2 to 3	Comparative examples 2 to 4
Item		Example 2-1	Examples 2 to 2	Comparative example 2-1	Comparative examples 2 to 2	Comparative examples 2 to 3	Comparative examples 2 to 4	Item	Material to be treated	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (1g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)
Dechlorinating agent	Sodium hydroxide (20g)	Potassium hydroxide (20g)	-	-	Slaked lime (20g)	Calcium carbonate (20g)			Material to be treated	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (1g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)
Dechlorinating agent	Sodium hydroxide (20g)	Potassium hydroxide (20g)	-	-	Slaked lime (20g)	Calcium carbonate (20g)	Temperature of		Measuring time	HCl concentration (not high) In)	HCl concentration (not high) In)	HCl concentration (not less than)	HCl concentration (not low) In)	HClConcentration (not low) In)	HCl concentration (not less than)
250	Rise time	ND	ND	ND	ND	ND	Temperature of	ND	Measuring time	HCl concentration (not high) In)	HCl concentration (not high) In)	HCl concentration (not less than)	HCl concentration (not low) In)	HClConcentration (not low) In)	HCl concentration (not less than)
	Rise time	ND	ND	ND	ND	ND	Retention time	ND	ND	ND	ND	ND	ND	ND
	300	Rise time	ND	ND	ND	450ppm	Retention time	1ppm	ND	ND	ND	ND	ND	ND	15ppm
Retention time		Rise time	ND	ND	ND	450ppm	ND	1ppm	ND	ND	1000ppm	4ppm	35ppm		15ppm
Retention time		350	Rise time	3ppm	ND	ND	ND	1000ppm	ND	ND	1000ppm	4ppm	35ppm	280ppm	350ppm
Retention time	ND		Rise time	3ppm	ND	ND	ND	1000ppm	60ppm	1000ppm	15ppm	50ppm		280ppm	350ppm
Retention time	ND		400	Rise time	ND	ND	ND	480ppm	60ppm	1000ppm	15ppm	50ppm	1000ppm	8ppm	20ppm
Retention time	ND	ND		Rise time	ND	ND	1000ppm	480ppm	1000ppm	ND	15ppm		1000ppm	8ppm	20ppm
Retention time	ND	ND		450	Rise time	1ppm	1000ppm	ND	1000ppm	ND	15ppm	1000ppm	650ppm	5ppm	10ppm
Retention time	ND	2ppm	1000ppm		Rise time	1ppm	400ppm	ND	ND	7ppm		1000ppm	650ppm	5ppm	10ppm
Retention time	ND	2ppm	1000ppm		500	Rise time	400ppm	ND	ND	7ppm	ND	500ppm	1000ppm	ND	3ppm
Retention time	ND	ND	4000ppm	580ppm		Rise time	ND	ND	ND		ND	500ppm	1000ppm	ND	3ppm
Retention time	ND	ND	4000ppm	580ppm		550	ND	Rise time	ND	ND	ND	200ppm	1000ppm	ND	ND
Retention time	ND	ND	240ppm	500ppm	ND		ND	Rise time		ND	ND	200ppm	1000ppm	ND	ND
Retention time	ND	ND	240ppm	500ppm	ND		ND	600	Rise time	ND	ND	60ppm	600ppm	ND	ND
Retention time	ND	ND	30ppm	50ppm	ND	ND			Rise time	ND	ND	60ppm	600ppm	ND	ND
Retention time	ND	ND	30ppm	50ppm	ND	ND	600-1000		Rise time	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND	ND			Rise time	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND	ND		Post-treatment of chlorine removal agent		Is soluble in water	Is soluble in water	-	-	Slightly soluble in water	Slightly soluble in water

TABLE 5

Item		Example 3-1	Examples 3 to 2	Comparative example 3-1	Comparative examples 3 to 2	Comparative examples 3 to 3
Item		Example 3-1	Examples 3 to 2	Comparative example 3-1	Comparative examples 3 to 2	Comparative examples 3 to 3	Item	Material to be treated	Poly(s) are polymerizedVinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (1g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)
Dechlorinating agent	Sodium bicarbonate (20g)	Sodium bicarbonate (20g)	-	Calcium carbonate (20g)	Slaked lime (20g)			Material to be treated	Poly(s) are polymerizedVinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (1g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)
Dechlorinating agent	Sodium bicarbonate (20g)	Sodium bicarbonate (20g)	-	Calcium carbonate (20g)	Slaked lime (20g)	Temperature of		Measuring time	HCl concentration (not higher than)	HCl concentration (not higher than)	HCl concentration (not lower than)	HCl concentration (not lower than)	HCl concentration (not lower than)
250	Rise time	ND	ND	ND	ND	Temperature of	ND	Measuring time	HCl concentration (not higher than)	HCl concentration (not higher than)	HCl concentration (not lower than)	HCl concentration (not lower than)	HCl concentration (not lower than)
	Rise time	ND	ND	ND	ND	Retention time	ND	ND	ND	ND	ND	ND
	300	Rise time	ND	ND	450ppm	Retention time	15ppm	ND	ND	ND	ND	ND	1ppm
Retention time		Rise time	ND	ND	450ppm	ND	15ppm	ND	1000ppm	35ppm	4ppm		1ppm
Retention time		350	Rise time	ND	ND	ND	1000ppm	ND	1000ppm	35ppm	4ppm	350ppm	280ppm
Retention time	ND		Rise time	ND	ND	ND	1000ppm	1000ppm	50ppm	15ppm		350ppm	280ppm
Retention time	ND		400	Rise time	ND	ND	ND	1000ppm	50ppm	15ppm	1000ppm	20ppm	8ppm
Retention time	ND	ND		Rise time	ND	1000ppm	ND	15ppm	ND		1000ppm	20ppm	8ppm
Retention time	ND	ND		450	Rise time	1000ppm	ND	15ppm	ND	ND	650ppm	10ppm	5ppm
Retention time	ND	ND	400ppm		Rise time	7ppm	ND	ND		ND	650ppm	10ppm	5ppm
Retention time	ND	ND	400ppm		500	7ppm	Rise time	ND	ND	ND	1000ppm	3ppm	ND
Retention time	ND	ND	580ppm	ND		ND	Rise time		ND	ND	1000ppm	3ppm	ND
Retention time	ND	ND	580ppm	ND		ND	550	Rise time	ND	ND	1000ppm	ND	ND
Retention time	ND	ND	500ppm	ND	ND			Rise time	ND	ND	1000ppm	ND	ND
Retention time	ND	ND	500ppm	ND	ND	600		Rise time	ND	ND	600ppm	ND	ND
Retention time	ND	ND	50ppm	ND	ND			Rise time	ND	ND	600ppm	ND	ND
Retention time	ND	ND	50ppm	ND	ND		Post-treatment of chlorine removal agent		Is soluble in water	Is soluble in water	-	Slightly soluble in water	Slightly soluble in water

TABLE 6

Item		Example 4-1	Example 4 to 2	Comparative example 4-1	Comparative example 4 to 2	Comparative examples 4 to 3
Item		Example 4-1	Example 4 to 2	Comparative example 4-1	Comparative example 4 to 2	Comparative examples 4 to 3	Item	Material to be treated	Polyvinylidene chloride (4g)	-	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)
-	Analog garbage (40g)	-	-	-					Polyvinylidene chloride (4g)	-	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)	Polyvinylidene chloride (4g)
-	Analog garbage (40g)	-	-	-	Dechlorinating agent	Potassium bicarbonate (10g)			Potassium bicarbonate (10g)	-	Slaked lime (20g)	Calcium carbonate (20g)
Temperature of	Measuring time	HCl concentration (not higher than)	HCl concentration (not higher than)	HCl concentration (not lower than)	Dechlorinating agent	Potassium bicarbonate (10g)		HCl concentration (not lower than)	Potassium bicarbonate (10g)	-	Slaked lime (20g)	Calcium carbonate (20g)	HCl concentration (not lower than)
Temperature of	Measuring time	HCl concentration (not higher than)	HCl concentration (not higher than)	HCl concentration (not lower than)	250	Rise time	ND	HCl concentration (not lower than)	ND	ND	ND	ND	HCl concentration (not lower than)
Retention time	ND	ND	ND	ND		Rise time	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND		300	Rise time	ND	ND	ND	450ppm	1ppm	15ppm
Retention time	ND	ND	1000ppm	4ppm	35ppm		Rise time		ND	ND	450ppm	1ppm	15ppm
Retention time	ND	ND	1000ppm	4ppm	35ppm		350	Rise time	ND	2ppm	1000ppm	280ppm	350ppm
Retention time	ND	7ppm	1000ppm	15ppm	50ppm			Rise time	ND	2ppm	1000ppm	280ppm	350ppm
Retention time	ND	7ppm	1000ppm	15ppm	50ppm	400		Rise time	ND	5ppm	1000ppm	8ppm	20ppm
Retention time	ND	2ppm	1000ppm	ND	15ppm			Rise time	ND	5ppm	1000ppm	8ppm	20ppm
Retention time	ND	2ppm	1000ppm	ND	15ppm		450	Rise time	ND	ND	650ppm	5ppm	10ppm
Retention time	ND	ND	400ppm	ND	7ppm			Rise time	ND	ND	650ppm	5ppm	10ppm
Retention time	ND	ND	400ppm	ND	7ppm	500		Rise time	ND	ND	1000ppm	ND	3ppm
Retention time	ND	ND	580ppm	ND	ND			Rise time	ND	ND	1000ppm	ND	3ppm
Retention time	ND	ND	580ppm	ND	ND		550	Rise time	ND	ND	1000ppm	ND	ND
Retention time	ND	ND	500ppm	ND	ND			Rise time	ND	ND	1000ppm	ND	ND
Retention time	ND	ND	500ppm	ND	ND	600		Rise time	ND	ND	600ppm	ND	ND
Retention time	ND	ND	50ppm	ND	ND			Rise time	ND	ND	600ppm	ND	ND
Retention time	ND	ND	50ppm	ND	ND		Post-treatment of chlorine removal agent		Is soluble in water	Is soluble in water	-	Slightly soluble in water	Slightly soluble in water

TABLE 7

		Example 5-1		Examples 5 and 2		Examples 5 to 3		Examples 5 to 4		Examples 5 to 5		Examples 5 to 6		Examples 5 to 7
		Example 5-1		Examples 5 and 2		Examples 5 to 3		Examples 5 to 4		Examples 5 to 5		Examples 5 to 6		Examples 5 to 7			Material to be treated	The ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		bulk RDF (40g)
Toxic components are removed Removing agent	NaHCO₃ 10g		NaHCO₃ 4g		KHCO₃ 3g		Na₂CO₃ K₂CO₃ 3g		NaOH 3g		KOH 3g		NaHCO₃ 10g				Material to be treated	The ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		the ground RDF is obtained by grinding the RDF, (40g)		bulk RDF (40g)
Toxic components are removed Removing agent	NaHCO₃ 10g		NaHCO₃ 4g		KHCO₃ 3g		Na₂CO₃ K₂CO₃ 3g		NaOH 3g		KOH 3g		NaHCO₃ 10g		Temperature of ℃		Measuring time	HCl concentrate Degree (not high) In)	SO₂Concentration of (not high) In)	HCl concentrate Degree (not high) In)	SO₂Concentration of (not high) In)	HCl concentration (not high) In)	SO₂Concentration of (not high) In)	HCl concentrate Degree (not high) In)	SO₂Concentration of (not high) In)	HCl concentrate Degree (not high) In)	SO₂Concentration of (not high) In)	HCl concentration (not high) In)	SO₂Concentration of (not high) In)	HCl concentration (not high) In)	SO₂Concentration of (not high) In)
250	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	Temperature of ℃	ND	Measuring time	HCl concentrate Degree (not high) In)	SO₂Concentration of (not high) In)	HCl concentrate Degree (not high) In)	SO₂Concentration of (not high) In)	HCl concentration (not high) In)	SO₂Concentration of (not high) In)	HCl concentrate Degree (not high) In)	SO₂Concentration of (not high) In)	HCl concentrate Degree (not high) In)	SO₂Concentration of (not high) In)	HCl concentration (not high) In)	SO₂Concentration of (not high) In)	HCl concentration (not high) In)	SO₂Concentration of (not high) In)
	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	Retention time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
	300	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	Retention time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
Retention time		Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND		ND
Retention time		350	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
Retention time	ND		Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	2ppm	5ppm		ND	ND
Retention time	ND		400	Rise time	ND	ND	ND	3ppm	ND	5ppm	2ppm	5ppm	ND	1ppm	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	2ppm	5ppm	1ppm	16ppm	15ppm
Retention time	ND	ND		Rise time	ND	ND	ND	3ppm	ND	5ppm	2ppm	5ppm	ND	1ppm	ND	ND	ND	ND	4ppm	ND	3ppm	ND	ND	ND	ND	8ppm	5ppm		1ppm	16ppm	15ppm
Retention time	ND	ND		450	Rise time	ND	ND	ND	ND	ND	1ppm	ND	ND	ND	ND	ND	ND	ND	4ppm	ND	3ppm	ND	ND	ND	ND	8ppm	5ppm	ND	ND	2ppm	2ppm
Retention time	ND	ND	ND		Rise time	ND	ND	ND	ND	ND	1ppm	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND		ND	ND	2ppm	2ppm
Retention time	ND	ND	ND		500	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND		Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND		ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND		550	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND		Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND		ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND		600	Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND	ND		Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND		ND	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND	ND		Of toxic constituent-removing agents Post-treatment		Is soluble in water		Is soluble in water		Is soluble in water		Is soluble in water		ND	ND	ND	ND	ND	ND	Is soluble in water		Is soluble in water		Is soluble in water

TABLE 8

		Comparison ofExample 5-1		Comparative examples 5 to 2		Comparative examples 5 to 3
		Comparison ofExample 5-1		Comparative examples 5 to 2		Comparative examples 5 to 3			Material to be treated	Treated crushed RDF40g		Treated crushed RDF20g		Treated blocks RDF40g
Toxic components are removed Removing agent	-		-		-				Material to be treated	Treated crushed RDF40g		Treated crushed RDF20g		Treated blocks RDF40g
Toxic components are removed Removing agent	-		-		-		Temperature of ℃		Measuring time	HCl concentration (not lower than)	SO₂Concentration of (not lower than)	HCl concentration (not lower than)	SO₂Concentration of (not lower than)	HCl concentration (not lower than)	SO₂Concentration of (not lower than)
250	Rise time	ND	ND	ND	ND	ND	Temperature of ℃	ND	Measuring time	HCl concentration (not lower than)	SO₂Concentration of (not lower than)	HCl concentration (not lower than)	SO₂Concentration of (not lower than)	HCl concentration (not lower than)	SO₂Concentration of (not lower than)
	Rise time	ND	ND	ND	ND	ND	Retention time	ND	ND	ND	ND	ND	ND	ND
	300	Rise time	ND	ND	ND	ND	Retention time	ND	ND	ND	ND	ND	ND	ND	ND
Retention time		Rise time	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND		ND
Retention time		350	Rise time	ND	7ppm	ND	ND	20ppm	ND	ND	ND	ND	ND	2ppm	6ppm
Retention time	16ppm		Rise time	ND	7ppm	ND	40ppm	20ppm	13ppm	17ppm	35ppm	60ppm		2ppm	6ppm
Retention time	16ppm		400	Rise time	70ppm	35ppm	40ppm	30ppm	13ppm	17ppm	35ppm	60ppm	13ppm	1000ppm	60ppm
Retention time	60ppm	30ppm		Rise time	70ppm	35ppm	3ppm	30ppm	7ppm	130ppm	20ppm		13ppm	1000ppm	60ppm
Retention time	60ppm	30ppm		450	Rise time	10ppm	3ppm	7ppm	7ppm	130ppm	20ppm	1ppm	4ppm	10ppm	10ppm
Retention time	2ppm	3ppm	ND		Rise time	10ppm	ND	7ppm	ND	5ppm		1ppm	4ppm	10ppm	10ppm
Retention time	2ppm	3ppm	ND		500	Rise time	ND	ND	ND	5ppm	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND		Rise time	ND	ND	ND		ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND		550	ND	Rise time	ND	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND		ND	Rise time		ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND		ND	600	Rise time	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND	ND			Rise time	ND	ND	ND	ND	ND	ND
Retention time	ND	ND	ND	ND	ND	ND	Of toxic constituent-removing agents Post-treatment		-		-		-

Claims

1. A method of removing a toxic element from a material to be treated containing the toxic element, comprising the steps of, in the order shown:

mixing a material to be treated with a toxic component remover to form a mixture, the toxic component remover comprising an alkali metal compound; and

heating the mixture to thermally decompose the material to be treated to produce a material containing a toxic component, and contacting and reacting the material containing the toxic component with the toxic component remover to produce a non-toxic compound.

2. A method for removing at least one of chlorine and sulfur from a material to be treated containing at least one of chlorine and sulfur, comprising the steps of, in the order shown:

mixing a material to be treated with a chlorine and sulfur removal agent to form a mixture, the chlorine and sulfur removal agent comprising an alkali metal compound;

and heating the mixture to thermally decompose the material to be treated to produce at least one of a chlorine-containing species and a sulfur-containing species, and contacting and reacting the at least one of a chlorine-containing species and a sulfur-containing species with the chlorine and sulfur removal agent to produce at least one of a non-toxic chloride and a sulfite.

3. A method of removing chlorine from a material containing chlorine to be treated comprising the steps of, in the order shown:

mixing a material to be treated with a chlorine removal agent to form a mixture, the chlorine removal agent containing an alkali metal compound;

the mixture is heated to thermally decompose the material to be treated to produce a chlorine-containing species which is contacted with the chlorine scavenger and reacted to produce a non-toxic chloride.

4. The method according to claim 3, wherein the chlorine removing agent contains at least one compound selected from the group consisting of an alkali metal carbonate, an alkali metal hydrogencarbonate and an alkali metal hydroxide.

5. The method according to claim 3, wherein the chlorine removing agent contains at least one compound selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, potassium carbonate, potassium bicarbonate and potassium sodium carbonate.

6. The method of claim 3, wherein the heating step comprises the step of heating the mixture under a low oxygen atmosphere.

7. The method of claim 3, wherein the heating step comprises the step of heating the mixture within a furnace that is substantially sealed to prevent fresh air from entering therein, wherein pressure within the furnace leaks out of the furnace.

8. A method according to claim 3, wherein the heating step comprises the step of heating the mixture so that the material to be treated undergoes retorting.

9. The method of claim 3, wherein the chlorine removal agent is in at least one form selected from the group consisting of agglomerates, flakes, porous bodies, particles, solutions, and suspensions.

10. The method according to claim 3, wherein the material to be treated is at least one selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, chlorine-containing synthetic resin and chlorine-containing rubber.

11. The method of claim 3, wherein the amount of said chlorine scavenger used in said mixing step is 0.05-10% by weight relative to the material to be treated prior to said mixing step.

12. The method according to claim 3, wherein in the case where the material to be treated is at least one selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, chlorine-containing synthetic resin and chlorine-containing synthetic rubber, the amount of the chlorine scavenger used in the mixing step is 10 to 70% by weight with respect to the material to be treated.

13. The method of claim 3, wherein the amount of said chlorine scavenger used in said mixing step is not less than the stoichiometric amount of chlorine generated by the material to be treated.

14. The method of claim 3, further comprising the step of adding the chlorine scavenger to the mixture during the heating step.

15. The method of claim 14 wherein the step of adding comprises adding the chlorine scavenger to the mixture before the material to be treated reaches a temperature at which thermal decomposition occurs.

16. The method of claim 14 wherein the step of adding comprises adding the chlorine scavenger to the mixture after the material to be treated reaches a temperature at which thermal decomposition occurs.

17. The method of claim 3, further comprising feeding the chlorine scavenger into the material to be treated within the furnace by at least one method selected from the group consisting of dosing and spraying.

18. The method as claimed in claim 3, wherein the heating step comprises heating the material to be treated within the range of 200-1000 ℃.

19. A toxic component remover used in a method of removing a toxic component from a material to be treated containing the toxic component, the toxic component remover containing an alkali metal compound, the toxic component remover being capable of contacting and reacting with a substance containing the toxic component generated from the material to be treated when the material to be treated is heated so as to generate a non-toxic compound.

20. A chlorine and sulfur remover for use in a method of removing at least one of chlorine and sulfur from a material to be treated containing at least one of chlorine and sulfur, the chlorine and sulfur remover containing an alkali metal compound, the chlorine and sulfur remover being capable of contacting and reacting with at least one of chlorine-containing substances and sulfur-containing substances produced by the material to be treated upon heating of the material to be treated so as to produce at least one of a chloride and a sulfite that are non-toxic.

21. A chlorine scavenger for use in a method of removing chlorine from a material to be treated containing chlorine, the chlorine scavenger containing an alkali metal compound, the chlorine scavenger being capable of contacting and reacting with chlorine-containing substances produced from the material to be treated by heating the material to be treated so as to form non-toxic chlorides.

22. The chlorine remover according to claim 21, wherein the alkali metal compound is at least one compound selected from the group consisting of an alkali metal carbonate, an alkali metal bicarbonate and an alkali metal hydroxide.

23. The chlorine remover according to claim 21, wherein the alkali metal compound is at least one compound selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, potassium carbonate, potassium bicarbonate and potassium sodium carbonate.

24. A chlorine scavenger for use in a process for removing at least one of chlorine and sulfur from a material to be treated containing at least one of chlorine and sulfur, comprising the following steps in the order indicated: mixing a material to be treated with a chlorine and sulfur removal agent to form a mixture, the chlorine and sulfur removal agent comprising an alkali metal compound; and heating the mixture to thermally decompose the material to be treated to produce at least one of a chlorine-containing species and a sulfur-containing species, and contacting and reacting the at least one of a chlorine-containing species and a sulfur-containing species with a chlorine and sulfur removal agent to produce at least one of a non-toxic chloride and a sulfite, wherein the chlorine removal agent comprises an alkali metal compound.

25. The chlorine remover according to claim 24, wherein the chlorine remover comprises at least one compound selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, and alkali metal hydroxides.

26. The chlorine remover according to claim 24, wherein the alkali metal compound is at least one compound selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, potassium carbonate, potassium bicarbonate and potassium sodium carbonate.

27. A system for removing at least one of chlorine and sulfur from a material to be treated containing at least one of chlorine and sulfur, comprising:

means for mixing the material to be treated with a chlorine and sulfur removal agent to form a mixture, said chlorine and sulfur removal agent comprising an alkali metal compound;

a furnace for feeding a mixture of a material to be treated and chlorine and a sulfur removing agent, the furnace being adapted to form a low oxygen concentration atmosphere in the interior thereof;

heating means for heating a mixture in said furnace and in a low oxygen concentration atmosphere to thermally decompose the material to be treated to effect destructive distillation of the material to be treated, wherein said mixture produces at least one of a chlorine-containing species and a sulfur-containing species, and at least one of the chlorine-containing species and the sulfur-containing species is contacted with a chlorine and sulfur removal agent and reacted to produce at least one of a non-toxic chloride and sulfite.

28. The method according to claim 1, wherein the toxic component removing agent contains at least one compound selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, and alkali metal hydroxides.

29. The method according to claim 1, wherein the toxic component remover contains at least one compound selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidiumhydroxide, cesium hydroxide, potassium carbonate, potassium bicarbonate and potassium sodium carbonate.

30. The method according to claim 2, wherein the chlorine and sulfur removing agent contains at least one compound selected from the group consisting of an alkali metal carbonate, an alkali metal bicarbonate and an alkali metal hydroxide.

31. The method according to claim 2, wherein the chlorine and sulfur removing agent contains at least one compound selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, potassium carbonate, potassium bicarbonate and potassium sodium carbonate.

32. The toxic component remover according to claim 19, wherein the toxic component remover contains at least one compound selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, and alkali metal hydroxides.

33. The toxic component remover according to claim 19, wherein the toxic component remover contains at least one compound selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, potassium carbonate, potassium bicarbonate, and potassium sodium carbonate.

34. The chlorine and sulfur remover according to claim 20, wherein said chlorine and sulfur remover contains at least one compound selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, and alkali metal hydroxides.

35. The chlorine and sulfur remover according to claim 20, wherein said chlorine and sulfur remover contains at least one compound selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, potassium carbonate, potassium bicarbonate and potassium sodium carbonate.

36. The system according to claim 27, wherein the chlorine and sulfur removal agent comprises at least one compound selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, and alkali metal hydroxides.

37. The system of claim 27, wherein the chlorine and sulfur removal agent comprises at least one compound selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, trona, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, potassium carbonate, potassium bicarbonate, and sodium potassium carbonate.