CZ280050B6 - Combined process of gasifying solid, pasty and liquid residual and waste substances - Google Patents

Abstract

Solid, pasty and liquid residual and / or waste materials, which exhibit a wide range of organic and inorganic harmful substances, are economically and environmentally beneficial in the process of pressure gasification. Solid and pasty residual and / or waste materials are gassed under pressure in a fixed bed gasification process, where hydrocarbon-containing condensates and fine-grained solid-bed gasification ash are treated with flow residual and / or effluent in a flow gasification process. and the residues of the water and gas treatment plants are recycled to the fixed bed gasification auxiliary plants. The field of application of the solution is fixed bed gasification, jet gasification, remediation of materials, and industry and fabrication and disposal of residual and waste materials. ŕ

Description

(57)

Waste substances with a wide range of organic and inorganic pollutants are economically and environmentally beneficial in the process of pressure gasification. The solid and pasty residual and / or waste materials are gasified under pressure conditions in a fixed bed gasification process, wherein the hydrocarbon-containing condensates and the fine-grained ash particles from the fixed bed gasification are treated together with the liquid residual and / or waste materials in a stream gasification process. and the residues from the water and gas treatment plants are fed back to the fixed bed pressure gasification equipment. Fields of application The solutions are fixed bed gasification, jet gasification, remediation of used substances, and industry and production dealing with substance disposal and treatment of residual and waste substances.

Process of combined gasification of solid, pasty and liquid residual and waste substances

Technical field

The invention relates to a process for the combined gasification of solid, pasty and liquid residual and waste materials.

BACKGROUND OF THE INVENTION

The least expensive way to remove solid waste is to deposit it in open or underground deposits. However, waste disposal sites pose serious problems. As a result of leaching, ground water is easily polluted, quality soil is lost and fires can also occur.

A more favorable method to alleviate these problems consists in sanitary ground treatment by composting and covering the garbage with soil.

However, in larger conurbations, this is not to be expected in any greater way, as places for its implementation are increasingly difficult to find. In both of these methods, waste incineration is planned before field treatment of the waste. This incineration of waste will significantly reduce the volume of waste and reduce the amount of pollution caused by leaching, but on the other hand brings new environmental problems, such as air pollution and an increase in the proportion of residual substances. Although it is possible to achieve a volume reduction of 80 to 90% by volume, the residual substances and ash are in any case not biologically inactive, so the field treatment must follow. As a result, the recovery of certain values is essentially minimal.

The proposal for a waste gasification solution provides the so-called Anderson method (U.S. Pat. No. 3,729,298). According to this, waste materials are supplied to the upper part of the vertically located shaft furnace and oxygen is supplied to the lower part. In carrying out this method, the crushed waste is unconcentrated. The liquid slag produced in the lower part is continuously tapped. The disadvantage of this process is that crushed waste is packed in the reactor, which entails disadvantages in terms of power reduction and explosion risk.

According to DE-OS 26 19 302, gasification of waste in the form of pellets in shaft furnaces has not been proposed. However, this method can only be used to gasify pre-specified pellets from normal pressure and to remove liquid slag.

DE-AS 23 23 654 describes a process in which solid waste from domestic waste is introduced into the upper part of the reactor and liquid hydrocarbon and liquid waste gas condensate from the gas purification into the lower part. The disadvantage of this method is that there is no targeted fixation or elimination of organic and inorganic pollutants. The synthesis of dioxin and furan cannot be excluded when the gas is designed to cool to 300 ° C.

-1GB 280050 B6

According to DE-OS 33 42 383, in a combined device consisting of a fixed bed pressure gasifier and a jet gasifier in a primary process, the slurry is gasified and in the secondary a lump gasifier is gasified, the waste slag being collected in a molten sodium carbonate bath.

This method serves to prevent the reaction of heavy metals, especially vanadium, with the lining.

The disadvantage of this method is that only limited limits are reserved in the solid and liquid waste stream, whereby the disposal of hydrocarbons and dioxin in the secondary reactor can only be partially achieved.

The object and object of the present invention is to utilize, economically and at the same time, with respect to the environment, liquid, pasty and solid residual and / or waste substances which are burdened with harmful substances of inorganic and / or organic origin.

SUMMARY OF THE INVENTION

This object is achieved by the method of combined gasification of solid, pasty and liquid residual and waste substances, in parallel fixed bed gasification and jet gasification, according to the invention, which consists in the fact that in fixed bed gasification 1 to 80% by weight of solid or 1 to 60% by weight, solid and / or 1 to 20% by weight, of pasty residual and / or waste materials containing carbon and loaded with organic and / or inorganic pollutants into a useful gas, the heating time of residual and / or waste substances in a reducing atmosphere to a temperature of> 350 ° C and <400 ° C, as well as a residence time of the residual and / or waste products under pressure gasification in a fixed bed until direct contact with the raw gas produced having a temperature of> 350 ° C and which after pressure gasification in a fixed bed rapidly cooled to a temperature of <200 ° C, is more than 1 h, and that at jet m gasification is converted into a useful gas of condensation components resulting from the cooling of the raw gas, dewatered to <25% by weight, of the water content, with or without liquid carbonaceous residual and waste materials which are burdened with organic and / or inorganic pollutants wherein the treatment of the gas or water with the resulting carbon black, heavy metal and salt residues is recycled to the fixed bed gasification and the fine-grained ash particles from the fixed bed gasification where the detectable heavy metal eluates may be mixed with and from 1 to 30 wt.% of the feed to the gasification, in which the fine-grained ash particles from the fixed bed gasification are granulated with the additional fixation of heavy metal fractions from the liquid residues and / or waste.

The solid and / or pasty residual and / or waste may be, for example, contaminated soil, plastic waste, wood, rubber products, oil-containing waste, pharmaceutical residues, tar residues, color deposits, sewage sludge in fine-grained, coarse-grained, pasty or agglomerated form, and may still be loaded with, for example, aliphatic, aromatic or chlorinated hydrocarbons, polychlorinated biphenyls, dioxins, furans, sulfur compounds and heavy metals.

The pressure gasification in the fixed bed separates the volatile organic compounds which, when the raw gas is cooled in the closed system, falls off in the form of hydrocarbon fractions.

Polychlorinated biphenyls, dioxins and furans are completely destroyed when heated under pressure fixed gasification in a reducing atmosphere to> 1200 ° C.

If, after all, their proportions are carried off by means of the raw gas, these substances, by virtue of their properties, will enter the liquid hydrocarbons formed during the condensation.

These are either converted into a useful gas, which is rapidly cooled to the exit gasifier at or above a temperature of> 1300 ° C and a residence time of> 3 s, either with or without liquid residual and / or waste substances which are burdened with organic pollutants. temperature <200 ° C.

The liquid, pumpable residual or waste materials can be, for example, used oil, solvents, lacquer and paint sludge and color substance suspensions containing analogous pollutant groups as mentioned above.

At the bottom of the fixed bed pressure gasifier, at > 1200 ° C, targeted granulation of the resulting ash into non-elongable melting junctions occurs, in which the heavy metals contained in the batch are preferably bound.

Elutable fine ash particles are in the ratio of 1 to 30% by weight, admixed with the liquid residues and / or waste substances are at a temperature> 1300 C ^e at current gasifier gasification. At the same time, non-volatile heavy metals are processed from the liquid feedstock.

The volatile heavy metals enter the aqueous phase and are preferably captured as sulfides, hydroxides, oxides and carbonates.

In the treatment of the soot water as well as the subsequent biological treatment of the process water together with the resulting biological sludge, this proportion is separated and returned to the pressure gasification in a fixed bed for connection to the slag.

Throughout the process, sulfur particles are separated from the gas stream by known methods and are obtained as a valuable raw material.

According to the proposed method, it is possible to carry out a complex use of non-hazardous solid, pasty and liquid residual and / or waste materials. The synergistic and combinational effect allows for an almost residual appreciation with a high degree of metabolic efficiency. The fission gas produced can be transported or stored as an energy carrier or undergoes a direct conversion into a chemical raw material.

-3GB 280050 B6

Overview of the drawings

The attached drawing shows an example of an embodiment of a device which performs the method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

A fixed bed pressure gasifier 1 operated under a pressure of 2.5 MPa was loaded with t brown coal briquettes t contaminated soil 3 with a hydrocarbon content of 5% by weight, with a dioxin contamination of 2000 mg / kg and 800 mg chromium / kg, 800 mg lead / kg, 600 mg / copper / kg t plastic waste 3 t oil-polluted wood 3

0.5 tonnes of process water treatment residues 34.

Through the rotary grate 4, the fixed bed gasifier 1 was supplied as a mixture of 5 2400 m ³ / h of oxygen and 15.6 t / h of gasification steam. Above the rotating grate 4, a mixture of slag and fly ash is fed to a sorting device of known construction.

Here, in the case of the elimination of fine-grained ash 25, this can be separated and fed to a mixing device 24 for slagging in a jet gasifier. The resulting slag granulate 36 from the fixed bed gasifier and the jet gasifier can be utilized as a filler material or as an additional building material.

In a fixed bed gasifier 1, 1 to 80 wt.%, Solid or 1 to 60 wt.% Solid and / or 1 to 20 wt.%, Pasty residual and / or waste materials containing carbon and loaded with organic and / or inorganic pollutants are converted into useful gas, wherein the time of heating the residual and / or waste materials in a reducing atmosphere at a temperature of> 350 ° C and <400 ° C as well as the residence time of the residual and / or waste substances in the fixed bed gasifier 1 until direct contact with the raw gas produced which has a temperature of> 350 ° C and which, after leaving the fixed bed gasifier, is rapidly cooled to <200 ° C, is more than 1 h.

In a pressure gasifier, the hydrocarbons contained in the contaminated soil and the wood used are distilled off, split and partially converted into a useful gas. The dioxin contained in the contaminated soil is destroyed in a fixed bed gasifier 1 in a reducing atmosphere at 300-800 ° C. If minute fractions reach the hydrocarbon fractions of the condensate 17, the final reaction in the gasifier 23 follows. The plastic wastes 3 contained in the gasification mixture of the fixed bed gasifier 1 react from 50 to 70% by weight, into the gaseous components and 20 to 50% by weight of hydrocarbons. 2 to 5 wt.% Goes to a mixture of slag and fly ash 6.

The hydrocarbon fractions from the spent used wood as well as from the contaminated soil which have been charged are distilled off, split or converted into gas. The wood used 3 is itself gasified, the residual parts of the soil with heavy metal particles forming an ineligible part of the slag / ash mixture 6.

The organic constituents of the process water treatment residue 2 are converted into a useful gas, the inorganic constituents are melted into a mixture of slag and fly ash 6.

The raw gas collecting space 7 is fed to a scrubber cooler 9 with 19 700 m ^{3 of} dry raw gas / h with an oil and tar content of 80 g / m ³ and 0.7 kg of water vapor / m ³ via the raw gas evacuation 8. Here, the hot gas 20 ° C is cooled by 20 m ^{3 of} cooling water to 195 ° C. The cooled raw gas 11 is indirectly cooled to ambient temperature by means of cooling water 13 in other coolers 12. The cooled raw gas 14 passes to conventional scrubbing equipment and is subsequently used either materially or energetically. The waste condensates 15 are separated in the treatment of water 16 into the process water fraction 31 and to the hydrocarbon fraction.

Approximately 1.58 t of hydrocarbons 17 are fed through the pump 18 together with 12 t of used oil 19, which is mixed in the mixing device 24 with 1.3 t / h fine ash, and additionally with 10 500 m ^{3 of} oxygen / ha 6.8 t high-pressure steam 21 / h, fed through the burner 22 to the gasifier 23, to be converted into fission gas at 2.5 MPa and 1350 ° C.

The fission gas 26 at 45,000 m / h is cooled to 195 ° C by 60 t / h of cooling water 27, and from the cooling chamber the cooled fission gas 29 is discharged through the cooling and purification stages for material or energy recovery. The resulting slag granulate 36 contains non-elutable proportions of heavy metals of charged ash and used oil and can be used in the construction industry. The resulting soot water 30, together with the process water 31, is introduced into the process water and soot water treatment, which consists of different process stages. Waste residues 34 with either biological sludge or soot are fed back to the fixed bed pressure gasifier 1, the purified process water can be reused or discharged to a drain.

Claims (1)

A method for the combined gasification of solid, pasty and liquid residual and waste materials, in parallel fixed bed gasification and jet gasification, characterized in that in fixed bed gasification, 1-80% by weight, solid or 1-60% by weight, solids and / or 1 to 20 wt.%, pasty residual and / or waste materials containing carbon and burdened with organic and / or inorganic pollutants into a useful gas, the heating time of the residual and / or waste in a reducing atmosphere to > C and < 400 ° C as well as the residence time of the residual and / or waste products under pressure gasification in the fixed bed until direct contact with the raw gas produced, which has a temperature> 350 ° C, and which is quenched after pressure gasification in the fixed bed to a temperature of <200 ° C, is more than 1 h, and that in a gasification process they are converted to an already condensation gas condensation components, resulting from the cooling of raw gas, dewatered to <25% by weight, of water content, with or without liquid and carbon-containing residual and waste substances, loaded with organic and / or inorganic pollutants, or the water formed by the soot, heavy metal and salt residues is returned to the fixed bed gasification and the fine-grained ash particles from the fixed bed gasification, where detectable heavy metal eluates may occur, are mixed with the liquid residuals to form 1 to 30% by weight, of a portion of the feed to the gasification, in which the fine-grained ash particles from the fixed bed gasification are granulated with the additional fixation of heavy metal fractions from liquid residues and / or waste materials.