JPH10140167A - Method and apparatus for separation and gasification of combustible, residue and waste each having carbon and ash - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for utilizing wastes containing carbon and ash to generate heat or to form a product usable as a raw material, which process is freed from the necessity for purifying flue gas on a large scale and from a risk of the formation of toxic substances such as dioxins and is not detrimental to the environment. SOLUTION: This process comprises subjecting wastes 35 to a dry distillation process at a temperature up to about 800 deg.C under exclusion of air in a heat decomposer 2, separating the formed heat decomposition gas 26 from a solid heat decomposition residue 21, subjecting the residue 24 to a separation process to obtain a fine product concentrated and ground with a coke-like component and coarse product 23 mainly consisting of a metallic component, feeding the heat decomposition gas 20 and the ground fine product suspended in a flowable carrier medium and additional flowable combustibles 27 into a gasifier 9, converting them into a gas 31 containing CO and H2 and a mineral residue, cooling them, bringing them into contact with water, granulating them, and discharging the cooled gas and the granulated slag from the reactor 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for the separation and gasification of combustibles, residues and wastes containing carbon and ash, and a method for carrying out the method, according to the first claim. Device. Gasification is effected by oxygen or an oxygen-containing oxidizing agent at a temperature of at least 1100 ° C. at elevated pressure or atmospheric pressure in the flame reaction. Combustibles, residues and wastes containing carbon and ash include solid combustibles (fuels), such as lignite and black coal and their coke, which has a slightly higher ash content anyway,
Oils with low inorganic content, fuel oil boiled to high temperatures based on crude oil processing, residual oils and tars based on thermal processes,
For the processing of oil-solid waste mixtures or oil-solid waste-water mixtures, municipal and industrial sludge, waste oil, PCB-containing oils, plastics, subdivided refuse from homes or their separated products, automobiles, cables and electronics scrap It is understood that solids and liquids based on light crushed materials and wastes such as contaminated organic aqueous solutions and recycling activities.

[0002] The present invention relates to the extent to which heavy metals and toxic organic compounds or organic chlorides are produced while producing uncontaminated, extensively material-economically and energetically usable gases and non-absorptive pure mineral residues. Regardless of the invention, the present invention relates to a method for heat utilization of waste having various properties and flammable or organic components of origin. In particular, the method is suitable for environmentally friendly use of waste such as household waste, plastic-containing industrial waste, colored residue, used car sorting recycle shreds or oily waste.

[0003]

2. Description of the Prior Art In order to generate electrical energy and to use the encapsulated energy as thermal energy, to destroy toxic organic components and to dramatically reduce the amount of over-deposited bulk, for example, such as dust. It is known to burn waste containing flammable components.

[0004] Combustion systems for such wastes have the risk of forming highly toxic organic chlorides such as dioxins and furans from chlorides in the materials used, especially during combustion or during cooling of the primary combustion gases. Requires very expensive flue gas purification. The solid residue (ash) and flying dust generated during combustion are bulky, sensitive to the elution of heavy metals by atmospheric moisture, and are difficult to deposit. Therefore, a later dissolution of the ash for conversion to a glassy, elution-resistant slag (also inevitably costly) has been proposed.

It is further known to mix waste and gasification residues. A gasification technique that can be used for this purpose is partial oxidation with oxygen in the splash stream.
At that time, combustibles, residues or wastes containing oxygen are converted into gases rich in carbon monoxide and hydrogen, often under high pressure, in a flame reaction. The process proceeds at a temperature such that the mineral component already forms a molten slag which first solidifies on cooling and upon contact with a water bath into glassy slag granules. In the elution-resistant slag, a considerable portion of the heavy metals contained in the waste used are bound. Under the gasification conditions, the organic chloride contained in the product is completely changed first, and the contained chlorine is converted into hydrogen chloride or non-toxic inorganic chloride. De-novo-synthesis is eliminated under these conditions. Therefore, the evolved gas also has no dioxins and furans. The generated gas is used for energy purposes for driving gas turbines and gas motors and also as syngas after cooling and mechanical purification of the contained sulfur, which has been practically completely converted to hydrogen sulfide.

[0006] The gasification in the entrained stream is carried out if the use for the gasification process is not present in a free-flow manner in order to achieve a continuous and well-adjustable feed to the gasification reactor. It is assumed that it must not. Free-flowing materials are understood to be gaseous and liquid substances, solid muddy water finely divided in liquid, or slag-like solid substances suspended in a carrier gas. However, often the combustibles, residues and wastes to be used are of such hardness that a mechanical or thermomechanical processing route must be used to produce a uniform charge for gasification. Exists in size.

It has been proposed and studied that the waste undergoes a wide variety of modes of pyrolysis, that is to say thermal conversion at temperatures between 300 ° C. and 700 ° C. For this pyrolysis, a large number of rotary tube furnaces with external heating are provided, which have the advantage that not only bulk but also fine-grained, free-flowing charge can be used. During pyrolysis, carbon-containing residues, hydrocarbon-containing blast furnace gas and condensable tar oils are formed. It has been found that the tar oil cannot be processed or can only be processed with a very high expenditure of fuel, fuel oil or material available. Due to the blast furnace gas itself or the flue gas generated during its combustion, a large-scale purification device is required which is approximately equivalent to the device for flue gas purification in refuse incinerators. Solid residues, especially fine fractions containing carbon, are eventually difficult to deponieren because of their flammability.

[0008] EP-A-302310 proposes a method and apparatus for thermal waste treatment, in which the pyrolysis of the waste is carried out with the subsequent combustion of a carbonization gas with non-volatile pyrolysis residues. Can be combined. that time,
First, coarse inorganic components such as metal pieces, glass, and stone are retained from the pyrolysis solid residue through a separation step, and the remaining carbon-containing portion is vitrified after being cooled together with a hydrocarbon-containing dry distillation gas under excess air and mineral components. It burns at a temperature that results in a molten stream that exists in the form. With this proposal, the above-mentioned problems in containing pyrolysis products are suppressed and the mineral component is obtained in vitreous form.

[0009] Experience with combustion technology has shown that substances contained in the charge or newly formed during combustion and slightly volatile heavy metals evaporate and sublimate on subsequent heat exchanger surfaces,
The formation of deposits with slag droplets and incompletely burned coke particles suspended in the flue gas, causing operational disturbances, effective removal of which also results in high investment and operational costs, and possibly further performance limitations Bring. Otherwise,
To limit the emission of sulfur dioxide, hydrogen chloride, nitric oxide and volatile heavy metals, very extensive flue gas cleaning is still necessary, as in waste incinerators.

[0010] It has further been proposed and studied that plastics or plastic mixtures are melted by treatment with steam under high temperature and pressure, and that the plastic melt is used energetically by burning. As before, the same problem occurs.

In addition, a number of technical variants have been developed in which industrial and municipal sludges are mechanically and thermally pre-dried, alone or together with lignite or black coal, in special or conventional combustion units. Burned. Even in this case, the above-described problem of large-scale flue gas purification is not sufficiently understood.

[0012]

Based on such prior art, the object of the present invention was to address the disadvantages of combustion, in particular the subsequent need for extensive flue gas purification and the generation of toxic substances such as dioxins. An object of the present invention is to create an environmentally friendly method for utilizing combustibles, residues and wastes containing carbon and ash which are thermally and raw materials while avoiding danger. Furthermore, an apparatus for carrying out the method is developed.

[0013]

This object is achieved by the features of the features described in claims 1 and 4. Advantageous embodiments are set out in the dependent claims.

An advantage of the present invention is that lumps, fine granules, gypsum and liquid combustibles, residues and wastes which are non-uniformly structured and have different sources have different ash contents, heavy metals, toxic organic compounds and organic compounds. Regardless of the degree of harmful substances such as chlorides, clean, widespread, energy-efficient gases and pure mineral solid residues that are resistant to elution, available and easily deposited And without toxicity by, for example, polychlorinated bibenzodioxins and polychlorinated bivensofurans. By a combination of process steps known per se, such as drying, grinding, sorting, pyrolysis or extrusion, gasification and gas purification, household waste or household waste fractions, plastic-containing industrial waste, colored residues,
Combustibles, residues and wastes containing carbon and ash, such as used tires, crushed lightweights of automobiles, oil contaminated wastes and municipal and industrial sludges are treated. Various technical combinations are effective depending on the characteristics of the charged materials.

To carry out the process, the gasification of the mechanically or thermomechanically screened charge is carried out in an entrained flow reactor with oxygen or an oxygen-containing gasifying agent, the reaction chamber being It is surrounded by a completely cooled shade or by a profile consisting of a partially cooled shade and partially cooled refractory masonry wall. The ratio of the oxygen-free gasifying agent to the mechanically or thermomechanically sorted charge is such that the temperature regulated in the gasification reactor is higher than the melting point of the gasification mineral residue and the enamel melting slag is It is estimated that the resulting organic components of the charge are converted to gas containing CO and H ₂ by self-heating.

The molten enamel slag is cooled, granulated in contact with water and taken out of the gasification reactor. C
The gaseous gas rich in O and H ₂ is similarly cooled, liberating sulfides, hydrogen halides and aerosols.

[0017]

BRIEF DESCRIPTION OF THE DRAWING The invention will be described with reference to five schematic illustrations and two exemplary embodiments of the method and the equipment required for it.

Embodiment 1 relates to gasification of refuse from home. The supplied household waste 35 is, after pre-cutting not shown in the chart, passed through a silo 1 to a pyrolysis furnace 2 in the form of a rotary tube furnace 2 for heating the gas from the outside with pure gas produced by this apparatus. Supplied and subject to a carbonization process at a final temperature of about 650 ° C. Technically normal adoption
Eject-and-Austragsschleusevorricht
ungen), the carbonization process proceeds in effect with air cutoff. Under these preconditions, the organic contents of the household waste 35 are transformed into the pyrolysis residue 24 such as coke while separating the pyrolysis raw gas 26 having the vapor hydrocarbon. This residue is taken out of the rotary pipe 2 through a common descending case 25 having an airtight take-out passage together with a wide range of unchanged inorganic components of household waste, and supplied to the crusher 4. Pyrolysis raw gas 26 descends upward Case 2
5 and solid particles are removed in the dust separator 3 without substantial cooling.

The effluent from the crusher 4 passes through a filter 5 having a filter cloth with a mesh width of about 15 mm, whereby the coke-containing components are not contaminated with the concentrated fines and mainly from metal components without organic contamination. A crude product is obtained.
The fine matter 22 is mixed with the dust 21 from the dust separator 3 derived from the pyrolysis gas 26 by about 0.5 in the tube mill 6.
Milled to a particle size smaller than mm.

The pulverized fine material 19 is supplied to the air conveying device 8.
Is supplied as a fluidized stream 18 together with nitrogen as carrier gas 28 to a gasification reactor 9 operating according to the splash flow principle. In the gasification reactor 9, the compressor 7
The thermal decomposition raw gas 20 is introduced. It has been found that a minimum final compression temperature of 300 ° C. is sufficient or preferred.

The gasification reactor 9 comprises an outer pressure vessel containing a columnar reaction chamber which is designed for high-temperature operation and is connected below to a quenching chamber 10. In forming the reaction chamber,
The finish was demonstrated to be a tube wall structure that was cooled with pressurized water, covered with a fire resistant compressive body on the side of the reaction chamber, and hermetically welded. Pulverized pyrolysis coke, raw pyrolysis gas 20, and industrial oxygen O as a gasifying agent in fluidized stream 18
₂ and natural gas as an additional combustible for maintaining the supporting flame are introduced into the reaction chamber via a burner at the head of the reactor 9. The conversion to CO and H ₂ -containing gas takes place in the form of a flame reaction, wherein the oxygen O ₂ for the hydrocarbons or carbon contained in the pyrolysis raw gas 20, pyrolysis coke 19 and additional combustibles respectively. The proportions are estimated such that the temperature adjusted at the end of the reaction chamber is above the melting point of the mineral residue and enamel melt slag results. Usually about 140
A temperature of 0 ° C. is sufficient. For this purpose, an oxygen amount O ₂ equivalent to about 45% of the oxygen amount required for “stoichiometric combustion” of the combustible components introduced into the reaction chamber is required.

The gas generated in the reaction chamber mainly comprises CO and H ₂ as useful components, and further comprises CO ₂ and steam. NH ₃ , H ₂ S and HCl are minor components. The gas has no organic chlorides such as hydrocarbons and dioxins. This is a quenching room 10 with sulfur containing slag.
And is contacted with quenching water supplied via conduit 11. In doing so, the gas is cooled down to the saturation temperature, at the same time saturated with water vapor and released from residual dust, HCl and NH ₃ . The enamel molten slag solidifies and is collected in the pool 32 of the quenching chamber 10. It decomposes into granules 29 of glass structure on contact with water. Slag discharge unit 1 consisting of a recovery tank equipped with a scraper zone and filled with water
3 and discharged through the slag passage section 12.

The saturated gasified gas 31 is cooled in the gas cooler 14 while generating residual heat, and releases H ₂ S and NH ₃ in the gas purifier 15 in a usual manner. The H ₂ S fraction is ultimately processed into sulfur suitable for sale.

The remaining pure gas 16 is used for driving the gas motor 17 unless it is used for lower heating of the rotary tube furnace 2. Flue gas 30 generated at the time of lower firing of the rotary tube furnace 2
Is derived.

The condensate generated during cooling is quenching water 11
And returned to the quenching chamber 10. But quenching room 1
Residual water remaining without vaporization within 0 is derived from the circulation route. The chlorine load (Chlorfracht) of the charge contained and present as chloride ions is free of organic pollutants. The treatment is performed according to a known method (concentration).

Water content 20% Ash content 41.6% (no water) Carbon 33.1% Hydrogen 3.8% Oxygen 20.2% Nitrogen 0.7% Sulfur 0.1% Chlorine 0.5% Heat value With a charge of 20 t / h of household waste 35 having an approximate composition of 13.1 MJ / kg, a condensed hydrocarbon content of about 180 g / m ³ and a heating value (carbonization of 18.0 MJ / m ³ _N) 5200m ³ _N having a water vapor hydrogen vapors including) and 6000 m ³ _N / h
/ H of dry pyrolysis gas 26 is generated.

An additional 9500 kg / h of solid residue 24 is produced, which is divided into 2800 kg / h for large fractions 23 and 7300 kg / h for fines without carbon. Large fractions 23, which are resistant to dissolution and consist essentially exclusively of mineral and metallic components, are brought to further sorting and utilization or dust collection sites, while the ground fines 19 having an ash content of about 53% are converted to water vapor. And the pyrolysis gas 26 having hydrocarbon vapors are supplied to the gasification reactor 9 after the separation process in the separator 3.

The gasification is 5850 m at a pressure of 2 bar^Three _N/
h by technical oxygen conversion. At that time, you can add
600m as fire 27^Three _N/ H of natural gas is used
Is considered. 8.9 MJ / m^Three _NCalorific value and next set
19600m^Three _N/ H of gasification gas 31
: 37% H_Two  39% CO 20% CO_Two  4% N_Two The gas is 4 g / m in the form of hydrogen chloride.^Three _NChlorine and steam
Chloride salts (NaCl, KCl). This
The salts are contained in the quenching chamber 10 by washing water,
Approximately 150 kg / h solid salt after evaporative concentration of process wastewater
Produces a kind. Furthermore, the above gas is separated in the gas purifier and
About 0.8 g / m that is oxidized to 15 kg / h elemental sulfur^Three _N
Containing hydrogen sulfide. About 25% pure gas 16 rotates
It is returned to the heating of the tube furnace 8.

In the purified gas, about 5 mg / m ³ _N
Of sulfur is present. This corresponds to an SO ₂ content in the waste gas of about 2.5 mg SO ₂ / m ³ _N after the combustion or injection of the pure gas 16 in the gas motor 17 and satisfies all the requirements of environmental protection.

The melt stream gives 3600 kg / h of solidified glassy granules 29 which can be deposited without danger according to the dissolution tests carried out. The second embodiment relates to the gasification of an oil-solids mixture having a slight ash content, as shown in FIG. 3 et seq.

An oil-solids mixture having a slight ash content, eg, about 1%, is pumped by a pump 37 to maintain a large amount of the mixture in a circuit having a storage vessel 36.
Only the part 38 conveyed by the gasification and supplied for gasification is supplied to the burner of the gasification reactor 9 and converted into a synthesis gas together with oxygen and water vapor. The reaction partner is estimated such that the outlet temperature of the resulting gas from the reactor 9 reaches about 1400 ° C. Due to the low ash content of about 1 Ma%, it is possible to provide the cooling shade 39 only in the lower part of the reaction chamber and to refractory lining the upper part 41. This minimizes possible heat losses. The synthesis gas and the liquid slag are cooled in the quenching chamber 10. Further developments are described in Embodiment 1 above. If waste oil with a very low ash content of only 0.1 Ma%, residual oil from essential oil technology or pretreated plastic fractions is used, the reaction chamber according to FIG.
Lined enough. Long travel time (Reisezeite
To obtain n), only the slag outflow 40 is installed as a cooling system. The gasification process and gas separation are performed as described above.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the course of a method for using garbage leaving home.

FIG. 2 is a schematic diagram showing a gasification reactor provided with a cooling shade.

FIG. 3 is a schematic diagram showing the course of the method when utilizing an oil / solids mixture.

FIG. 4 is a schematic diagram showing a gasification reactor with a partially cooled shade.

FIG. 5 is a schematic diagram showing a gasification reactor with a refractory lining and a cooled slag effluent.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silo 2 Pyrolysis furnace 3 Dust separator 4 Crusher 5 Filter 6 Tube mill 7 Compressor 8 Conveying device 9 Gasification reactor 10 Quenching chamber 11 Conduit for quenching water 12 Slag passage part 13 Slag discharge part 14 Gas Cooler 15 Gas purification unit 16 Pure gas 17 Gas motor 18 Flowing flow 19 Fine substance / pyrolysis coke 20 Pyrolysis raw gas 21 Solid pyrolysis residue 22 Fine substance 23 Crude / large fractionated substance 24 Pyrolysis residue 25 Falling case 26 Pyrolysis raw gas 27 Additional combustibles / natural gas 28 Carrier gas 29 Granules 30 Flue gas 31 Gasification gas 32 Reservoir 35 Household waste / residue and waste 36 Storage container 37 Pump 38 Oil / solids mixture 39 Cooling shade 40 Slag effluent 41 Refractory lining 42 Separation bottom 43 Slit (Spalt)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Heinz Rolson, Germany Day 97261 Günthersleben Würzburger Strasse 14b (72) Inventor Wolfgang Heinrich Germany, Day 09599 Freiberg Schönlewestrasse 21

Claims (9)

[Claims] 1. Separation and gasification of combustibles, residues and wastes containing carbon and ash by a combination of process steps known per se such as drying, crushing, pyrolysis, classification, gasification and gas purification. The residue and waste (35) are subjected to a carbonization process at a temperature of up to about 800 ° C. in a pyrolysis furnace (2) with air cut-off, where heat containing vaporous hydrocarbons is obtained. A pyrolysis gas (26) and a solid pyrolysis residue (24) are generated, and the pyrolysis gas (26) is separated from the solid pyrolysis residue (21) at a temperature equal to or higher than the condensation temperature of the vaporized hydrocarbon being carried, The solid pyrolysis residue (24) undergoes a separation process consisting of a crushing and classifying step (4,5,6), where the fines (22) concentrated and crushed with coke-like components and mainly metal-free without organic contamination Consisting of ingredients The crude product (23) is obtained and the raw pyrolysis gas (20) separated from the solid pyrolysis residue, the finely divided material suspended in a fluid carrier medium and, optionally, an additional fluid combustible (27) are gaseous. reactor (9) is supplied to where they release oxygen containing gasifying agent (O ₂₎ CO and H ₂ in autothermal while forming a flame in a scattered stream having a
The ratio of the amount of free oxygen to the carbon contained in each of the pyrolysis gas, fines and optionally additional fluid combustibles is converted to a gasification reactor (31) and mineral residue. It is estimated that the temperature adjusted in 9) is above the melting point of the mineral residue and an enamel melt slag is produced, which slag is cooled with CO and H ₂ rich gas and comes in contact with water (11). The gas, which has been granulated and then cooled, and the granulated slag are discharged from the gasification reactor (9), the reaction chamber being completely defined by the cooling shade (39) and hermetically welded Sorting and gasification method using a gasification reactor consisting of a cooled, water cooled and vertically or spirally arranged tube. 2. The gasification reactor according to claim 1, wherein the combustibles, residues and waste are pulverized into fluidizable fines and supplied to the gasification reactor by a fluidized carrier medium. The method described in. 3. A pyrolysis raw gas (20) separated from a pyrolysis residue (24) of solids is heated by a heated gas compressor (7) at a temperature not lower than the boiling point of hydrocarbons contained in the pyrolysis gas. Aspirated and compressed to the pressure of the gasification reactor (9),
2. The process according to claim 1, wherein the final temperature of the compressor is maintained above the condensation temperature of the hydrocarbons, so that the temperature is typically above 300.degree. 4. An apparatus for implementing any one of claims 1 to 3, wherein the cooling shade (39) has a separation bottom (42) between the reaction chamber (9) and the quenching chamber (10). Characterized in that it is securely mounted on the device and can be freely moved upward. 5. The apparatus according to claim 4, wherein the cooling pipe is attached and covered with a compacted SiC mass. 6. A slit (43) formed between the cooling slag (39) and the pressure jacket and flushed with oxygen and condensate-free gas.
An apparatus according to claim 1. 7. A cooling shade (39) comprising a vertically or helically arranged tube which is hermetically welded at the bottom and cooled with water.
5. The apparatus according to claim 4, wherein a gasification reactor having a reaction chamber (9) comprising a refractory lining (41) at the top is used. 8. The reaction chamber (9) is completely surrounded by a refractory lining (41) and the cooling system comprises a slag effluent (4).
Device according to claim 7, characterized in that the device is limited to 0). 9. A transport pump (37) for combustibles, residues and wastes having a pumping function and consistently from a storage container (36).
9. The apparatus according to claim 4, which is fed directly to the burner of the gasification reactor via.