DE3011157A1 - Municipal refuse disposal - by gasification after crushing, grinding and glass and metal extraction - Google Patents

Abstract

In a refuse gasification plant the refuse is reduced in particle size to under 2 mm, followed by gasification in a reactor at a working pressure of up to 200 bar. Before the gasification, glass, magnetic materials and aluminium are picked out and a pumpable slurry is produced by an admixture of waste oil and/or sludge and/or prime fuel. Several by-products can be recovered for re-use. No preparation is needed for sludge. The slurry simplifies the charging procedure in the reactor. The granulated ash residue causes no environmental pollution.

Description

Garbage disposal

by gasification with recovery of valuable substances The invention relates to a process for the gasification of household waste and hazardous waste.

The volume of household and household-like commercial waste in the Federal Republic Around 72% of Germany is currently being landfilled, around 25% in Waste incineration plants (MVA) incinerated and approx. 3.4% composted. The remainder is either through direct agricultural utilization or disposed of by other means of disposal. Waste incineration has significant shortcomings on: environmental pollution caused by smoke gases, leachability in landfills Residues to be deposited, hazardous waste (car tires, faeces, etc.) cannot be used in waste incineration plants, the recoverable energy cannot be stored. Through the indispensable flue gas cleaning, the profitability of tVA is decisive influenced. In addition, there is the seasonal dependency: only in winter time can the recovered energy can be fed into a district heating network. So is the generation of electricity Due to free capacities in summer only economically interesting in winter. In addition, the different amounts of waste must be taken into account. The garbage accumulation is considerably larger in the Seine than in winter.

There have long been efforts to use waste incineration plants instead of waste incineration plants to use. The gasification is a substoichiometric reaction ilt oxygen, combustion a stoichiometric reaction with oxygen.

With zero gasification, a gas is to be generated that is economical Use can be supplied. The use can e.g. B. by using it as a synthesis or fuel gas.

None of these attempts have yet become relevant in practice Solution led. This means that such pre-gassing systems are still in use in practice can not enforce. The causes are again primarily in the exhaust gas too Looking for.

The invention is based on the object of the Solving problems of conventional disposal through waste incineration. That will achieved according to the invention in that the garbage is initially reduced to a grain size # 2 mm is crushed and then gasified in a reactor. The gassing takes place autothermal in the presence of oxygen and / or oxygen-containing compounds at temperatures above the respective ash melting point under pressures of 10 - 200 bar ata, subsequent cooling of the resulting synthesis gas and the combustion residues and direct discharge of the solidified combustion residues.

In the case of waste gasification, the sulfur falls into the form of the production gas the connection H2S. The low compared to the flue gas in the garbage incineration The amount of product gas is used in a much less expensive gas scrubbing process - e.g. a Rectisol scrubbing - supplied to remove the hydrogen sulfide residue, to be stored in a downstream Claus plant the hydrogen sulfide an economic use to be able to supply. Accumulating HC1 will remain in the condensate and can after neutralization be repelled.

In a further embodiment of the invention, glass and magnetic materials are used and aluminum separated from the garbage prior to gasification.

This has multiple advantages: - These valuable substances can be recycled are fed.

- The efficiency of the gas generation system is increased.

- The effective throughput of the gas generator is increased.

It is particularly advantageous to remove the shredded garbage prior to gasification Used oil and / or sludge and / or wholesome substances are added. The waste oil causes an increase in calorific value.

Whole nutrients have the same effect. Come as full ingredients especially coals in finely ground form.

The possibility given by the gasification process according to the invention for the recovery of sludge has the following advantages: So far were Significant difficulties are associated with the removal of sludge. The sludge had to go with big.

technical effort are processed. This problem is eliminated by this invention. At the same time, the sludge is used in the method according to the invention as a water supplier. A pumpable "slurry" can be produced with the bad.

As a puwpfahiger slurry, the charge can be easily poured into the Enter reactor.

Granulated residues remain after gasification according to the invention Ash that is not leachable and cannot pollute the environment.

In the drawing, the invention is shown using two flow charts. The figures show: FIG. 1 a garbage preparation, FIG. 2 a garbage mixing with others Waste, Gasification and Gas Treatment.

According to FIG. 1, household waste is fed to a pre-shredding device 1. The pre-shredding device 1 consists of a crusher. The coarsely chopped Household waste comes from the pre-shredder 1 in one pre-sorting 2 = 'there he becomes household waste with the aid of sieves or by sorting with compressed air of non-combustible ones Substances largely exempted. The remaining combustible household garbage ends up in a Fine size reduction 3. The fine size reduction consists of a suitable mill, the Mill crushes household waste to a particle size of # 2 mm. The one in pre-sorting Separated waste is fed to a magnetic cutter 4. The magnetic cutter 4 removes magnetic substances. Non-magnetic substances get into a drum separator 5. The drum separator 5 is used to sort out glass.

The drum separator 5 is followed by a post-sorting 6, in FIG the non-ferrous metals except for aluminum are sorted out. This is what happens, for example again using gravity by inflating with compressed air.

The remaining garbage particles become one from the re-sorting 6 Fine crushing 7 supplied. The fine comminution 7 in turn consists of a suitable additive, which has a similar degree of fineness as fine grinding 3 works.

The particles comminuted in the fine comminution 7 pass through a fine sorting 8 in which aluminum is separated out. The streams from the crushing 3 and the fine sorting 8 are then merged.

With the plant a firm, storable, bacteriologically neutral one becomes Fuel won. The fuel has a calorific value of around 16 GJ / kg. The so Household waste processed as fuel is reduced in volume to a fraction of its original volume has been reduced and is very suitable for transport by rail and road. Thus can smaller municipalities are also assigned a system for garbage disposal and the processed waste is fed to a central gasification plant.

A mixer 13 is connected upstream of the waste gasification plant.

In the mixer 13, the processed household waste from a supply line 9, waste oil from a supply line 10, crushed waste tires with a particle size # 2 2 mm from a feed line 11 and sewage sludge from a feed line 12.

1. fischer 13 creates a homogeneous feedstock for a downstream Dust gasification plant 17. The input product is a solids containing approx. 50% pumpable suspension (slurry). Dis Suspsnsion is with overpressure against an operating pressure of, for example, 80 bar i. Reactor of the gasification plant 17 in the reactor pumped. At the same time, oxygen enters the reactor through a feed line 15. The oxygen can be supplied from an air separation plant via a feed line 14 will. The nitrogen 16 from the air separation can be used when shredding old tires Find use.

Oxygen and feed are in direct current at temperatures between 1,573 and 1,773 ° K (1400 to 1500 ° C) autothermally fermented. The resulting slag In liquid form, it enters a water bath located under the reactor, granulated there and is discharged from the system via a sluice. The slag discharge is denoted by 18.

A downstream waste heat system removes it from the production gas sensible warmth. This heat is used to generate steam. The final cooling of the Production gas takes place in a downstream quench cooler, which is in the gas deposited solid particles carried along. The gas cooled in this way is used in further Processing stages 19 processed for synthesis gas purposes and, if necessary, a conversion and / or lethanization stage fed. Instead of the use marked 20 As a synthesis gas, it is also used as town gas, shown schematically at 21 or natural gas / replacement gas possible.

Claims (6)

Claims 1. Garbage gasification, characterized by a garbage comminution to a particle size of # 2 mm and subsequent gasification in a reactor up to an operating pressure of 200 bar. 2. The method of claim 1, characterized in that prior to gasification Glass, magnetic substances and aluminum can be removed from the garbage. 3. The method of claim 1 or 2, characterized by the admixture of waste oil and / or sludge and / or of wholefood materials. 4. The method according to claim 3, characterized in that with the Slurry a pumpable slurry is produced. 5. The method according to one or more of claims 1 to 4, characterized by obtaining oxygen necessary for gasification by a known one Separation of air and use of the incipient nitrogen as a protective gas against Oxygen when shredding waste. 6. The method according to claim 5, characterized by the use of nitrogen gas for shredding old tires.