WO2011014094A1

WO2011014094A1 - Method and device for recycling moist waste matter comprising organic materials

Info

Publication number: WO2011014094A1
Application number: PCT/RU2009/000560
Authority: WO
Inventors: Александр Яковлевич ШВАРЦМАН; Виктор Анатольевич МАЛКОВ; Емельян Иванович БАРБУС; Игорь Игоревич СМИРНОВ; Андрей Васильевич САМЧУК; Михаил Ремович ПАХОЛКОВ; Сергей Васильевич БЕШЕНЦЕВ
Original assignee: Shwarzman Alexander Jakovlevich; Malkov Viktor Anatol Evich; Barbus Emel Jan Ivanovich; Smirnov Igor Igorevich; Samchuk Andrej Vasil Evich; Paholkov Mihail Removich; Beshencev Sergej Vasil Evich
Priority date: 2009-07-29
Filing date: 2009-10-16
Publication date: 2011-02-03

Abstract

The invention relates to methods for recycling organic waste matter with an increased moisture content and a high concentration of harmful substances. The recycling of moist waste matter comprising organic materials is performed in a thermal decomposition chamber, namely a metallic continuous-action charcoal retort. The progression of the waste matter within the retort is ensured with the aid of a rotor. Metered charging of the waste matter ensures a composition of gaseous products of pyrolysis which maintains stable combustion in the combustion chamber. The combustion chamber is in the form of a cyclone-vortex chamber and is equipped with blowing fans. Carbon residue is combusted in the lower zone of the combustion chamber, and complete combustion of the carbon residue and combustion of the gaseous products of pyrolysis fed from the retort are performed in the central and upper zones. The effluent gases are fed outside the retort and within the rotor for heating the recycled waste matter. The technical result consists in ensuring the ecological safety of the process, extending the range of recycled waste matter, reducing energy consumption and increasing efficiency.

Description

Method and device for the disposal of wet waste containing organic materials

The present invention relates to methods for the disposal of organic waste with high humidity and a high concentration of harmful substances that are hazardous to the environment, by the method of thermochemical processing, in particular, chicken droppings, excrement of other domestic animals, lignin, wood waste, silt sediment, etc.

Three comparable methods of thermochemical processing of organic waste are known: direct burning, gasification, and pyrolysis. At the same time, each method has its own sector, determined by technological features.

With a wide variety of technological solutions proposed by both domestic and foreign experts, technologies that provide:

1. high environmental safety of the proposed process;

2. disposal of waste directly at the place of its occurrence;

3. unified technology for the disposal of a wide range of waste having different chemical and mineralogical composition;

4. low energy intensity of the recycling process itself;

5. non-waste technological process;

6. obtaining output products that are safe for placement, or having commercial value. A known method of disposing of waste containing organic materials, according to the patent of the Russian Federation N ° 2338122. The method and device described in this patent, as the closest to the proposed solution by its essential feature, are taken as a prototype. A known solution includes loading waste into a thermal decomposition chamber (KTP), heating and decomposing organic matter in KTP to form gaseous and solid products, burning them, catalytic decontamination, cooling in a heat exchanger and dust cleaning of flue gases. The waste is loaded into the thermal decomposition chamber through a sluice device constantly flushed with inert gas. The waste is subjected to oxygen-free thermal decomposition at a temperature of 550-700 ° C in a metal chamber heated externally by flue gases from burning external fuel in a burner located in the immediate vicinity of it, flue gases from a cyclone furnace obtained from burning therein at a temperature of 1200-1300 ° C gaseous pyrolysis products, and flue gases from combustion on the grate of solid pyrolysis products. The heat transfer in the internal volume of the thermal decomposition chamber is intensified by constant mixing of the waste and the creation of artificial circulation of the gas phase by supplying inert gas heated to 600-700 ° C to its lower part, the preparation of which is carried out due to the thermal potential of the flue gases. Gaseous products from the thermal decomposition chamber are introduced into the cyclone furnace by injection. As injection medium, pressurized air is used, preheated to 350-400 ° C with flue gases, the sludge trapped in the scrubber is sent for re-pyrolysis to the thermal decomposition chamber, and the entire process is carried out under vacuum. EFFECT: waste utilization with ensuring conditions for safe operation of equipment and environmental emissions acceptable under environmental conditions. The disadvantages of the known method and device are:

1. high energy intensity and lack of efficiency, since the use of external sources of heat and inert gas is required;

2. insufficient productivity, since it is impossible to continuously load recyclable waste and its continuous processing. The objective of the invention is the development of such a method and device for the disposal of organic waste, which would ensure high environmental safety of the proposed process, the possibility of disposal a wide range of waste, would have low energy intensity, high efficiency and productivity.

To solve this problem, it is proposed in a method for the disposal of wet waste containing organic materials, including continuous loading of waste into the thermal decomposition chamber, pyrolysis of the waste with constant stirring in the thermal decomposition chamber heated externally by flue gases obtained from burning pyrolysis products in the combustion chamber, as a thermal decomposition chamber, use a continuous continuous metal charcoal retort. It is proposed to place a rotor inside the retort, which moves the waste along the retort in the direction of increasing temperature. At the same time, due to the metered loading of utilized waste, such a concentration of a mixture of gases and water vapor released during the pyrolysis of waste is provided that is necessary to maintain stable combustion in the combustion chamber. It is proposed to additionally pass flue gases inside the rotor, thereby increasing the contact surface of the waste waste heating. The combustion chamber is proposed to be made in the form of a cyclone-vortex combustion chamber, in the lower zone of which the coal residue is burned, in the middle and upper zones, the coal residue is burned and gaseous products from the retort are burned to produce useful thermal energy and ash residue.

Additional differences of the proposed method is that:

- the dimensions of the retort are determined by the required performance of the device, while the ratio of its length to diameter should be 15: 1;

- part of the pyrolysis gases is diverted from the retort to the gas piston power plant; - as wet waste containing organic materials, there may be chicken droppings, excrement of other domestic animals, lignin, wood waste, silt deposits, etc.

To solve this problem, it is proposed in a device for the disposal of wet waste, including a thermally insulated body, inside which there is a thermal decomposition chamber connected to the combustion chamber, at In this case, the thermal decomposition chamber is equipped with a gas-tight device for loading waste waste and a gas-tight device for unloading pyrolysis products, while the combustion chamber is equipped with a flue gas outlet connected through a heat exchanger to the chimney, and the thermal decomposition chamber is connected by a gas exhaust pipe to the combustion chamber, and the thermal decomposition chamber perform in the form of a continuous charcoal retort. It is proposed to place a rotor inside the retort connected to the combustion chamber by a second gas exhaust pipe. It is proposed to load utilized waste using a gas-tight metering device. Whereas, the combustion chamber is proposed to be made in the form of a cyclone-vortex chamber and equipped with blow fans.

Additional differences of the proposed device is that:

- the dimensions of the retort are determined by the required performance of the device, while the ratio of its length to diameter should be 15: 1,

- that the retort is connected to a gas piston power plant.

- as wet waste containing organic materials, there may be chicken droppings, excrement of other domestic animals, lignin, wood waste, silt deposits, etc.

Thus, the solution of the problem in the described method is achieved through the application of methods of thermochemical processing of organic waste. Wastes coming to incineration (with humidity up to 75%) are subjected to preliminary thermodynamic treatment (pyrolysis) immediately before incineration as part of the incinerator due to part of the incineration energy.

Thermodynamic treatment ensures the combination of drying processes with the release of water vapor, the beginning of their gasification and thermal decomposition (pyrolysis) with the release of unbound carbon (coal residue).

As a result, gaseous СО, H ₂ , CnHm (hydrocarbons), as well as a coal residue with a sufficient calorific value, enter the combustion ability providing stable and complete combustion, as well as water vapor, which provides reduced emissions of NOx and SOx.

The result of the process is useful heat for steam supply, heating and hot water supply, ash and coal residues as products for various purposes (fertilizers, etc.).

The proposed solution has the following advantages:

1. A continuous process is ensured without the use of extraneous energy sources organized by burning other types of fuels, and using the utilized product released during the combustion of pyrolysis gases and coal residue to conduct the process of its own energy ..

2. The product is disposed of with a moisture content of up to 75%, and the released moisture ("vapor") in the form of water vapor, performs useful functions for disposal:

- serves during combustion to suppress the emission of harmful NOx and Sox, ensuring the environmentally friendly disposal process;

- serves as a coolant for the intensification of heat transfer in the retort reactor;

- together with pyrolysis gases creates excess pressure in the retort, which prevents the ingress ("suction") of atmospheric air and provides an oxygen-free process of thermal decomposition of the utilized product (litter).

3. Inside the rotor, incandescent flue gases move, as a result, there is no need to use an inert gas (as in the prototype) and unnecessary heat energy to heat it.

4. The method also differs in that due to the precise dosing of the utilized product during its transportation in the retort in the direction of increasing temperature, its "zone" heat treatment is provided.

The first zone with a temperature of 100 ° C ÷ 200 ° C provides evaporation of moisture. The 2nd zone with a temperature of 200 ° C ÷ 400 ° C provides heating and the beginning of pyrolysis.

The 3rd zone with a temperature of 400 ° C ÷ 800 ⁰ C provides fast pyrolysis and the release of coal residue and pyrolysis gases.

Such “zone” treatment provides in retort the concentration of a mixture of gases and water vapor (vapor) with a constant composition necessary for stable combustion.

5. If the moisture content of the utilized product is less than 70%, it is possible to isolate part of the coal residue as a useful technological product, or to divert part of the pyrolysis gases to the gas-piston power plant, since at such humidity the calorific value of the pyrolysis gases or coal residue is enough to conduct the recycling process. The proposed device is an energy technology unit that produces technological and energy products. To intensify the technological processing of waste, a cyclone-vortex burner device and the supply of flue gases into the rotor pipe were used. Figure l shows a diagram of a device for the disposal of wet waste containing organic materials, where:

1 Cyclone-vortex combustion chamber

2 Boron part

3 Retorts

4 Gas tight discharge device

5 Spark containment chamber

6 heat exchanger

7 Chimney

8 rotor

9 Gas tight metering device

10 Gas tight loading device

11 Retort body

12 Ash pan with cooler

13 Rotor drive

14 Dosing device drive

15 Blow fans

16 gas outlet pipe

17 Second exhaust pipe

flue gas in the rotor

> Product to be disposed of

Thermal decomposition products recyclable product (steam and gas)

Ash

ι Coal residue

> Flue gas

- = "- Air

The cyclone-vortex combustion chamber 1 consists of 3 combustion zones that are spaced apart along its height and are serviced by draft blower fans 15 with an adjustable combustion air supply.

In the lower zone of the combustion chamber, coal residue is burned as solid fuel coming from retort 3.

In the middle and upper zone, the afterburning of the coal residue and the combustion of gaseous products from the retort 3 occur.

The excess air (αt) (on which the content of toxic NOx and SOx depends) is regulated in each zone within the necessary limits - 0.9 ÷ 1.16.

In the upper zone, a gas mixture is burned - pyrolysis gas + H ₂ O (steam) - steam and gas, which also suppresses the appearance of NOx and SOx in the combustion gases. The presence of a sufficient concentration of water vapor provides the conditions for reducing the content of NOx and SOx:

- temperature 1300 - HOO ⁰ C;

- injection into the combustion zone of H ₂ O.

The combustion chamber 1 with its boron part 2 is connected with a thermally insulated housing 11, in which the retort 3 is placed, and the retort 3 is in turn connected with the combustion chamber 1 with a gas-tight discharge device 4 and a gas exhaust pipe 16.

Through the boron part, combustion gases from the furnace enter the housing 1 1, where along the path of their movement to the chimney 7, through the spark-collecting chamber 5 and the heat exchanger 6, the walls of the retort and the utilized product moving inside it are heated.

The movement of the utilized product and its intensive mixing is ensured by being placed in the retort 3 body by the rotor 8. The rotor 8 is a pipe to which the blades are welded (screw).

The movement of the product to be disposed of from the metering device 9 to the unloading device 4 occurs along the inner surface of the retort 3 with a temperature from IQO ⁰ C to 800 ⁰ C inside the retort 3. As a result, thermal decomposition of the product to be disposed of. The products of thermal decomposition of coal residue and combined-cycle gases through the discharge device 4 and the exhaust pipe 16 are fed into the combustion chamber 1 for low-temperature combustion. If necessary, the coal residue can be discharged separately as a technological product, and pyrolysis gases can be discharged to a gas piston power plant. Through the exhaust pipe 17 flue gases enter the rotor, increasing the hot contact surface, for additional heating of the utilized product. The design of the retort 3 (its dimensions - length and diameter) is determined by the required performance of the device. Determining is the necessary contact surface of the heating, along which the utilized product moves.

The ratio of the length of the retort to its diameter> 15: 1 was derived empirically and by calculation, so for a productivity of 500 kg / h the length of the retort is 9 m and its diameter is 0.6 m. In this case, the useful (contact) heating surface is 8.5 m ² .

The operation of the device is as follows. To bring the device into operating mode, a pre-dried fuel is loaded into the receiving hopper 10 with a metering device 9 equipped with level sensors of the feed material (this can be a recyclable product or other fuel, for example, dry sawdust). Based on 30 - 50 minutes of operation of the device.

The drive of the device’s transport system (the drive of the dosing device, the drive of the retort mixer, the drive of the draft blowing machines) is turned on.

When dried fuel passes through the entire system and enters the combustion chamber, it is ignited. It burns. As a result of retort

3 heats up to a temperature> 800 ° C in its front part, located above the boron part of combustion chamber 1, for ~ 30 minutes.

From this time, the feed of the product to be utilized starts from the metering device 9 and the device goes into operating mode.

As you move along the constantly heated retort and, intensively mixing, the utilized product goes through the drying - evaporation stage, heating and pyrolysis. As a result, the coal residue heated to a temperature of ~ 700 ° C enters the unloading device 4, and the vapor-gas mixture enters the gas exhaust pipe 16, which enter the combustion chamber for combustion. The energy of combustion provides constant heating of the retort.

The burning of coal residue occurs in the lower part of the combustion chamber and is provided by its blow fan 15.

Combustion of a gas-vapor mixture occurs in the upper part of the combustion chamber and is supported by a torch from burning coal residue. The air supply to the upper and middle part of the combustion chamber is also carried out by separate blower fans 15.

Cyclonic air supply by fans provides:

- repeated circulation of burning fuel particles and due to this, stable and complete combustion;

- high pressure in the combustion chamber prevents the coal residue and ash from settling to the bottom.

The high pressure in the combustion chamber, which is created by the blower fans, provides overpressure in the entire system without the use of a smoke exhaust (fan for smoke extraction) and the effective operation of the gravitational spark trap 5.

When there is enough energy for burning a gas-vapor mixture to support the utilization process, the entire coal residue is discharged into the quencher hopper.

An example of the practical application of the proposed method. ~ 2000 kg with a humidity of 72% were processed in a plant with a design designed for the disposal of 500 kg / h of chicken manure.

After ignition of the furnace with dry wood sawdust for 25 minutes, the following parameters were established in the device: 1. The temperature in the combustion chamber is 1150 ° C

2. Temperature at the front of the retort

(at the exit from the hog) - 970 ° C

3. The temperature of the combustion gases at the outlet of the housing - 504 ⁰ C

4. Temperature in the retort - in front - 730 ° C

- at the rear (at the metering device) - 28O ⁰ C

After these parameters were established, the supply of litter to the retort began.

Within 15 minutes after the start of litter delivery, the following parameters were established: 1. Temperature in the combustion chamber - 940 ° C

2. Temperature at the front of the retort

(at the exit from the hog) - 790 ° C

3. The temperature of the combustion gases at the outlet of the housing - 48O ⁰ C

4. Temperature in the retort

- in front of - 690 ⁰ C

- in the back (at the metering device) - 1 10 ⁰ C

Over the next 20 minutes, a regime was established that lasted for the next 180 minutes of processing 2000 kg of litter.

1. The temperature in the combustion chamber is 1050 ⁰ C

2. Temperature at the front of the retort

(at the exit from the hog) - 870 ⁰ C

3. The temperature of the combustion gases at the outlet of the housing - 490 ⁰ C 4. The temperature in the retort

- in front - 69O ⁰ C

- in the back (at the dosing device) - 115 ° C

According to the results of measuring the temperature and volume of the exhaust gases in the chimney, 480 kW of thermal energy was generated.

According to the results of monitoring the concentration of emissions into the atmosphere, emissions of harmful substances did not exceed the MPC.

Nitrogen oxides - 0.042 mg / nm ³

Sulfur dioxide - 0.25 mr / nm ³ The results of the study of the properties of the produced coal residue are given in table. 1 and 2.

Table.l Results of the study of some properties of pyrolyzed carbon samples.

1 P - pyrolyzed litter,

2K - pyrolyzed feed,

Sample Ш - ash content of 71% wt. (600 ° C), sample 2K - ash content of 65% wt.

Table 2

The results of the study of some sorption properties of pyrolyzed carbon samples in comparison with activated carbon BAU

*) initial concentration of 0.98 mg / l;

**) initial concentration of 1.01 mg / l;

***) oxidizability of the initial dist.water 0.75 mgOg / L.

The tables show that the pyrolyzed litter has pronounced sorption properties.

The research results allow us to draw the following conclusions:

1. The applied method and device for the disposal of wet waste reduce the volume, tonnage and hazard class of waste disposed, thereby reducing the environmental burden on the environment and significantly reducing the cost of waste disposal and maintenance. Both products (ash and coal residue, consisting of 29% activated carbon and 71% mineral component) have a wide range of applicability - from feed additives and fertilizers to fillers and binders in the construction industry.

Claims

Claim

1. The method of disposal of wet waste containing organic materials, including loading the waste into the thermal decomposition chamber, pyrolysis of the waste with constant mixing in the thermal decomposition chamber, heated externally by flue gases obtained from the combustion of pyrolysis products in the combustion chamber,

It is due to the fact that the thermal decomposition chamber is a continuous metal charcoal retort, inside of which there is a rotor, which moves the waste along the retort in the direction of increasing temperature, while due to the metered loading of utilized waste such a concentration of a mixture of gases and water vapor released during the pyrolysis of waste is provided that is necessary to maintain stable combustion in the combustion chamber, flue gases are additionally passed in three rotors, thereby increasing the contact surface of the heating of utilized waste, the combustion chamber is made in the form of a cyclone-vortex combustion chamber, in the lower zone of which the coal residue is burned, in the middle and upper zones, the coal residue is afterburned and gaseous products from the retort are burned, with obtaining useful thermal energy and ash residue

2. The method according to claim 1, with the fact that the dimensions of the retort are determined by the required performance of the device, while the ratio of its length to diameter should be 15: 1.

3. The method according to claim 2, with the fact that part of the pyrolysis gases is diverted from the retort to the gas piston power plant.

4. The method according to p.Z., on the basis of the fact that as wet waste containing organic materials, there may be chicken droppings, excrement of other domestic animals, lignin, wood waste, silt deposits and etc.

5. A device for the disposal of wet waste, including a thermally insulated body, inside which there is a thermal decomposition chamber connected to the combustion chamber, while the thermal decomposition chamber is equipped with a gas tight device for loading recyclable waste and a gas tight device for unloading the pyrolysis products, while the combustion chamber is equipped with an outlet for flue gases connected through a heat exchanger with a chimney, and the thermal decomposition chamber is connected by a gas exhaust pipe to the combustion chamber,

characterized in that the thermal decomposition chamber is made in the form of a continuous charcoal burning retort, inside of which there is a rotor connected to the combustion chamber by a second gas exhaust pipe, utilized waste is loaded with a gas-tight metering device, the combustion chamber is made in the form of a cyclone-vortex chamber and is equipped with blow fans.

6. The device according to claim 5, characterized in that the dimensions of the retort are determined by the required performance of the device, while the ratio of its length to diameter should be 15: 1

7. The device according to claim 6, with the proviso that the retort is connected to a gas piston power plant.

8. The device according to claim 7., Characterized in that as the wet waste containing organic materials, there may be chicken droppings, excrement of other domestic animals, lignin, wood waste, silt deposits, etc.