WO2015017904A1

WO2015017904A1 - Method for mixing and feeding of catalysts and promoters in the combustion of carbon-containing solid fuels

Info

Publication number: WO2015017904A1
Application number: PCT/BG2014/000014
Authority: WO
Inventors: Todor Kirilov PANCHEV; Rumen Ivanov Kunev
Original assignee: KOVACHKI, Hristo Atanasov
Priority date: 2013-08-08
Filing date: 2014-03-25
Publication date: 2015-02-12
Also published as: BG111548A; BG67339B1

Abstract

Method for mixing and feeding of catalysts and promoters of salts, oxides and hydroxides of metals and metalloids in combustion processes, using a variety of carbon-containing raw materials.

Description

METHOD FOR MIXING AND FEEDING OF CATALYSTS AND PROMOTERS IN THE COMBUSTION OF CARBON-CONTAINING SOLID FUELS

FIELD OF THE INVENTION

Combustion of carrx>n-containing substances in combustion plants. BACKGROUND OF THE INVENTION

On the addition of catalysts for enhancing the combustion of carbon-containing fuels, the main problem is their retention on the surface of the fuel particles for a longer period in order to maximize the effect.

The task of the present invention is to provide a method for mixing and feeding of chemical reagents for enhancing the combustion of carbon-containing fuels, reducing the unburned residue after the combustion process and for increasing the efficiency of combustion plants.

TECHNICAL SUMMARY OF THE INVENTION

The method for mixing and feeding of catalysts and promoters in the combustion of carbon-containing solid fuels consists of mixing the catalyst and the promoter in a ratio from 20 to 10, to 1, the particle size of the promoter particles should be smaller than that of the catalyst. The particle size of the catalyst is up to 1 mm and of the promoter up to 0.5 mm. The resulting mixture is ground to particle size less than the particle size of the fuel, but not greater than 1 mm. This operation is necessary for providing the necessary number of catalyst particles for each fuel particle with minimum amount. The catalyst mixture prepared in this way is dispensed to the fuel in a second mixer. The moisture content of the fuel is not limited in order to retain the catalyst particles on its surface. The so treated fuel is fed into the combustion plant before any kind of drying, prior to feeding the fuel into the burner of the respective plant.

The method is implemented by adding to various carbon-containing raw materials as catalysts compounds of transition metals, weak metals and metalloids, promoted with compounds of alkaline and alkaline earth metals.

The method according to the present invention is applicable to all types of combustion plants using solid carbon-containing fuel, including but not limited to power boilers on coal, biomass and different types of carbon-containing wastes.

The mixing of the catalytic mixture with the fuel in pulverized fuel boilers takes place before the mills of the boilers.

The mixing of the catalytic mixture in coal-fired boilers takes place depending on the type of boiler or burner in one of the two ways, indicated for grate-fired and for pulverized fuel fired boilers, respectively.

The mixing of the catalytic mixture in biomass boilers takes place depending on the type of boiler or burner in one of the two ways, indicated for grate-fired and for pulverized fuel fired boilers, respectively.

The mixing of the catalytic mixture in incinerators takes place according to the method of feeding the waste to the incinerator plant in one of the two ways, indicated for grate-fired and for pulverized fuel fired boilers, respectively. The mixing of the catalytic mixture in gasif iers of carbon-containing raw materials takes place depending on the mode of feeding the raw material to the gasifier in one of the two ways, indicated for grate-fired and for pulverized fuel fired boilers, respectively..

The following figures illustrate the invention:

Figure 1. Mixing of catalyst with coal in grate-fired boilers

1. Catalyst feed line

2. Promoter feed line

3. Mixer-dispenser

4. Raw coal line

5. Mixer for fuel and catalytic mixture

6. Line with treated fuel

7. Dispenser of fuel to the furnace

8. Grate

9. Furnace chamber

Figure 2. Mixing of catalyst with coal in boiler with mill

. Catalyst feed line

2. Promoter feed line

3. Mixer-dispenser

4. Raw coal line

5. Mixer for fuel and catalytic mixture

6. Line with treated fuel

7. Dispenser of fuel to the furnace

8. Mill

9. Burners

10. Furnace chamber

EMBODIMENTS

EXAMPLE 1

In grate-fired power boilers the mixing of the fuel (4) with the catalytic mixture takes place in a mixer (5) before the furnace dosing device (7). The catalytic mixture itself is prepared beforehand by mixing the catalyst (1) and the promoter (2) in a separate mixer-dispenser (3). From it the necessary amount of mixture is dosed into the mixer, as shown in Figure 1. After that the fuel mixture is fed to the furnace dispenser (7) and from there to the fuel grate.

The size of the catalyst particles should not be less than 1 mm in order to achieve the necessary effect with lower dosage of catalyst.

EXAMPLE 2

In power boilers with pulverized fuel burners the catalytic mixture is prepared as in grate-fired boilers in a mixer (3) and is dispensed into a mixer for coal (5), as shown in Figure 2. From there on conveyor belt (6) together with the fuel, through dispenser (7) it enters the mill (8), where the fuel mixture is milled and fed through the burners (9) into the furnace (10).

There is double mixing of the catalytic mixture and the fuel here, first a rough one in the mixer and then final in the mill. The particle size of the catalyst mixture should also be less than 1 mm. EXAMPLE 3

Biomass boilers are in principle most similar to coal-fired boilers. They can also be grate-fired and pulverized fuel fired. Therefore, the patterns of mixing are the same as in coal-fired. The requirement for the particles of the catalyst mixture is to be smaller or at most equal to the fuel particles. Otherwise it will be necessary to dispense a significantly greater amount of catalyst without the necessary effect.

EXAMPLE 4

There are many types of mcinerators specialized for different types of hazardous waste. The common between them is that they all have one or more incendiary and in most cases supporting burners as well, operating on gaseous or liquid fuel. The mixing of the catalytic mixture with the hazardous waste takes place outside the incinerator. Depending on the construction of the incinerator, the presence or absence of mill, the mixing is either according to Figure 1 or to Figure 2.

EXAMPLE 5

For improving the oxidation part of the processes in gasifiers by the method, according to the invention, the most suitable of the metal compounds sited in the description are the oxides and hydroxides.

The pattern of mixing of the catalyst with the raw material here is as in the power boilers, illustrated in Figure 1 and Figure 2. Which one of the two methods will be used depends on the type of the gasifier. The particle size of the catalytic mixture should be smaller than the particles size of the input raw material here as well.

Claims

PATENT CLAIMS

1. A method for mixing and feeding of catalysts and promoters in the combustion of carbon-containing fuels with the use of chemical reagents, characterized in that, catalyst and promoter are mixed in a ratio from 20 to 10, to 1, prior to mixing the particle size of the catalyst is up to 1 mm and of the promoter up to 0.5 mm, the resulting catalytic mixture is dispensed to the fuel, which is with non-limited moisture content and is fed for combustion before any drying of the fuel material.

2. A method according to claim 1, characterized in that, catalysts are compounds of transition metals, weak metals and metalloids.

3. A method according to claims 1 and 2, characterized in that, promoters are compounds of alkaline and alkaline earth metals.