CZ20003012A3 - Waste treatment, especially based on organic substances - Google Patents

Abstract

According to the solution, the waste is first subjected to pyrolysis in the inert atmosphere of the pyrolysis unit and then the gaseous and/or solid pyrolysis product is fed together with combustion air and/or fuel to the blast furnace exhaust area, in a weight ratio of the pyrolysis product to the blast furnace charge ranging from 1:100 to 2:1.

Description

(57) Annotation:

According to the solution, the waste is first subjected to pyrolysis in the inert atmosphere of the pyrolysis unit and then the gaseous and/or solid pyrolysis product is fed together with combustion air and/or fuel to the blast furnace exhaust area, in a weight ratio of the pyrolysis product to the blast furnace charge ranging from 1:100 to 2:1.

CZ 2000 - 3012 A3

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Waste processing method, especially based on organic substances

Technical field

The invention relates to a method of processing waste, especially based on organic substances, based on the use of the pyrolysis process and the subsequent use of pyrolysis products as raw material or fuel in a blast furnace, which allows for the disposal of solid and liquid waste containing harmful substances in an environmentally friendly manner without negative impact on the environment while ensuring favorable economic parameters of the entire process.

State of the art

A method of thermal waste treatment is known, carried out by direct combustion of waste with sufficient air access with subsequent combustion of gaseous products at an elevated temperature. The combustion conditions, i.e. high temperature and excess oxygen, are chosen so as to completely decompose particularly stable chlorine compounds.

The disadvantage of this process is the increase in the concentration of nitrogen oxides in the flue gases, while the increased temperature makes it difficult to quickly cool the products to a temperature at which new formation of polychlorinated dibenzo-dioxins or furans no longer occurs. Therefore, the resulting flue gases must be subsequently cleaned, and the cleaning of the flue gases itself is more expensive than the combustion process. Cleaning the flue gases again creates toxic waste that must be stabilized.

Another well-known method of thermal waste treatment is pyrolysis. These processes are based on the thermal decomposition of organic substances by heat in the absence of air or with limited air access. The advantage of this process is the possibility of controlled uniform decomposition, while the formation of polychlorinated dibenzo-dioxins or furans is minimal. The gaseous product is a gas containing carbon monoxide, carbon dioxide, water vapor and hydrogen. The gas can be used as fuel after purification.

The disadvantage of this method is the difficulty in controlling the pyrolysis process, which can lead to explosions, especially with regard to the uneven composition of the waste.

A common drawback of both of the above methods is that the occurrence of municipal waste in particular is seasonal, with the amount of waste increasing in the summer. However, consumption decreases during this period.

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fuel to power units. The time mismatch between production and consumption results in uneconomical use of energy.

A method of processing waste by disposing of it in a blast furnace is also known, in which the waste is added to the blast furnace charge.

However, the disadvantage of this process is that the organic substances do not completely decompose in the upper part of the furnace and that the products of distillation and incomplete pyrolysis are carried away with the blast furnace gas, while existing gas purification plants do not allow for perfect gas purification, so that the final consumer receives gas containing pollutants.

Furthermore, a method of processing waste in a blast furnace is known, where solid and liquid waste substances are introduced into the blast furnace in the area of the discharges. In this case, all pollutants are completely burned.

However, the disadvantage is that it only allows for the processing of a limited amount of waste.

The essence of the invention

The above-mentioned shortcomings are largely eliminated by a method of processing waste, especially based on organic substances, in which the waste is first subjected to pyrolysis in an inert atmosphere of a pyrolysis unit, according to the invention, the essence of which lies in the fact that the gaseous and/or solid pyrolysis product is further fed together with combustion air and/or fuel into the blast furnace in the exhaust area, with the weight ratio of the pyrolysis product to the blast furnace charge ranging from 1:100 to 2:1.

The advantage of the method according to the invention is to achieve economically favorable waste disposal without negative impact on the environment and technological operation of the equipment, during their further evaluation. It is also an advantage that the risk of explosions during pyrolysis is minimized. Another advantage is that in a period of increased waste production with current low energy demand, a large volume of toxic waste is no longer landfilled, but part of the mass is converted into a solid product that can be more easily landfilled and used only in times of increased energy demand.

Example of embodiment of the invention

To illustrate the method according to the invention, an example of processing pasty waste containing aromatic hydrocarbons is given. Waste containing 12% by weight of toluene and 6% by weight of ·· 00

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0000 chlorobenzene was subjected to pyrolysis in a pyrolysis unit operated in an inert atmosphere and connected to a blast furnace. The pyrolysis product was a solid residue with a carbon content of 72% by weight. The product was added to the oil blown into the blast furnace in the exhaust area in an amount of 0.1 kg per liter of oil. The gaseous pyrolysis product was sucked in by the blown air. Analysis of the blast furnace gas showed that the gas composition corresponded to normal furnace operation. There was no increase in the concentration of undesirable substances during processing. The added amount did not affect the operating parameters of the blast furnace or negatively affect the course of the process.

Claims (1)

PATENT CLAIMS A method for treating waste, in particular based on organic substances, in which the waste is first subjected to pyrolysis under an inert atmosphere of a pyrolysis unit, characterized in that the gaseous and / or solid pyrolysis product is further fed together with the combustion air and / or fuel into the blast furnace in the exhaust region, wherein the weight ratio of the pyrolysis product to the blast furnace charge ranges from 1: 100 to 2: 1.