KR102439355B1 - Blomas gasification system - Google Patents

Abstract

The present invention is to provide a biomass gasification system capable of obtaining biochar with high economic value from fly ash discharged from the gasifier. Synthesis of a gasifier for gasifying by burning and pyrolysis of biomass and the high heat generated in the gasifier A biomass gasification system provided with a heat exchanger for separating residues such as tar, moisture and foreign substances by lowering the temperature of the gas through heat exchange and a scrubber for separating and removing fine residues in the heat-exchanged syngas, installed between the gasifier and the heat exchanger with cyclones; a vertical fly ash pipe installed at the bottom outlet of the cyclone; a cooling device installed with a height difference on the outside of the fly ash pipe; It features a biomass gasification system consisting of; a fly ash tank installed at the lower end of the fly ash pipe.

Description

Biomass gasification system {Blomas gasification system}

The present invention relates to a biomass gasification system for pyrolyzing biomass to produce syngas, and in particular, through a cyclone disposed between a gasifier and a heat exchanger, it is possible to obtain biochar with high economic efficiency in high yield. It relates to a biomass gasification system.

Biomass refers to living organisms, including plants, cells, and animals that feed on them, generated by photosynthesis of plants and microorganisms receiving solar energy.

Biomass resources include starch-based resources such as grains, cellulose-based resources including agricultural products such as wood, straw, and rice husks, sugar-based materials such as sugar cane and sugar beets, and organic wastes such as food waste.

Straw is a very difficult fuel to corrosive under the operating conditions of general high-pressure and high-temperature steam line power plants because of its low calorific value compared to coal, oil, and natural gas, but strong reactivity due to chlorine and alkali components.

CHP using biomass is more expensive than coal CHP, but demand is increasing due to the expansion of renewable energy, reduction of CO ₂ emission, and increasing severity of waste treatment problems.

According to the research results, the biomass gasification system is so effective that it has achieved 94% efficiency by using natural gas, petroleum, straw, and wood chips as a multi-fuel CHP facility with a heating capacity of 570 MW.

About 0.1% of solar energy is stored as biomass. The advantage of biomass is that there is essentially no environmental impact caused by carbon dioxide.

Biomass is being considered as an alternative resource for petroleum as subsequent processes that can produce heat, electricity, liquid fuel, and basic chemical fuel materials from syngas, a clean fuel obtained from biomass, are developed.

In order to use biomass in the existing energy production system, it must be converted into gaseous syngas, and the technology required for this is a biomass gasification system.

A biomass gasification system includes a gasifier for gasifying straw, wood snow, waste wood, etc., a heat exchanger for separating impurities by exchanging the gas generated in the gasifier, and a scrubber for removing residual impurities in the gas from which impurities are separated by heat exchange. include

There are two types of gasifiers: upflow and downflow. The upflow gasifier has a section for partial combustion, reduction, and pyrolysis and a drying section. Oxygen is supplied to the lower part of the gasifier to react with the biomass, and the generated gas moves to the upper part. Since the high-temperature gas passes through the biomass fuel layer, it maintains a low temperature and has high efficiency.

Downflow gasifier is supplied to the lower side of the biomass raw material stocked with air moves to the lower part of the gasifier. Unlike the upflow gasifier, it can reduce tar affecting the engine for power generation, but it is difficult to treat biomass fuel with low efficiency and moisture and ash remaining after burning biomass, and the ignition time is long.

When biomass is gasified in a gasifier, unreacted carbon powder remains with ash, and water, tar, and volatile matter are separated from the syngas. Ash, water, tar and volatile matter are impurities. Bio, which is composed of carbon monoxide, hydrogen, methane, etc., can be used as energy for transportation, power generation, and heating, and can also produce high value-added fuels such as synthetic natural gas, FT diesel, and bio-hydrogen through catalytic synthesis or biological conversion In order to increase the purity of the mass gas, the residue should be separated as much as possible.

Moisture and volatile matter evaporate from the coal charged in the melting furnace, and the volatile matter rises to the reduction furnace to reduce the ore, and the char (fixed carbon content and ash) from which the moisture and volatile matter has been removed descends to the bottom of the melting furnace for final reduction and melting of the ore. After being used in a gasifier, it is converted into syngas and is directed to a heat exchanger and a scrubber (Registration Patent No. 10-1170410).

Failure to lower the temperature of the high-temperature fly ash exceeding 800°C exiting the gasifier of the biomass gasification system may cause a fire.

In addition, biochar may remain in the fly ash, and the conventional biomass gasification system cannot generate residual biochar from the fly ash.

Registered Patent No. 10-1170410

An object of the present invention is to provide a biomass gasification system capable of obtaining high economic value biochar from fly ash discharged from a gasifier.

The technical problem of the present invention is a gasifier for gasifying by burning and pyrolysis of biomass, and a heat exchanger and heat exchanger for separating the residues such as tar, moisture and foreign substances by lowering the temperature through heat exchange of the high-heat syngas generated in the gasifier A biomass gasification system having a scrubber for separating and removing fine residues in the synthesized gas, comprising: a cyclone installed between the gasifier and a heat exchanger; a vertical fly ash pipe installed at the bottom outlet of the cyclone; a cooling device installed with a height difference on the outside of the fly ash pipe; It can be implemented as a biomass gasification system consisting of; a fly ash tank installed at the bottom of the fly ash pipe.

Among the biomass gas that exits the gasifier and flows into the cyclone, the high-temperature fly ash is rapidly cooled by the cooling device in the process of falling down the fly ash tube to generate char, and the char is collected in the fly ash tank.

Since the biomass gas exiting the gasifier is rapidly cooled in a cyclone before passing through the heat exchanger, high-quality char can be obtained quickly and efficiently.

In addition, since the high-temperature fly ash discharged from the gasifier is cooled to a low temperature and stored in the fly ash tank, the risk of fire when falling to the ground disappears.

1 is a conceptual diagram of a biomass gasification system according to the present invention;
2 is a structural diagram of a cyclone;

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings prepared based on preferred embodiments.

1 is an overall configuration diagram of a biomass gasification system equipped with a cyclone 10 for generating char.

That is, a gasifier (1) for gasifying biomass by combustion and thermal decomposition, and a heat exchanger ( 2) and a pipe line (4) connecting the gasifier (1) and the heat exchanger (2) based on the existing biomass gasification system provided with a scrubber (3) for separating and removing fine residues in the heat-exchanged syngas ) on the cyclone 10 is installed.

The cyclone 10 is described more clearly in FIG. 2 . A vertical fly ash pipe 11 is installed at the outlet formed at the lower end of the cyclone 10 , and a cooling device 12 is installed on the outside of the fly ash pipe 11 .

The fly ash 14 in the biomass gas flowing into the cyclone 10 has a high temperature exceeding 800°C. Water, volatiles, and ash are mixed in the high temperature fly ash 14 . Water and volatile substances are evaporated and volatilized immediately, and the gasified flue gas 15 is discharged to the heat exchanger 2, and the dried char 16 is dried by evaporation and volatilization of water and volatile substances through the fly ash pipe 11. descend

A cooling device 12 is installed on the outside of the fly ash pipe 11 . The cooling device 12 is arranged at equal intervals with a predetermined height difference on the fly ash tube 11 to cool the fly ash in a short time and evaporate and volatilize the residue and volatile matter to promote charring.

The char 16 that changes shape by rapid cooling and falls is contained in the chartong installed at the lower end of the fly ash tube 11 , that is, the fly ash tube 13 .

The char 16 collected from the fly ash bin 13 is charged together with coal in the production of molten iron, thereby contributing to raising the furnace temperature and reducing energy costs for manufacturing molten iron.

1: gasifier
2: heat exchanger
3; scrubber
10: Cyclone
11: Fly Ash Hall
12: chiller
13: fly ashtong
14: fly ash

Claims (1)

A cyclone for generating char, a vertical fly ash pipe installed at the bottom outlet of the cyclone, a gasifier that burns and pyrolyzes biomass to gasify it, and the high-heat syngas generated in the gasifier is lowered by heat exchange to lower the temperature, such as tar, moisture, foreign matter, etc. In the biomass gasification system provided with a heat exchanger for separating the residue of, and a scrubber for separating and removing fine residues in the heat-exchanged syngas,
a cooling device installed with a height difference on the outside of the fly ash pipe; a fly ash tube installed at the lower end of the fly ash tube; Biomass gasification system, characterized in that consisting of.

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