A rotary kiln low-rank pulverized coal pyrolysis upgrading method with gas circulation

Abstract

The invention provides a rotary furnace low-order powdered coal pyrolysis upgrading method with coal gas circulation. The rotary furnace low-order powdered coal pyrolysis upgrading method comprises the following steps: heating and drying raw material powdered coal with the granularity less than or equal to 30mm to be 110-280 DEG C in a low-order powdered coal rotary drying system with dust collection, and removing 85% of coal dust with the granularity less than 0.5mm in the powdered coal; feeding the dried coal with the granularity of 0.5-30mm to a downstream rotary pyrolysis system to react at 500-700 DEG C so as to generate upgraded coal and a high-temperature oil gas; feeding the high-temperature upgraded coal to a rotary cooling passivating furnace for primary cooling and medium / low temperature passivation, further cooling by using a spiral cooling machine, spraying water, and discharging out the product; feeding the high-temperature oil gas into an oil gas recycling system, and performing temperature reduction separation, thereby obtaining coal tar, pyrolysis water and pyrolysis coal gas; preheating a part of the pyrolysis coal gas, circulating back to the pyrolysis furnace, and discharging out the rest part of the pyrolysis coal gas.

Description

technical field

[0001] The invention relates to a new process technology for industrialized low-rank pulverized coal pyrolysis and upgrading, in particular to an industrial technology and equipment for pyrolysis upgrading using low-rank pulverized coal as raw material, which belongs to a new type of coal chemical industry technology field. Background technique

[0002] my country is rich in coal resources, among which low-rank coal accounts for more than 50% of the total coal in my country. However, low-rank coal usually has the characteristics of high oxygen content, high moisture, poor stability and low calorific value, so it is difficult for this type of coal to be used as a large-scale coal mine. Industrial gasification raw materials are mostly used as power fuels in local areas. Pyrolysis upgrading of low-rank coal can greatly change its pore structure, reduce its moisture and volatile content, improve its calorific value and thermal stability, and recover part of tar a...

Examples

Embodiment 1

[0049] 2 tons of Shenfu pulverized coal (0-30mm) are continuously sent to the direct and indirect combined rotary drying furnace, and the flue gas from the 600°C rotary pyrolysis furnace is passed through the jacket as a heat source to heat and dry the coal to 250°C. The water content is reduced to 0wt%; at the same time, 300°C circulating drying gas is introduced into the rotary drying furnace, and under the action of the gradual change combined distributor, more than 85% of the coal dust with a particle size of <0.5mm in the pulverized coal is removed.

[0050] The dry gas discharged from the rotary drying furnace entrains coal dust and water vapor, enters the dry gas processing unit to separate coal dust, cool down and recover dry water, pressurize the drying circulation fan, heat up the cooling heat exchanger to 300°C, and then return to the rotary drying Furnace, forming a closed loop of circulating drying gas.

[0051] The dry coal of 0.5-30mm from the rotary drying furn...

Embodiment 2

[0055] 6 tons of Shenfu pulverized coal (0-30mm) are continuously sent to the direct heating rotary drying furnace, and 450°C clean flue gas (O 2 Content 2vol%) as the drying heat source, heat and dry the coal to 250°C, and reduce the water content to 0wt%; at the same time, under the action of the gradual change combined distributor, the coal dust < 0.5mm and more than 85% in the pulverized coal remove.

[0056] The dry gas discharged from the rotary drying furnace entrains coal dust and water vapor, and enters the dry gas processing unit to separate coal dust, cool down and recover dry water, pressurize the drying circulation fan, and heat the cooling heat exchanger to 300 °C to supplement part of the rotary heat The high-temperature flue gas at the exit of the furnace jacket is returned to the rotary drying furnace to form a closed-circuit cycle of circulating drying gas.

[0057] The dry coal of 0.5-30mm from the rotary drying furnace enters the rotary pyrolysis furnace. ...

technical field

[0001] The invention relates to a new process technology for industrialized low-rank pulverized coal pyrolysis and upgrading, in particular to an industrial technology and equipment for pyrolysis upgrading using low-rank pulverized coal as raw material, which belongs to a new type of coal chemical industry technology field. Background technique

[0002] my country is rich in coal resources, among which low-rank coal accounts for more than 50% of the total coal in my country. However, low-rank coal usually has the characteristics of high oxygen content, high moisture, poor stability and low calorific value, so it is difficult for this type of coal to be used as a large-scale coal mine. Industrial gasification raw materials are mostly used as power fuels in local areas. Pyrolysis upgrading of low-rank coal can greatly change its pore structure, reduce its moisture and volatile content, improve its calorific value and thermal stability, and recover part of tar a...

Examples

Embodiment 1

[0049] 2 tons of Shenfu pulverized coal (0-30mm) are continuously sent to the direct and indirect combined rotary drying furnace, and the flue gas from the 600°C rotary pyrolysis furnace is passed through the jacket as a heat source to heat and dry the coal to 250°C. The water content is reduced to 0wt%; at the same time, 300°C circulating drying gas is introduced into the rotary drying furnace, and under the action of the gradual change combined distributor, more than 85% of the coal dust with a particle size of <0.5mm in the pulverized coal is removed.

[0050] The dry gas discharged from the rotary drying furnace entrains coal dust and water vapor, enters the dry gas processing unit to separate coal dust, cool down and recover dry water, pressurize the drying circulation fan, heat up the cooling heat exchanger to 300°C, and then return to the rotary drying Furnace, forming a closed loop of circulating drying gas.

[0051] The dry coal of 0.5-30mm from the rotary drying furn...

Embodiment 2

[0055] 6 tons of Shenfu pulverized coal (0-30mm) are continuously sent to the direct heating rotary drying furnace, and 450°C clean flue gas (O 2 Content 2vol%) as the drying heat source, heat and dry the coal to 250°C, and reduce the water content to 0wt%; at the same time, under the action of the gradual change combined distributor, the coal dust < 0.5mm and more than 85% in the pulverized coal remove.

[0056] The dry gas discharged from the rotary drying furnace entrains coal dust and water vapor, and enters the dry gas processing unit to separate coal dust, cool down and recover dry water, pressurize the drying circulation fan, and heat the cooling heat exchanger to 300 °C to supplement part of the rotary heat The high-temperature flue gas at the exit of the furnace jacket is returned to the rotary drying furnace to form a closed-circuit cycle of circulating drying gas.

[0057] The dry coal of 0.5-30mm from the rotary drying furnace enters the rotary pyrolysis furnace. ...

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