Method for preparing blast furnace blowing semicoke from low-rank coal based on high-pressure hydrothermal reaction

Abstract

The invention relates to a treatment method for dehydrating and upgrading high-moisture and high-volatile low-rank coal, and discloses a method for preparing blast furnace blowing semicoke by upgrading low-rank coal based on a high-pressure hydrothermal reaction, wherein the method comprises four steps of low-rank coal pretreatment, high-pressure hydrothermal upgrading, waste heat recycling and upgraded semicoke dehydration and drying. According to the method, low-heat-value low-rank coal is converted into high-quality blast furnace blowing upgrading semicoke by utilizing a high-pressure hydrothermal reaction upgrading technology, wherein the moisture content of the semicoke air drying base is less than 6%, the volatile component content is less than 25%, the Hardgrove grind ability indexis greater than 60, the high-order heat generation value is greater than 24000 kJ / kg, soluble potassium salt, sodium salt and sulfate components in ash are dissolved out, the organic sulfur in coal iseffectively separated out, and the upgraded semicoke can meet the performance index requirements of coal for blast furnace blowing; and the method provided by the invention effectively solves the problems of high water content, high volatile component content, low heat value and high harmful element content of blast furnace blowing of low-rank coal, and provides a clean, efficient, low-energy-consumption and high-added-value low-rank coal upgrading utilization method.

Description

technical field

[0001] The invention relates to a treatment method for dehydration and upgrading of low-rank coal with high moisture content, high volatile matter and low calorific value, in particular to a method for preparing blast furnace injection semi-coke by upgrading low-rank coal based on hydrothermal reaction . Background technique

[0002] The exploitation and utilization of fossil fuels play a vital role in the progress and development of human society. As one of the three major fossil fuels, coal resources are important energy and chemical raw materials for industrial production and life. Compared with oil and natural gas, the traditional coal utilization process has the disadvantages of low energy utilization efficiency and large pollutant emissions. From the perspective of long-term goals, "de-coalization" is the development direction of my country's energy transformation, but the characteristics of my country's energy reserves are "rich in coal, short of oil,...

Examples

Embodiment 1

[0030] The method of preparing blast furnace injection semi-coke from low-rank coal based on hydrothermal reaction, such as figure 1 shown, including the following steps:

[0031] (1) Low-rank coal raw coal pretreatment: crush the low-rank raw coal to a level less than 1mm, transport the crushed coal powder to the slurry storage tank through pipelines, and add water to the pulverized coal in the slurry storage tank to stir and mix, control The coal slurry moisture in the slurry storage tank is 40%;

[0032] (2) Coal slurry preheating treatment: After the coal slurry in the slurry storage tank is pressurized to 0.1MPa by a high-pressure coal slurry pump, it is transported to the coal slurry heat exchanger through a pipeline for preheating, and the coal slurry is preheated to 80°C;

[0033] (3) Hydrothermal carbonization treatment: The pressurized and preheated coal slurry is injected into the hydrothermal treatment system through pipelines, and the hydrothermal carbonization t...

Embodiment 2-5

[0038] Embodiment 2-5 provides a method for preparing blast furnace injection semi-coke from low-rank coal based on hydrothermal reaction. Compared with Embodiment 1, the difference is that the coal in step (1) and step (2) is changed The moisture content of the slurry, the delivery pressure of the high-pressure coal slurry pump, and the preheating temperature of the coal slurry are shown in Table 1.

[0039] Table 1 Coal slurry moisture content, high-pressure coal slurry pump delivery pressure and coal slurry preheating temperature corresponding to Examples 2 to 5

[0040]

[0041] The quality-improving semi-coke prepared in each embodiment was tested, and the results are shown in Table 2:

[0042] Performance of the upgraded semi-coke prepared in step (5) in Table 2 Examples 2-5

[0043]

[0044] As can be seen from Table 2, the water heat content of the air-dried base of the upgraded semi-coke prepared in Examples 2 to 5 is between 3.2% and 3.5%, the volatile matter ...

Embodiment 6～13

[0046] Examples 6-13 provide a method for preparing blast furnace injection semi-coke from low-rank coal based on hydrothermal reaction. Compared with Example 1, the difference is that the hydrothermal carbonization temperature and treatment in step (3) are changed Time, the specific values ​​of each embodiment corresponding hydrothermal carbonization temperature and processing time are as shown in table 3:

[0047] Table 3 Embodiment 6~13 corresponding hydrothermal carbonization temperature and processing time

[0048] Example heating temperature, ℃ Processing time, h Example 6 300 4 Example 7 320 3.5 Example 8 340 3 Example 9 360 2 Example 10 380 1.5 Example 11 400 1 Example 12 340 4 Example 13 340 2

[0049] The quality-improving semi-coke prepared in each embodiment was tested, and the results are shown in Table 4:

[0050] Performance of the upgraded semi-coke prepared in step (5) in Table 4 Exampl...

technical field

[0001] The invention relates to a treatment method for dehydration and upgrading of low-rank coal with high moisture content, high volatile matter and low calorific value, in particular to a method for preparing blast furnace injection semi-coke by upgrading low-rank coal based on hydrothermal reaction . Background technique

[0002] The exploitation and utilization of fossil fuels play a vital role in the progress and development of human society. As one of the three major fossil fuels, coal resources are important energy and chemical raw materials for industrial production and life. Compared with oil and natural gas, the traditional coal utilization process has the disadvantages of low energy utilization efficiency and large pollutant emissions. From the perspective of long-term goals, "de-coalization" is the development direction of my country's energy transformation, but the characteristics of my country's energy reserves are "rich in coal, short of oil,...

Examples

Embodiment 1

[0030] The method of preparing blast furnace injection semi-coke from low-rank coal based on hydrothermal reaction, such as figure 1 shown, including the following steps:

[0031] (1) Low-rank coal raw coal pretreatment: crush the low-rank raw coal to a level less than 1mm, transport the crushed coal powder to the slurry storage tank through pipelines, and add water to the pulverized coal in the slurry storage tank to stir and mix, control The coal slurry moisture in the slurry storage tank is 40%;

[0032] (2) Coal slurry preheating treatment: After the coal slurry in the slurry storage tank is pressurized to 0.1MPa by a high-pressure coal slurry pump, it is transported to the coal slurry heat exchanger through a pipeline for preheating, and the coal slurry is preheated to 80°C;

[0033] (3) Hydrothermal carbonization treatment: The pressurized and preheated coal slurry is injected into the hydrothermal treatment system through pipelines, and the hydrothermal carbonization t...

Embodiment 2-5

[0038] Embodiment 2-5 provides a method for preparing blast furnace injection semi-coke from low-rank coal based on hydrothermal reaction. Compared with Embodiment 1, the difference is that the coal in step (1) and step (2) is changed The moisture content of the slurry, the delivery pressure of the high-pressure coal slurry pump, and the preheating temperature of the coal slurry are shown in Table 1.

[0039] Table 1 Coal slurry moisture content, high-pressure coal slurry pump delivery pressure and coal slurry preheating temperature corresponding to Examples 2 to 5

[0040]

[0041] The quality-improving semi-coke prepared in each embodiment was tested, and the results are shown in Table 2:

[0042] Performance of the upgraded semi-coke prepared in step (5) in Table 2 Examples 2-5

[0043]

[0044] As can be seen from Table 2, the water heat content of the air-dried base of the upgraded semi-coke prepared in Examples 2 to 5 is between 3.2% and 3.5%, the volatile matter ...

Embodiment 6～13

[0046] Examples 6-13 provide a method for preparing blast furnace injection semi-coke from low-rank coal based on hydrothermal reaction. Compared with Example 1, the difference is that the hydrothermal carbonization temperature and treatment in step (3) are changed Time, the specific values ​​of each embodiment corresponding hydrothermal carbonization temperature and processing time are as shown in table 3:

[0047] Table 3 Embodiment 6~13 corresponding hydrothermal carbonization temperature and processing time

[0048] Example heating temperature, ℃ Processing time, h Example 6 300 4 Example 7 320 3.5 Example 8 340 3 Example 9 360 2 Example 10 380 1.5 Example 11 400 1 Example 12 340 4 Example 13 340 2

[0049] The quality-improving semi-coke prepared in each embodiment was tested, and the results are shown in Table 4:

[0050] Performance of the upgraded semi-coke prepared in step (5) in Table 4 Exampl...

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