1 thought on “Influencing factors of coal methane adsorption capacity”
Myra
2.5.2.1 The main control of coal deterioration on the adsorption capacity of coal Figure 2.28 The index fitting relationship between the balance between the balancing coal sample and the coal grade in North China The degree of quality of coal to coal Adsorption performance has an important control effect. After fitting the measured mirror -based reflectance RO and Lan's volume V1, it is found that the two have a significant S -shaped curve fitting relationship: V = E238/R. In this shows that for the high coal -level coal and rock samples in North China, with the increase of the reflectivity of the coal rock mirror group, the adsorption capacity of the coal is enhanced. Among them, when RO u003C1.1 % is 1.1 % After that, the growth gradually slowed down (Figure 2.28), which was basically the same as the results of their predecessors. The change of coal adsorption capacity with the change of coal grade shows that the adsorption capacity of coal -grade coal plays a major control role. The main reason is that the pore structure in the coal grade has changed regularly, and the large holes gradually close, and the small pores and micro -pores gradually increase. , Improve the adsorption capacity of coal. 2.5.2.2 The impact of coal rock organic microcomposition The material composition of coal includes organic microscopic components and minerals, which has an important impact on the adsorption capacity of coal. The organic microcomposition of coal includes three types: mirror group, inertial group, and shell group. The mirror group is a glue -like substance formed by the action of plants by planting. The lazy group is the product of silk carbonization. The shell group is derived from the leather tissue and secretions of the plant, as well as secondary substances related to these substances, namely spores, horny and bark. It is generally believed that the adsorption capacity of the shell group is the lowest, while the adsorption capacity of the mirror group and the inertial group is strong. Regarding the comparison of the adsorption ability of the mirror group and the inertia group and the impact of the two on the adsorption ability, different scholars hold different views. The impact of coal display micro -components on adsorption capacity is more complicated. It is necessary to consider coal grades, water in coal, ash, etc., and sometimes it is necessary to consider the impact of sedimentary background or coal phase. In from the perspective of the relationship between coal display microcomposition and adsorption capacity in North China, the adsorption capacity of coal has a significant positive correlation with the total content of the mirror group and the inertial group in the coal, that is, with the content of the components of the two components, the content of the two components content Increase, the adsorption capacity of coal is gradually enhanced (Figure 2.29A). Studies have found that the impact of the two mirror groups on adsorption capacity is less, and the effects of the amount of inertial content on coal adsorption must be considered at the same time. Due to the great impact of coal -grade coal adsorption capacity, and coal display micro components change with the change of coal grades, the interference of the coal grade must be ruled out. To this end Folding drawing (Figure 2.29B). It can be seen from the figure that with the increase in coal levels, the content of the inertia group in the coal shows the characteristics of phased changes. When the RO is less than 2.05 %, the coal adsorption capacity is not obvious with the inertial content of the coal, but then the coal adsorption of coal adsorption The law of enhancement with the increase in the content of the lazy group is very obvious, that is, the two always obtain high and low value at the same time, indicating that the impact of the inertia group in the low and China coal -level stages on coal is compared. Small, and in the early stages of smoke -free coal, it has a great impact. This may be related to the performance of coal absorbing methane. Methane is always adsorbed in pores with smaller pores. In the low coal grade stage, the increase in micropores in the mirror group is the main reason for the increase of adsorption. The pores in a large number of developed inertia groups have become the main adsorption space. Therefore, in the high coal level, the adsorption capacity of coal is positively correlated with the content of the inertial group. Figure 2.29 The relationship between the content of the "mirror group inertia group" (A), the content of the ivy group (B) and the Lan family of the coal 2.5.2.3 coal carbon and hydrogen components The impact of the content The carbon and hydrogen component content in coal has a good correlation. The relationship between carbon content and Lan's volume shows that the adsorption capacity of coal is increased accordingly with the increase of the carbon content (Figure 2.30A), and the hydrogen content decreases with the increase of hydrogen content. The relationship between the carbon content and the volume of the Lan family (Figure 2.30B) can be seen that as the content of the coal -grade carbon component fluctuates high and low, the changes in the carbon content in the coal -grade are similar to the coal grade. The changes are significant positively. This law shows that the content of carbon and hydrogen in coal itself will also affect the adsorption of coal, but the impact is less impact than the coal grade. If Figure 2.30 The relationship between the content of carbon components in coal and the volume of Lan's 2.5.2.4 The effect of water in coal Water is an important component in coal. Significant influence. The moisture content in coal is related to the structure of coal grades and coal. The moisture content of the regional coal is mainly distributed between 1 % and 4 %. When the RO is less than 1.1 %, the moisture content in the coal decreases rapidly with the increase of the coal grade. The minimum value (less than 1 %), and then the water of the coal -level increased coal gradually increased, up to 4 % (Figure 2.31A). The folding line diagram (Figure 2.31B) with the change of water and Lan's volume with coal grades can be seen that the high value of the moisture content will be accompanied by the low value of Lan's volume in the similar interval of the coal grade, and vice versa. It shows that the existence of moisture in coal reduces the adsorption performance of coal. This law is more obvious after the fertilizer (RO is approximately 1.1 %). This law is exactly consistent with the law of coal -level changes. When the RO is less than 1.1 %, the impact of moisture is not obvious. The main reason is that the water in the coal was mainly free of water, and the moisture content gradually decreased with the coal grade. The main role. After RO greater than 1.1 %, the structure of the structure of the coal gradually increased, and the coal adsorption capacity increased slowly with the increase in coal grade (Figure 2.31A). Therefore, the existence of structural moisture in coal began to play a role. The main reason for the negative impact of the structure of the structure of the coal on adsorbing ability is the adsorption space of structural water filling coal filling, which must occupy a certain surface area, resulting in a reduction in the absorption of methane. Figure 2.31 The relationship between the moisture content in the coal in North China and the coal grade (A) The relationship between the volume of Lan's volume with the coal grade (B) Figure 2.32 The relationship between the gray content in the coal and the volume of the Lan family The effects of R n2.5.2.5 The relationship between the gray score in coal The relationship between the gray content in the coal and the volume of Lan's, as shown in Figure 2.32. The volume of coal has gradually increased with the decrease in the gray content. The reason is that the gas is mainly stored in the micro -holes, and the existence of ash blocks blocks some microporous, resulting in a decrease in coal ratio surface area, thereby reducing the adsorption performance of coal (Zhang Qun and Yang Xilu, 1999); another type; It is believed that the existence of the gray in the coal reduces the organic substances of adsorption of methane gas in the coal, and plays a diluted effect on the adsorbed methane concentration, thereby reducing the adsorption performance of the coal (et al., 1999). But in general, the existence of ash in coal reduces the adsorption performance of coal. In analysis of the adsorption characteristics of coal in the medium and high -deterioration coal areas in North China, the main factors that affect the adsorption capacity of coal reservoirs are coal deterioration, coal rock group points, coal element components, etc. Control the adsorption capacity of coal. Of course, there may be some other factors that affect the adsorption capacity of coal, such as the characteristics of the microporous structure of coal. This part of the content will be detailed in this chapter.
2.5.2.1 The main control of coal deterioration on the adsorption capacity of coal
Figure 2.28 The index fitting relationship between the balance between the balancing coal sample and the coal grade in North China
The degree of quality of coal to coal Adsorption performance has an important control effect. After fitting the measured mirror -based reflectance RO and Lan's volume V1, it is found that the two have a significant S -shaped curve fitting relationship: V = E238/R.
In this shows that for the high coal -level coal and rock samples in North China, with the increase of the reflectivity of the coal rock mirror group, the adsorption capacity of the coal is enhanced. Among them, when RO u003C1.1 % is 1.1 % After that, the growth gradually slowed down (Figure 2.28), which was basically the same as the results of their predecessors. The change of coal adsorption capacity with the change of coal grade shows that the adsorption capacity of coal -grade coal plays a major control role. The main reason is that the pore structure in the coal grade has changed regularly, and the large holes gradually close, and the small pores and micro -pores gradually increase. , Improve the adsorption capacity of coal.
2.5.2.2 The impact of coal rock organic microcomposition
The material composition of coal includes organic microscopic components and minerals, which has an important impact on the adsorption capacity of coal. The organic microcomposition of coal includes three types: mirror group, inertial group, and shell group. The mirror group is a glue -like substance formed by the action of plants by planting. The lazy group is the product of silk carbonization. The shell group is derived from the leather tissue and secretions of the plant, as well as secondary substances related to these substances, namely spores, horny and bark. It is generally believed that the adsorption capacity of the shell group is the lowest, while the adsorption capacity of the mirror group and the inertial group is strong. Regarding the comparison of the adsorption ability of the mirror group and the inertia group and the impact of the two on the adsorption ability, different scholars hold different views. The impact of coal display micro -components on adsorption capacity is more complicated. It is necessary to consider coal grades, water in coal, ash, etc., and sometimes it is necessary to consider the impact of sedimentary background or coal phase.
In from the perspective of the relationship between coal display microcomposition and adsorption capacity in North China, the adsorption capacity of coal has a significant positive correlation with the total content of the mirror group and the inertial group in the coal, that is, with the content of the components of the two components, the content of the two components content Increase, the adsorption capacity of coal is gradually enhanced (Figure 2.29A). Studies have found that the impact of the two mirror groups on adsorption capacity is less, and the effects of the amount of inertial content on coal adsorption must be considered at the same time. Due to the great impact of coal -grade coal adsorption capacity, and coal display micro components change with the change of coal grades, the interference of the coal grade must be ruled out. To this end Folding drawing (Figure 2.29B). It can be seen from the figure that with the increase in coal levels, the content of the inertia group in the coal shows the characteristics of phased changes. When the RO is less than 2.05 %, the coal adsorption capacity is not obvious with the inertial content of the coal, but then the coal adsorption of coal adsorption The law of enhancement with the increase in the content of the lazy group is very obvious, that is, the two always obtain high and low value at the same time, indicating that the impact of the inertia group in the low and China coal -level stages on coal is compared. Small, and in the early stages of smoke -free coal, it has a great impact. This may be related to the performance of coal absorbing methane. Methane is always adsorbed in pores with smaller pores. In the low coal grade stage, the increase in micropores in the mirror group is the main reason for the increase of adsorption. The pores in a large number of developed inertia groups have become the main adsorption space. Therefore, in the high coal level, the adsorption capacity of coal is positively correlated with the content of the inertial group.
Figure 2.29 The relationship between the content of the "mirror group inertia group" (A), the content of the ivy group (B) and the Lan family of the coal
2.5.2.3 coal carbon and hydrogen components The impact of the content
The carbon and hydrogen component content in coal has a good correlation. The relationship between carbon content and Lan's volume shows that the adsorption capacity of coal is increased accordingly with the increase of the carbon content (Figure 2.30A), and the hydrogen content decreases with the increase of hydrogen content. The relationship between the carbon content and the volume of the Lan family (Figure 2.30B) can be seen that as the content of the coal -grade carbon component fluctuates high and low, the changes in the carbon content in the coal -grade are similar to the coal grade. The changes are significant positively. This law shows that the content of carbon and hydrogen in coal itself will also affect the adsorption of coal, but the impact is less impact than the coal grade.
If Figure 2.30 The relationship between the content of carbon components in coal and the volume of Lan's
2.5.2.4 The effect of water in coal
Water is an important component in coal. Significant influence. The moisture content in coal is related to the structure of coal grades and coal. The moisture content of the regional coal is mainly distributed between 1 % and 4 %. When the RO is less than 1.1 %, the moisture content in the coal decreases rapidly with the increase of the coal grade. The minimum value (less than 1 %), and then the water of the coal -level increased coal gradually increased, up to 4 % (Figure 2.31A).
The folding line diagram (Figure 2.31B) with the change of water and Lan's volume with coal grades can be seen that the high value of the moisture content will be accompanied by the low value of Lan's volume in the similar interval of the coal grade, and vice versa. It shows that the existence of moisture in coal reduces the adsorption performance of coal. This law is more obvious after the fertilizer (RO is approximately 1.1 %). This law is exactly consistent with the law of coal -level changes. When the RO is less than 1.1 %, the impact of moisture is not obvious. The main reason is that the water in the coal was mainly free of water, and the moisture content gradually decreased with the coal grade. The main role. After RO greater than 1.1 %, the structure of the structure of the coal gradually increased, and the coal adsorption capacity increased slowly with the increase in coal grade (Figure 2.31A). Therefore, the existence of structural moisture in coal began to play a role. The main reason for the negative impact of the structure of the structure of the coal on adsorbing ability is the adsorption space of structural water filling coal filling, which must occupy a certain surface area, resulting in a reduction in the absorption of methane.
Figure 2.31 The relationship between the moisture content in the coal in North China and the coal grade (A) The relationship between the volume of Lan's volume with the coal grade (B)
Figure 2.32 The relationship between the gray content in the coal and the volume of the Lan family The effects of R n2.5.2.5 The relationship between the gray score in coal
The relationship between the gray content in the coal and the volume of Lan's, as shown in Figure 2.32. The volume of coal has gradually increased with the decrease in the gray content. The reason is that the gas is mainly stored in the micro -holes, and the existence of ash blocks blocks some microporous, resulting in a decrease in coal ratio surface area, thereby reducing the adsorption performance of coal (Zhang Qun and Yang Xilu, 1999); another type; It is believed that the existence of the gray in the coal reduces the organic substances of adsorption of methane gas in the coal, and plays a diluted effect on the adsorbed methane concentration, thereby reducing the adsorption performance of the coal (et al., 1999). But in general, the existence of ash in coal reduces the adsorption performance of coal.
In analysis of the adsorption characteristics of coal in the medium and high -deterioration coal areas in North China, the main factors that affect the adsorption capacity of coal reservoirs are coal deterioration, coal rock group points, coal element components, etc. Control the adsorption capacity of coal. Of course, there may be some other factors that affect the adsorption capacity of coal, such as the characteristics of the microporous structure of coal. This part of the content will be detailed in this chapter.