CN104194812B - A kind of method suppressing pyrolytic process low-rank coal or resinous shale efflorescence - Google Patents

Abstract

The invention discloses a method for suppressing pulverization of low-rank coal or oil shale in the pyrolysis process, which belongs to the technical field of chemical industry. Use the direct liquefaction residue of Shenhua coal and low-rank coal or oil shale to mix according to a certain ratio and then perform co-pyrolysis in a fixed bed to achieve effective adhesion and capture of pulverized products, reduce the amount of powder, and solve the problem of low-rank coal or oil The pulverization problem in the shale pyrolysis processing process, and the fixed bed pyrolysis processing of the liquefaction residue.

Description

A method for suppressing pulverization of low-rank coal or oil shale during pyrolysis

technical field

The invention relates to a method for suppressing pulverization of low-order coal or oil shale in the pyrolysis process, and belongs to the technical field of chemical industry.

Background technique

Low-rank coal has a high moisture content (30% to 60%), is prone to weathering and spontaneous combustion, is not suitable for long-term storage, has high transportation costs, and low combustion efficiency. Therefore, the key to large-scale development and utilization of low-rank coal is to thermally upgrade low-rank coal, reduce its moisture content, increase energy density, and meet the needs of long-distance transportation, safe storage and use of low-rank coal as thermal coal or chemical raw material coal. requirements. However, due to the special coal quality characteristics of low-rank coal itself, there is a serious pulverization phenomenon in the process of thermal upgrading, especially the pulverized coal products below 1mm, resulting in a high amount of dust in the production process, and system blockage often occurs , and it is difficult to separate the liquid product from the pulverized product, which affects the further processing and transformation of the liquid product. The same problem also occurs in the process of oil shale processing. During the pyrolysis process, the oil shale is subjected to coupling effects such as sudden vaporization of surface water and thermal stress, resulting in collapse, which seriously affects the normal operation of the process. With the reduction of high-quality coal resources in my country and the increase in the difficulty of mining, the demand for upgrading low-rank coal has increased significantly; my country's oil resources are in short supply, and it has become a new hot spot to obtain shale oil through oil shale pyrolysis processing to supplement the shortage of oil . However, in the existing pyrolysis technology, the problems of dust removal, dust prevention and dust separation during the thermal processing of low-rank coal or oil shale are always the key difficulties, which have not been well solved so far.

Contents of the invention

In order to overcome the deficiencies of the prior art, the present invention provides a method for inhibiting pulverization of low-rank coal or oil shale during pyrolysis.

The purpose of the present invention is to reduce the pulverization degree of low-rank coal (or oil shale) in the pyrolysis process, solve the crux of the low-rank coal and oil shale pyrolysis process, and realize the fixed bed pyrolysis processing of liquefaction residue use.

A method for suppressing the pulverization of low-rank coal or oil shale in the pyrolysis process, comprising the following steps;

Step 1), respectively crushing, screening, and grinding the low-rank coal (or oil shale) and the liquefaction residue to prepare to corresponding particle size grades, and the particle size ranges of the two are respectively low-rank coal or oil shale: greater than 13mm; Coal liquefaction residue: 6mm ~ 0.5mm;

Step 2), weighing a certain amount of low-rank coal (or oil shale) and liquefaction residue according to the set weight ratio;

The weight ratio range of materials is:

Low-rank coal (or oil shale): liquefaction residue = 9.5-7.0: 0.5-3.0;

Step 3), uniformly mix the weighed low-rank coal (or oil shale) with the liquefaction residue, and the mixing method is circular rotation stirring; in order to make the materials evenly mixed, the mixing operation method is the three-way mixing method:

① Circumferentially mixing 1/2 weight portion of low-rank coal (or oil shale) and 1/2 weight portion of liquefied residue to form mixture A, and the mixing time is 10 to 50 minutes;

②The remaining 1/2 weight share of the two materials is circularly mixed to form a mixture B, and the mixing time is 10 to 50 minutes;

③Mix mixture A and mixture B again in a circle, and the mixing time is 10-50 minutes to form the final mixture product A-B;

Step 4), add the final mixed product A-B into the fixed-bed reactor, carry out the co-pyrolysis upgrading with the final temperature of 400°C-900°C, and the upgrading time is 1h-6h, after the gas product precipitation is basically complete, it is cooled and discharged .

The advantage of the present invention is that at a final temperature of 400°C to 900°C, the yield of powders less than 1 mm after pyrolysis and upgrading of low-rank coal-liquefaction residue is 0.5% to 10%, while low-rank coal raw coal is pyrolyzed under the same conditions The final yield of powder less than 1mm is 6% to 23%. Compared with the pyrolysis of low-rank coal raw coal under the same conditions, the yield of powder less than 1mm is reduced by 5.5% to 13%. Oil shale-liquefaction residue The yield of powder less than 1mm after pyrolysis is 0.5% to 5%, while the yield of powder less than 1mm after pyrolysis of oil shale raw rock under the same conditions is 4% to 13%. The pyrolysis of raw shale rocks reduces the yield of powders less than 1 mm by 3.5% to 8%. The method has a good inhibitory effect on the output of fine powder after pyrolysis of low-rank coal or oil shale.

detailed description

Obviously, many modifications and changes made by those skilled in the art based on the gist of the present invention belong to the protection scope of the present invention.

Example 1: A method for inhibiting the pulverization of low-rank coal or oil shale in the pyrolysis process, specifically using the direct liquefaction residue of Shenhua coal and low-rank coal or oil shale to mix in a fixed bed Carry out co-pyrolysis to achieve effective adhesion and capture of pulverized products, reduce the amount of pulverization, solve the problem of pulverization in the pyrolysis process of low-rank coal or oil shale, and realize fixed-bed pyrolysis processing of liquefied residues.

The direct liquefaction residue of Shenhua coal is characterized by its strong cohesive properties in a hot state (above 200 °C), and it is impossible to obtain rich oil and gas products through pyrolysis processing in a fixed-bed reactor. After the liquefaction residue is mixed with low-rank coal or oil shale in a certain proportion, it can not only inhibit the pulverization of fossil fuel, but also inhibit the cohesiveness of the residue, so that it can realize fixed-bed pyrolysis. On the other hand, the liquefaction residue has a high hydrogen content, which can have a synergistic effect with coal during the upgrading process to improve the quality of oil and gas products. Therefore, during the pyrolysis process of low-rank coal or oil shale, taking advantage of its strong cohesiveness to collect pulverized products by adhesion can achieve the effect of suppressing dust and improve the quality of pyrolysis products at the same time. As a kind of industrial waste, the liquefaction residue can be co-pyrolyzed with low-rank coal (or oil shale) to restrict pulverization, which can not only solve the key problems in the pyrolysis processing of low-rank coal (or oil shale), but also It also realizes the high-value utilization of waste resources to a certain extent.

Embodiment 2: A method for suppressing pulverization of low-rank coal or oil shale in the pyrolysis process,

Step 1), crushing, screening, and grinding the lignite and liquefaction residue respectively to prepare to corresponding particle size grades, the particle size ranges of the two are lignite: 25-13mm; liquefaction residue: 3-1mm;

Step 2), weighing lignite and liquefaction residue according to the set weight ratio;

The weight ratio range of materials is:

Lignite: liquefaction residue = 8:2;

Step 3), the lignite after weighing and liquefaction residue are uniformly mixed, and the mixing method is circular rotation and stirring; in order to make the materials evenly mixed, the operation method of mixing is a three-way mixing method:

Add a fixed bed for co-pyrolysis at 500°C for 1 hour, and the yield of powders less than 1mm in the pyrolysis product is 1.57%. up 6.89%.

Embodiment 3: A method for suppressing pulverization of low-rank coal or oil shale in the pyrolysis process,

Mix the 25-13mm lignite and 6-3mm liquefaction residue with a weight ratio of 9:1 by circular stirring and evenly mix them, add them to a fixed bed for co-pyrolysis at 600°C for 2 hours, and obtain a powdery product yield of less than 1mm in the pyrolysis product It was 0.91%. Under the same conditions, the yield of lignite raw coal powder less than 1mm after pyrolysis was 13.53%, which was 12.62% lower than that.

Embodiment 4: A method for suppressing pulverization of low-rank coal or oil shale in the pyrolysis process,

The 25-13mm long-flame coal and the 3-1mm liquefied residue with a weight ratio of 8.5:1.5 were mixed evenly by circular stirring, and then added to a fixed bed for co-pyrolysis at 700°C for 2 hours to obtain a powder of less than 1mm in the pyrolysis product. The product yield rate is 2.01%. Under the same conditions, the yield rate of the powdery material less than 1 mm after pyrolysis of long-flame coal is 6.50%, which is 4.49% lower than that.

Embodiment 5: A method for suppressing pulverization of low-rank coal or oil shale in the pyrolysis process,

Mix 25-13mm oil shale and 3-1mm liquefaction residue with a weight ratio of 8:2, and mix them evenly in a circular motion, add them to a fixed bed for co-pyrolysis at 600°C for 1 hour, and obtain a powder of less than 1mm in the pyrolysis product The product yield is 0.95%. Under the same conditions, the yield of oil shale powder less than 1mm after pyrolysis is 4.76%, which is 3.81% lower than that.

Embodiment 6: A method for suppressing pulverization of low-rank coal or oil shale in the pyrolysis process, comprising the following steps;

Step 1), respectively crushing, screening, and grinding the low-rank coal (or oil shale) and the liquefaction residue to prepare to corresponding particle size grades, and the particle size ranges of the two are respectively low-rank coal or oil shale: greater than 13mm; Coal liquefaction residue: 6mm ~ 0.5mm;

Step 2), weighing a certain amount of low-rank coal (or oil shale) and liquefaction residue according to the set weight ratio;

The weight ratio range of materials is:

Low-rank coal (or oil shale): liquefaction residue = 9.5: 0.5

Step 3), uniformly mix the weighed low-rank coal (or oil shale) with the liquefaction residue, and the mixing method is circular rotation stirring; in order to make the materials evenly mixed, the mixing operation method is the three-way mixing method:

① 1/2 weight portion of low-rank coal (or oil shale) and 1/2 weight portion of liquefaction residue are circularly mixed to form mixture A, and the mixing time is 15 minutes;

②Circularly mix the two materials with the remaining 1/2 weight share to form a mixture B, and the mixing time is 15 minutes;

③The mixture A and the mixture B are circularly mixed again, and the mixing time is 20 minutes to form the final mixture product A-B;

Step 4), add the final mixed product A-B into the fixed bed reactor, carry out co-pyrolysis upgrading with a final temperature of 400°C to 900°C, and the upgrading time is 3 hours, and cool and discharge after the reaction is completed.

Embodiment 7:

A method for suppressing the pulverization of low-rank coal or oil shale in the pyrolysis process, comprising the following steps;

Step 1), respectively crushing, screening, and grinding the low-rank coal (or oil shale) and the liquefaction residue to prepare to corresponding particle size grades, and the particle size ranges of the two are respectively low-rank coal or oil shale: greater than 13mm; Coal liquefaction residue: 6mm ~ 0.5mm;

Step 2), weighing a certain amount of low-rank coal (or oil shale) and liquefaction residue according to the set weight ratio;

The weight ratio range of materials is:

Low-rank coal (or oil shale): liquefaction residue = 7.0:3.0

Step 3), uniformly mix the weighed low-rank coal (or oil shale) with the liquefaction residue, and the mixing method is circular rotation stirring; in order to make the materials evenly mixed, the mixing operation method is the three-way mixing method:

① 1/2 weight portion of low-rank coal (or oil shale) and 1/2 weight portion of liquefaction residue are circularly mixed to form mixture A, and the mixing time is 10 minutes;

②Circularly mix the two materials with the remaining 1/2 weight share to form a mixture B, and the mixing time is 10 minutes;

③The mixture A and the mixture B are circularly mixed again, and the mixing time is 10 minutes to form the final mixture product A-B;

Step 4), add the final mixed product A-B into the fixed bed reactor, carry out the co-pyrolysis upgrading at the final temperature of 400°C to 900°C, the upgrading time is 1.5h, and cool and discharge after the reaction is completed.

Embodiment 8:

A method for suppressing the pulverization of low-rank coal or oil shale in the pyrolysis process, comprising the following steps;

Step 1), respectively crushing, screening, and grinding the low-rank coal (or oil shale) and the liquefaction residue to prepare to corresponding particle size grades, and the particle size ranges of the two are respectively low-rank coal or oil shale: greater than 13mm; Coal liquefaction residue: 6mm ~ 0.5mm;

Step 2), weighing a certain amount of low-rank coal (or oil shale) and liquefaction residue according to the set weight ratio;

The weight ratio range of materials is:

Low-rank coal (or oil shale): liquefaction residue = 8.0:2.0

Step 3), uniformly mix the weighed low-rank coal (or oil shale) with the liquefaction residue, and the mixing method is circular rotation stirring; in order to make the materials evenly mixed, the mixing operation method is the three-way mixing method:

① Circumferentially mixing 1/2 weight portion of low-rank coal (or oil shale) and 1/2 weight portion of liquefied residue to form mixture A, and the mixing time is 50 minutes;

②Circularly mix the two materials with the remaining 1/2 weight share to form a mixture B, and the mixing time is 50 minutes;

③The mixture A and the mixture B are circularly mixed again, and the mixing time is 50 minutes to form the final mixture product A-B;

Step 4), add the final mixed product A-B into the fixed bed reactor, carry out the co-pyrolysis upgrading at the final temperature of 400°C to 900°C, the upgrading time is 1.5h, and cool and discharge after the reaction is completed.

As mentioned above, although the Example of this invention was demonstrated in detail, it is obvious to those skilled in the art that many modifications can be made as long as the inventive point and effect of this invention are not substantially deviated. Therefore, all such modified examples are also included in the protection scope of the present invention.

Claims (1)

1. suppress a method for pyrolytic process low-rank coal or resinous shale efflorescence, it is characterized in that containing following steps;

Step 1), low-rank coal or resinous shale and liquefied residue are carried out fragmentation, screening, grinding respectively, preparation is to corresponding particle size fraction, and both size fraction ranges are respectively low-rank coal or resinous shale: be greater than 13mm; Coal liquefaction residue: 6mm ~ 0.5mm;

Step 2), according to the weight proportion of setting, take low-rank coal or resinous shale and liquefied residue;

The weight proportion scope of material is:

Low-rank coal or resinous shale: liquefied residue=9.5 ~ 7.0:0.5 ~ 3.0;

Step 3), carry out Homogeneous phase mixing by taking the low-rank coal after weight or resinous shale and liquefied residue, hybrid mode be circular-rotation stir; For making material mix, the working method of mixing is three hybrid systems:

1. the liquefied residue of the low-rank coal of 1/2 weight quota or resinous shale and 1/2 weight quota is carried out circumference and be mixed to form batch mixing A, mixing time is 10 ~ 50min;

2. two kinds of materials of residue 1/2 weight quota are carried out circumference and be mixed to form mixed material B, mixing time is 10 ~ 50min;

3. batch mixing A and mixed material B are carried out circumference mixing again, mixing time is 10 ~ 50min, forms final mix product A-B;

Step 4), final mix product A-B is added fixed-bed reactor, carry out the copyrolysis upgrading that final temperature is 400 DEG C ~ 900 DEG C, the upgrading time is 1h ~ 6h, until gaseous product separate out basic completely after cooling discharging.