CN106635104A - Method for preparing high-performance compound machine-made charcoal - Google Patents

Abstract

The invention relates to a preparation method of high-performance composite machine-made carbon, which belongs to the technical field of resource comprehensive utilization. First, the biomass raw material and lignite with a moisture content of less than 5% are broken into particles with a particle size of less than 1cm; the obtained biomass raw material particles are pyrolyzed to obtain biochar; Mix evenly to obtain a mixed material, press the mixed material into a carbon rod with a central hole; heat the obtained carbon rod with a central hole at a heating rate of 30-200 °C/min to 400-700 °C for 1-12 hours, After cooling, a composite mechanism carbon is obtained. The preparation process uses abundant, low-cost, renewable and easily crushed biomass and low-cost lignite as carbon sources. It has the advantages of low mass production price, high yield, high calorific value, and high porosity. Welcome to the potential of composite mechanism charcoal.

Description

A kind of preparation method of high-performance composite machine-made carbon

technical field

The invention relates to a preparation method of high-performance composite machine-made carbon, which belongs to the technical field of resource comprehensive utilization.

Background technique

For a long time, charcoal has been widely used as living fuel. Charcoal is produced by burning or pyrolyzing wood under anoxic conditions. The production of charcoal requires a large amount of forest resources, which seriously damages the ecological environment. my country's forest coverage The area is less than 10% of the country's land. The formation of forests requires a certain growth cycle. A large number of deforestation does not meet the requirements of protecting the ecological environment, creating a low-carbon society, and developing a circular economy; the traditional production method of charcoal is to put wood into kilns The earth kiln charcoal making process of medium pyrolysis has the disadvantages of poor sealing, long production cycle, low output, high cost, etc., and the flue gas in the pyrolysis process is directly discharged, which not only wastes resources but also causes environmental pollution. In recent years, with the With the improvement of national environmental protection requirements, it will be the general trend that earth kiln charcoal will be eliminated;

Agricultural and forestry biomass raw materials are typical renewable energy sources, which have the advantages of wide sources, abundant reserves, and short growth cycle. The total amount of biomass produced on the earth every year is about 140-180 billion tons, and the annual discarded straw in my country is as high as more than 6 billion tons, which has great resource potential, and the biochar obtained from the pyrolysis of agricultural and forestry biomass raw materials has a well-developed pore structure and is easy to burn . However, agricultural and forestry biomass resources also have their limitations. The main manifestations are: the distribution is not concentrated, and it is not easy to collect. my country's lignite resources are abundant and the price is low, but lignite has high volatile components (>40%), low fixed carbon content, and undeveloped pore structure, and the combustion effect of mechanism charcoal prepared by using lignite alone is not ideal. For the application of lignite, using lignite as raw material, medium and low temperature dry distillation is used to carbonize lignite, remove most of the water and volatile matter, and obtain lignite semi-coke with better performance, and mix it with biomass charcoal, which can expand its application range.

Based on the above background, this paper proposes a composite mechanism carbon preparation method that not only overcomes the low yield of biomass charcoal, but also solves the problems of low fixed carbon content of lignite and underdeveloped pore structure. The invention aims to make full use of renewable agricultural and forestry biomass resources and lignite with low price and abundant reserves. Firstly, the pyrolysis (dry distillation) technology is used to process the agricultural and forestry biomass raw materials, and the flue gas in the pyrolysis process is fully utilized, and The by-product biochar produced by pyrolysis (small ratio) is mixed with lignite with abundant reserves (large ratio) and then carbonized in the second step. During the carbonization process, the flue gas is volatilized and removed, which increases the porosity of the composite carbon. , and the flue gas is discharged into the pool to be absorbed, and the moisture absorbed by the flue gas is recycled to the carbon batching link of the composite mechanism. The composite machine-made charcoal prepared by the invention not only solves the limitations of both biomass charcoal and lignite, but also the resources are recycled, which meets the requirements of energy saving, environmental protection and green development.

Contents of the invention

Aiming at the problems and deficiencies in the above-mentioned prior art, the present invention provides a method for preparing high-performance composite machine-made carbon. The preparation process uses abundant, low-cost, renewable and easily crushed biomass and low-cost lignite as carbon sources. It has the advantages of low mass production price, high yield, high calorific value, and high porosity. Welcome to the potential of composite mechanism charcoal. The present invention is realized through the following technical solutions.

A kind of preparation method of high-performance composite mechanism carbon, its specific steps are as follows:

(1) Firstly, the biomass raw material and lignite with a moisture content of less than 5% are crushed to particles with a particle size of less than 1cm;

(2) Pyrolyzing the biomass raw material particles obtained in step (1) at a temperature of 400°C to 900°C to obtain biochar, and further treating the biomass gas generated during the pyrolysis process as fuel;

(3) The biochar obtained in the step (2) with a mass percentage of 10-40%, the lignite obtained in the step (1) with a mass percentage of 40-70%, the mass percentage of 1-10% binder, and the mass percentage of 1 ~10% is a combustion aid, and water with a mass percentage of 5~14% is mixed evenly to obtain a mixed material, and the mixed material is pressed into a carbon rod with a central hole;

(4) The carbon rod with a central hole obtained in step (3) is heated to 400-700°C for 1-12 hours at a heating rate of 30-200°C/min and carbonized for 1-12 hours, and the composite mechanism carbon is obtained after cooling.

The biomass raw material in the step (1) is one or a mixture of several of walnut shells, pine nut shells, coconut shells, corncobs, bagasse, furfural residue, coffee shells, and peanut shells in any proportion.

The preparation method of the binder in the step (3) is: crush the peat, lignite or weathered coal containing more than 30wt% humic acid until the particle size is less than 1mm, and add it to the The binder is prepared by stirring in a NaOH solution with a percentage concentration of 5-30% at a temperature of 80-120° C. for 20-40 minutes.

The combustion accelerant obtained in the step (3) is a mixture of 50-80wt% manganese dioxide, 15-30wt% aluminum oxide and 5-20wt% calcium carbonate.

The pyrolysis flue gas produced during the carbonization process in the step (4) will be introduced into the reservoir through the pipeline to be absorbed by the water, and the sewage in the reservoir will be recycled and used as the water in the step (3) as the mixed material.

The beneficial effects of the present invention are: the fixed carbon content of the machine-made charcoal is ≥ 80%, the ash content is ≤ 5%, the calorific value is ≥ 35MJ/Kg, and the minimum temperature during combustion is greater than or equal to 420°C; the biomass raw material and lignite used in the machine-made charcoal The price is low, the deashing effect is good, and the porosity is high. The carbonization of this mechanism adopts two steps in the preparation process. The first carbonization process is the pyrolysis (dry distillation) of biomass raw materials. The by-product biomass charcoal has been fully utilized; the second step is the carbonization of mixtures of biomass charcoal (small proportion) and lignite (large proportion), which increases the fixed carbon content of lignite and produces a large amount of volatile matter during the removal process. Pores are conducive to the combustion of machine-made charcoal. In addition, the pyrolysis flue gas is discharged into the pool to be absorbed, and the moisture absorbed by the flue gas is recycled to the compound machine-made charcoal batching link. The composite machine-made charcoal prepared by the invention not only solves the limitations of both biomass charcoal and lignite, but also obtains comprehensive utilization of resources and meets the requirements of green development.

detailed description

The present invention will be further described below in combination with specific embodiments.

Example 1

The preparation method of the high-performance composite mechanism carbon, its specific steps are as follows:

(1) First, the biomass raw material with a moisture content of less than 5% (walnut shell, pine nut shell, coconut shell and corn cob mixed biomass raw material with a mass ratio of 1:1:1:1) and lignite are crushed to a particle size of less than 1cm particle;

(2) The biomass raw material particles obtained in step (1) were pyrolyzed at a temperature of 400°C for 3 hours to obtain biochar, and the biomass gas generated during the pyrolysis process was further processed and used as fuel gas;

(3) The biochar obtained in the step (2) with a mass percentage of 10%, the lignite obtained in the step (1) with a mass percentage of 70%, a binder with a mass percentage of 10%, and a combustion aid with a mass percentage of 1%. 9% water is mixed evenly to obtain a mixed material, and the mixed material is pressed into a carbon rod with a central hole; the preparation method of the binder is: pulverize the peat containing more than 30wt% humic acid until the particle size is less than 1mm, according to The liquid-solid ratio is 10:1ml/g, add it to the NaOH solution with a percentage concentration of 5%, and stir at a temperature of 80°C for 20 minutes to prepare a binder; the combustion aid is 50wt% manganese dioxide, 30wt% aluminum oxide And 20wt% calcium carbonate mixture;

(4) Heat the carbon rod with a central hole obtained in step (3) to 700°C at a heating rate of 200°C/min for carbonization for 1 hour, and obtain a composite mechanism carbon after cooling; the pyrolysis flue gas generated during the carbonization process will pass through the pipeline Introduced into the storage tank to be absorbed by water, the sewage in the storage tank will be recycled to be used as the water of the mixed material in step (3).

The results showed that the yield of biomass carbonization was 32%. After testing, the fixed carbon content of the composite mechanism carbon was 83wt%, the ash content was 5wt%, the calorific value was 35MJ/Kg, and the maximum temperature during combustion could reach 420°C.

Example 2

The preparation method of the high-performance composite mechanism carbon, its specific steps are as follows:

(1) First, the biomass raw material (bagasse) and lignite with a moisture content of less than 5% are crushed to particles with a particle size of less than 1cm;

(2) The biomass raw material particles obtained in step (1) were pyrolyzed at a temperature of 600°C for 2.5 h to obtain biochar, and the biomass gas generated during the pyrolysis process was further processed and used as fuel gas;

(3) The biochar obtained in the step (2) with a mass percentage of 30%, the lignite obtained in the step (1) with a mass percentage of 50%, the binder with a mass percentage of 5%, and the combustion improver with a mass percentage of 10% 5% water is mixed evenly to obtain a mixed material, and the mixed material is pressed into a carbon rod with a central hole; the preparation method of the binder is: pulverize the lignite containing more than 30wt% humic acid until the particle size is less than 1mm, according to the liquid A solid ratio of 1:1ml/g was added to a NaOH solution with a percentage concentration of 20%, and the binder was prepared by stirring at a temperature of 80°C for 20 minutes; the combustion aid was 60wt% manganese dioxide, 20wt% aluminum oxide and 20wt% calcium carbonate mixture;

(4) Heat the carbon rod with a central hole obtained in step (3) to 500°C for 8 hours at a heating rate of 100°C/min, and then obtain composite mechanism carbon after cooling; the pyrolysis flue gas generated during the carbonization process will pass through the pipeline Introduced into the storage tank to be absorbed by water, the sewage in the storage tank will be recycled to be used as the water of the mixed material in step (3).

The results show that the yield of biomass carbonization is 28%. After testing, the fixed carbon content of the composite mechanism carbon is 81wt%, the ash content is 4wt%, the calorific value is 39MJ/Kg, and the maximum temperature can reach 440°C during combustion.

Example 3

The preparation method of the high-performance composite mechanism carbon, its specific steps are as follows:

(1) First, the biomass raw material with a moisture content of less than 5% (furfural residue with a mass ratio of 1:1:1, coffee husk and peanut husk mixed biomass) and lignite are respectively crushed to particles with a particle size of less than 1cm;

(2) The biomass raw material particles obtained in step (1) were pyrolyzed at a temperature of 900°C for 1.5 hours to obtain biochar, and the biomass gas generated during the pyrolysis process was further processed and used as fuel gas;

(3) The biochar obtained in the step (2) with a mass percentage of 40%, the lignite obtained in the step (1) with a mass percentage of 40%, the mass percentage of 1% binder, the mass percentage of 5% as a combustion aid, and the mass percentage 14% water is mixed evenly to obtain a mixed material, and the mixed material is pressed into a carbon rod with a central hole; the binder preparation method is: pulverize the weathered coal containing more than 30wt% humic acid to a particle size of less than 1mm, according to The liquid-solid ratio is 5:1ml/g, add it to the NaOH solution with a percentage concentration of 30%, and stir at a temperature of 100°C for 30 minutes to prepare a binder; the combustion aid is 80wt% manganese dioxide, 15wt% aluminum oxide And 5wt% calcium carbonate mixture;

(4) Heat the carbon rod with a central hole obtained in step (3) to 400°C at a heating rate of 30°C/min for carbonization for 12 hours, and obtain a composite mechanism carbon after cooling; the pyrolysis flue gas generated during the carbonization process will pass through the pipeline Introduced into the storage tank to be absorbed by water, the sewage in the storage tank will be recycled to be used as the water of the mixed material in step (3).

The results show that the yield of biomass carbonization is 25%. After testing, the fixed carbon content of the composite mechanism carbon is 86wt%, the ash content is 3.5wt%, the volatile matter content is 10%, and the calorific value is 37MJ/Kg. The highest temperature can reach 430°C.

Example 4

The preparation method of the high-performance composite mechanism carbon, its specific steps are as follows:

(1) First, the biomass raw material (peanut shell) and lignite with a moisture content of less than 5% are crushed to particles with a particle size of less than 1cm;

(2) Biomass raw material particles obtained in step (1) were pyrolyzed at 800°C for 2 hours to obtain biochar, and the biomass gas generated during the pyrolysis process was further processed and used as fuel gas;

(3) The biochar obtained in the step (2) with a mass percentage of 35%, the lignite obtained in the step (1) with a mass percentage of 50%, the mass percentage of 1% binder, the mass percentage of 6% as a combustion aid, and the mass percentage 8% water is mixed evenly to obtain a mixed material, and the mixed material is pressed into a carbon rod with a central hole; the binder preparation method is: pulverize the weathered coal containing more than 30wt% humic acid until the particle size is less than 1mm, according to A liquid-solid ratio of 5:1 ml/g was added to a NaOH solution with a percentage concentration of 20%, and the binder was prepared by stirring at a temperature of 120°C for 40 minutes; the combustion promoter was 65wt% manganese dioxide, 20wt% di Aluminum and 15wt% calcium carbonate mixture;

(4) Heat the carbon rod with a central hole obtained in step (3) to 600°C at a heating rate of 120°C/min for carbonization for 10 hours, and obtain composite carbon after cooling; the pyrolysis flue gas generated during the carbonization process will pass through the pipeline Introduced into the storage tank to be absorbed by water, the sewage in the storage tank will be recycled to be used as the water of the mixed material in step (3).

The specific embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention within the scope of knowledge possessed by those of ordinary skill in the art .

Claims (5)

1. a kind of preparation method of high-performance compounding machine charcoal processing, it is characterised in that comprise the following steps that：

（1）First biomass material that moisture content is less than 5%, brown coal are crushed to into respectively particle of the granularity less than 1cm；

（2）By step（1）The biomass raw material particle for obtaining pyrolysis in the case where temperature is for 400 DEG C～900 DEG C obtains charcoal, by heat The biomass gas produced in solution preocess are used as combustion gas after further processing；

（3）By mass percent be 10～40% the step of（2）The charcoal that obtains, mass percent are 40～70% steps（1） The brown coal that obtain, mass percent be 1～10% binding agent, mass percent 1～10% be combustion adjuvant, mass percent be 5～ 14% water is well mixed and obtains mixed material, and mixed material is pressed into into the carbon rod with centre bore；

（4）By step（3）The carbon rod with centre bore for obtaining is warming up to 400～700 with the heating rate of 30～200 DEG C/min DEG C charing 1～12h, compounding machine charcoal processing is obtained after cooling.

2. the preparation method of high-performance compounding machine charcoal processing according to claim 1, it is characterised in that：The step（1）In Biomass material be walnut shell, pine nut shell, cocoanut shell, corncob, bagasse, furfural dregs, coffee shell, peanut shell in one kind or Several arbitrary proportion mixtures of person.

3. the preparation method of high-performance compounding machine charcoal processing according to claim 1, it is characterised in that：The step（3）In Binding agent preparation method is：Mud coal containing more than 30wt% humic acids, brown coal or weathered coal are crushed to into particle diameter and are less than 1mm, according to Liquid-solid ratio is 1～10:1ml/g is added in the NaOH solution that percent concentration is 5～30%, is stirred in the case where temperature is for 80～120 DEG C Mix 20～40min and prepare binding agent.

4. the preparation method of high-performance compounding machine charcoal processing according to claim 1, it is characterised in that：The step（3） The combustion adjuvant for arriving is 50～80wt% manganese dioxide, 15～30wt% alundum (Al2O3)s and 5～20wt% calcium carbonate mixtures.

5. the preparation method of high-performance compounding machine charcoal processing according to claim 1, it is characterised in that：The step（4）Charcoal The pyrolysis smoke that change process is produced will be incorporated in cistern by pipeline and will be only absorbed by the water, and the sewage in cistern will be recycled In step（3）The middle water as mixed material.