CN101966990B - Method for preparing activated carbon from kernel of common macrocarpium fruit - Google Patents

Abstract

The invention discloses a method for preparing activated carbon from the kernel of common macrocarpium fruit serving as a raw material, which comprises the following steps of: stirring by using an intermittent tank reactor which is treated by an anti-corrosion material to fully knead the pretreated raw material and an active agent, and carbonizing and activating at a certain temperature to obtain an activated material; and recovering the active agent, rinsing, dehydrating, drying and the like to obtain finished activated carbon. The kernel of the common macrocarpium fruit is forest product waste which is not utilized at present, so that the problem of multi-layer composite utilization of the forest product common macrocarpium fruit is solved, the production cost of the activated carbon is greatly reduced; meanwhile, a new resource capable of producing the activated carbon with high adsorption property is found for the activated carbon industry.

Description

A kind of method of preparing active carbon with dogwood fruit stone

technical field

The invention relates to the technical field of preparing activated carbon. Specifically, the present invention relates to a method for preparing activated carbon from dogwood fruit stones.

Background technique

Cornus officinalis Sieb.et Zucc. is a small tree or shrub of the genus Cornus in the family Cornaceae. Its mature fruit is also known as cornus, medicinal jujube, and jujube bark after the pitting is removed. Dogwood is distributed in northern temperate and subtropical alpine regions. It is mainly produced in China, Japan, South Korea, the United Kingdom, the United States and other countries. In my country, it is mainly produced in more than 10 provinces such as Shaanxi, Henan, Zhejiang, Shanxi, Shandong, Sichuan, Anwei, and Gansu. Among them, Foping in Hanzhong, Shaanxi is known as the "Hometown of Dogwood", and its annual output has exceeded 1 million kg. The weight of the dried fruit stone of dogwood is about 1/3 of the pulp. There are mature products of dogwood pulp, but there are relatively few studies on the utilization of the fruit stone. Waste of valuable biomass resources. Therefore, in view of the relatively hard characteristics of dogwood fruit stones, we have developed a new process to convert dogwood fruit stones into activated carbon.

Activated carbon is a porous carbon material with developed pore structure and large specific surface area prepared from biological organic substances (such as wood, coke, petroleum coke, various nut shells, etc.). Different raw materials and different processes are used for preparation, and then biomass activated carbon with different properties is obtained. The preparation of traditional activated carbon using wood as raw material is limited by the protection of the ecological environment, so the use of forest by-products as raw materials to prepare activated carbon has been paid more and more attention.

There has been no report so far on the preparation of activated carbon from Cornus officinalis.

Contents of the invention

The purpose of the present invention is to provide a method for preparing activated carbon with discarded dogwood fruit stones as raw materials, which not only solves the technical difficulties in the process of preparing activated carbon from dogwood fruit stones, but also fully utilizes the discarded dogwood fruit stones to expand the new way of activated carbon sources .

Technical solution: a method for preparing activated carbon from dogwood fruit stones, comprising the following steps:

(1) removing impurities from the peeled dogwood fruit core, drying at 105±5°C, crushing and sieving to make 20-mesh powder;

(2) Immerse the dogwood fruit stone powder obtained in step 1 in an activator, and use a batch reactor treated with a corrosion-resistant material to stir and accelerate kneading in two directions. After the kneading is sufficient, it is sucked out for subsequent use;

(3) the dogwood fruit stone powder gained in step 2 is packed into a rotary kiln, and at a certain temperature, heating charcoal is activated under a protective gas (such as nitrogen) under an oxygen barrier condition;

(4) The activated granules in step 3 are pickled, washed with water, dried, pulverized and sieved to prepare the finished activated carbon.

In the method for preparing activated carbon, the activator in the step (2) adopts a zinc chloride solution with a mass concentration of 30% to 65%.

In the method for preparing activated carbon, in the step (2), the solid-liquid ratio of the Cornus officinalis fruit stone powder to the activator is 1:1-1:5.

In the method for preparing activated carbon, the soaking time in the step (2) is 3-9 hours.

In the method for preparing activated carbon, the carbon activation temperature of the dogwood fruit stone powder in the step (3) is 400-900°C.

In the method for preparing activated carbon, the carbon activation time in the step (3) is 1 to 5 hours.

In the method for preparing activated carbon, the rotating speed of the batch tank reactor in the step (2) is 4r/min, and turns 1 time in the opposite direction every 2min.

In the method for preparing activated carbon, non-condensable gas is used as a protective gas during the carbon activation process in the step (3).

During the carbon activation reaction process, at the start-up stage of the whole system, nitrogen is used as a protective gas to pass into the activation tube, and a condensation facility is added at the tail gas outlet to collect liquid substances such as wood vinegar and tar, and the non-condensable gas is collected in the gas tank. . After the system has been running for 20 minutes, start the vacuum pump, pass the non-condensable gas in the gas tank into the rotary furnace as a protective gas, and stop the nitrogen input at the same time.

Compared with prior art, the advantages and effects that the present invention has are as follows:

(1) The raw material for the preparation of activated carbon adopted in the present invention is relatively new, that is, the research on the preparation of activated carbon with the fruit stone of Cornus officinalis has not been reported yet. In addition, the application of activated carbon made from dogwood fruit stones can expand the source of raw materials for preparing activated carbon from the perspective of raw materials.

(2) The raw material for preparing activated carbon adopted in the present invention is easy to get, and cost is low. Cornus officinalis fruit stone is the waste after obtaining cornus officinalis pulp. If it is directly burned, it will pollute the environment and waste forestry resources. The production of activated carbon from Cornus officinalis not only turns waste into treasure, greatly improves the utilization value of the by-products of Cornus officinalis, but also reduces the manufacturing cost of activated carbon.

(3) The present invention utilizes the batch tank reactor treated with corrosion-resistant materials for two-way agitation to accelerate kneading, greatly shorten the immersion time, and improve efficiency.

(4) The present invention utilizes the non-condensable gas product produced in the carbon activation process as the protective gas, which reduces the loss of protective gas (such as nitrogen) and saves the cost.

(5) The present invention adopts the technique of chemical activation method to prepare cornus officinalis activated carbon, and its product adsorption properties are all higher than relevant standards.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments.

Example 1:

Drying: remove impurities from the fruit cores of Cornus officinalis, and dry them at 105±5°C for 12 hours for dehydration.

Pulverization: pulverize the dried raw materials through a 20-mesh sieve.

Impregnation: mix with 60% zinc chloride solution according to the weight ratio of material to liquid ratio 1:1.5, use the intermittent tank reactor treated with corrosion-resistant materials for two-way stirring, impregnate for 3 hours, and accelerate kneading. Then filter it out and set aside.

Charcoal activation reaction: put the impregnated raw material into a rotary furnace, pass through a protective gas, such as nitrogen, and activate the charcoal at a temperature of 550°C for 4 hours, so that the pore structure of the raw material is gradually developed and finally becomes activated carbon.

Pickling: After the activation material is cooled, boil it with 1mol/L hydrochloric acid solution for 30-60 minutes.

Washing: Rinse the activated material with hot distilled water to make the pH value close to 7. In this way, the content of iron and other impurities in the activation material can be reduced, and the product quality can be improved.

Drying: After drying the activated material in an oven, crush it through a 200-mesh sieve to obtain the finished activated carbon.

Example 2:

Drying: remove impurities from the fruit cores of Cornus officinalis, and dry them at 105±5°C for 12 hours for dehydration.

Pulverization: pulverize the dried raw materials through a 20-mesh sieve.

Impregnation: Mix with 50% zinc chloride solution according to the weight ratio of material to liquid ratio 1:3, use the batch tank reactor treated with corrosion-resistant materials to stir in both directions, impregnate for 6 hours, the speed is 4r/min, every 2min, turn 1 time in the opposite direction to speed up kneading. Then filter it out and set aside.

Charcoal activation reaction: put the impregnated raw material into a rotary furnace, pass through a protective gas, such as nitrogen, and activate the charcoal at a temperature of 650°C for 3 hours, so that the pore structure of the raw material will gradually develop and finally become activated carbon.

Pickling: After the activation material is cooled, boil it with 1mol/L hydrochloric acid solution for 30-60 minutes.

Washing: Rinse the activated material with hot distilled water to make the pH value close to 7. In this way, the content of iron and other impurities in the activation material can be reduced, and the product quality can be improved.

Drying: After drying the activated material in an oven, crush it through a 200-mesh sieve to obtain the finished activated carbon.

Example 3:

Drying: remove impurities from the fruit cores of Cornus officinalis, and dry them at 105±5°C for 12 hours for dehydration.

Pulverization: pulverize the dried raw materials through a 20-mesh sieve.

Impregnation: mix with 35% zinc chloride solution according to the weight ratio of material to liquid ratio 1:4.5, use the batch tank reactor treated with corrosion-resistant materials to stir in both directions, impregnate for 9 hours, the speed is 4r/min, every 2min, turn 1 time in the opposite direction to speed up kneading. Then filter it out and set aside.

Charcoal activation reaction: put the impregnated raw material into a rotary furnace, pass through a protective gas, such as nitrogen, and activate the charcoal at a temperature of 800°C for 2 hours, so that the pore structure of the raw material is gradually developed and finally becomes activated carbon.

Pickling: After the activation material is cooled, boil it with 1mol/L hydrochloric acid solution for 30-60 minutes.

Washing: Rinse the activated material with hot distilled water to make the pH value close to 7. In this way, the content of iron and other impurities in the activation material can be reduced, and the product quality can be improved.

Drying: After drying the activated material in an oven, crush it through a 200-mesh sieve to obtain the finished activated carbon.

Example 4:

In order to further illustrate the present invention, 500g of dogwood fruit stones that have been removed from impurities and passed through a 20-mesh sieve are weighed, and after soaking, carbon activation, pickling, water washing, drying, and crushing according to the steps and process conditions of the present invention, 192g of Cornus officinalis is obtained. Finished activated carbon.

According to the method that the present invention utilizes dogwood fruit stone to produce gac, its performance index is listed in table 1 compared with standard index

Table 1 The detection result of the present invention and the comparison table of standard index

The standard indicators in the table are issued by the Ministry of Chemical Industry of the People's Republic of China according to HG3-1290-80, the activated carbon ministry standard, and the test results are the test item indicators detected by the present invention. It can be seen from Table 1 that the adsorption capacity of the main performance index of the activated carbon made from the fruit stone of Cornus officinalis is greater than the ministerial standard.

Therefore, the technological process of the method for producing activated carbon provided by the present invention is perfect, and the product quality exceeds the ministerial standard.

It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present invention.

Claims (1)

1. a method for preparing gac with cornus fruit stone, is characterized in that, comprises the following steps: (1) Remove impurities from the peeled Cornus officinalis fruit stones, dry them at 105±5° C., crush and sieve to make 20 mesh Cornus officinalis fruit stones powder; (2) Immerse the Cornus officinalis fruit core powder obtained in step 1 in an activator, use a batch reactor treated with a corrosion-resistant material to accelerate kneading by two-way stirring, and after the kneading is sufficient, then filter it out for subsequent use; The activator adopts a zinc chloride solution with a mass concentration of 30% to 65%; the solid-liquid ratio of the dogwood fruit stone powder to the activator is 1:1 to 1:5; the soaking time is 3 to 9 hours ; The rotating speed of the batch reactor is 4r/min, every 2min, turn 1 time in the opposite direction; (3) the dogwood fruit stone powder of gained in step 2 is packed in the rotary kiln, and at a certain temperature, heating charcoal activation under the condition of filling protective gas and oxygen barrier; in the charcoal activation reaction process, the start-up stage of the whole system, Nitrogen is used as a protective gas to pass into the activation tube, and a condensation facility is added at its tail gas outlet to collect liquid substances including wood vinegar and tar, and non-condensable gases are collected in the gas tank; when the system is running for 20 minutes, start the vacuum pump to The non-condensable gas in the gas tank is passed into the rotary furnace as a protective gas, and the nitrogen input is stopped at the same time; the charcoal activation temperature of the dogwood fruit stone powder is 400-900°C; the charcoal activation time is 1-5h; (4) The activated granules in step 3 are pickled, washed with water, dried, pulverized and sieved to prepare the finished activated carbon.