阅读说明：本技术 一种蔗渣活性炭及其制备方法 (Bagasse activated carbon and preparation method thereof ) 是由 李长宁 农倩 林丽 谢金兰 莫璋红 于 2020-12-09 设计创作，主要内容包括：本发明公开了一种蔗渣活性炭及其制备方法,包括预处理、炭化、活化、酸洗、干燥和后处理对甘蔗渣进行处理。本发明采用二次活化法制备活性炭,先采用气体活化,再采用试剂活化法,可以进一步提高活性炭的表面积,制备过程简便、对环境友好,本发明制备的活性炭具有比表面积大、孔径小、吸附能力强,本发明采用甘蔗渣为原料来制备活性炭,不但为解决甘蔗渣的再利用、避免资源的浪费和环境污染提供了有效途径,而且甘蔗渣本身是一种安全无毒的可再生生物质材料,由其制备得到的活性炭可用于部分食品类加工,产品附加值高,可产生良好的社会和经济效益,并且本发明的活性炭脱色能力强,稳定性好,强度高,安全无毒。(The invention discloses bagasse active carbon and a preparation method thereof. The invention adopts a secondary activation method to prepare the activated carbon, firstly adopts gas activation, and then adopts a reagent activation method, so that the surface area of the activated carbon can be further improved, the preparation process is simple and convenient and is environment-friendly, the prepared activated carbon has large specific surface area, small aperture and strong adsorption capacity, bagasse is adopted as a raw material to prepare the activated carbon, an effective way is provided for solving the reutilization of the bagasse, the waste of resources and environmental pollution are avoided, the bagasse is a safe and nontoxic renewable biomass material, the activated carbon prepared by the method can be used for processing partial foods, the product is high, and good social and economic benefits can be generated, and the activated carbon has strong decolorization capacity, good stability, high strength, safety and no toxicity.)

1. The bagasse activated carbon and the preparation method thereof are characterized by comprising the following steps:

a. pretreatment: fully crushing bagasse, screening to 2-5 mm, washing with deionized water for 4-5 times, and placing in a drying oven to dry at 90-105 ℃ to obtain dry bagasse for later use;

b. carbonizing: under the protection of nitrogen, placing the dried bagasse in a quartz boat, transferring the quartz boat into a closed tube furnace, heating until the carbon granules are red or no longer generate gas, stopping heating, cooling to room temperature, feeding the carbon granules into a grinder for grinding, and sieving by a 30-40-mesh sieve to obtain bagasse carbon granules;

c. and (3) activation: activating the obtained bagasse carbon granules by using water vapor for about 12 hours at 800 ℃, and then activating the bagasse carbon granules by using a mixed gas of 13% of carbon dioxide and 87% of water vapor for about 12 hours at 850 ℃;

d. acid washing: washing activated bagasse with an equal volume of dilute acid, adding distilled water, boiling, keeping the temperature for 20-30min, and washing with distilled water until the solution is neutral to obtain an activated carbon semi-finished product;

e. and (3) drying: putting the acid-washed activated carbon semi-finished product into an electric heating constant-temperature blast drying oven at the temperature of 90-110 ℃ for drying for 4-5 hours;

f. and (3) post-treatment: and (4) drying the mixture in a drying oven at 90-110 ℃ to obtain the bagasse activated carbon.

2. The bagasse activated carbon and the preparation method thereof according to claim 1, wherein the activation is performed by steam activation or by phosphoric acid or by zinc chloride.

3. The bagasse activated carbon and the preparation method thereof according to claim 2, wherein the dried bagasse is mixed with a phosphoric acid solution with a mass fraction of 40.6% in a ratio of 1: the mixture was mixed at a sucrose acid ratio of 1.5 to carry out activation treatment.

4. The bagasse activated carbon and the preparation method thereof according to claim 2, wherein the mass concentration of the zinc chloride solution is 190 g/L.

5. The bagasse activated carbon and the preparation method thereof according to claim 1, wherein the diluted acid in step d is one or more of carbonic acid, nitric acid and phosphoric acid, the concentration of the carbonic acid is 0.1-0.3 mol/L, the concentration of the nitric acid is 0.05-0.2 mol/L, and the concentration of the phosphoric acid is 0.1-0.2 mol/L.

Technical Field

The invention relates to the field of activated carbon materials, in particular to bagasse activated carbon and a preparation method thereof.

Background

The bagasse is a renewable resource, has low price, centralized raw material source, simple collection, rich fiber and large specific surface area, and is an ideal material for preparing the activated carbon. The activated carbon prepared from the bagasse has a very large specific surface area, and can be applied to metal ion adsorption in wastewater treatment. At present, bagasse produced by a sugar mill is mainly used for incineration of a boiler and provided for paper making in a paper mill, and the utilization value of the bagasse is low. Therefore, the bagasse can be economically and effectively utilized to prepare the activated carbon, the economic added value of the bagasse is improved, the environment is protected, and a new idea is provided for the comprehensive utilization of the sugarcane. Only one activation method is adopted in the steps for preparing the activated carbon at present.

The activated carbon activation method can be classified into a physical gas activation method and a chemical agent activation method. The physical gas activation method usually adopts water vapor, air and carbon dioxide as activation media, and the chemical reagent activation method mainly adopts cobalt sulfate solution, zinc chloride solution and the like as activation reagents. The chemical reagent activation method can shorten the production period, is beneficial to forming a porous structure, and the produced product has better quality.

In recent years, researchers have made bagasse into activated carbon, which is used for adsorption treatment of heavy metal wastewater, and certain effects are achieved. However, the bagasse activated carbon has the problems of poor adsorption stability, low strength, general adsorption performance and the like in the use process, thereby restricting the use of the bagasse activated carbon

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides bagasse activated carbon and a preparation method thereof.

In order to solve the technical problems, the invention provides the following technical scheme:

the invention relates to bagasse activated carbon and a preparation method thereof, and the preparation method specifically comprises the following steps:

a. pretreatment: fully crushing bagasse, screening to 2-5 mm, washing with deionized water for 4-5 times, and placing in a drying oven to dry at 90-105 ℃ to obtain dry bagasse for later use;

b. carbonizing: under the protection of nitrogen, placing the dried bagasse in a quartz boat, transferring the quartz boat into a closed tube furnace, heating until the carbon granules are red or no longer generate gas, stopping heating, cooling to room temperature, feeding the carbon granules into a grinder for grinding, and sieving by a 30-40-mesh sieve to obtain bagasse carbon granules;

c. and (3) activation: activating the obtained bagasse carbon granules by using water vapor for about 12 hours at 800 ℃, and then activating the bagasse carbon granules by using a mixed gas of 13% of carbon dioxide and 87% of water vapor for about 12 hours at 850 ℃;

d. acid washing: washing activated bagasse with an equal volume of dilute acid, adding distilled water, boiling, keeping the temperature for 20-30min, and washing with distilled water until the solution is neutral to obtain an activated carbon semi-finished product;

e. and (3) drying: putting the acid-washed activated carbon semi-finished product into an electric heating constant-temperature blast drying oven at the temperature of 90-110 ℃ for drying for 4-5 hours;

f. and (3) post-treatment: and (4) drying the mixture in a drying oven at 90-110 ℃ to obtain the bagasse activated carbon.

In a preferred embodiment of the present invention, the activation is performed by steam activation or by phosphoric acid activation or by zinc chloride activation.

As a preferred technical scheme of the invention, the dried bagasse and a phosphoric acid solution with the mass fraction of 40.6% are mixed according to the weight ratio of 1: the mixture was mixed at a sucrose acid ratio of 1.5 to carry out activation treatment.

As a preferable technical scheme of the invention, the mass concentration of the zinc chloride solution is 190 g/L.

In a preferred technical scheme of the invention, the dilute acid in the step d is one or more of carbonic acid, nitric acid and phosphoric acid, the concentration of the carbonic acid is 0.1-0.3 mol/L, the concentration of the nitric acid is 0.05-0.2 mol/L, and the concentration of the phosphoric acid is 0.1-0.2 mol/L.

Compared with the prior art, the invention has the following beneficial effects:

1: the invention adopts a secondary activation method to prepare the activated carbon, firstly adopts gas activation, and then adopts a reagent activation method, so that the surface area of the activated carbon can be further improved, the preparation process is simple and convenient and is environment-friendly, the prepared activated carbon has large specific surface area, small aperture and strong adsorption capacity, bagasse is adopted as a raw material to prepare the activated carbon, an effective way is provided for solving the reutilization of the bagasse, the waste of resources and environmental pollution are avoided, the bagasse is a safe and nontoxic renewable biomass material, the activated carbon prepared by the method can be used for processing partial foods, the product is high, and good social and economic benefits can be generated, and the activated carbon has strong decolorization capacity, good stability, high strength, safety and no toxicity.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of illustration and description, and is in no way intended to limit the invention.

Example 1

The invention provides bagasse activated carbon and a preparation method thereof, and the preparation method specifically comprises the following steps:

a. pretreatment: fully crushing bagasse, screening to 2-5 mm, washing with deionized water for 4-5 times, and placing in a drying oven to dry at 90-105 ℃ to obtain dry bagasse for later use;

b. carbonizing: under the protection of nitrogen, placing the dried bagasse in a quartz boat, transferring the quartz boat into a closed tube furnace, heating until the carbon granules are red or no longer generate gas, stopping heating, cooling to room temperature, feeding the carbon granules into a grinder for grinding, and sieving by a 30-40-mesh sieve to obtain bagasse carbon granules;

c. and (3) activation: activating the obtained bagasse carbon granules by using water vapor for about 12 hours at 800 ℃, and then activating the bagasse carbon granules by using a mixed gas of 13% of carbon dioxide and 87% of water vapor for about 12 hours at 850 ℃;

d. acid washing: washing activated bagasse with an equal volume of dilute acid, adding distilled water, boiling, keeping the temperature for 20-30min, and washing with distilled water until the solution is neutral to obtain an activated carbon semi-finished product;

e. and (3) drying: putting the acid-washed activated carbon semi-finished product into an electric heating constant-temperature blast drying oven at the temperature of 90-110 ℃ for drying for 4-5 hours;

f. and (3) post-treatment: and (4) drying the mixture in a drying oven at 90-110 ℃ to obtain the bagasse activated carbon.

Example 2

The invention provides bagasse activated carbon and a preparation method thereof, and the preparation method specifically comprises the following steps:

a. pretreatment: fully crushing bagasse, screening to 2-5 mm, washing with deionized water for 4-5 times, and placing in a drying oven to dry at 90-105 ℃ to obtain dry bagasse for later use;

b. carbonizing: under the protection of nitrogen, placing the dried bagasse in a quartz boat, transferring the quartz boat into a closed tube furnace, heating until the carbon granules are red or no longer generate gas, stopping heating, cooling to room temperature, feeding the carbon granules into a grinder for grinding, and sieving by a 30-40-mesh sieve to obtain bagasse carbon granules;

c. and (3) activation: activating the obtained bagasse carbon granules by water vapor at 800 ℃ for about 12 hours, wherein the volume fraction of phosphoric acid is 17%, the content of additive x is 5%, the activation temperature is 500 ℃, and the activation time is 0.3 hour, the yield of the activated carbon sample prepared under the process conditions is 45.68%, the iodine adsorption value is 1562.52mg/g, and after l0 times of cyclic recycling of the activated carbon phosphoric acid, the iodine adsorption value of the sample is 958.6mg/g, and the yield is 58.62%;

d. acid washing: washing activated bagasse with an equal volume of dilute acid, adding distilled water, boiling, keeping the temperature for 20-30min, and washing with distilled water until the solution is neutral to obtain an activated carbon semi-finished product;

e. and (3) drying: putting the acid-washed activated carbon semi-finished product into an electric heating constant-temperature blast drying oven at the temperature of 90-110 ℃ for drying for 4-5 hours;

f. and (3) post-treatment: and (4) drying the mixture in a drying oven at 90-110 ℃ to obtain the bagasse activated carbon.

Example 3

The invention provides bagasse activated carbon and a preparation method thereof, and the preparation method specifically comprises the following steps:

a. pretreatment: fully crushing bagasse, screening to 2-5 mm, washing with deionized water for 4-5 times, and placing in a drying oven to dry at 90-105 ℃ to obtain dry bagasse for later use;

b. carbonizing: under the protection of nitrogen, placing the dried bagasse in a quartz boat, transferring the quartz boat into a closed tube furnace, heating until the carbon granules are red or no longer generate gas, stopping heating, cooling to room temperature, feeding the carbon granules into a grinder for grinding, and sieving by a 30-40-mesh sieve to obtain bagasse carbon granules;

c. and (3) activation: activating the obtained bagasse carbon granules by using water vapor at 800 ℃ for about 12 hours, then activating at 850 ℃, with the mass concentration of a zinc chloride solution being 190g/L for 1 hour, wherein the yield of the obtained bagasse activated carbon adsorbent is 30.3%, the iodine adsorption value is 1060mg/g, the methylene blue adsorption value is 13.0mL, the concentration of an activating agent is 2.0mol/L, and the mass ratio of the activating agent to the bagasse is 5: 1, the activation time is 24 hours, the carbonization temperature is 500-600 ℃, the carbonization time is 50min, nitrogen is used as protective gas, the flow is 2.6L/min, the iodine value of the prepared active carbon is 520mg/g, the yield is 38.6 percent, and the specific surface area is 752m²G, mean pore diameter of 2.4nm, pore volume of 7.1X10^-2/g；

d. Acid washing: washing activated bagasse with an equal volume of dilute acid, adding distilled water, boiling, keeping the temperature for 20-30min, and washing with distilled water until the solution is neutral to obtain an activated carbon semi-finished product;

e. and (3) drying: putting the acid-washed activated carbon semi-finished product into an electric heating constant-temperature blast drying oven at the temperature of 90-110 ℃ for drying for 4-5 hours;

f. and (3) post-treatment: and (4) drying the mixture in a drying oven at 90-110 ℃ to obtain the bagasse activated carbon.

The invention adopts a secondary activation method to prepare the activated carbon, firstly adopts gas activation, and then adopts a reagent activation method, so that the surface area of the activated carbon can be further improved, the preparation process is simple and convenient and is environment-friendly, the prepared activated carbon has large specific surface area, small aperture and strong adsorption capacity, bagasse is adopted as a raw material to prepare the activated carbon, an effective way is provided for solving the reutilization of the bagasse, the waste of resources and environmental pollution are avoided, the bagasse is a safe and nontoxic renewable biomass material, the activated carbon prepared by the method can be used for processing partial foods, the product is high, and good social and economic benefits can be generated, and the activated carbon has strong decolorization capacity, good stability, high strength, safety and no toxicity.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.