1. A method for preparing desulfurization and denitrification activated carbon without coal tar is characterized by comprising the following steps:

1) preparation of adhesive solution: mixing sodium/calcium lignosulfonate with water, standing in a water bath, and obtaining an adhesive solution after the sodium/calcium lignosulfonate is completely dissolved;

2) preparing the desulfurization and denitrification active carbon: mixing the adhesive solution obtained in the step 1) with coal powder and water in proportion to form coal paste, molding by a granulator, uniformly carbonizing for 1 hour in a carbonization furnace with a temperature gradient of 350-650 ℃, feeding into an activation furnace, uniformly activating for 2 hours at a temperature gradient of 700-850 ℃, discharging, cooling and screening to obtain the desulfurization and denitrification activated carbon.

2. The method for preparing the desulfurization and denitrification activated carbon without the coal tar according to claim 1, wherein the mass ratio of sodium/calcium lignosulfonate to water in the step 1) is 2: 3.

3. The method for preparing the desulfurization and denitrification activated carbon without the coal tar according to claim 1, wherein the temperature of the water bath in the step 1) is 60-80 ℃, and the standing time in the water bath is 4 hours.

4. The method for preparing desulfurization and denitrification activated carbon from coal tar-free coal as claimed in claim 1, wherein the raw materials used in step 2) comprise the following components in parts by mass: 70-80 parts of coal powder, 10-15 parts of adhesive solution and 5-10 parts of water.

5. The method for preparing the desulfurization and denitrification activated carbon without the coal tar according to claim 1, wherein the mixing time of the binder solution, the coal powder and the water is 10 minutes, and the particle size of the molding material after the molding of the granulator is 9-10 mm.

6. The method for preparing desulfurization and denitrification activated carbon without coal tar according to claims 1-5, wherein in the step 2), gradient carbonization is performed for 5min at 350 ℃, 5min at 450 ℃, 5min at 550 ℃, 5min at 650 ℃ and 5min at the heating rate of 10 ℃/mim; gradient activation is that the temperature is maintained at 700 ℃ for 10min, 750 ℃ for 10min, 800 ℃ for 10min, 850 ℃ for 60min, and the heating rate is 5 ℃/min.

Background

In recent years, due to the development of the national environment-friendly situation, the dry desulfurization and denitrification technology is widely applied to sintering, waste incineration power generation and coking tail gas desulfurization and denitrification purification treatment in the steel industry, the annual demand of domestic desulfurization and denitrification activated carbon markets is about 50 million tons, and the capacity is about 100 million tons. The desulfurization and denitrification active carbon is prepared by mixing coal powder, tar and water according to a certain proportion, granulating or extruding for molding, and carbonizing and activating. Where the coal tar acts as a binder. There are major problems:

a. coal tar contains a large amount of volatile toxic and harmful substances, such as carcinogenic substances like benzene, anthracene oil, naphthalene and the like, and volatilizes in the using process, so that the physical and mental health of operators and the environment of an operation site are seriously affected, and if an effective VOC gas treatment device is additionally arranged, the manufacturing cost of the activated carbon is increased.

b. Due to the development of coal tar downstream industry and the dependence of the sharp increase of the yield of coal-based activated carbon on coal tar, the price of the coal tar is continuously increased, so that the manufacturing cost of the desulfurization and denitrification activated carbon is high.

Therefore, the preparation research of the desulfurization and denitrification activated carbon by finding the nontoxic, tasteless and low-price adhesive to replace coal tar has practical significance, and is a technical problem which needs to be solved urgently in the domestic activated carbon industry at present.

Disclosure of Invention

The invention provides a method for preparing desulfurization and denitrification activated carbon without coal tar, aiming at solving the technical problems that the coal tar used for preparing desulfurization and denitrification activated carbon is volatile, toxic and harmful substances and has high cost in the prior art.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a method for preparing desulfurization and denitrification activated carbon without coal tar comprises the following steps:

1) preparation of adhesive solution: mixing sodium/calcium lignosulfonate with water, standing in a water bath, and obtaining an adhesive solution after the sodium/calcium lignosulfonate is completely dissolved;

2) preparing the desulfurization and denitrification active carbon: mixing the adhesive solution obtained in the step 1) with coal powder and water in proportion to form coal paste, molding by a granulator, uniformly carbonizing for 1 hour in a carbonization furnace with a temperature gradient of 350-650 ℃, feeding into an activation furnace, uniformly activating for 2 hours at a temperature gradient of 700-850 ℃, discharging, cooling and screening to obtain the desulfurization and denitrification activated carbon.

Further, the mass ratio of sodium/calcium lignosulfonate to water in the step 1) is 2: 3.

Further, the temperature of the water bath in the step 1) is 60-80 ℃, and the standing time in the water bath is 4 hours.

Further, the raw materials used in the step 2) are prepared from the following raw materials in parts by mass: 70-80 parts of coal powder, 10-15 parts of adhesive solution and 5-10 parts of water.

Furthermore, the time for mixing the adhesive solution with the coal powder and the water is 10 minutes, and the particle size of the molding material after molding by the granulator is 9-10 mm.

Preferably, the gradient carbonization in the step 2) is kept at 350 ℃ for 5min, at 450 ℃ for 5min, at 550 ℃ for 5min and at 650 ℃ for 5min, and the heating rate is 10 ℃/mim; gradient activation is that the temperature is maintained at 700 ℃ for 10min, 750 ℃ for 10min, 800 ℃ for 10min, 850 ℃ for 60min, and the heating rate is 5 ℃/min.

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

1. the adhesive is nontoxic and tasteless, and can effectively reduce occupational health hazards to field operators.

2. The adhesive has low price and small dosage, and the adhesive powder is dissolved in water to be prepared into solution for use, thereby effectively reducing the preparation cost of the desulfurization and denitrification activated carbon.

3. In the using process of the adhesive, no organic matter volatilizes, and the problem of environmental pollution in the production process of the desulfurization and denitrification active carbon is solved.

Drawings

FIG. 1 is a flow chart of the preparation method of the present invention.

Detailed Description

The present invention is further illustrated by the following specific examples.

Example 1

1. Preparation of adhesive solution: using sodium lignosulfonate, with water at a ratio of 2:3, standing in a water bath at 60-80 ℃ for 4 hours to completely dissolve the sodium/calcium lignosulfonate to prepare a solution, and using the solution as an adhesive to prepare the desulfurization and denitrification active carbon.

2. And (3) preparing a finished product: mixing 80 parts of coal powder, 10 parts of adhesive solution and 10 parts of water according to a proportion, mixing for 10 minutes to form coal paste, molding by a granulator, forming the material with the particle size of 9-10mm, uniformly carbonizing for 1 hour (the gradient carbonization is maintained at 350 ℃ for 5min, the temperature is maintained at 450 ℃ for 5min, the temperature is maintained at 550 ℃ for 5min, the temperature is maintained at 650 ℃ for 5min, the heating rate is 10 ℃/mim), entering an activation furnace, uniformly activating for 2 hours under the temperature gradient of 700 ℃ to 850 ℃ (the gradient activation is maintained at 700 ℃ for 10min, the temperature is maintained at 750 ℃ for 10min, the temperature is maintained at 800 ℃ for 10min, the temperature is maintained at 850 ℃ for 60min, the heating rate is 5 ℃/min), discharging, cooling and screening to obtain the required desulfurization and denitrification active carbon, wherein the parameters of the prepared desulfurization and denitrification active carbon are shown in Table 1.

Example 2

1. Preparation of adhesive solution: using calcium lignosulfonate, with water at a rate of 2:3, standing in a water bath at 60-80 ℃ for 4 hours to completely dissolve the sodium/calcium lignosulfonate to prepare a solution, and using the solution as an adhesive to prepare the desulfurization and denitrification active carbon.

2. And (3) preparing a finished product: mixing 78 parts of coal powder, 13 parts of adhesive solution and 7 parts of water according to a proportion, mixing for 10 minutes to form coal paste, molding by a granulator, forming the material with the particle size of 9-10mm, uniformly carbonizing for 1 hour (the gradient carbonization is maintained at 350 ℃ for 5min, the temperature is maintained at 450 ℃ for 5min, the temperature is maintained at 550 ℃ for 5min, the temperature is maintained at 650 ℃ for 5min, the heating rate is 10 ℃/mim), entering an activation furnace, uniformly activating for 2 hours under the temperature gradient of 700 ℃ to 850 ℃ (the gradient activation is maintained at 700 ℃ for 10min, the temperature is maintained at 750 ℃ for 10min, the temperature is maintained at 800 ℃ for 10min, the temperature is maintained at 850 ℃ for 60min, the heating rate is 5 ℃/min), discharging, cooling and screening to obtain the required desulfurization and denitrification active carbon, wherein the parameters of the prepared desulfurization and denitrification active carbon are shown in Table 1.

Example 3

1. Preparation of adhesive solution: using sodium lignosulfonate, with water at a ratio of 2:3, standing in a water bath at 60-80 ℃ for 4 hours to completely dissolve the sodium/calcium lignosulfonate to prepare a solution, and using the solution as an adhesive to prepare the desulfurization and denitrification active carbon.

2. And (3) preparing a finished product: mixing 70 parts of coal powder, 15 parts of adhesive solution and 5 parts of water according to a proportion, mixing for 10 minutes to form coal paste, molding by a granulator, forming the material with the particle size of 9-10mm, uniformly carbonizing for 1 hour (the gradient carbonization is maintained at 350 ℃ for 5 minutes, the temperature is maintained at 450 ℃ for 5 minutes, the temperature is maintained at 550 ℃ for 5 minutes, the temperature is maintained at 650 ℃ for 5 minutes, the heating rate is 10 ℃/mim), entering an activation furnace, uniformly activating for 2 hours under the temperature gradient of 700 ℃ to 850 ℃ (the gradient activation is maintained at 700 ℃ for 10 minutes, the temperature is maintained at 750 ℃ for 10 minutes, the temperature is maintained at 800 ℃ for 10 minutes, the temperature is maintained at 850 ℃ for 60 minutes, the heating rate is 5 ℃/min), discharging, cooling and screening to obtain the required desulfurization and denitrification active carbon, wherein the parameters of the prepared desulfurization and denitrification active carbon are shown in Table 1.

Comparative example

Mixing 70 parts of coal powder, 15 parts of coal tar and 5 parts of water according to a proportion, mixing for 10 minutes to form coal paste, molding by a granulator, forming the material with the particle size of 9-10mm, uniformly carbonizing for 1 hour (the gradient carbonization is kept for 10 minutes at 350 ℃, 10 minutes at 450 ℃, 10 minutes at 550 ℃, 10 minutes at 650 ℃, and 10 minutes at 15 ℃/mim), entering an activation furnace, uniformly activating for 2 hours at the temperature gradient of 700-850 ℃ (the gradient activation is kept for 10 minutes at 700 ℃, 10 minutes at 750 ℃, 10 minutes at 800 ℃, 60 minutes at 850 ℃, and the heating rate is 5 ℃/min), discharging, cooling and screening to obtain the required desulfurization and denitrification activated carbon, wherein the parameters of the prepared desulfurization and denitrification activated carbon are shown in table 1.

Table 1 parameters of the desulfurization and denitrification activated carbon products prepared in examples 1 to 3 and comparative example:

as can be seen from Table 1, the performance of the desulfurization and denitrification activated carbon prepared by using the adhesive of the invention is superior to that of a comparative example, and on the premise that key adsorption indexes are close, the wear-resisting strength and the compressive strength are superior to those of the desulfurization and denitrification activated carbon prepared by coal tar, so that the service life of the desulfurization and denitrification activated carbon can be effectively prolonged, and meanwhile, the price of the adhesive used by the invention is lower than that of the coal tar, so that the production cost of the desulfurization and denitrification activated carbon can be effectively reduced.