1. The method for preparing the fertilizer anticaking agent raw material by capturing carbon dioxide by using nanofiltration seawater is characterized by comprising the following steps: 1) nano-filtered seawater is taken as a raw material, and a proper amount of talcum powder is added and stirred uniformly; 2) trapping carbon dioxide in nanofiltration seawater containing talcum powder, and fully mixing high-concentration salt in the nanofiltration seawater with the carbon dioxide for reaction to generate precipitate; 3) concentrating and crystallizing the nanofiltration seawater containing the precipitate, and performing solid-liquid separation, wherein the solid mixture mainly comprises magnesium carbonate, calcium carbonate and the like; 4) and then drying and crushing the solid mixture into powder to obtain the fertilizer anticaking agent raw material.

2. The method for preparing fertilizer anti-caking agent raw material by capturing carbon dioxide with nanofiltration seawater according to claim 1, wherein the method comprises the following steps: the particle size of the talcum powder is 600 meshes-800 meshes, and the density is 0.41-0.45 g/cm 3.

3. The method for preparing a fertilizer anti-caking agent raw material by capturing carbon dioxide using nanofiltration seawater according to claim 1 or 2, wherein: the addition amount of the talcum powder is 0.5-1.0% of the total amount of the salt compounds in the seawater.

Background

The surface area of the earth is 71% of the ocean, and seawater is the largest material resource on the earth, so that mankind has long begun to utilize seawater. At present, the industries using seawater as a production raw material have two major categories: one is salt chemical industry, which extracts various salt products or element substances in seawater from seawater; the other is the seawater desalination industry, i.e. extracting fresh water from seawater, which is a water treatment technology based on the principle that energy separates salt water into two parts, one part being fresh water with low salt content and the other part being brine with high salt content. The biggest disadvantage of both of the above industries is the discharge of the remaining seawater after production back into the sea. Because the residual seawater is incomplete, the content of various components in seawater in an offshore water area is changed, so that marine organisms die or change, and finally, a semi-closed bay like a Bohai bay becomes a dead sea. To date, this worldwide problem has not been completely solved.

Thus, while the greenhouse effect is most interesting among the problems related to global environmental protection, scientific research has shown that the main cause of the greenhouse effect is the large emission of greenhouse gases caused by human activities, although there are many factors that contribute to the greenhouse effect. Wherein the contribution of carbon dioxide to the greenhouse effect is about 55%. In 2010, the global fossil energy greenhouse gas emission amount reaches 306 hundred million tons, but high cost is a main bottleneck for preventing carbon dioxide capture and utilization technology marketization, a newly-built power plant is increased by 30-50% in cost, the power generation cost is greatly increased by modifying the existing power plant, and the development of a high-efficiency, low-energy and low-cost carbon dioxide separation technology becomes a research hotspot.

Patent CN102701822B discloses a method and apparatus for producing plant nutrient solution for nitrogen fertilizer from seawater, which comprises adding ammonia gas and carbon dioxide gas into seawater to fully mix salt compounds in seawater with ammonia and carbon dioxide to produce ammonia-carbon composite water, and adding ammonium nitrate into the ammonia-carbon composite water to fully mix the ammonium nitrate and the carbon dioxide to produce the nutrient solution for nitrogen fertilizer. Patent CN200910063076.8 discloses a method for directly mineralizing and isolating carbon dioxide in non-separated flue gas, which comprises placing calcium or magnesium silicate mineral powder in a reactor filled with water, introducing flue gas into the reactor, and introducing CO in the flue gas₂Reacting with silicate mineral in water solution to obtain carbonate. The teaching of the university of Sichuan, Hexie, in patents CN201110382112.4 and 201210188734.8, discloses a CO-production of potassium-rich solution₂A mineralization method, crushing ore rich in potassium feldspar into powder; placing the crushed ore powderAdding calcium chloride solution into the reactor, introducing carbon dioxide gas and CO₂Mineralized to generate calcium carbonate, and the potassium feldspar is dissolved to generate a solution rich in potassium ions. The method can break through CO in the prior art₂The mineralization method is due to CO₂Low added value of mineralized product, CO₂The mineralization technology is difficult to realize industrially, which is helpful for solving global CO₂The emission reduction problem can also provide sufficient potassium resources for the production of the potash fertilizer, and the trouble of shortage of the potassium fertilizer production resources is solved. However, in the patent, potassium feldspar-rich ore needs to be crushed into powder and even activated at high temperature, the mineralization reaction needs to be carried out at 150-350 ℃ under the conditions of high temperature and high pressure with the partial pressure of carbon dioxide not lower than 1.0MPa and even up to 35MPa, the energy consumption is large in the production process, and the potassium conversion rate in the potassium feldspar is low (60% -90%), so that the popularization of the potassium feldspar is hindered.

Disclosure of Invention

The invention aims to solve the technical problems in the prior art, provides a method for preparing a fertilizer anticaking agent raw material by using nanofiltration seawater to capture carbon dioxide, and the method is helpful for solving global CO₂The emission reduction problem can also provide a method with zero emission and environmental benefit for seawater desalination and seawater resource utilization.

The technical scheme of the invention is as follows:

the method for preparing the fertilizer anticaking agent raw material by capturing carbon dioxide by using nanofiltration seawater is characterized by comprising the following steps: 1) nano-filtered seawater is taken as a raw material, and a proper amount of talcum powder is added and stirred uniformly; 2) trapping carbon dioxide in nanofiltration seawater containing talcum powder, and fully mixing high-concentration salt in the nanofiltration seawater with the carbon dioxide for reaction to generate precipitate; 3) concentrating and crystallizing the nanofiltration seawater containing the precipitate, and performing solid-liquid separation, wherein the solid mixture mainly comprises magnesium carbonate, calcium carbonate and the like; 4) and then drying and crushing the solid mixture into powder to obtain the fertilizer anticaking agent raw material.

The particle size of the talcum powder is 600 meshes to 800 meshes, and the density is 0.41g/cm to 0.45g/cm³。

The addition amount of the talcum powder is 0.5-1.0% of the total amount of the salt compounds in the seawater.

The invention takes the residual nanofiltration seawater generated in the seawater desalination industry as the raw material, collects carbon dioxide, processes and prepares the high value-added fertilizer anticaking agent, does not generate residual seawater, and eliminates the pollution discharge. Not only reduces the seawater desalination cost and improves the production benefit, but also captures the carbon dioxide in the waste gas and benefits the human society.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the present invention is not limited to the specific examples.

Example 1

The method for preparing the fertilizer anticaking agent raw material by capturing carbon dioxide by using nanofiltration seawater is characterized by comprising the following steps: 1) nano-filtered seawater is taken as a raw material, and talcum powder accounting for 0.5 percent of the total amount of salt compounds in the seawater is added, wherein the granularity of the talcum powder is 600 meshes, and the density of the talcum powder is 0.41g/cm³Stirring uniformly; 2) trapping carbon dioxide in nanofiltration seawater containing talcum powder, and fully mixing high-concentration salt in the nanofiltration seawater with the carbon dioxide for reaction to generate precipitate; 3) concentrating and crystallizing the nanofiltration seawater containing the precipitate, and performing solid-liquid separation, wherein the solid mixture mainly comprises magnesium carbonate, calcium carbonate and the like; 4) and then drying and crushing the solid mixture into powder to obtain the fertilizer anticaking agent raw material.

The preparation method of the existing fertilizer powder anti-caking agent is not changed, and the fertilizer anti-caking agent is prepared by only replacing 20% of the powder in the existing fertilizer powder anti-caking agent by the raw material of the fertilizer anti-caking agent prepared by the invention according to the weight part. The anti-caking effect is shown in Table 1.

Example 2

The method for preparing the fertilizer anticaking agent raw material by capturing carbon dioxide by using nanofiltration seawater is characterized by comprising the following steps: 1) nano-filtered seawater is taken as a raw material, and talcum powder accounting for 1.0 percent of the total amount of salt compounds in the seawater is added, wherein the granularity of the talcum powder is 800 meshes, and the density of the talcum powder is 0.45g/cm³Stirring uniformly; 2) trapping carbon dioxide in nanofiltration seawater containing talcum powder, and fully mixing high-concentration salt in the nanofiltration seawater with the carbon dioxide for reaction to generate precipitate; 3) concentrating the nanofiltration seawater containing precipitatePerforming condensation crystallization and solid-liquid separation, wherein the solid mixture mainly contains magnesium carbonate, calcium carbonate and the like; 4) and then drying and crushing the solid mixture into powder to obtain the fertilizer anticaking agent raw material.

The preparation method of the existing fertilizer powder anti-caking agent is not changed, and the fertilizer anti-caking agent is prepared by only replacing 30% of powder in the existing fertilizer powder anti-caking agent by the raw material of the fertilizer anti-caking agent prepared by the invention according to the weight part. The anti-caking effect is shown in Table 1.

Example 3

The method for preparing the fertilizer anticaking agent raw material by capturing carbon dioxide by using nanofiltration seawater is characterized by comprising the following steps: 1) nano-filtered seawater is taken as a raw material, and talcum powder accounting for 0.8 percent of the total amount of salt compounds in the seawater is added, wherein the granularity of the talcum powder is 700 meshes, and the density is 0.43g/cm³Stirring uniformly; 2) trapping carbon dioxide in nanofiltration seawater containing talcum powder, and fully mixing high-concentration salt in the nanofiltration seawater with the carbon dioxide for reaction to generate precipitate; 3) concentrating and crystallizing the nanofiltration seawater containing the precipitate, and performing solid-liquid separation, wherein the solid mixture mainly comprises magnesium carbonate, calcium carbonate and the like; 4) and then drying and crushing the solid mixture into powder to obtain the fertilizer anticaking agent raw material.

The preparation method of the existing fertilizer powder anti-caking agent is not changed, and the fertilizer anti-caking agent is prepared by only replacing 40% of powder in the existing fertilizer powder anti-caking agent by the raw material of the fertilizer anti-caking agent prepared by the invention according to the weight part. The anti-caking effect is shown in Table 1.

Example 4

The method for preparing the fertilizer anticaking agent raw material by capturing carbon dioxide by using nanofiltration seawater is characterized by comprising the following steps: 1) nano-filtered seawater is taken as a raw material, and talcum powder accounting for 0.6 percent of the total amount of salt compounds in the seawater is added, wherein the granularity of the talcum powder is 650 meshes, and the density is 0.42g/cm³Stirring uniformly; 2) trapping carbon dioxide in nanofiltration seawater containing talcum powder, and fully mixing high-concentration salt in the nanofiltration seawater with the carbon dioxide for reaction to generate precipitate; 3) concentrating and crystallizing the nanofiltration seawater containing the precipitate, and performing solid-liquid separation, wherein the solid mixture mainly comprises magnesium carbonate, calcium carbonate and the like; 4) then drying the solid mixture to obtain powderAnd crushing into powder to obtain the fertilizer anticaking agent raw material.

The preparation method of the existing fertilizer powder anti-caking agent is not changed, and the fertilizer anti-caking agent is prepared by only replacing 50% of the powder in the existing fertilizer powder anti-caking agent by the raw material of the fertilizer anti-caking agent prepared by the invention according to the weight part. The anti-caking effect is shown in Table 1

The fertilizer anti-caking agent obtained in the embodiments 1 to 4 is used for a fertilizer anti-caking agent test in an experiment according to the generally recommended dosage of the fertilizer anti-caking agent, and the test results are shown in table 1:

TABLE 1 anticaking effect of powder anticaking agent

The test result shows that the fertilizer anticaking agent raw material prepared by trapping carbon dioxide by using the nanofiltration seawater can be used in a fertilizer powder anticaking agent, and the anticaking effect is not influenced, but the powder in the anticaking agent powder is required to be controlled within 30 weight percent instead of the powder. From the above table, the anti-caking effect of the fertilizer powder anti-caking agent raw material (the dosage is controlled to be between 20 and 30 weight percent) prepared by the invention reaches the anti-caking effect of the existing powder anti-caking agent. Not only reduces the seawater desalination cost and improves the production benefit, but also captures the carbon dioxide in the waste gas and benefits the human society.