阅读说明：本技术 一种尿素醛及其衍生物的高效环保反应挤出一体化连续加工工艺 (Efficient environment-friendly reactive extrusion integrated continuous processing technology for urea aldehyde and derivatives thereof ) 是由 向阳 刘亚青 耿阳阳 赵贵哲 于 2021-02-06 设计创作，主要内容包括：本发明具体涉及一种尿素醛及其衍生物的高效环保反应挤出一体化连续加工工艺；具体为首先制备得到羟甲基脲溶液,然后将其送入到反应挤出一体机中,加入或者不加入磷酸盐或其它中微量元素肥料,启动反应挤出一体机的反应单元进行反应,同时启动抽真空脱挥单元脱除反应体系中的水分；反应结束后,启动反应挤出一体机的挤出单元,挤出得到条状产物,经烘干造粒后得到成品。本发明通过将挤出单元与反应单元一体化,实现了反应单元输出端的强制出料,进而实现了尿素醛的连续化生产。此外,在反应挤出一体机上加装抽真空脱挥单元,可以实现不同固含量原料的反应挤出,使终产物的养分组成和含量灵活多变,从而制得适配不同作物养分需求的专用尿素醛。(The invention particularly relates to a high-efficiency environment-friendly reaction extrusion integrated continuous processing technology of urea aldehyde and derivatives thereof; firstly, preparing a hydroxymethyl urea solution, then sending the hydroxymethyl urea solution into a reaction and extrusion integrated machine, adding or not adding phosphate or other medium and trace element fertilizers, starting a reaction unit of the reaction and extrusion integrated machine for reaction, and simultaneously starting a vacuumizing devolatilization unit to remove water in a reaction system; and after the reaction is finished, starting an extrusion unit of the reaction extrusion all-in-one machine, extruding to obtain a strip product, and drying and granulating to obtain a finished product. The invention realizes the forced discharging of the output end of the reaction unit by integrating the extrusion unit and the reaction unit, thereby realizing the continuous production of the urea aldehyde. In addition, the vacuumizing devolatilization unit is additionally arranged on the reaction extrusion all-in-one machine, so that the reaction extrusion of raw materials with different solid contents can be realized, the nutrient composition and content of a final product are flexible and changeable, and the special urea aldehyde adaptive to different crop nutrient requirements is prepared.)

1. An efficient environment-friendly reactive extrusion integrated continuous processing technology for urea aldehyde is characterized by comprising the following steps:

(1) adding a calculated amount of formaldehyde into a reactor, then adding a calculated amount of urea, and reacting at a set temperature to obtain a hydroxymethyl urea solution;

(2) sealing a die orifice of the reaction extrusion all-in-one machine, and then adding the hydroxymethyl urea solution obtained in the step (1) into the reaction extrusion all-in-one machine;

(3) starting a stirring shaft of a reaction unit of the reaction and extrusion all-in-one machine, reacting at a set temperature and a set rotating speed, and simultaneously starting a vacuumizing devolatilization unit to remove water in a reaction system until the reaction system becomes viscous;

(4) opening a die orifice of the reaction and extrusion integrated machine, starting an extrusion unit of the reaction and extrusion integrated machine, and extruding to obtain a strip-shaped product;

(5) drying the strip-shaped product at 100 ℃ and granulating to obtain urea-formaldehyde granules with good granule shape.

2. An efficient environment-friendly reactive extrusion integrated continuous processing technology of urea aldehyde derivatives is characterized by comprising the following steps:

(1) adding a calculated amount of formaldehyde into a reactor, then adding a calculated amount of urea, and reacting at a set temperature to obtain a methylol urea solution;

(2) sealing a die orifice of the reaction extrusion all-in-one machine, adding the hydroxymethyl urea solution obtained in the step (1) into the reaction extrusion all-in-one machine, and then adding calculated amount of phosphate, medium and trace element fertilizer or a mixture of the phosphate and the trace element fertilizer;

(3) starting a stirring shaft of a reaction unit of the reaction and extrusion all-in-one machine, reacting at a set temperature and a set rotating speed, and simultaneously starting a vacuumizing devolatilization unit to remove water in a reaction system until the reaction system becomes viscous;

(4) opening a die orifice of the reaction and extrusion integrated machine, starting an extrusion unit of the reaction and extrusion integrated machine, and extruding to obtain a strip-shaped product;

(5) drying the strip-shaped product at 100 ℃ and granulating to obtain urea-formaldehyde derivative granules with good granule shape.

3. The efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde according to claim 1 or the efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde derivative according to claim 2, wherein the molar ratio of urea to formaldehyde is 0.5-4: 1.

4. The efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde according to claim 1 or the efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde derivative according to claim 2, wherein the reaction temperature of urea and formaldehyde is 20-100 ℃.

5. The efficient environment-friendly reactive extrusion integrated continuous processing technology of urea aldehyde derivatives as claimed in claim 2, wherein the phosphate is one or more of hydroxyapatite, ammonium dihydrogen phosphate, calcium superphosphate and potassium dihydrogen phosphate; the medium trace element fertilizer is one or more of ferrous sulfate, manganese sulfate, zinc sulfate, copper sulfate, boric acid, sodium silicate and potassium silicate.

6. The efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde according to claim 1 or the efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde derivative according to claim 2, wherein the temperature of the reaction unit of the reactive extrusion integrated machine is 30-100 ℃.

7. The efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde according to claim 1 or the efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde derivatives according to claim 2, wherein the stirring speed of the reaction unit of the reactive extrusion integrated machine is 0-50 r/min.

8. The efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde according to claim 1 or the efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde derivatives according to claim 2, wherein the degree of vacuum pumping of the vacuum pumping and devolatilization unit of the reactive extrusion integrated machine is 0 to-0.1 MPa.

9. The efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde according to claim 1 or the efficient environment-friendly reactive extrusion integrated continuous processing process for urea aldehyde derivative according to claim 2, wherein the extrusion rate of the extrusion unit of the reactive extrusion integrated machine is 0-50 r/min.

Technical Field

The invention belongs to the technical field of slow and controlled release fertilizers, and particularly relates to a high-efficiency environment-friendly reactive extrusion integrated continuous processing technology for urea aldehyde and derivatives thereof.

Background

In order to solve the problem of low nutrient utilization rate of the traditional fertilizer, the slow-release fertilizer becomes a hotspot of the current fertilizer research and is rapidly developed in China. The urea-aldehyde slow-release nitrogen fertilizer is a slow-release fertilizer which is researched and developed successfully at the earliest time and is commercialized at the first time, is the most potential slow-release fertilizer variety at present, and has a far-reaching practical significance for promoting the upgrade of the nitrogen fertilizer industry in China and relieving energy and environmental stress.

For urea aldehyde and its derivatives, the currently widely used production methods include a dilute solution method and a concentrated solution method. The dilute solution process is that urea and formaldehyde react in dilute solution to produce urea-formaldehyde suspension, which is solid-liquid separated, dried and crushed to produce the product, and the mother liquid is reused. The method has the characteristics of good product quality, complex process, high cost and difficulty in realizing large-scale mass production. The concentrated solution method is that urea and formaldehyde react in the form of concentrated solution, and the intermediate product of the reaction is directly added with catalyst (curing agent) without solid-liquid separation to be cured into a product. The process is simple, the production cost is low, but the obtained high-viscosity urea aldehyde and the derivative thereof are difficult to automatically discharge from a reaction device and can only stay in a small-batch production stage, even a laboratory stage. The difficulty in automatic discharging from a reaction device becomes one of the main reasons which bother the realization of industrial scale-up and continuous production of the urea-formaldehyde polymerization reaction at present. Therefore, the key of the continuous production technology of the reaction is how to automatically discharge the high-viscosity urea aldehyde and the derivatives thereof after the polymerization reaction is finished.

The reactive extrusion technology in the polymer field has become a new polymer molding technology in recent years. The technology combines two mutually independent processes of material synthesis and processing molding, and the production process is continuous, diverse, simple and efficient. However, the production technology is still related in the agricultural field, and the production and processing of the urea aldehyde and the derivatives thereof by utilizing the reactive extrusion technology are expected to solve the problem of continuous production of the high-viscosity urea aldehyde and the derivatives thereof.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides a high-efficiency environment-friendly reactive extrusion integrated continuous processing technology for urea aldehyde and derivatives thereof.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

an efficient environment-friendly reactive extrusion integrated continuous processing technology of urea aldehyde comprises the following steps:

(1) adding a calculated amount of formaldehyde into a reactor, then adding a calculated amount of urea, and reacting at a set temperature to obtain a methylol urea solution;

(2) sealing a die orifice of the reaction extrusion all-in-one machine, and then adding the hydroxymethyl urea solution obtained in the step (1) into the reaction extrusion all-in-one machine;

(3) starting a stirring shaft of a reaction unit of the reaction and extrusion all-in-one machine, reacting at a set temperature and a set rotating speed, and simultaneously starting a vacuumizing devolatilization unit to remove water in a reaction system until the reaction system becomes viscous;

(4) opening a die orifice of the reaction and extrusion integrated machine, starting an extrusion unit of the reaction and extrusion integrated machine, and extruding to obtain a strip-shaped product;

(5) drying the strip-shaped product at 100 ℃ and granulating to obtain urea-formaldehyde granules with good granule shape.

An efficient environment-friendly reactive extrusion integrated continuous processing technology of urea aldehyde derivatives comprises the following steps:

(1) adding a calculated amount of formaldehyde into a reactor, then adding a calculated amount of urea, and reacting at a set temperature to obtain a methylol urea solution;

(2) sealing a die orifice of the reaction extrusion all-in-one machine, adding the hydroxymethyl urea solution obtained in the step (1) into the reaction extrusion all-in-one machine, and then adding calculated amount of phosphate, medium and trace element fertilizer or a mixture of the phosphate and the trace element fertilizer;

(3) starting a stirring shaft of a reaction unit of the reaction and extrusion all-in-one machine, reacting at a set temperature and a set rotating speed, and simultaneously starting a vacuumizing devolatilization unit to remove water in a reaction system until the reaction system becomes viscous;

(4) opening a die orifice of the reaction and extrusion integrated machine, starting an extrusion unit of the reaction and extrusion integrated machine, and extruding to obtain a strip-shaped product;

(5) drying the strip-shaped product at 100 ℃ and granulating to obtain urea-formaldehyde derivative granules with good granule shape.

Further, in the efficient environment-friendly reactive extrusion integrated continuous processing technology for the urea aldehyde or the urea aldehyde derivative, the molar ratio of urea to formaldehyde is 0.5-4: 1.

Further, in the efficient environment-friendly reaction extrusion integrated continuous processing technology of the urea aldehyde or the urea aldehyde derivative, the reaction temperature of the urea and the formaldehyde is 20-100 ℃.

Further, in the efficient environment-friendly reactive extrusion integrated continuous processing technology of the urea aldehyde derivative, the phosphate is one or more compounds of hydroxyapatite, ammonium dihydrogen phosphate, calcium superphosphate and potassium dihydrogen phosphate; the medium trace element fertilizer is one or more of ferrous sulfate, manganese sulfate, zinc sulfate, copper sulfate, boric acid, sodium silicate and potassium silicate. The addition amount of the phosphate or the medium trace element fertilizer is determined according to the growth requirements of different crops.

Further, in the efficient environment-friendly reaction extrusion integrated continuous processing technology of the urea aldehyde or the urea aldehyde derivative, the temperature of a reaction unit of the reaction extrusion integrated machine is 30-100 ℃.

Further, in the efficient environment-friendly reaction extrusion integrated continuous processing technology for the urea aldehyde or the urea aldehyde derivative, the stirring speed of the reaction unit of the reaction extrusion integrated machine is 0-50 r/min.

Further, in the efficient and environment-friendly reaction extrusion integrated continuous processing technology of the urea aldehyde or the urea aldehyde derivative, the vacuum degree of a vacuumizing and devolatilization unit of the reaction extrusion integrated machine is 0-0.1 MPa.

Further, in the efficient and environment-friendly reaction extrusion integrated continuous processing technology for the urea aldehyde or the urea aldehyde derivative, the extrusion rate of the extrusion unit of the reaction extrusion integrated machine is 0-50 r/min.

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

(1) the extrusion unit and the reaction unit are integrated, so that forced discharging of the output end of the reaction unit is realized, continuous production of the urea aldehyde and the derivatives thereof is realized, and the problem that the automatic discharging cannot be realized in the reaction production process of the traditional urea aldehyde, and the continuous production cannot be realized is solved;

(2) according to the invention, the vacuumizing devolatilization unit is additionally arranged on the reaction extrusion integrated machine, so that the reaction extrusion of raw materials with different solid contents can be realized, the nutrient composition and content of the final product are flexible and changeable, and urea aldehyde adaptive to different crop nutrient requirements can be prepared;

(3) the urea-formaldehyde fertilizer produced by the process can be added with medium and trace elements necessary for the growth process of plants, such as boron, silicon, iron, copper, manganese, zinc and the like according to the growth needs of crops, so that the soil components are effectively adjusted, and the requirements of the crops on the medium and trace elements in the whole growth process are met;

(4) the urea-formaldehyde fertilizer produced by the process can be produced on the existing high polymer material reaction extrusion granulation device, and has the advantages of small investment and short recovery period. In addition, the structure of the existing product is enriched, a high-end product is formed, and both economic benefit and social benefit are remarkable.

Drawings

FIG. 1 is a flow chart of a high-efficiency and environment-friendly reaction-extrusion integrated continuous processing process for urea aldehyde and derivatives thereof.

Detailed Description

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

As shown in fig. 1, the specific processing process flow of the invention is as follows: and uniformly mixing formaldehyde and urea, and then reacting to obtain the hydroxymethyl urea solution. And (2) feeding the hydroxymethyl urea solution into the reaction and extrusion all-in-one machine, adding or not adding phosphate and other medium and trace element fertilizers, starting a reaction unit of the reaction and extrusion all-in-one machine for reaction, and simultaneously starting a vacuumizing devolatilization unit to remove water in a reaction system. And after the reaction is finished, opening a die orifice of the reaction extrusion all-in-one machine, starting an extrusion unit of the reaction extrusion all-in-one machine, extruding to obtain a strip product, and drying, granulating, screening, metering and packaging to obtain a finished product.

Example 1

The efficient environment-friendly reactive extrusion integrated continuous processing technology for preparing the urea aldehyde derivative comprises the following steps:

(1) 5000g of formaldehyde and 1920g of urea are added into the reactor and reacted for 30min at 80 ℃ to obtain hydroxymethyl urea solution.

(2) The die of the reaction extrusion all-in-one machine was sealed, and then the above methylol urea solution was added to the reaction extrusion all-in-one machine, followed by the addition of 50g of hydroxyapatite.

(3) Setting the temperature of the reaction unit of the reaction and extrusion integrated machine to be 100 ℃, adjusting the rotating speed of the stirring shaft to be 50r/min for reaction, and simultaneously starting the vacuumizing and devolatilizing unit to remove the water in the reaction system until the reaction system becomes viscous, wherein the vacuum degree is-0.07 MPa.

(4) And opening a die orifice of the reaction extrusion all-in-one machine, starting an extrusion unit of the reaction extrusion all-in-one machine, and extruding at an extrusion rate of 10r/min to obtain a strip product.

(5) Drying the strip-shaped product at 100 ℃ and granulating to obtain the polymer sustained and controlled release nitrogen, phosphorus and potassium fertilizer granules.

Example 2

The efficient environment-friendly reaction extrusion integrated continuous processing technology for preparing the urea aldehyde comprises the following steps:

(1) 5000g of formaldehyde and 1920g of urea are added into the reactor and reacted for 30min at 80 ℃ to obtain hydroxymethyl urea solution.

(2) And sealing the die orifice of the reaction extrusion all-in-one machine, and then adding the hydroxymethyl urea solution into the reaction extrusion all-in-one machine.

(3) Setting the temperature of the reaction unit of the reaction and extrusion integrated machine to be 100 ℃, adjusting the rotating speed of the stirring shaft to be 50r/min for reaction, and simultaneously starting the vacuumizing and devolatilizing unit to remove the water in the reaction system until the reaction system becomes viscous, wherein the vacuum degree is-0.07 MPa.

(4) And opening a die orifice of the reaction extrusion all-in-one machine, starting an extrusion unit of the reaction extrusion all-in-one machine, and extruding at an extrusion rate of 10r/min to obtain a strip product.

(5) Drying the strip-shaped product at 100 ℃ and granulating to obtain urea-formaldehyde fertilizer granules.

Comparative example 1

The processing technology for preparing the urea aldehyde derivative comprises the following steps:

(1) 5000g of formaldehyde and 1920g of urea are added into the reactor and reacted for 30min at 80 ℃ to obtain hydroxymethyl urea solution.

(2) The die of the reaction extrusion all-in-one machine was sealed, and then the above methylol urea solution was added to the reaction extrusion all-in-one machine, followed by the addition of 50g of hydroxyapatite.

(3) Setting the temperature of the reaction unit of the reaction and extrusion integrated machine as 100 ℃, adjusting the rotating speed of the stirring shaft to 50r/min for reaction, and vacuumizing the reaction process until the reaction system becomes viscous.

(4) And opening a die orifice of the reaction extrusion all-in-one machine, starting an extrusion unit of the reaction extrusion all-in-one machine, and extruding at an extrusion rate of 10r/min to obtain a strip product.

(5) Drying the strip-shaped product at 100 ℃ and granulating to obtain the polymer sustained and controlled release nitrogen, phosphorus and potassium fertilizer granules.

Comparative example 2

The processing technology for preparing the urea aldehyde derivative comprises the following steps:

(1) 5000g of formaldehyde and 1920g of urea are added into the reactor and reacted for 30min at 80 ℃ to obtain hydroxymethyl urea solution.

(2) Adding the hydroxymethyl urea solution into a vertical reaction kettle, setting the temperature of the reaction kettle at 100 ℃, and then adding 50g of hydroxyapatite for reaction until the reaction system becomes viscous.

(3) And manually taking out the sticky substance from the vertical reaction kettle, adding the sticky substance into an extrusion granulator, and extruding to obtain a strip product.

(4) Drying the strip-shaped product at 100 ℃ and granulating to obtain the polymer sustained and controlled release nitrogen, phosphorus and potassium fertilizer granules.

The properties of the urea aldehydes and derivatives thereof obtained in examples 1 to 2 and comparative examples 1 to 2 were measured, and the results are shown in Table 1.

TABLE 1 Properties of Urea aldehydes and derivatives thereof processed

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.