阅读说明：本技术 基于磷酸的烷醇胺盐的新型磷肥 (Novel phosphate fertilizer based on alkanolamine salts of phosphoric acid ) 是由 斯图尔特·沃德 维多利亚·巴特勒 于 2018-11-20 设计创作，主要内容包括：本发明涉及磷酸的烷醇胺盐作为无铵肥料的用途。本发明还公开了水性组合物,包括磷酸的烷醇胺盐和至少一种烷醇胺金属络合物。(The present invention relates to the use of alkanolamine salts of phosphoric acid as ammonium-free fertilizers. Also disclosed are aqueous compositions comprising alkanolamine salts of phosphoric acid and at least one alkanolamine metal complex.)

1. Use of an alkanolamine salt of phosphoric acid as an ammonium-free fertilizer.

2. Use according to claim 1, characterized in that the alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine and triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine, and mixtures thereof.

3. Use according to any one of claims 1 to 2, characterized in that the alkanolamine is monoethanolamine.

4. Use according to any one of claims 1 to 3, characterized in that the fertilizer is an aqueous fertilizer solution.

5. Use according to claim 4, characterized in that the amount of said fertilizer is such that it is sufficient to obtain a fertilizer having a high yieldP in the aqueous fertilizer solution₂O₅The content is 5 to 40 wt% (w/w).

6. Use according to any one of claims 2 to 5, characterized in that the molar ratio between phosphoric acid and monoethanolamine is 3: 1 to 1: 3, more preferably 2: 1 to 1: 2.5, most preferably 1: 1 to 1: 2.

7. use according to any one of claims 4 to 6, characterized in that the aqueous fertilizer solution is applied to the soil by spraying on the soil, pouring into the soil, lashing, incorporation into the seedbed during drilling, by fertilizing or hydroponic systems, by foliar fertilization, or by seed coating.

8. An aqueous composition comprising an alkanolamine salt of phosphoric acid and at least one alkanolamine metal complex.

9. The aqueous composition of claim 8 wherein the alkanolamine of the alkanolamine metal complex is monoethanolamine.

10. The aqueous composition of claim 9, wherein the molar ratio of phosphoric acid and monoethanolamine in the monoethanolamine salt of phosphoric acid is 3: 1 to 1: 3, more preferably 2: 1 to 1: 2.5, most preferably 1: 1 to 1: 2.

11. aqueous composition according to any one of claims 8 to 10, characterized in that P is present in said composition relative to the total weight of said aqueous composition₂O₅The content is 5 to 40 wt% (w/w).

12. The aqueous composition as claimed in any one of claims 8 to 11, characterized in that the alkanolamine metal complex is selected from the group consisting of boroethanolamine, copper ethanolamine, zinc ethanolamine and iron ethanolamine.

13. The aqueous composition according to any one of claims 8 to 12, further comprising an ammonium-free nitrogen source and/or a potassium source.

14. The aqueous composition according to any one of claims 8 to 13, wherein the nitrogen source is urea or a nitrate compound and/or the potassium source is potassium nitrate or potassium sulfate.

15. The aqueous composition of any one of claims 8 to 14, further comprising one or more elements selected from the group consisting of calcium, magnesium, sulfur, sodium, boron, copper, iron, manganese, molybdenum, and zinc.

16. Use of an aqueous composition according to any one of claims 8 to 15 as a fertilizer.

Technical Field

The present invention relates to the use of alkanolamine salts of phosphoric acid as fertilizers and to the use of aqueous compositions comprising monoethanolamine salts of phosphoric acid, in particular as ammonium-free fertilizers.

Background

Plant nutrients can be divided into three main categories: primary or macronutrients such as nitrogen (N), phosphorus (P) and potassium (K); secondary nutrients such as calcium (Ca), magnesium (Mg), sulfur (S), and sodium (Na); micronutrients, such as boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn). An adequate supply of these nutrients is essential for healthy growth of plants, and it is common practice in modern agriculture to apply inorganic fertilizers to crops to improve yield and quality. Solid fertilizers, such as pellets or granules, containing one or more primary nutrients (N, P and K) are the most common type of fertilizer and are typically applied to soil. However, liquid fertilizers are also commercially available and are becoming increasingly important in many markets due to the benefits they offer to the grower in terms of convenience, flexibility, shipping accuracy and ease of use. Liquid fertilizers containing primary, secondary and micronutrients, used alone or in combination, are widely available and can be applied using a variety of methods, such as spraying onto soil, pouring into soil, lashing (binding), incorporation into seedbeds during drilling; in irrigation water (by fertilization or hydroponic systems); application to the leaves of crops by spraying (foliar application); or in seed processing.

It is desirable that the liquid fertilizer be as concentrated as possible to minimize shipping and storage costs, reduce packaging waste, increase productivity and facilitate modern application and dosing methods.

Phosphorus is one of the primary nutrients of plants, and therefore, a phosphate fertilizer (i.e., a phosphorus-containing fertilizer) plays a very important role in the market. Typical phosphorus sources in the production of solid particulate fertilizers to be applied to soil include monoperphosphate (monoperphosphate), triperphosphate and dicalcium phosphate, which are only partially soluble in water. For applications requiring complete dissolution of the fertilizer, such as fertigation, water-soluble phosphates such as monoammonium phosphate (MAP), diammonium phosphate (DAP), monopotassium phosphate (MKP), and dipotassium phosphate (DKP) are widely used and liquid fertilizer products can be made.

A major drawback of the prior art liquid fertilizer products comprising phosphorus is that the concentration of phosphorus in the aqueous composition achieved is relatively low. The chemical and physical handbook, 83 th edition, lists the solubility at 25 ℃ of each of the above phosphates, as follows:

in fact, the relatively high crystallization temperatures of these aqueous solutions will further limit the concentration. If other nutrients are added to the aqueous solution, the achievable P may be further reduced₂O₅And (4) content.

Another disadvantage of water-soluble phosphates such as monoammonium phosphate (MAP), diammonium phosphate (DAP) is that they also contain a certain amount of ammonium nitrogen. Thus, it is not possible to produce ammonium-free phosphorus-containing fertilizers using the widely used MAP and/or DAP compounds, and it is not possible to mix these compounds with nitrogen-containing compounds without changing their N content (e.g. in NPK fertilizers).

In some cases, phosphoric acid is used as a P fertilizer. A typical commercial grade concentration is 75% by weight, corresponding to P₂O₅The content was 54 wt%. The freezing point of 75 wt% phosphoric acid is-20 deg.c, thus representing a very stable liquid source of P. However, the strong acidity of phosphoric acid is problematic in many cases. For example, it can be severely damaging to crops when applied to foliage, has poor compatibility with certain other forms of nutrients and agrochemicals, and its corrosiveness can damage equipment.

Disclosure of Invention

Aspects of the invention are specified in the independent claims. Preferred features are specified in the dependent claims.

The present invention relates to the use of alkanolamine salts of phosphoric acid as ammonium-free fertilizers. Such use is not disclosed in the prior art. It has been found that such compounds have extremely high water solubility and can therefore be formulated to have very high P₂O₅Content of a stabilizing solution. Furthermore, such formulations have been demonstrated to have desirable agronomic properties such as excellent crop safety, efficient absorption, and broad compatibility with other plant nutrients. Preferably, in a specific application, this use is the only use of the claimed compounds as an ammonium-free fertilizer without an ammonium P-source.

According to one embodiment, the alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine and triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine, and mixtures thereof. In particular, the alkanolamine is monoethanolamine.

The compound according to the invention is prepared by reacting phosphoric acid and an alkanolamine in an aqueous solution in a molar ratio of 3: 1 to 1: 3, more preferably 2: 1 to 1: 2.5, most preferably 1: 1 to 1: 2, in contact with each other. No water is removed and thus no ester formation is expected. The compounds according to the invention therefore have the general formula alkanolamine H₃PO₄。

In particular, by reacting phosphoric acid with monoethanolamine (IUPAC name: 2-aminoethanol; CAS number 141-43-5; formula: NH)₂CH₂CH₂OH) in an aqueous solution in a molar ratio of 3: 1 to 1: 3, more preferably 2: 1 to 1: 2.5, most preferably 1: 1 to 1: 2 to prepare the salt of monoethanolamine and phosphoric acid. The compounds according to the invention may have the general formula C₂H₁₀NO₅P and/or C₄H₁₇N₂O₆And P. Preferably, the temperature of the aqueous solution comprising phosphoric acid and monoethanolamine is kept below 50 ℃ during the production process.

According to one embodiment, the fertilizer is an aqueous fertilizer solution. The aqueous fertilizer solution has a very high P content₂O₅A very stable solution of the alkanolamine salt of phosphoric acid at a level. Typically, the P of the aqueous fertilizer solution is relative to the total weight of the aqueous composition₂O₅The content is 5 to 40 wt% (w/w), more specifically 10 to 40 wt% (w/w), more specifically 20 to 40 wt% (w/w), more specifically 30 to 40 wt% (w/w). In the definition of range, the endpoints of the range are included.

According to one embodiment, the aqueous fertilizer solution is applied to the soil by spraying on the soil, pouring into the soil, lashing, incorporation into the bed during drilling, by fertilizing or hydroponic systems, by foliar application or by seed coating.

The present invention also relates to an aqueous composition comprising an alkanolamine salt of phosphoric acid and at least one alkanolamine metal complex. Surprisingly, alkanolamines were found to be good complex formers for micronutrients such as boron (B), copper (Cu), iron (Fe) and zinc (Zn). The alkanolamine metal complex is fully miscible and soluble in aqueous compositions comprising alkanolamine salts of phosphoric acid and thus, such compositions are good carriers for the addition of micronutrients to fertilizer compositions.

According to one embodiment, the alkanolamine of the alkanolamine metal complex is monoethanolamine.

According to one embodiment, the alkanolamine of the monoethanolamine salt is monoethanolamine, and the molar ratio of phosphoric acid and monoethanolamine in the monoethanolamine salt of phosphoric acid in the aqueous composition includes the monoethanolamine salt of phosphoric acid from 3: 1 to 1: 3, more preferably from 2: 1 to 1: 2.5, most preferably from 1: 1 to 1: 2. Preferably, such aqueous compositions consist essentially of water, a monoethanolamine salt of phosphoric acid and one or more alkanolamine metal complexes, preferably one or more monoethanolamine metal complexes.

It has been found that such aqueous compositions can have extremely high P₂O₅And (4) content. Furthermore, such aqueous compositions have been demonstrated to have desirable agronomic properties such as excellent crop safety, efficient absorption and broad compatibility with other plant nutrients. Generally, the fertilizer is applied relative to the total weight of the aqueous compositionP of stock solution₂O₅The content is 5 to 40 wt% (w/w), more particularly 10 to 40 wt% (w/w), more particularly 20 to 40 wt% (w/w), most particularly 30 to 40 wt% (w/w). In the definition of range, the endpoints of the range are included.

According to one embodiment, the alkanolamine metal complex is selected from the group consisting of boroethanolamine, copper ethanolamine, zinc ethanolamine and iron ethanolamine.

According to one embodiment, the aqueous composition further comprises an ammonium-free nitrogen source and/or a potassium source, in particular wherein the nitrogen source is urea or a nitrate salt and/or the potassium source is potassium nitrate or potassium sulfate.

According to one embodiment, the aqueous composition further comprises one or more elements selected from the group consisting of calcium, magnesium, sulfur, sodium, boron, copper, iron, manganese, molybdenum and zinc. These elements are considered secondary nutrients and micronutrients. It has surprisingly been found that such solutions are very stable, i.e. the secondary nutrients and micronutrients do not crystallize or form precipitates or deposits in a short time.

The aqueous composition is preferably used as a fertilizer.

Detailed Description

The present invention will now be further described with reference to the following examples, but is not limited thereto.

Experimental example 1: containing 34 wt% of P₂O₅Phosphate fertilizer

The following shows that 1kg of a catalyst containing 34 wt% of P is produced at a molar ratio of 1 mol of monoethanolamine to 1 mol of phosphoric acid₂O₅The liquid phosphorus fertilizer contains 34 wt% of P₂O₅The liquid phosphorus fertilizer of (a) is based on the monoethanolamine salt of phosphoric acid. The monoethanolamine used was a 90 wt% aqueous solution. The phosphoric acid used is 75 wt% of food grade, P₂O₅The content was 54.3 wt%.

The phosphoric acid was placed in a glass vessel equipped with a cooling jacket and an impeller stirrer. Monoethanolamine was slowly added to the stirred acid, the rate of addition being controlled in such a way as to maintain the temperature below 50 ℃. After the addition of monoethanolamine was completed, stirring was continued while the solution was cooled to room temperature. Water was then added to adjust the batch weight to 1000 g. The product obtained was a clear, colorless, slightly viscous solution with the following physicochemical characteristics:

the product remains stable for at least one year at room temperature.

It should be noted that by omitting the addition of water by using more concentrated acid and monoethanolamine solutions and allowing the heat of reaction to evaporate water from the reaction mixture, a higher concentration product can be produced.

In order to evaluate the crop safety of the above compositions, greenhouse trials were conducted. The test was carried out using a radish test crop, which was planted in pots in sandy medium and fed by nutrient solution. A random block design using 4 repeats was employed. The product was sprayed by foliar application at the 5 th leaf growth stage at a rate of 10 kg/ha in 200l/ha water (equivalent to 3.4 kg P/ha)₂O₅The input amount of (c). For comparison, the same delivery of P per hectare was also performed as ammonium polyphosphate, phosphoric acid, monoammonium phosphate, monopotassium phosphate and potassium pyrophosphate₂O₅And (4) processing. The phytotoxicity symptoms of the crops were evaluated 7 days after spraying.

The only treatment that showed signs of crop damage (leaf burn) was treatment with phosphoric acid. This test therefore demonstrates the safety of the product based on the monoethanolamine salt of phosphoric acid.

Further greenhouse tests were conducted for the efficacy of the above compositions compared to traditional phosphorus sources (phosphoric acid and potassium polyphosphate). The test was performed in 6 replicates on test tomato plants grown in pots mixed with sand/calcareous soil medium. Applying nutrients through the fertilization system; in each case 31mg/l of P are added in various forms₂O₅To irrigationIn water. The experiment was performed for 6 weeks, with the following parameters evaluated: number of flowers and fruits; the nutritional status; root fresh and dry matter.