GB2072644A - Process for the production of nitrogenous fertilizer - Google Patents

Process for the production of nitrogenous fertilizer Download PDF

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Publication number
GB2072644A
GB2072644A GB8106210A GB8106210A GB2072644A GB 2072644 A GB2072644 A GB 2072644A GB 8106210 A GB8106210 A GB 8106210A GB 8106210 A GB8106210 A GB 8106210A GB 2072644 A GB2072644 A GB 2072644A
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GB
United Kingdom
Prior art keywords
fertilizer
urea
calcium nitrate
urea phosphate
phosphate
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB8106210A
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GB2072644B (en
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Ruhrchemie AG
ThyssenKrupp Industrial Solutions AG
Original Assignee
Uhde GmbH
Ruhrchemie AG
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Publication of GB2072644A publication Critical patent/GB2072644A/en
Application granted granted Critical
Publication of GB2072644B publication Critical patent/GB2072644B/en
Expired legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C05—FERTILISERS; MANUFACTURE THEREOF
    • C05B—PHOSPHATIC FERTILISERS
    • C05B17/00—Other phosphatic fertilisers, e.g. soft rock phosphates, bone meal

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Fertilizers (AREA)

Abstract

Preparation of a nitrogenous fertilizer comprises adding, whilst heating, urea and phosphoric acid or urea phosphate or a mixture of any two or more thereof to a fertilizer feedstock comprising calcium nitrate. Preferably polymerized urea phosphate is formed or added to give a proportion of in the range of from 0.1 to 5.0 % by weight in the fertilizer. A nitrogenous fertilizer comprising calcium nitrate and polymerized urea phosphate is also provided.

Description

SPECIFICATION Process for the production of nitrogenous fertilizer The invention relates to a processforthe production of nitrogenous fertilizer.
A variety of methods have been adopted in the past to increase the nitrogen content in fertilizer.
Experience has shown that the nitrogen content may only be increased to a limited extent, or sometimes not at all, when adding urea to NP or NPK fertilizers (fertilizers containing nitrogen and phosphates or containing nitrogen, phosphates and potassium) because urea and ammonium nitrate together form a eutectic mixture, the fusion point of which is below 40 C and which is very hygroscopic.
Several methods have been proposed to avoid these disadvantages, see for example German Auslegeschriften Nos. 1767547 and 20 40 561 and British Patent Specification No.1 313431,the selected fertilizerfeedstock in each case being ammonium phosphate. Other proposals using a basis of ammonium nitrate have been described in Auslegeschriften Nos. 1592748 and 1592793.
The production of a liquid fertilizer, during which phosphoric acid is purified by reaction with urea thus forming urea phosphate, has been described in a publication of the Tennessee Valley Authority 12th Demonstration, October 18-19, 1978, pages 47 et seq.
The processes previously proposed have the dis advantage that they have a high energy consumption and that they require a large amount of equipment in order to produce a fertilizer with an increased nitrogen content.
There is a need for processes which considerably increase the nitrogen content in fertilizers using simple means, i.e. of achieving a nitrogen content in the range of from 20 to 34 % by weight.
The present inention provides a process for the preparation of a nitrogenous fertilizer which com prises adding, whilst heating, urea and phosphoric acid or urea phosphate or a mixture of any two or more thereof to a fertilizer feedstock comprising caUcum nitrate.
We have found that, using calcium nitrate as the fertilizer feedstock, the process of the invention yields a considerably higher total nitrogen content without requiring a particularly large amount of equipment.
Suitably urea phosphate, or urea phosphate and phosphoric acid, or urea phosphate and urea is added to the calcium nitrate. In a preferred embodiment of the invention which is particularly advantageous, polymerized urea phosphate is added to the calcium nitrate. The addition of polymerized urea phosphate permits stabilization and modification of any eutectic mixture formed to be achieved in a particularly favourable way and appears to prevent hygroscopisity of the mixture produced. It is prefer red that, when added to the calcium nitrate, the portion of polymerized urea phosphate is in the range of from 0.1 to 5% by weight. The degree of polymerization of the phosphate (H3PO4) may be adjusted by modifying the reaction time and the temperature.
Generally, the temperature at which the process of the invention is carried out is in the range of 100 to 1300C.
We have found it useful in the process of the invention to use calcium nitrate dihydrate as the fertilizer feedstock; this means that the feedstock is already partly dehydrated as it only contains 2 moles of water of crystallization per mole of calcium nitrate. We have found that when carried out at a temperature in the range of from 100 to 1300C, the process of the invention yields a product containing up to 30 % by weight of nitrogen by the addition of about 0.5 /O by weight of polymerized urea. Calcium nitrate tetrahydrate may also be used as the fertilizer feedstock for the process of the invention.
The present invention further provides a nitrogenous fertilizer which comprises calcium nitrate and polymerized urea phosphate; the latter is preferably present in an amount in the range of from 0.1 to 5 % by weight.
The nitrogenous fertilizer prepared by the process of the invention may be granulated or prilled as appropriate, if desired.
It is possible, by the process of the invention, to produce a solid or liquid fertilizer; it is preferred, however, to use solid starting materials.
In carrying out the process of the invention it may be desirable to add small amounts of ammonium nitrate in order to be sure of preventing the formation of biuret.
The process of the invention will now be described, by way of example only, with the aid of the accompanying flow diagram.
Firstly, the calcium nitrate feedstock is prepared by removing Ca(NO3)2.4H2O and by washing at stage 1.
Then, at stage 2, any nitric acid still present is neutralized, if necessary, with the addition of about 4 % by weight of ammonium nitrate (AN), the slurry being heated to 100"C approximately. The AN inlet is marked as line 11.
At stage 3, 2 moles of water of crystallization per mole of Ca(NO3)2 are evaporated and the calcium nitrate dihydrate thus formed is fed to stage 4.
At stage 4, phosphoric acid is added (line 6) and also urea (line 7) to the calcium nitrate; heating to a temprature of approximately 120"C takes place at this stage (the application of heat is shown as line 5).
The heat released by the polymerization of the urea phosphate also heats the melt. The melt is withdrawn at 8 and, if desired, is granulated and/or prilled, and may be screened to the desired grain size. Afinal drying stage may be dispensed with.
It is possible that, instead of adding phosphoric acid and urea separately (at lines 6 and 7) urea phosphate may also be added; this possibility is represented by the broken-line section - arrow 9 and reactor box 10. Polymerization to polyphosphate may be performed at stage 10.
1. A process for the preparation of a nitrogenous fertilizer which comprises adding, whilst heating, urea and phosphoric acid or urea phosphate or a
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Process for the production of nitrogenous fertilizer The invention relates to a processforthe production of nitrogenous fertilizer. A variety of methods have been adopted in the past to increase the nitrogen content in fertilizer. Experience has shown that the nitrogen content may only be increased to a limited extent, or sometimes not at all, when adding urea to NP or NPK fertilizers (fertilizers containing nitrogen and phosphates or containing nitrogen, phosphates and potassium) because urea and ammonium nitrate together form a eutectic mixture, the fusion point of which is below 40 C and which is very hygroscopic. Several methods have been proposed to avoid these disadvantages, see for example German Auslegeschriften Nos. 1767547 and 20 40 561 and British Patent Specification No.1 313431,the selected fertilizerfeedstock in each case being ammonium phosphate. Other proposals using a basis of ammonium nitrate have been described in Auslegeschriften Nos. 1592748 and 1592793. The production of a liquid fertilizer, during which phosphoric acid is purified by reaction with urea thus forming urea phosphate, has been described in a publication of the Tennessee Valley Authority 12th Demonstration, October 18-19, 1978, pages 47 et seq. The processes previously proposed have the dis advantage that they have a high energy consumption and that they require a large amount of equipment in order to produce a fertilizer with an increased nitrogen content. There is a need for processes which considerably increase the nitrogen content in fertilizers using simple means, i.e. of achieving a nitrogen content in the range of from 20 to 34 % by weight. The present inention provides a process for the preparation of a nitrogenous fertilizer which com prises adding, whilst heating, urea and phosphoric acid or urea phosphate or a mixture of any two or more thereof to a fertilizer feedstock comprising caUcum nitrate. We have found that, using calcium nitrate as the fertilizer feedstock, the process of the invention yields a considerably higher total nitrogen content without requiring a particularly large amount of equipment. Suitably urea phosphate, or urea phosphate and phosphoric acid, or urea phosphate and urea is added to the calcium nitrate. In a preferred embodiment of the invention which is particularly advantageous, polymerized urea phosphate is added to the calcium nitrate. The addition of polymerized urea phosphate permits stabilization and modification of any eutectic mixture formed to be achieved in a particularly favourable way and appears to prevent hygroscopisity of the mixture produced. It is prefer red that, when added to the calcium nitrate, the portion of polymerized urea phosphate is in the range of from 0.1 to 5% by weight. The degree of polymerization of the phosphate (H3PO4) may be adjusted by modifying the reaction time and the temperature. Generally, the temperature at which the process of the invention is carried out is in the range of 100 to 1300C. We have found it useful in the process of the invention to use calcium nitrate dihydrate as the fertilizer feedstock; this means that the feedstock is already partly dehydrated as it only contains 2 moles of water of crystallization per mole of calcium nitrate. We have found that when carried out at a temperature in the range of from 100 to 1300C, the process of the invention yields a product containing up to 30 % by weight of nitrogen by the addition of about 0.5 /O by weight of polymerized urea. Calcium nitrate tetrahydrate may also be used as the fertilizer feedstock for the process of the invention. The present invention further provides a nitrogenous fertilizer which comprises calcium nitrate and polymerized urea phosphate; the latter is preferably present in an amount in the range of from 0.1 to 5 % by weight. The nitrogenous fertilizer prepared by the process of the invention may be granulated or prilled as appropriate, if desired. It is possible, by the process of the invention, to produce a solid or liquid fertilizer; it is preferred, however, to use solid starting materials. In carrying out the process of the invention it may be desirable to add small amounts of ammonium nitrate in order to be sure of preventing the formation of biuret. The process of the invention will now be described, by way of example only, with the aid of the accompanying flow diagram. Firstly, the calcium nitrate feedstock is prepared by removing Ca(NO3)2.4H2O and by washing at stage 1. Then, at stage 2, any nitric acid still present is neutralized, if necessary, with the addition of about 4 % by weight of ammonium nitrate (AN), the slurry being heated to 100"C approximately. The AN inlet is marked as line 11. At stage 3, 2 moles of water of crystallization per mole of Ca(NO3)2 are evaporated and the calcium nitrate dihydrate thus formed is fed to stage 4. At stage 4, phosphoric acid is added (line 6) and also urea (line 7) to the calcium nitrate; heating to a temprature of approximately 120"C takes place at this stage (the application of heat is shown as line 5). The heat released by the polymerization of the urea phosphate also heats the melt. The melt is withdrawn at 8 and, if desired, is granulated and/or prilled, and may be screened to the desired grain size. Afinal drying stage may be dispensed with. It is possible that, instead of adding phosphoric acid and urea separately (at lines 6 and 7) urea phosphate may also be added; this possibility is represented by the broken-line section - arrow 9 and reactor box 10. Polymerization to polyphosphate may be performed at stage 10. CLAIMS
1. A process for the preparation of a nitrogenous fertilizer which comprises adding, whilst heating, urea and phosphoric acid or urea phosphate or a mixture of any two or more thereof to a fertilizer feedstock comprising calcium nitrate.
2. A process as climed in claim 1, wherein urea phosphate is added to the fertilizer feedstock.
3. A process as claimed in claim 1, wherein urea phosphate and phosphoric acid are added to the fertilizer feedstock.
4. A process as claimed in claim 1, wherein urea phosphate and urea are added to the fertilizer.
5. A process as claimed in any one of claims 1 to 4, wherein polymerized urea phosphate is added to the fertilizer feedstock.
6. A process as claimed in claim 5, wherein the proportion of polymerized urea phosphate in the fertilizer after addition is in the range of from 0.1 to 5.0 % by weight.
6. A process as climed in claim 5, wherein the portion of polymerized urea phosphate is in the range of from 0.1 to 5.0 % by weight.
7. A process as claimed in any one of claims 1 to 6, wherein the process is carried out at a temperature in the range of from 100 to 1300C.
8. A process as claimed in any one of claims 1 to 7, wherein the fertilizer feedstock comprises calcium nitrate dihydrate.
9. A process as claimed in any one of claims 1 to 7, wherein the fertilizer feedstock comprises calcium nitrate tetrahydrate.
10. A process as claimed in any one of claims 1 to 10, wherein the product obtained is subjected to granulation and/or prilling.
11. A process as claimed in claim 1,which is carried out substantially as described herein with reference to the accompanying drawing.
12. A nitrogenous fertilizer whenever prepared by a process as claimed in any one of claims 1 to 11.
13. A nitrogenous fertilizer which comprises calcium nitrate and polymerized urea phosphate.
14. A nitrogenous fertilizer as claimed in claim 13, which contains in the range of from 0.1 to 5.0 % by weight of polymerized urea phosphate.
15. A nitrogenous fertilizer as claimed in claim 13 or claim 14, which has been granulated or prilled.
New claims or amendments to claims filed on 14.5.81 Superseded claim 6 New or amended claim
GB8106210A 1980-02-28 1981-02-27 Process for the production of nitrogenous fertilizer Expired GB2072644B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19803007486 DE3007486C2 (en) 1980-02-28 1980-02-28 Process for producing a nitrogen fertilizer

Publications (2)

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GB2072644A true GB2072644A (en) 1981-10-07
GB2072644B GB2072644B (en) 1984-04-04

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DE (1) DE3007486C2 (en)
FR (1) FR2477171B1 (en)
GB (1) GB2072644B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992013813A2 (en) * 1991-01-31 1992-08-20 Grace Sierra Horticultural Products Company Improved solubility compound fertilizer compositions
US5171349A (en) * 1991-01-31 1992-12-15 Vetanovetz Richard P Solubility compound fertilizer compositions
US5454850A (en) * 1991-01-31 1995-10-03 Oms Investments, Inc. Calcium phosphate and urea phosphate soluble compound fertilizer compositions
EP1714951A3 (en) * 2005-04-07 2008-10-01 Liu, Yaqing Slow and controlled-release polymeric fertilizer with multiple nutrients, preparing process for the same and the use method of the same

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE295548C (en) *
DE286491C (en) *
DE423958C (en) * 1924-07-04 1926-01-14 Basf Ag Conversion of calcium nitrate into a fertilizer salt suitable for spreading
DE539807C (en) * 1929-01-27 1931-12-02 I G Farbenindustrie Akt Ges Process for the production of a fertilizer containing urea calcium nitrate
DE530499C (en) * 1929-03-27 1931-07-29 I G Farbenindustrie Akt Ges Process for the production of solid urea or fertilizers containing urea
DE530500C (en) * 1929-06-09 1931-07-29 I G Farbenindustrie Akt Ges Process for the production of a fertilizer containing urea calcium nitrate
FR820023A (en) * 1937-03-31 1937-10-30 Process for making a fertilizer using calcium cyanamide as raw material
FR1107730A (en) * 1954-06-26 1956-01-04 Azote Office Nat Ind Manufacturing process of calcium urea phospho-nitrates
FR1531437A (en) * 1966-04-01 1968-07-05 Toyo Koatsu Ind Inc Process for preparing a granular fertilizer
GB1109410A (en) * 1966-04-01 1968-04-10 Toyo Koatsu Ind Inc Production of granular fertilizer
FR1533272A (en) * 1967-05-22 1968-07-19 Ugine Kuhlmann Process for the preparation of liquid nitrogenous and phosphate fertilizers, and products obtained
IL32831A (en) * 1969-08-15 1972-11-28 Chem & Phosphates Ltd Nitrogen-phosphate fertilizers and their manufacture
FR2076321A5 (en) * 1970-01-09 1971-10-15 Ugine Kuhlmann Phosphoric acid-urea-ammonia reaction for - fertilizer prodn
BE760491A (en) * 1970-01-09 1971-05-27 Ugine Kuhlmann PROCESS FOR OBTAINING NEW REACTION PRODUCTS OF PHOSPHORIC ACID, UREA AND AMMONIA, AND THEIR APPLICATIONS AS FERTILIZERS
US4175943A (en) * 1973-12-19 1979-11-27 Triomf Fertilizers Water-soluble fertilizers
FR2299294A1 (en) * 1975-01-28 1976-08-27 Triomf Fertilizer Ltd Water-soluble fertiliser - prepd. by addn. of urea, phosphoric acid and potassium salt
GB2034682B (en) * 1978-10-30 1983-06-15 Stoller Ets High analysis liquid fertilizer

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992013813A2 (en) * 1991-01-31 1992-08-20 Grace Sierra Horticultural Products Company Improved solubility compound fertilizer compositions
WO1992013813A3 (en) * 1991-01-31 1992-10-29 Grace Sierra Horticultural Pro Improved solubility compound fertilizer compositions
US5171349A (en) * 1991-01-31 1992-12-15 Vetanovetz Richard P Solubility compound fertilizer compositions
US5395418A (en) * 1991-01-31 1995-03-07 Grace-Sierra Horticultural Products Solubility compound fertilizer compositions
US5454850A (en) * 1991-01-31 1995-10-03 Oms Investments, Inc. Calcium phosphate and urea phosphate soluble compound fertilizer compositions
AU663306B2 (en) * 1991-01-31 1995-10-05 Grace Sierra Horticultural Products Company Improved solubility compound fertilizer compositions
US5492553A (en) * 1991-01-31 1996-02-20 Oms Investments, Inc. Solubility compound fertilizer compositions
TR28925A (en) * 1991-01-31 1997-08-05 Grace Sierra Horticultural Pro Water-based fertilizer compounds that are useful for fertilizer nutrition, especially with fertilizer preparations.
EP1714951A3 (en) * 2005-04-07 2008-10-01 Liu, Yaqing Slow and controlled-release polymeric fertilizer with multiple nutrients, preparing process for the same and the use method of the same

Also Published As

Publication number Publication date
FR2477171B1 (en) 1985-08-23
DE3007486A1 (en) 1981-09-03
DE3007486C2 (en) 1983-08-04
GB2072644B (en) 1984-04-04
FR2477171A1 (en) 1981-09-04

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