PROCESS FOR PREPARATION OF NEEM OIL WATER EMULSION COATED UREA PRILLS,CAPABLE OF BEING INTEGRATED AT FERTILIZER PLANTS FOR A LARGE SCALE & CONTINUOUS COATING PROCESS

Abstract

A process for the preparation of neem oil water emulsion coated urea prills capable of being integrated at fertilizer plants for a large scale and continuous coating process; comprising the steps of :- a) mixing neem oil & emulsifier in the ratio of 4:1 in a concentrate preparation tank by recirculating the contents with the help of a pump at 4 Kg/cm2 for 15-25 minutes to get the neem oil emulsified concentrate ; b) mixing a predetermined amount of concentrate of step (a) through ejector nozzles in a span of 30 - 40 minutes to a predetermined quantity of water in the emulsion preparation tank, which is re circulated & agitated with the help of a pump at 3- 4 Kg/cm2 pressure through 2 nos.fanjet nozzles, when the neem oil water emulsion thus formed is led through 2 nos. acoustic nozzles where micronization of the emulsion is done to obtain a stable micronized neem oil water emulsion ; and . c coating neem oil water emulsion on urea prills with the help of a gear pump at a pressure of 3- 7 Kg /cm2 when the neem oil water emulsion is drawn from the emulsion storage tank & passed through 2 nos. of fan jet nozzles and full cone nozzles to spray on the urea curtain, such that it covers a maximum area on the urea curtain to get the

Full Text

The invention relates to a process for making neem oil water emulsion coated urea prills capable of being integrated at fertilizer plants for a large scale & continuous coating process; and in a very cost effective manner. Urea is a widely used nitrogenous fertilizer due to it's high nitrogen content (46.6 %). How ever , agronomic use efficiency of urea is abysmally low (about 30 - 40 %) under the predominantly sub tropical agricultural conditions in our country . Urea is lost in the soil in several ways : such as - leaching, ammonia volatilization, & through nitrification and de nitrification processes. Agricultural scientists at the Indian Agricultural Research Institute. New Delhi had observed that Neem products, such as - Oil, Cake & Neem extractives , when used with urea, increases it's agronomic use efficiency . How ever, due to the lack of a suitable technique for coating of urea with neem in a large scale. the benefit of increased use efficiency of neem coated urea was not conveniently available to the farmers. At best, manually coating urea with neem oil has so far been the general option available to the farmers. By using this process, neem coated urea can be made available to the farmers on a large scale & in a cost effective manner. BACKGROUND OF THE INVENTION :- Agricultural scientists observed that neem1'2 products such as oil, cake, and extractives when applied to urea, increases it's agronomic use efficiency. The following are some of the methods used in applying neem products to urea : i) Physically mixing urea prills with neem kernel powder. ii) Treating urea with coal tar and neemcake powder . iii) Treatment of urea with neem extractives . . All these methods were good enough for preparing neem coated urea prills on a very small scale only . No viable method is available to coat urea prills on a large scale . This invention aims at providing a process, in which urea can be coated with neem products on a large scale. The invention describes a process of preparation of neem oil - water emulsion & coating of urea in fertilizer plants, at site of urea production . Novelty : The novelty of this invention is that it makes neem oil - water emulsion using the ejector mixing of water with neem oil in the presence of a suitable emulsifier, when a stable emulsion is formed . The other novelty of the invention is the technique of micronization of the emulsion formed with the help of acoustic nozzles. This unique process produces high frequency vibrations, which further reduces the size of oil particles formed during the process of emulsification . The coating of urea with this emulsion is an improvement over other available methods, that the process allows coating of urea on a continuous basis at the site of urea manufacture. This process of coating of urea is novel that it can be integrated with operations in fertilizer plants for a continuous & large scale coating of urea with neem . References on Neem coating of Urea : 1. Bains.S.S.; Prasad.R; & Bhatia.P.C. ; Fertilizer News 16 (3) : 30-32; 1971. 2. Devakumar , and Mukerjee , S.K.; Neem News Letter 2 : 11-14 1985. 3. Ketkar, CM. ; Final Tech. Report-" Utilization of Neem and it's products' -Khadi and village Industries Commission, 1976 . Explicit Statement of Invention : The invention is a process for the preparation of neem oil water emulsion coated urea prills capable of being integrated at fertilizer plants for a large scale and continuous coating process, comprising steps of : a) mixing neem oil & emulsifier in the ratio of 4:1 in a concentrate preparation tank by re circulating the contents with the help of a pump at 4 Kg/cm2 for 15-25 minutes to get the neem oil - emulsifying surfactant concentrate ; b) mixing a predetermined amount of concentrate (10 - 30 %) of step (a) through ejector nozzles in a span of 30 - 40 minutes to a pre determined quantity of water in the emulsion preparation tank, which is re circulated and agitated with the help of a pump at 3-4 Kg/cm2 pressure through 2 nos. fan jet nozzles, when the neem oil water emulsion thus formed is led through 2 nos. of acoustic nozzles where micronization of the emulsion is done to obtain a stable micronized neem oil water emulsion ; and, c) coating neein oil water emusio on urea prills with the help of a gear pump at a pressure of 3 - 7 Kg/cm when the neem oil water emulsion is drawn from the emulsion tank and passed through 2 nos. of fan jet nozzles and full cone nozzles to spray on the urea curtain , such that it covers a maximum area on the urea curtain, and at a rate of 0.4 to 1.0% of urea flow, to enable a neem coating of 400 - 1000 ppm to get the desired DETAILED DESCRIPTION: Process for the preparation of Neem oil water emulsion : Details of the process developed are given as here under : Raw materials :- l.Neemoil from kernels from de pulped seeds as per I S 4765 (1975). The oil shall be free from any foreign & suspended matter. 2. Emulsifying surfactant (preferably nonionic, like ethylene oxide condensate of alkyl phenol) in liquid form , readily miscible with neem oil. 3. Water,free from any foreign & suspended matter, & hardness not more than 0.35 mg-eq /1, & pH in the range of 7 .0 - 8.0 . The first step in the process is to prepare neem oil & emulsifier surfactant concentrate. The concentrate is prepared in the concentrate preparation tank by mixing neem oil with emulsifier in pre determined ratio. The mix of the two is circulated with the help of a suitable pump & briskly stirred by passing the mixture through fan jet nozzles. The contents of the tank are kept under circulation for 15 - 25 minutes at the first instant. In the second step the concentrate as prepared above is used in the preparation of neem oil-water emulsion of the desired concentration . Neem oil- water emulsion is prepared in the tank designated as emulsion preparation tank . This tank is provided with a suitable pump for circulation & a set of three types of nozzles fitted on the common discharge header of the pump , as described below : Sl.no. Type of nozzle Function of nozzle 1 • Fan Jet Nozzle For agitation purposes . 2- Ejector mixing nozzle For jet mixing of concentrate with water to make neem oil - water emulsion . 3- Acoustic nozzle For micronization of neem oil water emulsion . The process of preparation of neem oil water emulsion is started by taking a known quantity of water in the emulsion preparation tank, which is kept under circulation and agitation with the help of fan jet nozzles. After wards, a known quantity of concentrate is made to flow to into ejector mixing nozzles where it meets a high velocity jet of water, thus starting the process of formation of neem oil water emulsion . This process is continued till all the required concentrate has been transferred into the emulsion preparation tank . This step takes about 30 - 40 minutes to complete . After completion of this step , acoustic nozzles are taken in line & brought into operation . These nozzles help in the micronization of the emulsion formed in the earlier step . This step is completed in 25-30 minutes time when a batch of stable micronized neem oil water emulsion gets prepared. On completion of this step, the contents of the emulsion preparation tank are passed through filters & transferred to emulsion storage tank for use in coating of urea prills . METHOD OF COATING OF UREA PRILLS WITH NEEM OIL WATER EMULSION : Neem oil water emulsion from the emulsion storage tank is drawn with the help of a transfer pump through a filter, and is discharged to the nozzles manifold at a pressure of 3.0 - 7.0 Kg / cm~ G pressure . The nozzles manifold consists of 1 - 3 calibrated spray nozzles having a "fan jet" & "full cone" spray pattern . Neem oil water emulsion is sprayed through these nozzles on to a curtain of urea prills , at a suitable location on the conveyor belt system available at the manufacturing plant . The sizing of the spray nozzle is done in such a manner that when neem oil water emulsion having a concentration varying from 10 , 20 , or 30 % , when sprayed on urea prills , will give a neem oil coating of 400 to 1000 ppm . Example 1 : Preparation of concentrate : Quantity of concentrate to be prepared ::= 200 Kgs. Ingredients requires : 1. Neem oil =160 Kgs (80%) 2. Emulsifier = 40 Kgs (20%) TOTAL = 100 Kgs (100 %) Take 100 Kgs of neem oil & 40 Kgs of emulsifier & transfer these to the concentrate preparation tank , haying capacity of 300 ltrs .On completion of transferring , start the circulation pump & re circulate the contents through fan jet nozzles so that a thorough mixing of the contents take place . This operation is carried out for 15- 20 minutes at the first instant . Later , when ever concentrate is required for t he preparation of neem oil water emulsion, the circulation pump is started again . Example 2 : Preparation of Neem oil water emulsion : Concentrate of neem oil in the neem oil water emulsion :- Case I =10%. Case II = 20%. Case III = 30%. Quantity of emulsion required = 200 Kgs . Ingredients required - Case 1 :- For 200 Kgs of 10% cone. Emulsion. 1. Water =175 Kgs. 2. Concentrate = 25 Kgs ( Neem oil = 20 kgs + emulsifier = 5 Kgs ) Distribution of ingredients in 10% neem oil water emulsion: 1. Water = 175 Kgs - 87.5% 2. Neem oil = 20 Kgs - 10.0% 3. Emulsifier = 5 Kgs - 2.5 % TOTAL = 200 Kgs - 100% Case 2 : For 200 Kgs of 20 % conc. Emulsion . 1. Water = 150 Kgs. 2. Concentrate = 50 Kgs (Neem oil = 40 Kgs + emulsifier = 10 Kgs ) Distribution of ingredients in 20 % cone. Neem oil water emulsion : 1. Water = 150 Kgs - 75 % 2. Neem oil = 40 Kgs - 20 % 3. Emulsifier = 10 Kgs - 5 % TOTAL = 200 Kgs - 100% Case 3 : For 200 Kgs of 30 % conc. Emulsion - 1. Water = 125 Kgs 2. Concentrate = 75 Kgs ( Neem oil = 60 Kgs + Emulsifier = 15 Kgs ) Distribution of ingredients in 30 % conc. Neem oil water emulsion : 1. Water = 125 Kgs - 62.5 % 2. Neem oil = 60 Kgs - 30.0 % 3. Emulsifier = 15 Kgs - 7.5 % TOTAL = 200 Kgs - 100 % Method of preparation : To start the process, water in accordance with the quantities as calculated in the examples given above for 10%, or 20%, or for 30% neem oil water emulsion is taken in the emulsion preparation tank and the circulation pump is put in operation . The fan jet nozzles are taken in line & brisk stirring of water is commenced . Next, the ejector mixing nozzles are taken in line & neem oil emulsifier concentrate is allowed to flow into these nozzles due to suction produced by the high velocity jet of circulating water . Due to the intense mixing of water and neem oil concentrate in side the jet mixing nozzles , neem oil water emulsion gets formed and the process of emulsion formation gets completed when neem oil concentrate as per specified quantities have been completely transferred to the emulsion preparation tank through the ejector mixing nozzles . This operation takes 30- 40 minutes to be completed . After this operation the acoustic nozzles are taken in line . These nozzles are used for the micronization of the emulsion prepared ; and this step is completed in 20-30 minutes time . At the end of this step, emulsion of the desired quantity & concentration is formed . The final product is then passed through filters for storage in the storage tank. rhe process of emulsion preparation is a batch process & the equipment has been sized to produce a batch of 200 Kgs at a time. I claim :- A process for the preparation of neem oil water emulsion coated urea prills capable of being integrated at fertilizer plants for a large scale and continuous coating process; comprising the steps of :- a) mixing neem oil & emulsifier in the ratio of 4:1 in a concentrate preparation tank by re circulating the contents with the help of a pump at 4 Kg /cm2 for 15- 25 minutes to get the neem oil emulsified concentrate ; b) mixing a predetermined amount of concentrate of step (a) through ejector nozzles in a span of 30 - 40 minutes to a predetermined quantity of water in the emulsion preparation tank, which is re circulated & agitated with the help of a pump at 3- 4 Kg/cm2 pressure through 2 nos.fanjet nozzles, when the neem oil water emulsion thus formed is led through 2 nos. acoustic nozzles where micronization of the emulsion is done to obtain a stable micronized neem oil water emulsion ; and , c) coating neem oil water eulsion on urea prills with the help of a gear pump at a pressure of 3- 7 Kg /cm2 when the neem oil water emulsion is drawn from the emulsion storage tank & passed through 2 nos. of fan jet nozzles and full cone nozzles to spray on the urea curtain, such that it covers a maximum area on the urea curtain to get the 2. A process as claimed in claim 1 where in a stable micronized neem oil water emulsion having 10-30% neemoil content is formed. 3. A process at claim 1 where in urea prills when sprayed with neem oil water emulsion at the specified rate of 0.4 to 1.0% of Urea, gives a coating of 400-1000 ppm of neem oil. 4. A process at claim 1 where emulsifying surfactant (preferably non ionic - such as ethylene oxide condensate of alkyl phenol) in liquid form which is readily miscible in neem oil is used . 5. A process at claim 1, where water free from any foreign & suspended matter, & hardness not more than 0.35mg-eq/l and pH in the range of 7.0-8.0 is used. 6. A process for preparation of neemoil water emulsion coated urea prills substantially as described here in with foregoing examples .