THE GAZETTE OF INDIA . EXTRAORDINARY
FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules. 2003
PROVISIONAL/COMPLETE SPECIFICATION
(See section 10 and rule 13)


1. TITLE OF THE lNVENTION"- “ INNOVATIVE PROCESS. TO SEPARATE SALTS OF ALKALI METALS FROM THE AQUEOUS STREAM BY NON EVAPORATIVE. ANT SOLVENT. BASED CRYSTALLIZATION. TECHNOLOGY.”
2. APPLICANT IS)
(a)NAME: GEIST RESEARCH PVT. LTD.
(b)NATIONALITY: INDIAN
(c)ADDRESS : H.No.-16, DAYANAND PARK SOC., Nr- GNFC TOWNSHIP,
AT POST-ZADESHWAR„ BHARUCH- 392011
GUJARAT, INDIA
3. PREAMBLE TO THE DESCRIPTION – REFER ANNEXURE-1
PROVISIONAL COMPLETE

The following specification describes the The following specification particularly describes
Invention the invention and the manner in which it is to be
performed
N.A ANNEXURE-1
4. DESCRIPTION (Description shall start from next page )
REFER ATTACHED COMPLETE SPECIFICATION
( ANNEXURE -1)
5... CLAIMS (not applicable 'or provisions' specification Claims should start with the preamble
“I/we Claim" or separate page)
REFER ANNEXURE-1
6 DATE AND SIGNATURE (to be given at the end of last page of specification )
7 ABSTRACT OF THE INVENTION (to be given along with complete specification on separate page)
REFER ANNEXURE -1
Note:
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Annexure 1
Complete Specification
Abstract:
The present invention deals with recovering salts of alkali metals e.g. Na2SO4 NaCl, KC1, K2SO4 and HCOONa etc from aqueous stream by nop-evaponalve method, in most of the chemical processes alkali metal salts remains in the aqueous stream, which need to be recovered. Presence of alkali metal salts in effluent stream makes effluent difficult to treat. Because of the high concentration of dissolved solids conventional biological treatment doesn't work efficiently. The conventional method for recovering these salts is to evaporate water from the solution. Reduction in water from the solution leads to super saturation of the stream & ultimately precipitation of salts. This however is energy intensive and economically unattractive, In this innovation salt of alkali metal is recovered by non-evaporative method by using anti-solvent crystallization technology. The purity of recovered salt by this innovative technology is equivalent or even better than the evaporation based crystallization technology.

Title: (GASCT: Geist's Anti-Solvent Crystallization Technology)
"Innovative process to separate sails of alkali metals from the aqueous stream h\ non evaporative anti-solvent base J crystallization technology. "
Field of the invention:
The present invention provides a Novel Process for precipitation/crystallization of salts of alkali metal e.g. sulfate, nitrates, carbonates, sulfite, phosphate, formates, acetates & other salts from the aqueous stream by non-evaporative Antisolvent based crystallization technology.
Background of the Invention*
in most of chemical-manufacturing processes, salts of alkali metals such as Sodium Chloride, Sodium Sulfate. Sodium Formate, Potassium Chloride. Potassium Sulfate etc. are used or generated during the reaction, which may ultimately comes out in the dissolved form along with the aqueous stream. These alkali metal salts had to be separated from aqueous stream. Such separations are conventionally done by evaporation of water, which is energy intensive and economically unattractive. Current invention comprises of the process to separate these salt from the aqueous stream by non-evaporative anti-solvent based crystallization technology}.
Object of Invention:
The invention relates to the No\e! Process to separate alkali metal salts such as Sodium Chloride, Sodium 'dilate. Potassium Chloride, Potassium Sulfate. Sodium formate etc: by anti-solvent based non-evaporative crystallization technology. Main object of this invention is to device a methodology that will reduce the separation cost, achieve the purity of the product equivalent or even better than the evaporative method, make the operation simpler & avoid corrosion problems particularly in case of separation of chlorides.
Summary of invention:
The following specification describes the nature of the invention.
The separation of alkali metal e.g. sodium chloride, sodium sulphate, potassium chloride, potassium sulfate, sodium formate etc is limited by
1} Solubility in solvent stream
2) Recovery & Solubility anti-sol von! used for separation.
In the present invention, these limitations are overcome by selecting the optimum condition for solubility of anti-solvent and crystallization of salt of alkali metals.

Detailed Description of the invention:
Present invention deals with the Novel Process to separate alkali metal salts e.g. Sodium Chloride. Sodium Sulfate. Potassium Chloride, Potassium Sulfate.
Sodium formate etc by non-evaporative anti-solvent based crystallization technology. Main object of this invention is to reduce the separation cost, to get the purity equivalent or better Than the evaporative method, to device the simpler operation & to avoid corrosion problems. Conventional evaporation method is not able to separate the undesirable high boilers/non volatiles. thus reduces the purity of main product.
In she present invention. Antisolvent is added in the aqueous stream & its operating parameters such as Temperature, Pressure, pH etc are adjusted. Adjusting the process conditions leads to dissolution of Antisolvent in the solution, which, causes super saturation of solute. & ultimately results in precipitation of die solute. Antisolvents are pure component/mixture of pure components, which reduces the solubility of the solute in the solution. The choice of Antisolvents is dependent on the nature of the stream. Specific Antisolvents work for specific streams such as acidic, basic & neutral. Choice of Antisolvent dictates operating conditions. The Antisolvents are applicable at a very wide operating temperature range typically but not limited to 10oC to 80°C. The amount of Antisolvent required generally based on the desired recovery of the salts. Generally weight fraction of Antisolvent can be varied from 0.01 to 0.99. In order to make the process economically. viable, recovery of the Antisolvent from the resultant aqueous stream should not be very energy intensive. Hence Antisolvents, which shows induced phase separation phenomenon, are ideally suitable for this process, Ideally suitable, Antisolvents are the substances/mixtures, which show; critical solution temperature with water. These anti-solvents show solubility as well as phase splitting with water as typified by Lower critical solution temperatures/ Upper critical solution temperatures. This dual property of anti-solvents (solubility and phase separation) makes them useful as anti solvents. In the dissolved form, anti solvents reduce the salt solubility thereby facilitating their separation and with change HI operating conditions causes phase separation that makes their recover}' and recycling easy. Solubility and phase separation are dependent on temperature, pressure, presence of impurities etc.
Advantages of Antisolvent based Crystallization processes are
1. Reduction in capital & operating cost
2. Improved/ comparable quality separated salt with evaporative crystallization
3. Simpler operations
4. Lesser corrosion while handling chloride streams
5. Reduction of effluent load

According to a present invention, alkali metal salts are separated from solvent stream by addition of anti-solvents for crystallization. The process is:
Anti-solvent
1120 + AX ► AX (ppt.) + H20
Modified Process Conditions
Where.
A - Alkali metal e.g. Na K etc
X - Cl Br. I. SO.; etc .is indicative not exhaustive.
Ppt - precipitation.
e.g.
Anti-solvent
H2O + Na2SO4, Na2SO4 (ppt.) -I- H2O
Solution Modified Process Conditions
Ami-solvent
1120 + KC1 KC1 (ppt.) + H2O)
Solution Modified Process Conditions
Ant' Solvent - Triethyl amine (TEA) Diisopropyl amine (DIPA). 2-Butoxy ethanol, Isobutyric Acid Methanol., Ethanol. Tetrahydrofuron Dimethyl Formamide, Dimethyl Sulphoxide. Sulpholane. Dimethyl Acetamide. Dimethyl isopropyl amine.
Ibis i:-. indicative of Anti-solvents and not exhaustive. The solvents exhibiting critical solution temperature phenomenon i.e. solubility and phase separation as a function of process parameters can be used as anti-solvent.
The process of the invention is described in detail in the following example
Example 1:
This example illustrates the separation of potassium chloride from 10% aqueous solution by using DIPA as an anti-solvent.
Anti-solvent crystallization of KCl from aqueous solution is carried out in stirred vessel of 1500 ml capacity,, having pitched blade dev award flow Impeller, and fitted with variable RPM motor, thermo pocket with thermometer for monitoring temperature.
Prepared 500 gins. 10% potassium chloride solution with water and charged in the stirred vessel. 500 gm of anti-solvent (Diisopropyl amine) was added under stirring.

Temperature of the solution was reduced. KC1 crystallized out at -15°C. The slurry thus
obtained was filtered. The wet cake was dried in the oven at 110°C for 2hrs to obtain 49.5
gins dry cake. The separated filtrate w-is filled in the separating flask & allowed its
temperature to rise to 30oC. After attaining the temperature, Antisolvents separated as an
upper organic layer, Upper organic & lower aqueous layers were separated. Salt of min.
99% purity was obtained. Recovery of the salt obtained was 99%.
Example 2 :
This example illustrates the separation of sodium chloride from 5% aqueous solution by using TEA as anti-solvent.
The hardware details are same as that of Example 1.
Prepared 200gms, 5% Sodium chloride solution in water and charged to the stirred vessel. Added 200 gin of anti-solvent (Triethyl amine) under stirring. Temperature of the solution was reduced. Sodium Chloride crystallized out at -10"C. The slurry was filtered to obtain a wet cake & filtrate, i lie oaks was dried at 1 10oC to get 9.5 gins Sodium Chloride. The filtrate was transferred to a separation 11 ask where its temperature was raised to 30°C. Because of temperature induced phase separation two layers were observed. 1 he lower aqueous & upper Antisolvent layers were separated. Salt of 99% purity was obtained. Salts recover) was 95%.
Example 3:
This example illustrates the separation of Sodium Sulfate from 20% aqueous solution by using Isobutyric acid as anti-solvent.
1 he hardware details are same as that of Example 1.
Prepared 500 gms, 20% of Sodium Sulfite solution with water and is charged to the stirrer! vessel Added 250 gm of anti-solvent. (Isobutyric acid) in the solution under stirring The temperature of the solution was increased gradually to 70°C. Sodium Sulfate crystallized at this temperature. The hot slurry was filtered to separate wet cake & the filtrate. The wet cake was oven dried to obtain 92 gms of Sodium Sulfate. The temperature of the filtrate was reduced to 15°C to obtained two layers, upper Antisolvent layer & lower aqueous layer. Salt of 99.5% purity was obtained. Recovery-'/ Separation of 92% is obtained.

Example 4:
This example illustrates the separation of sodium sulphate from 2% acidic aqueous solution by using isobutyric acid as anti-solvent.
The hardware details are same as that of Example 1.
Prepared 500gms. 2% Sodium Sulfate solution with water and is charged to the stirred vessel. The pH of the solution was adjusted to 2 using Sulfuric acid. 500 gm of anti-solvent (isobutyric acid' was added under stirring. The temperature of the solution was increased ;o 75°C. 'She crystallised Sodium Sulfate was separated by filtration. The wet cake was dried in the oven to obtain 9.6 gms of Sodium Sulfate. The temperature of the sol us ion was reduced to 20oC to get lower aqueous & upper Antisolvent layers. The organic & aqueous layers were separated. Sodium Sulfate of 99.5% purity was obtained. Recovery of Na2SO4 was 96%.
Example v
This example illustrates the separation of potassium sulphate from 25% aqueous solution by using 2-butoxyethanol as anti-solvent.
The hardware details are same as that of Example 1.
Prepared 500 gms, 25% Potassium sulfate with water and was charged to the stirred vessel. The temperature of the solution vas seduced gradually. 250 gms of Antisolvent (2-Butoxyethanol) was added in a control led rate, The addition rate of the Antisolvent. was adjusted so that addition was completed when the mixture temperature reaches -5°C. The temperature was reduced to –10oC. The slurry was filtered to obtain the wet cake. which was dried in the oven to get 114 gins needle shape Potassium Sulfate. The temperature of the filtrate was increased to 40°C to induce the phase separation. Both the layers, upper organic & lower aqueous were separated. Potassium Sulfate of 97% purity was obtained. Recovery of K2SO4 was 91,2%

Claims:
We claims the following
1. The GASCT process for recovery/separation of alkali metal by non-evaporative method comprises of crystallization by using Antisolvents exhibiting critical solution temperature phenomenon such as e.g. Triethyl amine (TEA), Diisopropyl amine (DIPA). 2-Butoxy Ethanol. Isobutyric Acid, Methanol, Ethanol. Tetrahydrofuran. Formamide, Sulphoxide. Sulpholane. and Dimethyl Acetamide etc.
2. A process claimed in claim 1 wherein anti-solvent means the substance/mixture, which exhibit critical solution temperature phenomenon.
3. A process is claimed in claim 1 wherein alkali metal salt is sodium chloride, sodium sulphate, potassium chloride, potassium sulphate etc.
4. A process is claimed in claim I wherein anti-solvent is selected from organic solvents such as methanol, ethanol, Triethyl amine, diisopropylamine. 2-butoxy ethanol. isobutyric acid, alky! amide such as Dimethyl Formamide or Dimethyl acetamide or Formamide, Sulphoxide. such as Dimethyl Sulphoxide or Tetrahydrothiophene. tetrahydrofuron etc.
5. A process is claimed in claim 1 wherein the weight fraction of anti-solvent is in the range of 0.01 to 0.99
6. A process is claimed in claim I wherein the concentration of main product/salt in stream is in between 0.5% to its saturation solubility.
7. A process is claimed in claim f wherein the crystallization is carried out in the temp. Range of-20 to 100 oC preferable between -15 to 60 "'C.