Claims:WE CLAIM
1. An adsorbent composition particles comprising:
i. at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide in an amount in the range of 20 to 91 mass% of the total mass of the adsorbent composition;
ii. a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides in an amount in the range of 9 to 80 mass% of the total mass of the adsorbent composition; and
iii. optionally a third component being a clay in an amount in the range of 20 to 40 %.
2. The adsorbent composition particles as claimed in claim 1, wherein one gram of said adsorbent composition has dynamic adsorbent capacity for processing contaminated sulpholane in the range of 26 to 65 grams.
3. The adsorbent composition particles as claimed in claim 1, wherein said particles are in the form of shaped bodies, wherein the shapes are selected from spherical beads, cylindrical, tri-lobed, tetra-lobed, star, ring, tablets, pellets, honeycomb structure and combinations thereof.
4. The adsorbent composition particles as claimed in claim 1, comprising a first component being alumina composite in the range of 20 to 80% by mass and a second component being a double layered hydroxide being hydrotalcite in an amount in the range of 20 to 80 % by mass.
5. The adsorbent composition particles as claimed in claim 1, comprising a first component being pseudoboehemite in an amount in the range of 20 to 80 % by mass and a second component being a double layered hydroxide being hydrotalcite in an amount in the range of 20 to 80 % by mass.
6. The adsorbent composition particles as claimed in claim 1, wherein said layered double hydroxide is a hydrotalcite selected from the group consisting of hydrotalcite having MgO to Al2O3 ratio of 4.5, and surface area in the range of 10 to 15 m2/g.
7. The adsorbent composition particles as claimed in claim 1, comprising a first component being 60% by mass of a raw alumina rich mineral oxide, a second component being 10 mass% of hydrotalcite and a third component being 30 mass% of a clay.
8. The adsorbent composition particles as claimed in claim 4, comprising 30% by mass of alumina composite and 70% by mass of hydrotalcite.
9. The adsorbent composition particles as claimed in claim 5, comprising 30% by mass of pseudoboehemite and 70% by mass of hydrotalcite. The adsorbent composition particles as claimed in claim 1, wherein said clay is at least one selected from the group consisting of bentonite, kaolinite, and attapulgite.
10. The adsorbent composition particles as claimed in claim 1, comprising 60% by mass of a raw alumina rich mineral oxide, 10% by mass of hydrotalcite and 30% by mass of bentonite.
11. The adsorbent composition particles as claimed in claim 1, wherein said particles are in the form of shaped bodies that have an average size in the range of 1.5 to 3 mm, crushing strength in the range of 1 to 10 Kgf/cm2, BET surface area in the range of 50 to 300 m2/g. and bulk density in the range of 0.4 to 0.7 g/cc.
12. The adsorbent composition particles as claimed in claim 1, wherein said particles are in the form of shaped bodies that have an average size in the range of 1.5 to 3 mm, crushing strength of 4 Kgf/cm2, BET surface area of 213 m2/g. and bulk density of 0.56 g/cc.
13. The adsorbent composition particles as claimed in claim 1, comprising a first component being alumina rich mineral oxide in the range of 75 to 91 mass% and a second component being a mixture of mineral oxides in the range of 9 to 25% by mass.
14. The adsorbent composition particles as claimed in claim 1, comprising 75 to 91% by mass of alumina and 9 to 25% by mass of mineral oxides consisting of 5-15 mass% of iron oxide, 2-6 mass% of SiO2, 1-3 mass% of TiO2 and 0.5-2 mass% of Calcium oxide.
15. The adsorbent composition particles as claimed in claim 14, wherein said particles have an average size in the range of 0.5 to 1 mm, surface area in the range of 75 to 175 m2/g, pore volume in the range of 0.05 cc/g to 0.35 cc/g, and pore size in the range of 0.5 to 0.8 Å.
16. A process for preparing adsorbent composition particles, said process including the step of mixing at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides.
17. The process as claimed in claim 17, comprising the following steps:
a. pugging and kneading, a mixture of a first component selected from the group consisting of alumina composite, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide, with an aqueous medium comprising an acid and a fatty acid in water, to obtain a pugged mixture;
b. extruding said pugged mixture to obtain extrudates;
c. drying said extrudates to obtain dried extrudates; and
d. calcining said dried extrudates to obtain said adsorbent composition particles.
18. The process as claimed in claim 18, wherein in the step (a), said aqueous medium comprises water in an amount in the range of 70-97 wt%, an acid in an amount in the range of 1 to 20 wt% and a fatty acid in an amount in the range of 1 to 10 wt%, of the total mass of the aqueous mixture.
19. The process as claimed in claim 19, wherein said acid is selected from the group consisting of nitric acid, orthophosphoric acid, and acetic acid.
20. The process as claimed in claim 19, wherein said fatty acid is selected from the group consisting of oleic acid, linoleic acid, and lauric acid.
21. The process as claimed in claim 18, wherein in step (a), pugging and kneading is carried out for a time period in the range of 1 minute to 60 minutes, preferably 5 minutes to 15 minutes.
22. The process as claimed in claim 18, wherein in step (iv), drying is carried out at a temperature in the range of 100 °C to 150 °C for a time period in the range of 30 minutes to 400 minutes.
23. The process as claimed in claim 18, wherein the step of calcining is carried out at a temperature in the range of 300 °C to 600 °C, under flowing air.
24. The process as claimed in claim 17, further comprising the step of mixing a third component being a clay; wherein said third component is in an amount in the range of 20 mass% to 30 mass% of the total mass of the composition.
25. The process as claimed in claim 25, comprising the following steps:
A. pugging and kneading a mixture of a first component selected from the group consisting of alumina composite, pseudoboehemite and raw alumina rich mineral oxide, a second component selected from the group consisting of a layered double hydroxide, and a third component being a clay with an aqueous medium comprising an acid and a fatty acid in water, to obtain a pugged mixture,;
B. extruding said pugged mixture to obtain extrudates;
C. drying said extrudates to obtain dried extrudates; and
D. calcining said dried extrudates to obtain said adsorbent composition particles.
26. The process as claimed in claim 17, wherein the process comprises mixing a first component being alumina rich mineral oxide with a second component being a mixture of mineral oxides to form an intermediate mixture, and thermally treating the intermediate mixture at a temperature in the range of 100 °C to 150 °C, to obtain said adsorbent composition particles.
27. A process for upgrading sulpholane contaminated with acidic impurities, by contacting the sulpholane with adsorbent composition particles comprising at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides, and a mixture of mineral oxides, and optionally a third component being a clay, to obtain an upgraded sulpholane.
28. The process as claimed in claim 28, wherein said upgraded sulpholane has a pH value in the range of 7.5 to 8.5, and a TAN value in the range of 0.04 to 0.12.
, Description:FIELD
The present disclosure relates to adsorbent composition particles, a process for preparing the adsorbent composition particles and a process for upgrading sulpholane contaminated with acidic impurities.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicates otherwise.
Pugging: The term “pugging” refers to working a material into a soft, plastic condition suitable for making different objects, without air pockets.
Contaminated sulpholane: The term “Contaminated sulpholane” refers to sulpholane containing acidic impurities that are formed as a result of oxidative or thermal degradation of sulfolane.
Upgraded sulpholane: The term “upgraded sulpholane” refers to sulpholane containing reduced acidic impurities, which is obtained by removal of the acidic impurities from the contaminated sulpholane by its treatment with an adsorbent.
Total Acid Number (TAN): The term “Total Acid Number” (TAN) is considered as a measure of corrosion caused by sulpholane containing acidic impurities and is defined as the number of milligrams of potassium hydroxide required to neutralize the acid content of one gram of sulpholane.
Layered double hydroxides (LDH): The term “layered double hydroxides” refers to ionic solids characterized by a layered structure with the generic layer sequence represented by the formula [M2+1-x M3+x (OH)2]x+ [An-x/n.yH2O]x-, where M2+ and M3+ are the di- and trivalent cations in the octahedral positions within the hydroxide layers. An- is an exchangeable interlayer anion.
Hydrotalcite: The term “hydrotalcite” refers to an anionic clay found in nature. Hydrotalcite (HT) is a layered double hydroxide (LDH) of general formula Mg6Al2CO3(OH)16•4(H2O). In hydrotalcite, the carbonate anions that lie between the structural layers are weakly bound, so hydrotalcite has anion exchange capabilities.
Dynamic Adsorption: The term “Dynamic Adsorption” refers to the process by which an adsorbent removes an impurity (such as acidic impurities) from a continuously flowing fluid stream (such as sulpholane contaminated with acidic impurities).
BACKGROUND
2,3,4,5-Tetrahydrothiophene-1,1-dioxide, which is commonly known as sulfolane, is a cyclic organosulfur compound having a polar sulfone functionality. Sulpholane is a clear liquid that is soluble in water due to the polar sulfone functionality, and miscible in non-polar hydrocarbons due to the four membered carbon ring. In refining and petrochemical industry, due to relatively lower ratios of sulpholane required for dissolving the hydrocarbons, sulpholane is widely used as a solvent for the extractive distillation for purifying hydrocarbon mixtures and natural gas, and for chemical reactions.
Sulfolane is highly stable, however in sulfolane extraction units the presence of impurities such as oxygen and/or chlorides degrade sulfolane into acidic byproducts. Similarly, sulfolane is thermally stable up to a temperature of 220°C, at which it starts to break down into sulfur dioxide (an intermediate in the production of sulfuric acid) and a polymeric material. Thus, oxidatively or thermally degraded sulfolane has a higher total acid number resulting in a lower pH value and a darker color as compared to the pure sulfolane. Therefore, sulpholane contaminated with acidic impurities leads to corrosion of system components in the refining and petrochemical industry. In addition, the oxygen degraded sulfolane tends to become less extractive of aromatics in the hydrocarbon extraction process.
To avoid sulfolane from becoming corrosive and from having limited extraction potential, most sulfolane extraction units incorporate a regeneration component for the sulpholane. The regeneration unit works to remove the degradation by-products such as acids, by employing vacuum distillation and ion exchange technologies for purification of sulpholane to preserve its integrity as a solvent. Other methods that have been developed to regenerate spent sulfolane include vacuum and steam distillation, back extraction, adsorption, and anion-cation exchange resin columns. However, these reported sulpholane regeneration methods are tedious, energy consuming, harmful to the environment and costly.
Therefore, there is felt a need to provide an adsorbent composition and a simple, environmentally friendly and cost effective process that mitigates the drawbacks mentioned herein above.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Another object of the present disclosure is to provide an adsorbent composition.
Still another object of the present disclosure is to provide a process for preparing the adsorbent composition.
Yet another object of the present disclosure is to provide a process for upgrading sulpholane that is simple, environmentally friendly and cost effective.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
In a first aspect, the present disclosure relates to adsorbent composition particles. The adsorbent composition particles comprise at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide in an amount in the range of 20 to 91 mass% of the total mass of the adsorbent composition, a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides in an amount in the range of 9 to 80 mass% of the total mass of the adsorbent composition, and optionally a third component being a clay in an amount in the range of 20 to 40 %.
In accordance with the present disclosure, one gram of the adsorbent composition particles have dynamic adsorption capacity for processing contaminated sulpholane in the range of 26 to 65 grams.
In accordance with the present disclosure, the adsorbent composition particles are in the form of shaped bodies, wherein the shapes are selected from spherical beads, cylindrical, tri-lobed, tetra-lobed, star, ring, tablets, pellets, honeycomb structure and combinations thereof.
In accordance with the present disclosure, the adsorbent composition particles comprise a first component being alumina composite in the range of 20 to 80% by mass and a second component being a double layered hydroxide being hydrotalcite in an amount in the range of 20 to 80 % by mass.
In accordance with the present disclosure, the adsorbent composition particles comprise a first component being pseudoboehemite in an amount in the range of 20 to 80 % by mass and a second component being a double layered hydroxide being hydrotalcite in an amount in the range of 20 to 80 % by mass.
In accordance with the present disclosure, the layered double hydroxide is a hydrotalcite selected from the group consisting of hydrotalcite having MgO to Al2O3 ratio of 4.5, and surface area in the range of 10 to 15 m2/g.
In accordance with one embodiment of the present disclosure, the adsorbent composition particles comprise a first component being 60% by mass of a raw alumina rich mineral oxide, a second component being 10 mass% of hydrotalcite and a third component being 30 mass% of a clay.
In accordance with another embodiment of the present disclosure, the adsorbent composition particles comprise 30% by mass of alumina composite and 70% by mass of hydrotalcite.
In accordance with yet another embodiment of the present disclosure, the adsorbent composition particles comprise 30% by mass of pseudoboehemite and 70% by mass of hydrotalcite.
In accordance with the present disclosure, the clay is at least one selected from the group consisting of bentonite, kaolinite, and attapulgite.
In accordance with still another embodiment of the present disclosure, the adsorbent composition particles comprise 60% by mass of a raw alumina rich mineral oxide, 10% by mass of hydrotalcite and 30% by mass of bentonite.
In accordance with the present disclosure, the adsorbent composition particles are in the form of shaped bodies that have an average size in the range of 1.5 to 3 mm, crushing strength in the range of 1 to 10 Kgf/cm2, BET surface area in the range of 50 to 300 m2/g. and bulk density in the range of 0.4 to 0.7 g/cc.
In accordance with one embodiment of the present disclosure, the adsorbent composition particles are in the form of shaped bodies that have an average size in the range of 1.5 to 3 mm, crushing strength of 4 Kgf/cm2, BET surface area of 213 m2/g. and bulk density of 0.56 g/cc.
In accordance with the present disclosure, the adsorbent composition particles comprise a first component being alumina rich mineral oxide in the range of 75 to 91 mass% and a second component being a mixture of mineral oxides in the range of 9 to 25% by mass.
In accordance with the present disclosure, the adsorbent composition particles comprise 75 to 91% by mass of alumina and 9 to 25% by mass of mineral oxides consisting of 5-15 mass% of iron oxide, 2-6 mass% of SiO2, 1-3 mass% of TiO2 and 0.5-2 mass% of Calcium oxide.
In accordance with the present disclosure, the adsorbent composition particles have an average size in the range of 0.5 to 1 mm, surface area in the range of 75 to 175 m2/g, pore volume in the range of 0.05 cc/g to 0.35 cc/g, and pore size in the range of 0.5 to 0.8 Å.
In a second aspect, the present disclosure provides a process for preparing the adsorbent composition particles. The process includes the step of mixing at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides.
In accordance with the present disclosure, the process comprises the steps of a) pugging and kneading a mixture of a first component selected from the group consisting of alumina composite, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide, with an aqueous medium comprising an acid and a fatty acid in water, to obtain a pugged mixture, b) extruding said pugged mixture to obtain extrudates, c) drying said extrudates to obtain dried extrudates, and d) calcining said dried extrudates to obtain said adsorbent composition particles.
In accordance with the present disclosure, in the step of pugging and kneading, the aqueous medium comprises water in an amount in the range of 70-97 wt%, an acid in an amount in the range of 1 to 20 wt% and a fatty acid in an amount in the range of 1 to 10 wt%, of the total mass of the aqueous mixture.
In the step of pugging and kneading, the acid is selected from the group consisting of nitric acid, orthophosphoric acid, and acetic acid.
In the step of pugging and kneading, the fatty acid is selected from the group consisting of oleic acid, linoleic acid, and lauric acid.
In accordance with the present disclosure, the step of pugging and kneading is carried out for a time period in the range of 1 minute to 60 minutes, preferably 5 minutes to 15 minutes.
In accordance with the present disclosure, the step of drying is carried out at a temperature in the range of 100 °C to 150 °C for a time period in the range of 30 minutes to 400 minutes.
In accordance with the present disclosure, the step of calcining is carried out at a temperature in the range of 300 °C to 600 °C, under flowing air.
In accordance with the present disclosure, the step of mixing further comprises the step of mixing a third component being a clay, wherein the third component is in an amount in the range of 0.01 wt% to 30 wt% of the total mass of the composition.
In accordance with the present disclosure, the process comprises the steps of a) pugging and kneading a mixture of a first component selected from the group consisting of alumina composite, pseudoboehemite and raw alumina rich mineral oxide, a second component selected from the group consisting of a layered double hydroxide, and a third component being a clay with an aqueous medium comprising an acid and a fatty acid in water, to obtain a pugged mixture, b) extruding said pugged mixture to obtain extrudates, c) drying said extrudates to obtain dried extrudates, and d) calcining said dried extrudates to obtain said adsorbent composition particles.
In accordance with one embodiment of the present disclosure, the process comprises mixing a first component being alumina rich mineral oxide with a second component being a mixture of mineral oxides to form an intermediate mixture, and thermally treating the intermediate mixture at a temperature in the range of 100 °C to 150 °C, to obtain said adsorbent composition particles.
In a third aspect, there is provided a process for upgrading sulpholane contaminated with acidic impurities, by contacting the sulpholane with adsorbent composition particles comprising at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides, and a mixture of mineral oxides, and optionally a third component being a clay, to obtain an upgraded sulpholane.
In accordance with the present disclosure, the upgraded sulpholane has a pH value in the range of 7.5 to 8.5, and a TAN value in the range of 0.04 to 0.12.

DETAILED DESCRIPTION
The present disclosure provides adsorbent composition particles.
The adsorbent composition particles of the present disclosure have enhanced efficacy and process reliability, longer catalytic life, and can be regenerated with ease and reused.
In a first aspect of the present disclosure, there are provided adsorbent composition particles. The adsorbent composition particles comprise at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide, in an amount in the range of 20 to 91 mass% of the total mass of the adsorbent composition, a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides, in an amount in the range of 9 to 80 mass% of the total mass of the adsorbent composition, and optionally a third component being a clay in an amount in the range of 20 to 40 %.
In accordance with the embodiments of the present disclosure, the adsorbent composition particles comprise a first component being alumina composite in the range of 20 to 80% by mass and a second component being a double layered hydroxide being hydrotalcite in an amount in the range of 20 to 80 % by mass.
In accordance with one embodiment of the present disclosure, the adsorbent composition particles comprise 30% by mass of alumina composite and 70% by mass of hydrotalcite.
In accordance with the embodiments of the present disclosure, the adsorbent composition particles comprise a first component being pseudoboehemite in an amount in the range of 20 to 80 % by mass and a second component being a double layered hydroxide being hydrotalcite in an amount in the range of 20 to 80 % by mass.
In accordance with one embodiment of the present disclosure, the adsorbent composition particles comprise g 30% by mass of pseudoboehemite and 70% by mass of hydrotalcite.
In accordance with the embodiments of the present disclosure, the layered double hydroxide is a hydrotalcite selected from the group consisting of hydrotalcite having MgO to Al2O3 ratio of 4.5, and surface area in the range of 10 to 15 m2/g.
In accordance with the embodiments of the present disclosure, the adsorbent composition particles comprise a first component being 60% by mass of a raw alumina rich mineral oxide, a second component being 10 mass% of hydrotalcite and a third component being 30 mass% of a clay.
In accordance with the embodiments of the present disclosure, the clay is at least one selected from the group consisting of bentonite, kaolinite, and attapulgite.
In accordance with one embodiment of the present disclosure, the adsorbent composition particles comprise 60% by mass of a raw alumina rich mineral oxide, 10% by mass of hydrotalcite and 30% by mass of bentonite.
In accordance with the embodiments of the present disclosure, the adsorbent composition particles are in the form of shaped bodies, wherein the shapes are selected from spherical beads, cylindrical, tri-lobed, tetra-lobed, star, ring, tablets, pellets, and honeycomb structure.
In accordance with the embodiments of the present disclosure, the diameter of the adsorbent composition particles in the form of extrudates is in the range of 1.0 mm to 3 mm, and the length of the adsorbent composition particles in the form of extrudates is in the range of 1.0 mm to 4.0 mm.
In accordance with the embodiments of the present disclosure, the adsorbent composition particles are in the form of shaped bodies that have an average size in the range of 1.5 to 3 mm, crushing strength in the range of 1 to 10 Kgf/cm2, BET surface area in the range of 50 to 300 m2/g. and bulk density in the range of 0.4 to 0.7 g/cc.
In accordance with one embodiment of the present disclosure, the adsorbent composition particles are in the form of shaped bodies that have an average size in the range of 1.5 to 3 mm, crushing strength of 4 Kgf/cm2, BET surface area of 213 m2/g. and bulk density of 0.56 g/cc
In accordance with the embodiments of the present disclosure, the adsorbent composition particles comprise a first component being alumina rich mineral oxide in the range of 75 to 91 mass% and a second component being a mixture of mineral oxides in the range of 9 to 25% by mass.
In accordance with one embodiment of the present disclosure, the adsorbent composition particles comprise 75 to 91% by mass of alumina and 9 to 25% by mass of mineral oxides consisting of 5-15 mass% of iron oxide, 2-6 mass% of SiO2, 1-3 mass% of TiO2 and 0.5-2 mass% of Calcium oxide
In accordance with the embodiments of the present disclosure, the adsorbent composition particles have an average size in the range of 0.5 to 1 mm, surface area in the range of 75 to 175 m2/g, pore volume in the range of 0.05 cc/g to 0.35 cc/g, and pore size in the range of 0.5 to 0.8 Å.
In accordance with one embodiment of the present disclosure, the adsorbent composition particles have particle size in the range of 0.5 to 1 mm, surface area of 119 m2/g, pore volume of 0.19 CC/g, and pore size of 64Å.
In accordance with the embodiments of the present disclosure, one gram of the adsorbent composition particles have dynamic adsorption capacity for processing contaminated sulpholane in the range of 26 to 65 grams.
In one embodiment one gram of the adsorbent composition particles have dynamic adsorption capacity for processing 55.9 grams of contaminated sulpholane.
In a second aspect of the present disclosure, there is provided a process for preparing the adsorbent composition particles. The process includes the step of mixing at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides.
In accordance with the embodiments of the present disclosure, the process comprises the steps of pugging and kneading a mixture of a first component selected from the group consisting of alumina composite, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide, with an aqueous medium comprising an acid and a fatty acid in water, to obtain a pugged mixture, followed by extruding said pugged mixture to obtain extrudates, drying the extrudates to obtain dried extrudates, and calcining said dried extrudates to obtain said adsorbent composition particles.
In the step of pugging and kneading, the aqueous medium comprises water in an amount in the range of 70-97 wt%, an acid in an amount in the range of 1 to 20 wt% and a fatty acid in an amount in the range of 1 to 10 wt%, of the total mass of the aqueous mixture.
In one embodiment, the aqueous mixture comprises 97 wt% of water of the total mass of the aqueous mixture.
In the step of pugging and kneading, the acid is selected from the group consisting of nitric acid, orthophosphoric acid, and acetic acid.
In one embodiment, the aqueous mixture comprises 10 wt% of acid, of the total mass of the aqueous mixture.
In one embodiment, the acid is acetic acid (10% aqueous solution).
In the step of pugging and kneading, the fatty acid is selected from the group consisting of oleic acid, linoleic acid, and lauric acid.
In one embodiment, the aqueous mixture comprises 2 wt% of fatty acid, of the total mass of the aqueous mixture.
In one embodiment, the fatty acid is oleic acid.
The step of pugging and kneading is carried out for a time period in the range of 1 minute to 60 minutes, preferably 5 minutes to 15 minutes.
Typically, the mixture of alumina composite and layered double hydroxide is pugged for a time period in the range of 1 minute to 60 minutes, preferably 5 minutes to 15 minutes.
In one embodiment, the extrudates have a size of 0.5 mm to 1 mm.
In another embodiment, the extrudates have a size of 1.5 mm to 3 mm.
The step of drying is carried out at a temperature in the range of 100 °C to 150 °C for a time period in the range of 30 minutes to 400 minutes.
The step of calcining is carried out at a temperature in the range of 300 °C to 600 °C, under flowing air.
In one embodiment, the extrudates are calcined at 550 °C for 300 minutes.
In another embodiment, the extrudates are calcined at 550 °C for 360 minutes.
In accordance with the embodiments of the present disclosure, the process further comprises the step of mixing a third component being a clay, wherein the third component is in an amount in the range of 20 mass% to 30 mass% of the total mass of the composition.
In accordance with the embodiments of the present disclosure, the process comprises the steps of pugging and kneading a mixture of a first component selected from the group consisting of alumina composite, pseudoboehemite and raw alumina rich mineral oxide, a second component selected from the group consisting of a layered double hydroxide, and a third component being a clay with an aqueous medium comprising an acid and a fatty acid in water, to obtain a pugged mixture. The pugged mixture is extruded to obtain extrudates, and then dried to obtain dried extrudates, which are calcined to obtain said adsorbent composition particles.
In accordance with one embodiment of the present disclosure, the process comprises mixing a first component being alumina rich mineral oxide with a second component being a mixture of mineral oxides to form an intermediate mixture, and thermally treating the intermediate mixture at a temperature in the range of 100 °C to 150 °C, to obtain said adsorbent composition particles.
Oxidative or thermal degradation of sulpholane results in formation of acidic impurities, which lead to corrosion of system components in the refining and petrochemicals industry.
The adsorbent composition particles of the present disclosure can be used for upgrading sulpholane contaminated with acidic impurities.
The adsorbent composition particles of the present disclosure have a desired combination of requisite basicity, surface area and pore volume for interaction with the acidic impurities present in the sulpholane. When the acidic impurities present in contaminated sulpholane come in contact with the adsorbent surface, acidic impurities get chemisorbed on the surface of the adsorbent. The developed process is also very proficient in removing almost all of the impurities over a wide range of temperature and pressure.
In a third aspect of the present disclosure, there is provided a process for upgrading sulpholane contaminated with acidic impurities, by contacting the sulpholane with adsorbent composition particles comprising at least one first component selected from the group consisting of alumina composite, alumina rich mineral oxide, pseudoboehemite and raw alumina rich mineral oxide, and a second component selected from the group consisting of a layered double hydroxide and a mixture of mineral oxides, and a mixture of mineral oxides, and optionally a third component being a clay, to obtain an upgraded sulpholane.
The acidic impurities in the contaminated sulpholane include sulfonic acids, carboxylic acids and polar non-ionic substances like aldehydes and ketones.
The contaminated sulpholane has a pH value in the range of 4.5 to 5, and TAN value in the range of 0 to 0.4.
In one embodiment, the contaminated sulpholane has a pH value in the range of 4.74 and a TAN value of 0.34.
The upgraded sulpholane has a pH value in the range of 7.5 to 8.5, and a TAN value in the range of 0.03 to 0.12.
In one embodiment, the upgraded sulpholane has a pH value of 7.7 and a TAN value of 0.08.
In another embodiment, the upgraded sulpholane has a pH value of 7.95 and a TAN value of 0.08.
One gram of the adsorbent composition particles have capacity for processing contaminated sulpholane in the range of 26 to 65 grams.
In the present disclosure, the reactor can be a fixed bed reactor or a column.
In one embodiment, the contaminated sulpholane is contacted with the adsorbent composition particles at an ambient pressure, at 20 °C, for 30 minutes.
It is observed that the prepared adsorbent having a size of 1.0 - 1.5 mm is useful for removing impurities from contaminated sulpholane. The adsorbent composition particles of the present disclosure are useful for removing impurities from the contaminated sulpholane at a temperature in the range of 25 to 150 °C and at a pressure in the range of ambient pressure to 10 bar. The adsorbent used in the process of the present disclosure is in the granules and/or extrudates form. The adsorbent of the present disclosure can be used in a batch operation or continuous operation. The adsorbent of the present disclosure can be used in a fixed bed or moving bed operations.
The present disclosure uses readily available and inexpensive components such as an alumina composite, layered hydroxides and clay, for preparing the adsorbent composition particles. It is observed that the performance of the adsorbent composition particlesbased on alumina composite and layered hydroxides have enhanced efficiency for the removal of acidic impurities from sulpholane. Surprisingly, it is observed that one gram of adsorbent composition particles of the present disclosure can process 26 to 65 grams of contaminated sulpholane.
The process of the present disclosure for preparing the adsorbent is simple and does not require high capital investment.
The adsorbent composition particles of the present disclosure can be readily regenerated/purified in a continuous manner, i.e. without discontinuing process, thereby reducing the costs of operation. The capacity of the regenerated/purified adsorbent for reducing the acidic impurities in sulphoane is comparable to the capacity of fresh adsorbent. Thus, the process of the present disclosure apart from protecting the system components in the refining and petrochemical industry from corrosion, also increases the life cycle of the adsorbent, sulpholane and the process equipment.
The process of the present disclosure for upgrading sulpholane is highly efficient resulting in recovery of >99% of upgraded sulpholane. Thus, the process of the present disclosure minimizes the loss of sulpholane and additives. The upgraded sulpholane has purity in the range of 98 to 99% and can be recycled back in the system.
The adsorbent composition particles of the present disclosure are considered to be spent when the efficiency of the adsorbent composition particles to remove acidic impurities from the sulpholane, is reduced to less than 50 % (due to continuous usage), with respect to the efficiency of the fresh adsorbent composition particles.
The spent adsorbent composition particles of the present disclosure are regenerated by calcining the spent adsorbent composition at a temperature in the range of 450 °C to 600 °C, for a time period in the range of 1 hour to 10 hours in an oxidizing atmosphere.
The spent adsorbent composition particles of the present disclosure can be regenerated without any significant loss in the efficiency of the regenerated adsorbent composition for removing acidic impurities from the contaminated sulpholane.
In one embodiment, the adsorbent composition particles of the present disclosure are subjected two successive regeneration cycles without any significant loss in the efficiency for removing acidic impurities from the contaminated sulpholane.
Therefore, the adsorbent composition particles of the present disclosure provide benefits of long service life, thereby avoiding the frequent adsorbent replacement and generation of huge solid waste. Further, the spent adsorbent composition particles are easily regenerated and efficiently used for removing acidic impurities from a contaminated sulpholane.
The present disclosure is further described in light of the following laboratory scale experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. These laboratory scale experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial/commercial scale.
Experimental details
Example 1:
Experiment 1: Preparation of shaped adsorbent composition particles comprising layered hydroxide and alumina composite
Hydrotalcite ( 70 g ) (20-80 wt%) and alumina composite (30 g) (80-20 wt%) were mixed on dry powder basis to obtain a mixture of alumina and hydrotalcite. An aqueous mixture of water (88 g), acetic acid (10 g, 10 % aqueous solution), and oleic acid (2 g) was added to the powdered mixture and the resultant mixture was subjected to pugging and kneading, to obtain a pugged mixture. The pugged mixture was then extruded mechanically using an extruder using a 2 mm die to obtain extrudates having average particle size in the range of 1.5 to 3 mm. The extrudates were dried at 100°C for 240 minutes, followed by calcination at 550 °C for 5.5 hours under flowing air to obtain the adsorbent composition particles. Alumina content in the final adsorbent composition (on loss free basis) was 30 % by weight.
The mechanical properties of the shaped bodies were measured. Extrudates of the present disclosure had crushing strength of 4 Kgf/cm2. The bulk density of the shaped bodies was 0.56 g/cc and BET surface area of 213 m2/g.
The adsorbent composition particles prepared in experiment 1, were evaluated for reducing the acidic content of contaminated sulpholane and the results are summarized in Table 1.
Experiment 2: Performance of adsorbent composition particles prepared in experiment 1 of Example 1, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (100 g, pH= 4.74, and TAN = 0.34) was contacted with adsorbent composition particles (20 g, obtained in Example 1, Experiment 1) at ambient temperature and pressure for 6 hours. The pH and TAN of the purified sulpholane were 7.70 and 0.08, respectively.
Dynamic adsorption capacity of the adsorbents prepared in the present disclosure was measured using the experimental set up shown in Figure 1.
Dynamic adsorption capacity of the adsorbent composition particles prepared in experiment 1 of Example 1, was evaluated for reduction of acidic content of contaminated sulpholane and the results are summarized in Table 2.
Experiment 3: Dynamic adsorption capacity of adsorbent composition particles prepared in experiment 1 of Example 1, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (3.8 litres, pH= 4.74, and TAN = 0.34) was passed at a liquid hourly space velocity (LHSV) of 1 h-1, through an adsorbent (68 grams) packed in a fixed bed column having an internal diameter of 2.5 cm and a height of 50 cm, at a pressure of 10 bar and at an ambient temperature. The Total Acid Number (TAN) of the treated sulpholane (3.8 litres) was found to be 0.11.
Experiment 4: Dynamic adsorption capacity of adsorbent composition particles prepared in experiment 1 of Example 1, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (2 litres, pH= 4.74, and TAN = 0.34) was passed at a liquid hourly space velocity (LHSV) of 1 h-1, through an adsorbent (68 grams) packed in a fixed bed column having an internal diameter of 2.5 cm and a height of 50 cm, at a pressure of 10 bar and at a temperature of 100 and 150 °C, respectively The TAN of treated sulpholane the (2 litres) was found to be 0.11.
In all the cases the composition of the treated sulpholane and additive remains the same as the pure sulpholane have.
Example 2:
Experiment 1: Preparation of shaped adsorbent composition particles comprising Alumina rich mineral oxide
Alumina rich mineral oxide (containing 40-60% alumina (Al2O3),15-30% H2O, and the rest comprises of Iron oxide ( 5-15%) , SiO2 (2-6 %) ,TiO2 (1-3 %) and Calcium oxide( 0.5 -2%) was thermally ( specifically at 150 °C) treated to provide Alumina rich mineral oxide particle having size in the range of 0.5 to 1 mm. The Alumina rich mineral oxide particles were found to have surface area of 119 m2/g, pore volume 0.19 cc/g, and pore size of 64 Å.
The adsorbent composition particles prepared in experiment 1 of Example 2, was evaluated for reducing the acidic content of contaminated sulpholane and the results are summarized in Table 1.
Experiment 2: Performance of adsorbent composition particles prepared in experiment 1 of Example 2, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (100 g, pH= 4.74, and TAN = 0.34) was contacted with thermally treated alumino silicate rich mineral oxide (20 g, obtained in Example 2, Experiment 1) at ambient temperature and pressure for 6 hours. The pH and TAN of the purified sulpholane were 8.40 and 0.05, respectively.
Dynamic adsorption capacity of the adsorbents prepared in the present disclosure was measured using the experimental set up shown in Figure 1.
Dynamic adsorption capacity of the adsorbent composition particles prepared in experiment 1 of Example 2, was evaluated for reduction of acidic content of contaminated sulpholane and the results are summarized in Table 2.
Experiment 3: Dynamic adsorption capacity of adsorbent composition particles prepared in experiment 1 of Example 2, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (3.6 litres, pH= 4.74, and TAN = 0.34) was passed at a liquid hourly space velocity (LHSV) of 1 h-1, through the thermally treated alumino silicate rich mineral oxide (68 grams) packed in a fixed bed column having an internal diameter of 2.5 cm and a height of 50 cm, at a pressure of 10 bar and an ambient temperature. The Total Acid Number (TAN) of the treated sulpholane (3.6 litres) was found to be 0.11.
Experiment 4: Dynamic adsorption capacity of adsorbent composition particles prepared in experiment 1 of Example 2, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (1.8 litres, pH= 4.74, and TAN = 0.34) was passed at a liquid hourly space velocity (LHSV) of 1 h-1, through an adsorbent (68 grams) packed in a fixed bed column having an internal diameter of 2.5 cm and a height of 50 cm, at a pressure of 10 bar and at a temperature of 100 and 150 °C , respectively. The TAN of treated sulpholane the (2 litres) was found to be 0.11.
In all the cases the composition of the treated sulpholane and additive remains the same as the pure sulpholane have.

Example 3:
Experiment 1: Preparation of shaped adsorbent composition particles comprising layered double hydroxides and pseudoboehmite
Hydrotalcite 70 g (20-80 wt%) and pseudoboehmite powder 30 g (80-20 wt%) were mixed on dry powder basis to obtain a mixture of pseudoboehmite and hydrotalcite. An aqueous mixture of water (88 g), acetic acid (10 g, 10 % aqueous solution), and oleic acid (2 g) was added to the powdered mixture and the resultant mixture was subjected to pugging and kneading, to obtain a pugged mixture. The pugged mixture was then extruded mechanically using an extruder using a 2 mm die to obtain extrudates having size of 2.25 mm (1.5 to 3 mm). The extrudates were dried at 100 °C for 240 minutes, followed by calcination at 550 °C for 5.5 hours under flowing air to obtain the adsorbent composition particles. Alumina content in the final adsorbent composition particles (on loss free basis) was 30 % by weight.
The mechanical properties of the shaped bodies were measured. Extrudates of the present invention had crushing strength of 1.5 Kgf/cm2. The bulk density of the shaped bodies was 0.6 g/cc and BET surface area of 120 m2/g.
Experiment 2: Performance of adsorbent composition particles prepared in experiment 1 of Example 3, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (100 g, pH= 4.74, and TAN = 0.34) was contacted with adsorbent (20 g, obtained in Example 3, Experiment 1) at ambient temperature and pressure. The pH and TAN of the purified sulpholane were 7.95 and 0.08, respectively.
Dynamic adsorption capacity of the adsorbents prepared in the present disclosure was measured using the experimental set up shown in Figure 1.
Dynamic adsorption capacity of the adsorbent composition particles obtained in experiment 1 of Example 3, was evaluated for reduction of acidic content from a sulpholane containing acidic impurities.
Experiment 3: Dynamic adsorption capacity of adsorbent composition particles prepared in experiment 1 of Example 3, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (3.0 litres, pH= 4.74, and TAN = 0.34) was passed at a liquid hourly space velocity (LHSV) of 1 h-1, through an adsorbent (70 grams) packed in a fixed bed column having an internal diameter of 2.5 cm and a height of 50 cm, at a pressure of 10 bar and an ambient temperature. The Total Acid Number (TAN) of the treated sulpholane (3.0 litres) was found to be 0.11.
Experiment 4: Dynamic adsorption capacity of adsorbent composition particles prepared in experiment 1 of Example 3, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (1.6 litres, pH= 4.74, and TAN = 0.34) was passed at a liquid hourly space velocity (LHSV) of 1 h-1, through an adsorbent (70 grams) packed in a fixed bed column having an internal diameter of 2.5 cm and a height of 50 cm, at a pressure of 10 bar and at a temperature of 100 and 150 °C, respectively. The TAN of treated sulpholane the (1.6 litres) was found to be 0.11.
Example 4:
Experiment 1: Preparation of shaped adsorbent composition particles comprising layered double hydroxides, alumina rich mineral oxide and bentonite
Hydrotalcite 10 g (10 wt%) and raw alumina rich mineral oxide 60 g (60 wt%) and bentonite (30 wt %) were mixed on dry powder basis to obtain a mixture of alumina, layered double hydroxide and clay. An aqueous mixture of water (88 g), acetic acid (10 g, 10 % aqueous solution), and oleic acid (2 g) was added to the powdered mixture and the resultant mixture was subjected to pugging and kneading, to obtain a pugged mixture. The pugged mixture was then extruded mechanically using an extruder using a 2.25 mm (1.5 to 3 mm) die to obtain extrudates having size of 2 mm. The extrudates were air dried at 100 °C for 240 minutes, followed by calcination at 550 °C for 5.5 hours under flowing air to obtain the adsorbent composition particles. Alumina content in the final adsorbent composition particles (on loss free basis) was 25-30 % by weight.
Experiment 2: Performance of adsorbent composition particles prepared in experiment 1 of Example 4, for reducing the acidic content of contaminated sulpholane Sulpholane contaminated with acidic impurities (100 g, pH= 4.74, and TAN = 0.34) was contacted with adsorbent (20 g, from Example 4, Experiment 1) at ambient temperature and pressure °C for 6 hours. The pH and TAN of the purified sulpholane were 7.70 and 0.08, respectively.
Experiment 3: Dynamic adsorption capacity of adsorbent composition particles prepared in experiment 1 of Example 4, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (2.5 litres, pH= 4.74, and TAN = 0.34) was passed at a liquid hourly space velocity (LHSV) of 1 h-1, through an adsorbent (70 grams) packed in a fixed bed column having an internal diameter of 2.5 cm and a height of 50 cm, at a pressure of 10 bar and an ambient temperature. The Total Acid Number (TAN) of the treated sulpholane (2.5 litres) was found to be 0.11.

Experiment 4: Dynamic adsorption capacity of adsorbent composition particles prepared in experiment 1 of Example 4, for reducing the acidic content of contaminated sulpholane
Sulpholane contaminated with acidic impurities (1.6 litres, pH= 4.74, and TAN = 0.34) was passed at a liquid hourly space velocity (LHSV) of 1 h-1, through an adsorbent (70 grams) packed in a fixed bed column having an internal diameter of 2.5 cm and a height of 50 cm, at a pressure of 10 bar and at a temperature of 100 and 150 °C, respectively. The TAN of treated sulpholane the (1.6 litres) was found to be 0.11.
In all the cases the composition of the treated sulpholane and additive remains the same as the pure sulpholane have.
Table 1: Performance of adsorbent composition particles prepared in present disclosure towards removal of acidic impurities from sulpholane containing acidic impurities.
Example No. Experiment No. Adsorbent Source Reaction Conditions Results
Temp.
(°C) Time
(h) Sulpholane (Feed) pH Upgraded Sulpholane (Product) pH Sulpholane (Feed) TAN Upgraded Sulpholane (Product) TAN
1 2 Example 1, Experiment 1 Ambient 6 4.74 8.3 0.34 0.04
2 2 Example 2, Experiment 1 Ambient 6 4.74 8.4 0.34 0.05
3 2 Example 3, Experiment 1 Ambient 6 4.74 7. 95 0.34 0.08
4 2 Example 4, Experiment 1 Ambient 6 4.74 7. 7 0.34 0.08

It is clearly observed from Table-1, that the adsorbent composition particles of Examples 1-4 of the present disclosure reduce the TAN of contaminated sulpholane from 0.34 to a TAN in the range of 0.04 to 0.08. The adsorbent composition particles of Examples 1-4 of the present disclosure improve the pH value of the contaminated sulpholane from 4.73 to a pH value in the range of 7.5 to 8.5. The adsorbent composition particles of the present disclosure are efficient in reducing the acidic impurities from the sulpholane containing acidic impurities.
Table 2: Dynamic adsorption capacity of the adsorbent composition particles prepared in present disclosure towards removal of acidic impurities from sulpholane containing acidic impurities.
Example No. Experiment No. Adsorbent Reaction Conditions Results
Source
(Example, Experiment) Amount used Temp.
(°C) LHSV
(h-1) Sulpholane (Feed) in litres Dynamic adsorption capacity (g of sulpholane per gram of adsorbent) Sulpholane (Feed) TAN Upgraded Sulpholane (Product) TAN
1 3 1, 1 68 g 25 1 3.8 55.9 0.34 0.11
4 150 1 2 29.4 0.34 0.11
2 3 2, 1 68 g 25 1 3.6 52.9 0.34 0.11
4 150 1 1.8 26.5 0.34 0.11
3 3 3, 1 70 g 25 1 3 42.8 0.34 0.11
4 150 1 1.6 22.8 0.34 0.11
4 3 4, 1 70 g 25 1 2.5 35.7 0.34 0.11
4 150 1 1.6 22.8 0.34 0.11

It is clearly observed from the dynamic adsorption capacity data presented in Table-2, that one gram of adsorbent composition particles of the present disclosure processes 26 to 65 grams of contaminated sulpholane having a pH value of 4.74 and a TAN value of 0.34 to provide an upgraded sulpholane having a TAN value of 0.11. At ambient temperature, the adsorbent composition particles of the present disclosure have a dynamic adsorption capacity to process 35.7 to 55.9 g of contaminated sulpholane per gram of adsorbent. At higher temperatures in the range of 100 to 150 °C, the adsorbent composition particles of the present disclosure have a dynamic adsorption capacity to process 22.8 to 29.4 g of contaminated sulpholane per gram of adsorbent.
Example 5:
Experiment 1: Regeneration of the spent adsorbent composition particles of the present disclosure.
The experiment 1 provide the studies for the regeneration of the spent adsorbent composition particles of the present disclosure. The adsorbent composition particles of the present disclosure are considered to be a spent when the efficiency of the adsorbent composition particles to remove acidic impurities from the sulpholane contaminated with acidic impurities, is reduced to less than 50 % (due to continuous usage), with respect to the efficiency of the fresh adsorbent composition particles.
Hot nitrogen ( 250 °C) was passed through the spent adsorbent to remove the hydrocarbons and other lighter impurities settled on the adsorbent. Further, the adsorbent was thermally treated (at 450 °C for 5 hours in presence of air) in a furnance to remove the chemically bounded species. The activity of the thermally treated adsorbents was checked in the manner described in Examples 1-4. The regenerated asdrobent was found to have 80% activity compared to the fresh adsorbent.
The adsorbent composition particles of the present disclosure are effectively used for reducing acidic impurities from sulpholane contaminated with acidic impurities. The key aspect of the present disclosure is that the adsorbent composition particles of the present disclosure are developed by using different ratios of alumina, long chain fatty acids, clay, and layered hydroxide. The adsorbent composition particles exhibit a higher adsorbent performance because when the contaminated sulpholane is passed through the adsorbent bed under optimized conditions, the high surface area, pore volume and basicity of the adsorbent provide the opportunity to the impurities to interact and get adsorbed on to the adsorbent. Also, the developed process works under the conditions where sufficient time is available for the impurities to interact with the adsorbent surface.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
- an adsorbent composition particles based on alumina and layered double hydroxides for removal of acidic impurities from sulpholane contaminated with acidic impurities;
- an adsorbent composition particles having higher stability and longer life and hence reducing the frequency of changeovers for loading the adsorbent;
- a process for preparing the adsorbent composition particles of the present disclosure that is simple, efficient, and economic;
- a process for reducing the acidic impurities from contaminated sulpholane using the adsorbent composition particles of the present disclosure that is simple, efficient, and economic; and
- an adsorbent composition that can be regenerated, thus reduces solid waste generation.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.