Process for synthesis of polyhydrocarbons as heat transfer agents

Abstract

The present invention provides a one-pot process of synthesis of phenyl naphthalene compounds that are employed as heat transfer agents. More particularly, the present invention provides a process of preparation of 1-phenylnaphthalene and 2-methyl-1-phenylnaphthalene using refinery spent catalyst. These molecules are known for application as synthetic heat transfer fluids that deliver outstanding performance and thermal stability at continuously high operating temperatures. The reaction is carried out in aqueous medium using a spent catalyst which is a palladium based charcoal catalyst as obtained from various refinery processes. Further, the present invention provides a heat resistant formulation using the synthesized polyhydrocarbons, wherein the formulation is optimized with a free radical scavenger.

Claims

1. A one-pot process of synthesis of a phenyl naphthalene compound, wherein the process comprises: a) grinding a spent catalyst obtained from a refining process; b) mixing the spent catalyst with tripotassium phosphate and sodium dodecyl sulfate to obtain a reaction mixture I, wherein molar ratio of mixing the tripotassium phosphate and the sodium dodecyl sulfate ranges from 1:1 to 7:1; c) adding water to the reaction mixture I followed by stirring to obtain a reaction mixture II; d) adding phenylboronic acid to the reaction mixture II followed by addition of a bromonaphthalene derivative at room temperature to obtain a reaction mixture III, wherein molar ratio of mixing the phenylboronic acid and the bromonaphthalene derivative ranges from 1:1 to 1.5:1; e) heating the reaction mixture III followed by vigorous stirring for 4-6 hours; and f) cooling down to room temperature followed by filtration to separate the catalyst from a synthesis product comprising the phenyl naphthalene.

2. The process as claimed in claim 1, wherein in step (e) the reaction mixture III is heated at a temperature ranging from 90-110° C.

3. The process as claimed in claim 1, wherein the phenyl naphthalene compound is selected from 1-phenylnaphthalene and 2-methyl-1-phenylnaphthalene.

4. The process as claimed in claim 3, wherein the bromonaphthalene derivative in step (d) in the process of preparation of 1-phenylnaphthalene is 1-bromonaphthalene.

5. The process as claimed in claim 3, wherein the bromonaphthalene derivative in step (d) in the process of preparation of 2-methyl-1-phenylnaphthalene is 1-bromo-2-methylnaphthalene.

6. The process as claimed in claim 1, wherein stirring in step (e) is carried out at a speed ranging from 300-500 rpm.

7. The process as claimed in claim 1, wherein the spent catalyst is a palladium-carbon based catalyst with palladium content ranging from 0.05 to 0.1 wt % of the catalyst.

8. The process as claimed in claim 1, wherein the refining process is fluid catalytic cracking process, resid fluid catalytic cracking process, high severity fluid catalytic cracking process, high severity propylene maximizing fluid catalytic cracking process, hydro processing, or an isomerization process.

9. The process as claimed in claim 1, wherein the process further comprises addition of a free radical scavenger in an amount ranging from 1000-2000 ppm.

10. The process as claimed in claim 9, wherein the free radical scavenger is an iron or cerium based compound selected from iron oxide and cerium oxide.

11. The process as claimed in claim 9, wherein the phenyl naphthalene compound is stable upto 450° C. on addition of the free radical scavenger.

12. The process as claimed in claim 1, wherein the phenyl naphthalene compound is comprised, mixed, or used as a heat transfer agent.

13. A heat resistant formulation comprising the phenyl naphthalene compound obtained from the process as claimed in claim 1 and a free radical scavenger; wherein the free radical scavenger is an iron or cerium based compound.

14. The formulation as claimed in claim 13, wherein the free radical scavenger is present in an amount ranging from 1000-2000 ppm.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 represents the XRD spectrum of Refinery spent catalyst

(2) FIG. 2 represents TGA analysis of Refinery spent catalyst.

DESCRIPTION OF THE INVENTION

(3) For the purpose of promoting an understanding of the principles of the present disclosure, reference will now be made to the specific embodiments of the present invention further illustrated in specific language to describe the same. The foregoing general description and the following detailed description are explanatory of the present disclosure and are not intended to be restrictive thereof. It will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended, such alterations and further modifications in the illustrated composition, and such further applications of the principles of the present disclosure as illustrated herein being contemplated as would normally occur to one skilled in the art to which the present disclosure relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one ordinarily skilled in the art to which this present disclosure belongs. The methods, products and examples provided herein are illustrative only and not intended to be limiting.

(4) The present invention provides a process for preparation of thermal fluid for high temperature solar thermal application. Accordingly, the present invention provides a process of preparation of 1-phenylnaphthalene and 2-methyl-1-phenylnaphthalene using refinery spent catalyst obtained from various refining processes. These molecules are known for application as synthetic heat transfer fluids. The molecules are resonance stabilized due to the presence of poly-aromatic ring. The present invention provides thermal fluid for use at high temperature (400-500° C.) using refinery spent catalyst and water as solvent medium. The refinery spent catalyst is palladium based on charcoal and is available from refinery unit. The refinery spent catalyst is selected based on characterization using X-ray Diffraction (XRD), X-ray fluorescence (XRF), Molecular spectrum analysis, elemental analysis by ICAP and thermal gravity analysis. High purity yields of the products 1-phenylnaphthalene and 2-methyl-1-phenylnaphthalene are obtained by the optimized process.

(5) The present invention provides a one-pot process of synthesis of a phenyl naphthalene compound, wherein the process comprises: a) grinding a spent catalyst obtained from a refining process; b) mixing the spent catalyst with tripotassium phosphate and sodium dodecyl sulfate to obtain a reaction mixture I, wherein molar ratio of mixing the tripotassium phosphate and the sodium dodecyl sulfate ranges from 1:1 to 7:1; c) adding water to the reaction mixture I followed by stirring to obtain a reaction mixture II; d) adding phenylboronic acid to the reaction mixture II followed by addition of a bromonaphthalene derivative at room temperature to obtain a reaction mixture III, wherein molar ratio of mixing the phenylboronic acid and the bromonaphthalene derivative ranges from 1:1 to 1.5:1; e) heating the reaction mixture III followed by vigorous stirring for 4-6 hours; and f) cooling down to room temperature followed by filtration to separate the catalyst.

(6) In an embodiment, the present invention provides a process wherein in step (e) the reaction mixture III is heated at a temperature ranging from 90-110° C.

(7) In an embodiment, the present invention provides a process of synthesis of 1-phenylnaphthalene and 2-methyl-1-phenylnaphthalene which are polyaromatic molecules and are derivatives of phenylnaphthalene.

(8) In an embodiment, the present invention provides a process of synthesis of 1-phenylnaphthalene wherein the bromonaphthalene derivative in step (d) in the process of preparation of 1-phenylnaphthalene is 1-bromonaphthalene.

(9) In an embodiment, the present invention provides a process of synthesis of 2-methyl-1-phenylnaphthalene wherein the bromonaphthalene derivative in step (d) in the process of preparation of 2-methyl-1-phenylnaphthalene is 1-bromo-2-methylnaphthalene.

(10) In an embodiment, the present invention provides a process of synthesis of a phenyl naphthalene compound wherein the reaction mixture is stirred at a speed ranging from 300-500 rpm.

(11) In another embodiment, the present invention provides a process wherein the spent catalyst is a palladium-carbon based catalyst with palladium content ranging from 0.05 to 0.1 wt % of the catalyst.

(12) In an embodiment, the present invention provides that the spent catalyst is obtained from different refining processes like fluid catalytic cracking process, residue fluid catalytic cracking process, high severity fluid catalytic cracking process, high severity propylene maximizing fluid catalytic cracking process, hydro processing, isomerization process or any other refinery process.

(13) In a preferred embodiment of the present invention, the process further comprises addition of a free radical scavenger in an amount ranging from 1000-2000 ppm; wherein the free radical scavenger is an iron or cerium based compound. Preferably, the free radical scavenger is selected from iron oxide and cerium oxide.

(14) In yet another embodiment of the present invention, the phenyl naphthalene compound obtained from the disclosed process is stable upto 450° C. on addition of the free radical scavenger.

(15) In another embodiment of the present invention, the phenyl naphthalene compound is a heat transfer agent.

(16) Further, the present invention provides a heat resistant formulation comprising the phenyl naphthalene compound obtained from the disclosed process and a free radical scavenger; wherein the free radical scavenger is an iron or cerium based compound.

(17) In another embodiment, the present invention provides that the free radical scavenger is present in the heat resistant formulation in an amount ranging from 1000-2000 ppm.

(18) Thus, the present invention exhibits the following advantages: The synthesis process involved use of universal solvent water as reaction medium. The recovered/recycled cost effective catalyst used in the process is easily available and highly economical. The recovered catalyst used in various refining processes is easily available and highly economical. The reaction medium is environmentally benign. The process produces product of high purity and in high yields thereby reducing purification steps and hence is cost effective process. Any isomerization and thermal degradation at high temperature is controlled by optimizing a formulation along with a free radical scavenger. The process is of single-step with no complexity involved and is easy to scale up. The reaction temperature is moderate (90-110° C.). Cost effective and highly value added products are synthesized viz. 1-phenylnaphthalene and 2-methyl-1-phenyl naphthalene. Using synthesized products, a heat stable formulation upto 450° C. is optimized along with free radical scavenger.

(19) The present invention is further illustrated based on the disclosed embodiments through several non-limiting working examples.

Catalyst

(20) Catalyst was collected from different refineries. It is Pd-carbon based catalyst. The palladium content is about 0.05 to 0.1% in the catalyst. The spent catalysts thus obtained was grinded in mortar and pestle to its powder form size prior to use. The catalyst was used without any further activation.

Dodecyl Sodium Sulphate

(21) Commercial dodecyl sodium sulphate was used with 96% purity. This reagent acts to stabilize palladium particles from agglomeration.

Tri Potassium Phosphate

(22) Commercial tri potassium phosphate was used with 97% purity. This component acts as base and has three different roles—(i) helps in the formation of the palladium complex, (ii) helps in the formation of the trialkyl/triaryl boron compound and (ii) accelerates the reductive elimination step by reaction of the alkoxide with the palladium complex.

Solvent

(23) Water was used as an environmentally benign solvent. Distilled water was used as reaction medium.

PREPARATION OF THERMAL FLUID MOLECULES

Example 1

Typical Reaction Procedure: One-Pot Synthesis of 1-phenylnaphthalene from 1-bromonaphthalene and phenylboronic acid

(24) Synthesis of 1-phenylnaphthalene was carried out in a glass reactor fitted with condenser and controlled heating system. In a typical reaction process, tri potassium phosphate (K.sub.3PO.sub.4) (0.15 mol), sodium dodecyl sulfate (SDS) (0.05 mol) and spent catalyst (10 gm) were taken in a round bottom flask. 200-400 ml of water was added to the reactor and stirred. Phenylboronic acid (0.13 mol) was added to the mixture followed by 1-bromonaphthalene (0.1 mol) at room temperature. Reaction progress was monitored by thin layer chromatography (TLC). The reaction mixture was then heated at 100° C. with vigorous stirring (300-500 rpm) for 4-6 hrs. The reaction mixture was cooled to room temperature and filtered to separate the catalyst. The filtered catalyst was washed with organic solvent viz diethyl ether, ethyl acetate (30 ml) for reuse. The reaction mixture was then extracted with ethyl acetate (50 ml×3). The organic layer was separated and evaporated to obtain the products. The products were purified by distillation. The identification of the product was carried out by GC and GC-MS analysis.

Typical Reaction Procedure: One-Pot Synthesis of 2-methyl-1-phenylnaphthalene from 1-bromo-2-methylnaphthalene and phenylboronic acid

(25) Synthesis of 2-methyl-1-phenylnaphthalene was carried out in a glass reactor fitted with condenser and controlled heating system. In a typical reaction process, tri potassium phosphate (K.sub.3PO.sub.4) (0.15 mol), sodium dodecyl sulfate (SDS) (0.05 mol) and spent catalyst (10 gm) were taken in a round bottom flask. 200-400 ml of water was added to the reactor and stirred. Phenylboronic acid (0.13 mol) was added to the mixture followed by 1-bromo-2-methylnaphthalene (0.1 mol) at room temperature. Reaction progress was monitored by thin layer chromatography (TLC). The reaction mixture was then heated at 100° C. with vigorous stirring (300-500 rpm) for 4-6 hrs. The reaction mixture was cooled to room temperature and filtered to separate the catalyst. The filtered catalyst was washed with organic solvent viz diethyl ether, ethyl acetate (30 ml) for reuse. The reaction mixture was then extracted with ethyl acetate (50 ml×3). The organic layer was separated and evaporated to obtain the products. The products were purified by distillation. The identification of the product was carried out by GC and GC-MS analysis.

Catalyst Characterization

(26) Analytical study was carried out on the powdered spent catalyst received from Purified Terephthalic Acid (PTA) unit of Refineries.

XRF Analysis

(27) The XRF (Na—U Scan) analysis showed the presence of Pd, Cr, Mo with presence of Ti, Si, Zn, Al, Sb, S, Mg in the Refinery spent catalyst.

XRD Analysis

(28) XRD analysis showed peaks of Pd metal (Pd lines included in plot) with some peaks (less crystalline graphitic peaks) of carbon. The XRD pattern of Refinery spent catalyst is shown in FIG. 1

Elemental Analysis

(29) The elemental analysis of Refinery spent catalyst showed the presence of Al, Ca, Cr, Fe, K, Mg, Pd and Ti in minor amounts as 166, 95, 51, 350, 65, 39, 253 and 71 ppm level quantity respectively. Palladium metal (Pd) was present in the Refinery spent catalyst in the range of 217-253 ppm. The presence of Pd metal was also confirmed by XRF analysis. The detailed metal content of the spent catalyst are given below in the Table 1.

(30) TABLE-US-00001 TABLE 1 Results of elemental analysis Aliquot Diluted to Conc Sample Description Vol. Vol. Analyte (ppm) Refinery spent catalyst 2.0953 25 Al 166.3 2.0953 25 Ca 95.2 2.0953 25 Cr 50.7 2.0953 25 Fe 349.7 2.0953 25 K 65.5 2.0953 25 Mg 39.0 2.0953 25 Pd 252.7 2.0953 25 Ti 71.1

Thermogravimetric Analysis (TGA) Analysis

(31) In the heterogeneous catalysts, stability of active sites on catalyst surface is very important. Thermogravimetric analysis is widely used to identify mass changes due to temperature. This method is used to characterize the presence of metal in the Refinery spent catalyst. The stability of Refinery spent catalyst was measured by Thermogravimetric analysis (TGA) on TG model 2950 Hi Resolution modulated TGA, with heating rates 10° C./min, temperature ramp up to 800° C. The results given in the FIG. 2 showed that weight loss of 13.01 wt. % was observed at 100° C. corresponding to the removal of loosely absorbed water on the surface. The decomposition of amorphous carbon at ˜300° C. producing oxides of carbon associated with weight loss of 13.14 wt. %. Further the weight loss of 72.83 wt. % at 400° C.-600° C. signifies the decomposition of carbon which is crystalline in nature thereby indicating higher activity of catalyst.

Example 2

Synthesis of 1-phenyl naphthalene in Absence of Refinery Spent Catalyst

(32) Tri potassium phosphate (K.sub.3PO.sub.4) (0.015 mol), sodium dodecyl sulfate (SDS) (0.005 mol) and 40 ml of water were taken in a round bottom flask. Phenylboronic acid (0.011 mol) was added to the mixture followed by 1-bromonaphthalene (0.01 mol) at room temperature. The reaction mixture was then heated at 100° C. with vigorous stirring for 12 hrs. Thin layer chromatography showed no reaction progress.

Example 3

Synthesis of 1-phenyl naphthalene in Absence of tri potassium phosphate and sodium dodecyl sulfate

(33) Spent catalyst 1 gm and 40 ml of water were taken in a round bottom flask. Phenylboronic acid (0.011 mol) was added to the mixture followed by 1-bromonaphthalene (0.01 mol) at room temperature in the open air. The reaction mixture was then heated at 100° C. with vigorous stirring for 12 hrs. The reaction did not occur as no changes were observed in thin layer chromatography.

Example 4

Synthesis of 1-phenyl naphthalene in Absence of tri potassium phosphate

(34) Sodium dodecyl sulfate (SDS) (0.005 mol), spent catalyst 1 gm and 40 ml of water were taken in a round bottom flask. Phenylboronic acid (0.011 mol) was added to the mixture followed by 1-bromonaphthalene (0.01 mol) at room temperature in the open air. The reaction mixture was then heated at 100° C. with vigorous stirring for 12 hrs. No reaction progress was observed on TLC and was also confirmed by GC-MS.

Example 5