[002] Embodiments of the present invention generally relate to a method of producing carbon nanoparticles and particularly to a method of producing carbon nanoparticles using waste polyolefins.
[003] Description of Related Art
[004] Today the plastic-wastes are increasing day by day because people all over the world have been using some often-familiar plastics used such as LD-PE, HD-PE (Low- and high-density ethylene), PP (Polypropylene), PS (Polystyrene), and PVS (Polyvinyl chloride) which come to be 74% of the total plastics waste. Presently, plastic production is greater than before all over the globe for over the last fifty years. Globally, plastic consumption yearly has inflated sharply from around five million tons in the 1950s to almost 280 million tons by 2012; nowadays, manufacturing of plastic has grown 56 times more in the last 62 years and it will reach over 530 million tons in 2020. Consumptions of virgin plastics are increasing because plastics have become an indispensable part of everyone’s life.
[005] Therefore, waste plastics slowly degrade because 300 to 500 years are needed for their complete degradation process. Their results are loss of natural resources, the contribution of global warming due to the contaminated gases (CO, CO2, SO2, NOx) release in the environment, and waste plastics are no longer suitable for the environment. The fractions collected from plastics by pyrolysis are very closely similar to fossil fuels because plastics are chemically made from carbon and hydrogen. Various researchers have primarily focused on waste plastics and tires into hydrocarbons through the pyrolysis method. HD-PE (high density polyethylene) is a very good feedstock for the pyrolysis process and its recovery rate is 10%.
[006] There is thus a need for a method for managing plastics waste more efficiently.
SUMMARY
[007] Embodiments in accordance with the present invention provide a Depicted here is a method for conversion of waste polyolefins into carbon nanoparticles. The method includes a step of blending, waste polyolefins with a catalyst in a blender, wherein the catalyst is Strontium Carbonate (SrCO3).
[008] The method includes a step of transferring, the blended waste into a glass reactor with a diameter of 160 millimeters (mm), a height of 158 mm, and a wall thickness of 3 mm.
[009] The method includes a step of heating, the glass reactor using a furnace, wherein the furnace has a variable temperature ranging from 23o C to a 360o C controlled using a regulator.
[0010] The method includes a step of condensing, the vapor using a condenser, wherein the condenser is a spiral condenser.
[0011] The method includes a step of collecting, the condensed vapors in a collection tank attached to the condenser.
[0012] The method includes a step of separating, the black residue from the walls of the glass reactor, wherein the black residue is the carbon nanoparticles.
[0013] The preceding is a simplified summary to provide an understanding of some embodiments of the present invention. This summary is neither an extensive nor exhaustive overview of the present invention and its various embodiments. The summary presents selected concepts of the embodiments of the present invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the present invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and still further features and advantages of embodiments of the present invention will become apparent upon consideration of the following detailed description of embodiments thereof, especially when taken in conjunction with the accompanying drawings, and wherein:
[0015] FIG. 1 depicts a catalytic pyrolysis process diagram, according to an embodiment of the present invention;
[0016] FIG. 1B depicts a TGA showing thermal stability of waste polyolefins, according to an embodiment of the present invention;
[0017] FIG. 1C depicts a characterization of waste polyolefins using Fourier-transform infrared spectroscopy, according to an embodiment of the present invention;
[0018] FIG. 1D depicts a Brunauer Emmett Teller curve, according to an embodiment of the present invention;
[0019] FIG.1E depicts a DFT pore size distribution curve, according to an embodiment of the present invention; and
[0020] FIG. 2 depicts a flowchart of a method for the conversion of waste polyolefins 102 into carbon nanoparticles, according to an embodiment of the present invention.
[0021] The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including but not limited to. To facilitate understanding, reference numerals have been used, where possible, to designate elements common to the figures. Optional portions of the figures may be illustrated using dashed or dotted lines unless the context of usage indicates otherwise.
DETAILED DESCRIPTION
[0022] The following description includes the preferred best mode of one embodiment of the present invention. It will be clear from this description of the invention that the invention is not limited to these illustrated embodiments but that the invention also includes a variety of modifications and embodiments thereto. Therefore, the present description should be seen as illustrative and not limiting. While the invention is susceptible to various modifications and alternative constructions, it should be understood, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
[0023] In any embodiment described herein, the open-ended terms "comprising," "comprises,” and the like (which are synonymous with "including," "having” and "characterized by") may be replaced by the respective partially closed phrases "consisting essentially of," consists essentially of," and the like or the respective closed phrases "consisting of," "consists of, the like.
[0024] As used herein, the singular forms “a”, “an”, and “the” designate both the singular and the plural, unless expressly stated to designate the singular only.
[0025] FIG. 1 depicts a catalytic pyrolysis process diagram 100, according to an embodiment of the present invention. The catalytic pyrolysis process diagram 100 may be a process of degradation of the polymeric materials by heating them in the absence of oxygen and the presence of a catalyst. According to an embodiment of the present invention, the polymeric material may be waste materials comprising polyolefins. The polyolefins may be collected from waste tires, in a preferred embodiment of the present invention. The polyolefins collected from waste tires (hereinafter referred to as waste polyolefins 102) may be, but not limited to, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very-low-density polyethylene (VLDPE), ultra-low-density polyethylene (ULDPE), medium-density polyethylene (MDPE), polypropylene (PP), polymethyl pentene (PMP), polybutene-1 (PB-1); ethylene-octene copolymers, stereo-block PP, olefin block copolymers, propylene–butane copolymers, polyisobutylene (PIB), poly(a-olefin)s, ethylene-propylene rubber (EPR), ethylene propylene diene monomer (M-class) rubber (EPDM rubber), and so forth. Embodiments of the present invention are intended to include or otherwise cover any type of the polyolefins 102 including known, related art, and/or later developed technologies. Further, the waste polyolefins 102 may be subjected to thermo-gravimetric analysis (TGA) to yield the thermal stability. The TGA analysis (as shown in FIG. 1B) may be performed using TGA 4000 thermo-gravimetric analyzer, in an embodiment of the present invention. Furthermore, the waste polyolefins 102 may be characterized using Fourier-transform infrared spectroscopy (FT-IR) to check the suitability for performing the pyrosis process (as shown in FIG. 1C).
[0026] In another embodiment of the present invention, the moisture, volatile matter fixed carbon value, and ash contents, essential to determine the suitability of the pyrolysis process may be checked by the proximate analysis of the waste polyolefins 102.
Analysis of proximate Weight % Analysis of ultimate Weight %
Moisture content 0.82 Carbon 80.30
Volatile matter 62.70 Hydrogen 5.18
Fixed carbon 32.31 Nitrogen 10.13
Ash content 4.17 Oxygen Nil
_ _ Sulphur Nil
Table 1 shows the proximate and ultimate analysis of solid tire material
[0027] Referring to table 1 the waste polyolefins 102 may comprise a moisture content of 0.82%, volatile matter in 62.70%, fixed carbon of 32.31%, and ash content of 4.17%, according to the proximate analysis. Further, according to an ultimate analysis, the waste polyolefins 102 comprises 80.30% of carbon, 5.18% of hydrogen, 10.13% of nitrogen.
[0028] According to embodiments of the present invention, the waste polyolefins 102 may be washed with caustic free washing powder. In an embodiment of the present invention, the washing may be performed to remove foreign particles attached to the waste polyolefins 102. The washed waste polyolefins may be rinsed with distilled water and later dried for a minimum period of 10 hours under the sun. The dried waste polyolefins 102 may be subjected to grinding using a grinder. The grinder may ground the waste polyolefins to a size of 3 to 4 mm2. According to embodiments of the present invention, the grounded waste polyolefins 102 may be mixed with a catalyst 104.
[0029] According to embodiments of the present invention, the catalyst may be Strontium carbonate (hereinafter referred to as SrCO3). According to embodiments of the present invention, the SrCO3 may be used to decrease the thermal stability of the waste polyolefins 102. The SrCO3 may be characterized using Brunauer Emmett Teller (BET) theory. The BET isotherm is obtained when P/P0 < 1 and c > 1 in the BET equation, where c is BET constant and P/P0 partial pressure. In an embodiment of the present invention, the surface area of SrCO3 from BET adsorption data is found to be 114 m2/g ( as shown in FIG. 1D). In another embodiment of the present invention, the pore size of SrCO3 is found to be 3.79 nanometers (nm) (as shown in FIG.1E) when nitrogen adsorption isotherm is measured at 77 Kelvin. In an embodiment of the present invention, the grounded waste polyolefins 102 may be blended with 5 grams of SrCO3. In another embodiment of the present invention, the grounded waste polyolefins 102 may be blended with 10 grams of SrCO3. In another embodiment of the present invention, the grounded waste polyolefins 102 may be kept unmixed for the process of pyrosis.
[0030] The waste polyolefins 102 and the catalyst 104 may be placed inside a glass reactor 106. The glass reactor 106 may be made up of laboratory-grade glass. The glass reactor 106 may have a diameter of 160 mm. In another embodiment of the present invention, the glass reactor 106 may be 158 mm in height with a neck 300 mm long. In another embodiment of the present invention, the glass reactor 106 may have a wall thickness of 3 mm. Further, the glass reactor 106 may be placed in a furnace 108. The furnace 108 may be configured to heat the glass reactor 106. In an embodiment of the present invention, the furnace 108 comprises a digital electricity meter 110 and a regulator 112.
[0031] The digital electricity meter 110 may be configured to measure the temperature of the furnace 108. In another embodiment of the present invention, the heating temperature of the furnace 108 may be controlled from the beginning to the end using the regulator 112. According to embodiments of the present invention, the furnace 108 may be started at 23° C room temperature reaching up to the maximum temperature of pyrolysis that is 390 °C. According to embodiments of the present invention, the temperature may reach from 23° C to 390 °C at a heating rate ranging from 20o Celsius per minute (C/min) to 24o Celsius per minute(C/min). The pyrosis process may crack the long chain of waste polyolefins 102 in short-chains leading to degradation of waste polyolefins 102. Further, the cracked carbon chains may come into the vapors phase inside the glass reactor 106 because of their lower molecular weight. After that, the vapors may be passed from the beginning to the end of a reactor neck to a condenser 114. The gases were condensed in the condenser 114 at 23 °C room temperature. The condensed gas may be collected in a collection tank 116. In a preferred embodiment of the present invention, the carbon nanoparticles may be separated from the walls of the glass reactor 106.
[0032] FIG. 1B depicts a TGA showing thermal stability of waste polyolefins 102, according to an embodiment of the present invention. The TGA may be plotted on an X-Y axis where X-axis represents a temperature in degree Celsius and Y-axis represent weight loss percentage.
[0033] FIG. 1C depicts a characterization of waste polyolefins 102 using Fourier-transform infrared spectroscopy, according to an embodiment of the present invention. The FT-IR may be plotted on the X-Y axis where X-axis represents wavenumber and Y-axis represent transmittance.
[0034] FIG. 1D depicts a Brunauer Emmett Teller curve, according to an embodiment of the present invention. The Brunauer Emmett Teller curve may be plotted based on Brunauer Emmett Teller (BET) theory. Further, the Bet curve represents relative pressure on X-axis and adsorbed volume on Y-axis.
[0035] FIG.1E depicts a Density Functional Theory (DFT) pore size distribution curve, according to an embodiment of the present invention. The DFT pore size distribution curve may be plotted on the X and Y plane, where X-axis represents pore width in nanometer (NM).
[0036] FIG. 2 depicts a flowchart of a method 200 for conversion of waste polyolefins 102 into carbon nanoparticles, according to an embodiment of the present invention.
[0037] At step 202, the waste polyolefins 102 may be blended with the catalyst 104 in a blender. The catalyst 104 may be Strontium Carbonate (SrCO3).
[0038] At step 204, the blended waste may be transferred into a glass reactor 106. The glass reactor may have a diameter of 160 millimeters (mm), a height of 158 mm, and a wall thickness of 3 mm.
[0039] At step 206, the glass reactor 106 may be heated using a furnace 108. The furnace 108 may have a variable temperature a starting temperature of 23o C reaching up to a temperature of 360o C that may be controlled using a regulator 112. The temperature of the furnace may be measured using a digital electricity meter 110.
[0040] At step 208, the vapor generated from the glass reactor 106 due to the heating may be condensed using a condenser 114. The condenser 114 may be a spiral condenser.
[0041] At step 210, the condensed vapor may be collected in a collection tank 116 attached to the condenser 114.
[0042] At step 212, the black residue may be separated from the walls of the glass reactor 106. The black residue may be the carbon nanoparticles that may be used in various applications.
[0043] While the invention has been described in connection with what is presently considered to be the most practical and various embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
[0044] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined in the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements within substantial differences from the literal languages of the claims.

CLAIMS

I/We Claim:

1. A method for conversion of waste polyolefins into carbon nanoparticles, the method comprising steps of:
blending, waste polyolefins (102) with a catalyst (104) in a blender, wherein the catalyst (104) is Strontium Carbonate (SrCO3);
transferring, the blended waste into a glass reactor (106) with a diameter of 160 millimeters (mm), the height of 158 mm, and the wall thickness of 3 mm;
heating, the glass reactor (106) using a furnace (108), wherein the furnace (108) has a variable temperature ranging from 23o C to a 360o C controlled using a regulator (112);
condensing, the vapor using a condenser (114), wherein the condenser (114) is a spiral condenser;
collecting, the condensed vapors in a collection tank (116) attached to the condenser (114); and
separating, the black residue from the walls of the glass reactor (106), wherein the black residue is the carbon nanoparticles.
2. The method as claimed in claim 1, wherein a process of pyrolysis is used to obtain carbon nanoparticles from the waste polyolefins (102).
3. The method as claimed in claim 1, the waste polyolefins (102) are selected from one of, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very-low-density polyethylene (VLDPE), ultra-low-density polyethylene (ULDPE), medium-density polyethylene (MDPE), polypropylene (PP), polymethyl pentene (PMP), polybutene-1 (PB-1); ethylene-octene copolymers, stereo-block PP, olefin block copolymers, propylene–butane copolymers, polyisobutylene (PIB), poly(a-olefin)s, ethylene-propylene rubber (EPR), ethylene propylene diene monomer (M-class) rubber (EPDM rubber), or a combination thereof.
4. The method as claimed in claim 1, wherein the furnace (108) is capable to operate at a heating rate of 20o Celsius per minute (C/min) to 24o Celsius per minute (C/min).
5. The method as claimed in claim 1, wherein the furnace (108) further comprises a digital electricity meter (110) configured to measure the temperature of the furnace 108.
6. The method as claimed in claim 1, the thermal stability of the waste polyolefins (102) is tested using a TGA 4000 thermo-gravimetric analyzer.
7. The method as claimed in claim 1, the waste polyolefins (102) are characterized using Fourier-transform infrared spectroscopy (FT-IR).
8. The method as claimed in claim 1, the catalyst (104) is characterized using Brunauer Emmett Teller (BET) theory.
9. The method as claimed in claim 1, the pore size of the catalyst (104) is calculated using Density Functional Theory (DFT).