A method for obtaining activated carbon from biocarbophen derived from tea wastes

Abstract

The invention relates to a method for obtaining firstly the biocarbophen component from non-functionalized tea wastes, then activated carbon suitable for use in the industrial field from the biocarbophen component, respectively.

Description

[0001] A METHOD FOR OBTAINING ACTIVATED CARBON FROM BIOCARBOPHEN DERIVED FROM TEA WASTES

[0002] TECHNICAL FIELD

[0003] The invention relates to a method for obtaining firstly the biocarbophen component from non-functionalized tea wastes, then activated carbon suitable for use in the industrial field from the biocarbophen component, respectively.

[0004] PRIOR ART

[0005] The tea plant (Camellia sinensis) is an evergreen shrub or small tree in the Theaceae family. The leaves of the tea are used in the production of the tea drink, which is widely consumed throughout the world. The Black Sea Region is the center of tea production in Turkey, with intensive tea cultivation especially in provinces such as Rize, Trabzon, Artvin, and Giresun. Tea cultivation and production in this region has an important place in the tea culture of Turkey. During the period of processing and consuming tea, tea wastes are generated.

[0006] Black tea is one of the most widely grown agricultural products in the world and is mostly discarded after brewing. Black tea, in particular, accounts for about 78% of tea consumption worldwide, and a significant amount of waste is generated after brewing.

[0007] Tea wastes are organic wastes with the potential to be utilized in various ways in the industry. Tea wastes are used in the production of compost due to its high content of organic matter. Compost is widely preferred in agriculture and horticulture to increase the fertility of the soil.

[0008] Tea wastes are included in some animal feed formulations. It is considered as a source of fiber, especially for ruminants. As a result, tea wastes stand out as a versatile raw material that can be utilized in various fields in the industry. Recycling and reuse of these wastes both contributes to environmental sustainability and increases economic value. Activated carbon is a carbon-based material, which generally has a high surface area and a porous structure. With these properties, it has the capacity to adsorb various substances in gases and liquids. Activated carbon is widely used in water and air filtration, chemical processing, and medical applications. The surface area of activated carbon generally varies between 500-1500 m2 / g, which makes activated carbon have a very high adsorption capacity.

[0009] It is possible to obtain activated carbon from tea wastes, therefore waste products that do not have industrial added value can be used as raw materials to obtain activated carbon with added value. The inventors of the present invention conduct research and development activities for the relevant technical field along with this technical teaching.

[0010] SUMMARY OF THE INVENTION

[0011] The present invention relates to obtaining activated carbon from biocarbophen component obtained from tea waste in order to eliminate the above-mentioned disadvantages and bring new advantages to the relevant technical field.

[0012] An object of the invention is to obtain activated carbon from the biocarbophen intermediate.

[0013] Another object of the invention is to transform tea waste into a high added value product by obtaining activated carbon.

[0014] While the activated carbon involves high cost and complex process steps in the art, the method of the invention is for providing a method for obtaining cost-reduced activated carbon.

[0015] BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 shows the XRD analysis as a result of reaction of biocarbophen intermediate obtained from tea waste with NaOH. Again, under Figure 1 , XRD analyzes reacted with different moles of NaOH solution are shown. Figure 1-a shows the XRD Analysis of 1 M NaOH-reacted biocarbophen. M-Y refers to heat-treated then washed biocarbophen containing different moles of NaOH.

[0017] Figure 1 -b shows the XRD Analysis of 1 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0018] Figure 1 -c shows the XRD Analysis of 3 M NaOH-reacted biocarbophen. Figure 1 -d shows the XRD Analysis of 3 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0019] Figure 1 -e shows the XRD Analysis of 5 M NaOH-reacted biocarbophen.

[0020] Figure 1 -f shows the XRD Analysis of 5 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0021] Figure 2 relates to the Raman Analysis of NaOH-reacted biocarbophen and heat-treated biocarbophen. Figure 2-a shows the Raman Analysis of 1 M NaOH-reacted biocarbophen. Figure 2-b shows the Raman Analysis of 1 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0022] Figure 2-c shows the Raman Analysis of 3 M NaOH-reacted biocarbophen. Figure 2-d shows the Raman Analysis of 3 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0023] Figure 2-e shows the Raman Analysis of 5 M NaOH-reacted biocarbophen. Figure 2-f shows the Raman Analysis of 5 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0024] Figure 3a shows the SEM analysis of 1 M NaOH-reacted biocarbophen. Figure 3b shows the SEM analysis of 1 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0025] Figure 4a shows the SEM analysis of 3 M NaOH-reacted biocarbophen. Figure 4b shows the SEM analysis of 3 M-Y heat-treated then washed, NaOH-reacted biocarbophen. Figure 5a shows the SEM analysis of 5 M NaOH-reacted biocarbophen. Figure 5b shows the SEM analysis of 5 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0026] Figure 6 shows the FTIR analysis of NaOH-reacted biocarbophen. Figure 6-a shows the FTIR analysis of 1 M NaOH-reacted biocarbophen. Figure 6-b shows the FTIR analysis of 1 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0027] Figure 6-c shows the FTIR Analysis of 3 M NaOH-reacted biocarbophen. Figure 6-d shows the FTIR analysis of 3 M-Y heat-treated then washed, NaOH-reacted biocarbophen.

[0028] Figure 6-e shows the FTIR analysis of 5 M NaOH-reacted biocarbophen.

[0029] DETAILED DESCRIPTION OF THE INVENTION

[0030] In this detailed explanation, the subject of the invention relates to a method for obtaining firstly the biocarbophen component from non-functionalized tea wastes, then activated carbon suitable for use in the industrial field from the biocarbophen component, respectively, and is described by way of non-limiting examples only for a better understanding of the subject matter.

[0031] The use of tea waste is crucial in terms of sustainability and waste management. Tea wastes are organic wastes generated in tea production and consumption processes and are utilized in various ways. Leaves, twigs, and other plant scraps generated during pruning of tea plants are wastes generated during the production process of tea leaves that cannot be used during tea processing or do not meet quality standards. Tea bags or tea pulps left over from use by the final consumer are wastes generated during consumption processes. Tea wastes are organic wastes with the potential to be utilized in various ways in the industry. Since the recovery of wastes is a priority, wastes generated during consumption are preferred.

[0032] Biocarbophen gel has high pH and negative ORP values and is alkaline (basic). The XRD analyzes of biocarbophen show that this material is a 2-dimensional (2D) material. Also, the presence of structures such as graphene oxide, honeycomb sp2-hybridized carbon, carbophen 2D carbon crystals in the XRD analysis of biocarbophen are clear indicators that this material is based on a 2-dimensional (2D) carbon-.

[0033] Activated carbon is a carbon-based material, which generally has a high surface area and a porous structure. With these properties, it has the capacity to adsorb various substances in gases and liquids. Activated carbon is widely used in water and air filtration, chemical processing, and medical applications. The surface area of activated carbon generally varies between 500-1500 m2 / g, which makes activated carbon have a very high adsorption capacity. The target product in the invention is to obtain activated carbon. The activated carbon obtained in this invention can be used wherever activated carbon can be used in the relevant technical field. The scope of protection of the invention is independent of where the activated carbon to be obtained will be used. The technical properties of the obtained activated carbon are shared in the following lines with the tests performed.

[0034] The inventors of the present invention, with the studies conducted, have determined that biocarbophen can be obtained first from tea wastes, and activated carbon from this intermediate. Said method essentially includes the following process steps:

[0035] - adding tea wastes to a solution containing at least one component with a pH value of 7 or above, reacting tea wastes with the component with a pH value of 7 or above in this prepared solution, and obtaining an intermediate biocarbophen with the reaction,

[0036] - heat-treating the obtained biocarbophen at a value between 400 °C to 600 °C,

[0037] - obtaining activated carbon with washing and drying processes after heat treatments.

[0038] In the solution into which the tea wastes of the invention are added, the component with a pH value of 7 or above is NaOH. With the use of NaOH, structural and chemical changes occur in the biomass, resulting in increases in the carbon content.

[0039] The decomposition of the biocarbophen organic material obtained in the invention and the increase in volume and surface area starts at 400 ° C and a micro- meso porous structure is obtained at 600 °C.

[0040] The tea wastes of the invention are reacted by adding them to NaOH at a value in the range of 1 to 6 moles by volume. As a result of the reacting tea wastes, biocarbophen intermediate is obtained. If the NaOH molarity exceeds 6 moles, it causes various mineral pollution in active / amorphous carbon. If it is 1 mole and less, the carbon bonds of the tea are broken and the active / amorphous carbon structure cannot be detected.

[0041] Said biocarbophen intermediate is subjected to X-Ray Diffractometer (XRD), Raman, Fourier Transform Infrared Spectrometry (FTIR), Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS), surface area, pore volume, pore size, and density tests.

[0042] In the washing process preferred in the method of the invention, the ultrasonic bath process step is applied.

[0043] In the XRD analyzes carried out in the invention, NaCO3peaks are seen due to the bonding of the NaOH chemical in the biocarbophen structure with the carbon material. Following the heat treatments, NaCO3is dissolved in water after applying a water bath with ultrasonic bath, and a decrease in the peak number is observed.

[0044] After the water bath, the biocarbophen is dried at 90 ° C to 120 ° C in a period of 1 to 3 hours and activated carbon is obtained.

[0045] In the XRD analyzes in Figure 1 ; peaks are seen in the range of 20=20 and 30°, and peaks at values of 20=26°, 43°, 44°, 45°, 55° are noteworthy. This shows that all materials have both an amorphous carbon structure and activated carbon properties.

[0046] According to the Raman analyzes in Figure 2, D band and G band are detected at approximately 1355cm1and 3000cm1values. This is an indication that the material is amorphous carbon and activated carbon.

[0047] According to the SEM analyzes in Figure 3, Figure 4 and Figure 5, porous structures are present in all samples with different molar volumes. Due to the dissolving of some materials after the ultrasonic washing process, pores appear and a more porous structure is seen.

[0048] In the samples prepared according to the FTIR analyzes in Figure 6, approximately 753cm1, 861cm1, 963cm1, 1037cm1, 1153cm1, 1241cm1, 1383cm1, 1348cm1, 1607cm1, 1736cm1, 2956cm1and 3546cm1values are noteworthy. These peaks show the structure of amorphous carbon. However, the absorption bands in the range 3373- 3546 cm-1are associated with the symmetric stress of the hydroxyl groups (OH-), while the band at 2943 cm-1is attributed to the C-H stress. Both group bond deformations of OH and C-H are located between 1607-1403cm1, respectively. Vibration bands associated with C=O stress and C-0 stress (1383-1037cm1) extending between 1748- 1736cm1are seen, and bands located in the region between 963-753cm1are attributed to C-C stress. If FTIR peaks are evaluated as activated carbon; it is seen as the peak of infrared transmission in the wavelength range of 3200-3650cm1. Here, the presence of a wide transmission band, the O-H stress mode of hydrogen-bonded hydroxyl groups formed due to moisture adsorbed on the structure or surface is noteworthy. For physicochemically activated samples, a low-signal transmission band appears at about 3729 cm-1, corresponding to the free O-H functional groups. 2 consecutive small peaks around 2900 and 2810 cnr1indicate the presence of asymmetrical and symmetrical C- H stress vibrations of the hydrocarbon structure, respectively. FTIR analyzes reveal that all samples in this study showed both amorphous carbon and activated carbon properties.

[0049] Table 1 shows the surface area test results of samples of different molar volumes.

[0050]

[0051] Table 1 - Surface Area

[0052] Table 2 shows the pore volume test results of samples of different molar volumes.

[0053] Table 2- Pore Volume

[0054] Table 3 shows the pore size test results of samples of different molar volumes.

[0055] Table -3 Pore Size

[0056] As can be seen in the surface area, pore volume, and pore size test results in Table 1 , Table 2 and Table 3, as the molar ratio of sodium hydroxide used in biocarbophen production increases, the surface area increases, while the pore volume and pore size decrease. The M-Y in the invention refers to a sample which has been heat-treated then washed, containing NaOH. Similarly, it is seen that the surface area of the samples increases after the ultrasonic washing process, but the pore volume and pore size decrease. This is a significant advantage. Because it offers surface area selection according to needs.

[0057] The table below shows the components of the biocarbophen intermediate before ultrasonic washing and after ultrasonic washing.

[0058] Table 4 - EDS Analysis of Biocarbophen

[0059] The EDS analyzes in Table 4 show the elements that may be present in the tea plant. The striking part of EDS analysis is that with the ultrasonic washing process, it is seen that other elements, especially the sodium element, can be removed from the structure with the decrease in the amount. This is also a sign that pure or near-pure amorphous or activated carbon can be obtained with a few washes. With the invention, it is possible to obtain activated carbon from tea wastes, therefore waste products that do not have industrial added value can be used as raw materials to obtain activated carbon with added value. In addition to recycling and reusing wastes, activated carbon is obtained at low cost without additional costs with the method of the invention.

[0060] The activated carbon obtained in the invention is used in the industry, in pharmaceuticals, alloy production, composite material production, electronic circuit element production, capacitor applications, battery applications and as a filter. The scope of protection of the invention is specified in the appended claims and cannot be limited to what is described for illustrative purposes in this detailed description. It is clear that a person skilled in the art can produce similar embodiments in the light of what is explained above, without deviating from the main theme of the invention.

Claims

CLAIMS1. A method for obtaining firstly the biocarbophen component from non-functionalized tea wastes, then activated carbon suitable for use in the industrial field from the biocarbophen component, respectively, characterized in that it comprises the process steps of;- adding tea wastes to a solution containing at least one component with a pH value of 7 or above, reacting tea wastes with the component with a pH value of 7 or above in this prepared solution, and obtaining an intermediate biocarbophen with the reaction,- heat-treating the obtained biocarbophen at a value between 400 °C to 600 °C,- obtaining activated carbon with washing and drying processes after heat treatments.

2. A method according to claim 1 , characterized in that the component with a pH value of 7 or above is NaOH.

3. A method according to one of the preceding claims, characterized in that the NaOH solution has a value between 1 to 6 moles volume.

4. A method according to one of the preceding claims, characterized in that the heat treatment is followed by ultrasonic bath treatment.

5. A method according to one of the preceding claims, characterized in that the drying is carried at a value between 90 °C to 120 °C.

6. A method according to one of the preceding claims, characterized in that the drying process takes between 1 to 3 hours.

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