WO2020234092A1 - Method for providing photoelectrochemical cells with the use of dyes extracted from winemaking residues - Google Patents

Method for providing photoelectrochemical cells with the use of dyes extracted from winemaking residues Download PDF

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Publication number
WO2020234092A1
WO2020234092A1 PCT/EP2020/063367 EP2020063367W WO2020234092A1 WO 2020234092 A1 WO2020234092 A1 WO 2020234092A1 EP 2020063367 W EP2020063367 W EP 2020063367W WO 2020234092 A1 WO2020234092 A1 WO 2020234092A1
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comprised
organic dye
electrode
winemaking
waste product
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PCT/EP2020/063367
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French (fr)
Inventor
Elisa MORETTI
Manuel MENEGHETTI
Stefano Meneghetti
Enrique Rodriguez Castellon
Aldo TALON
Emilio Celotti
Original Assignee
Vinicola Serena S.R.L. In Forma Breve V.S. S.R.L.
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Publication of WO2020234092A1 publication Critical patent/WO2020234092A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2059—Light-sensitive devices comprising an organic dye as the active light absorbing material, e.g. adsorbed on an electrode or dissolved in solution
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/761—Biomolecules or bio-macromolecules, e.g. proteins, chlorophyl, lipids or enzymes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2027—Light-sensitive devices comprising an oxide semiconductor electrode
    • H01G9/2031—Light-sensitive devices comprising an oxide semiconductor electrode comprising titanium oxide, e.g. TiO2
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/542—Dye sensitized solar cells

Definitions

  • the present invention relates to the extraction of an organic dye from a waste product of the winemaking process and the use of such organic dye as a sensitizing agent in photoelectrochemical cells.
  • the invention furthermore, comprises a method for providing photoelectrochemical cells that comprise such dye.
  • Photovoltaic cells are devices that are capable of converting solar energy to electricity and, among these, technologies based on the use of materials of organic origin are eliciting ever-increasing interest.
  • DSSC Downlink Sensitized Solar Cells
  • Graetzel cells photoelectrochemical solar cells with a sensitizing agent, known as“Dye Sensitized Solar Cells” (DSSC) and also as Graetzel cells, from the name of their inventor.
  • a Graetzel cell can be considered as a multi-layer structure, in which each layer must meet determined chemical/physical requirements as it has a specific and well-defined function in the process of generation of electric current.
  • Graetzel cells are generally constituted by a negative electrode, called a photoanode, which comprises a matrix of glass or other material transparent to solar radiation, which has a spectral range comprised between near-UV and near-infrared, and which is made electrically conducting by a thin layer of indium oxide and tin oxide, Sn0 2 /In 2 0r 3 (also known as indium oxide doped with tin) (ITO), or by tin dioxide doped with fluorine, Sn0 2 :F (FTO).
  • ITO indium oxide doped with tin
  • FTO tin dioxide doped with fluorine
  • Semiconductor nanocrystals of titanium oxide or zinc oxide are deposited on this base, forming a matrix on which a sensitizing agent, in the form of a dye, is adsorbed.
  • the dye acts by capturing sunlight and injecting electrons into the semiconductor on which it is adsorbed.
  • the dyes that can be used can be organic dyes, derived from extracts of plant foods like blueberries, blackcurrants, aubergines (G. Calogero et ah, 2012. Anthocyanins and betalains as light-harvesting pigments for dye- sensitized solar cells. Solar Energy, 86, 1563-1575 and G. Calogero et al, 2015 Vegetable-based Dye-Sensitized Solar Cells. Chem. Soc. Rev., 44, 3244-3294), or high-efficiency artificial dyes, which are usually based on ruthenium like N3 or N719 (Ruthenium-based dyes for Dye-sensitized Solar Cells - Sigma Aldrich).
  • Artificial dyes can be organic or inorganic.
  • inorganic dyes Although they offer high energy yields, inorganic dyes however have several drawbacks, such as for example high production costs, a certain toxicity that also affects the waste products deriving from their preparation, and low environmental sustainability, since they are neither recyclable nor biodegradable.
  • the aim of the present invention is to provide an environmentally sustainable organic dye for providing DSSC photoelectrochemical solar cells.
  • an object of the present invention is to provide a method for extracting the dye from a waste material of the agrifood sector.
  • Another object of the present invention is to provide a method for providing a DSSC photoelectrochemical cell which enables the renewable and sustainable production of electricity.
  • organic dye obtainable by way of the method according to the invention, wherein said organic dye comprises:
  • a method for providing a photoelectrochemical cell which comprises the steps of:
  • step (b) immersing an electrode comprising a titanium dioxide film in a solution of the organic dye extracted in step (a) for a time comprised between 12 and 24 hours, thus impregnating the titanium dioxide film with the organic dye.
  • a photoelectrochemical cell which comprises:
  • an electrode which comprises a titanium dioxide film impregnated with an organic dye according to the invention
  • said electrode and said backing electrode are assembled in a structure which comprises an electrolytic solution in the free space between them.
  • Figure 1 is a schematic diagram of a Graetzel cell according to the known art which comprises: conductive glass (1), nanocrystalline semiconductor film (2), dye (3), electrolyte (4), backing electrode (5).
  • Figure 2 shows a physisorption isotherm of N 2 at -196°C of a sample of titanium dioxide prepared according to Example 2.
  • Figure 3 shows an X-ray diffractogram of dust (XRD) in the range 10- 80° 20 of a sample of titanium dioxide.
  • Figure 4 shows the variation of absorbance over time of a diluate of dye extracted according to the method of the present invention, using various different solvents.
  • Figure 5 shows the characterization of dyes extracted from winemaking lees with various different solvents.
  • Figure 6 shows the curve of the current density and power density of the cell as a function of voltage.
  • a first aspect of the present invention relates to a method for extracting an organic dye from a waste product of a winemaking process, which comprises the steps of:
  • the waste product of the winemaking process is a winemaking lees.
  • the deposit that remains is called the lees, which is substantially composed of yeast cells, bacteria, plant residues and, to a large extent, bentonite.
  • Bentonite is a phyllosilicate clay and is used by wine-growers and wine-producers to reduce protein instability and to precipitate the suspended solids responsible for clouding the wine over time (Lira E., Salazar F. N., Rodriguez-Bencomo J. J., Vincenzi S., Curioni A., Lopez F., 2014. Effect of using bentonite during fermentation on protein stabilisation and sensory properties of white wine. Int. J. of Food Science and Technology, 49, 1070- 1078).
  • Bentonite furthermore slightly discolors red and white wines, because it retains the molecules responsible for the color of wines, such as anthocyans, tannins, catechins and polyphenols.
  • the deposit that is formed following the process of winemaking and clarification of the wine is therefore a suspension of clarification adjuvants, macromolecules deriving from grapes and from yeast, and wine.
  • this deposit is centrifuged to extract the wine still contained in it, leaving a red solid which is constituted mainly by clarification residues, polyphenols, polysaccharides and yeasts, which are treated as waste for disposal.
  • the method of the present invention therefore makes it possible to recover the principal waste product of a winemaking company and reinsert it into the production circuit, by extracting the organic dye necessary for the operation of DSSC photovoltaic cells.
  • the extraction method according to the invention comprises the step of mixing the solid residue, or winemaking lees, with a solution of ethanol, methanol and mixtures thereof, acidified with a strong acid.
  • the strong acid is concentrated hydrochloric acid (HC1).
  • the solvent is selected from ethanol and methanol.
  • the solution of ethanol or methanol is acidified by adding concentrated HC1 in a quantity comprised between 0.5 and 5.0% by volume. In an embodiment, in step (ii) the mixture is stirred for a time comprised between 1 and 8 hours.
  • step (ii) the mixture is stirred for a time comprised between 2 and 6 hours.
  • a second aspect of the present invention relates to an organic dye obtainable by way of the method of the invention in any of the embodiments described above, wherein said organic dye comprises:
  • anthocyans can vary as a function of the quality of the grape harvest.
  • a third aspect of the present invention relates to a method for providing a photoelectrochemical cell, which comprises the steps of:
  • step (b) immersing an electrode comprising a titanium dioxide film in a solution of the organic dye extracted in step (a) for a time comprised between 12 and 24 hours, thus impregnating the titanium dioxide film with the organic dye.
  • a fourth aspect of the present invention relates to a photoelectrochemical cell, which comprises:
  • an electrode which comprises a titanium dioxide film impregnated with an organic dye according to the invention
  • a backing electrode which is coated by a platinum film, wherein the electrode and the backing electrode are assembled in a structure which comprises an electrolytic solution in the free space between them.
  • the electrolytic solution comprises an iodide/tri-iodide (I /I 3 ) redox system.
  • the electrode and/or the backing electrode comprise a conducting and transparent oxide layer.
  • the conducting and transparent oxide is selected from indium oxide doped with tin (SnCk/h h Ch) and tin dioxide doped with fluorine (Sn0 2 :F).
  • the present invention provides an extraction method that makes it possible to recover a waste product material produced in great quantities, such as winemaking lees, producing a dye that can be advantageously used in photoelectrochemical cells.
  • Use of the dye in the present invention provides a solution that is extremely environmentally sustainable and has a low environmental impact for the generation of electric power, thus converting an agrifood waste product into a resource and improving the environmental index of wine growing and wine-making companies.
  • the suspension is taken and centrifuged, after which the dye obtained is placed in a container in darkness and in a refrigerator.
  • This method is used to test the solvents ethanol, methanol, water and an ethanol/water mixture in various different ratios, comprised between 1 :0.5 and 1 :2 weight/weight, monitoring the dye concentration trend over time.
  • the dye was conveniently diluted with deionized water so as to be able to register the UV-Vis spectra, considering the maximum of absorption at a wavelength of 525 nm.
  • extractions with methanol and ethanol result in a similar yield which is greater than the extraction conducted using the water: ethanol mixture.
  • the dyes obtained were characterized using various methods: anthocyans (Ribereau Gayon and Stonestreet, 1965); catechins (Zironi et al., 1992); total tannins; total polyphenols (Glories, 1978).
  • EXAMPLE 2 Synthesis via sol- gel process of titanium dioxide fTiC nanostructured with a high surface area and ordered mesoporositv
  • a titanium dioxide was obtained by following the following synthesis:
  • TTIP titanium isopropoxide
  • acetic acid acetic acid
  • polyethylene glycol phenyl ether in ethanol, in a molar ratio TTIP:H 2 0 comprised between 1.0:0.5 and 1.0:5.0.
  • the dispersion obtained is transferred to an autoclave for a hydrothermal treatment at 140-200 °C at autogenous pressure for 12-24 hours.
  • the solid obtained is centrifuged and washed with deionized water and ethanol.
  • the samples obtained are characterized by X-ray diffraction (XRD) ( Figure 3), physisorption of nitrogen at -196°C ( Figure 2), and scanning electronic microscope (SEM).
  • XRD X-ray diffraction
  • Figure 2 physisorption of nitrogen at -196°C
  • SEM scanning electronic microscope
  • the nanoparticles present titanium dioxide in anatase phase, with average dimensions of 20-50 nm.
  • the specific surface area is equal to 130-190 m 2 /g and the average diameter of the pores is less than 20 nm.
  • a viscous paste of titanium dioxide is prepared by grinding an aliquot of synthesized titanium dioxide with a mortar, adding glacial acetic acid and deionized water. The compound obtained is dispersed with ethanol (Ti0 2 :EtOH 1 : 10 weight/weight) and sonicated for 10-25 minutes.
  • a terpene alcohol is added as a dispersing agent, an alcoholic solution containing an alkylated cellulose is added, and proceed with sonication for 10-25 minutes.
  • a photoelectrochemical cell according to the invention was provided by assembling the following layers in succession:
  • a transparent photoanode (FTO glass) is conveniently covered with a blocking layer of titanium dioxide provided by deposition with the spray pyrolysis method followed by treatment at a temperature comprised between 400 and 550°C.
  • a layer of nano structured mesoporous titanium dioxide is then screen-printed on this glass, using the viscous titanium dioxide paste obtained in Example 2 and heat-treating the electrode until the deposited titanium dioxide is completely sintered.
  • the final thickness of the deposited oxide is measured with a stylus profilometer, and is comprised between 5 and 30 pm.
  • an electrode which is then immersed in an aqueous solution of TiCE, heated to a temperature comprised between 350 and 550°C and subsequently impregnated with the dye of the invention.
  • the impregnation occurs by completely immersing the electrode in the extracted dye, at ambient temperature and in darkness for a time comprised between 12 and 24 hours.
  • the backing electrode is provided by way of the spray pyrolysis method, depositing on FTO glass an alcoholic solution of hexachloroplatinic acid (H 2 PtCl 6 ), and subsequently heat-treating it.
  • H 2 PtCl 6 hexachloroplatinic acid
  • the electrode based on titanium dioxide/dye and the platinum backing electrode are assembled and sealed with ionomeric resin in a “sandwich” structure, introducing an electrolytic solution into the internal free space, preferably containing an iodide/tri-iodide (I /I 3 ) redox system.
  • the power of the cell and the photocurrent generated were measured using a solar simulator (Sunlight Solar Simulator, 100 W Xenon arc lamp, Abet Technologies) as a light source, so as to approximate the solar spectrum at sea level, and a multimeter (Tektronix Keithley 2410) connected directly to the cell.
  • a solar simulator Silicon Solar Simulator, 100 W Xenon arc lamp, Abet Technologies
  • a multimeter Tektronix Keithley 2410

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Abstract

A method for providing photoelectrochemical cells with the use of dyes extracted from winemaking residues, which comprises the steps of: (i) centrifuging a waste product of a winemaking process at a speed comprised between 3000 and 7000 rpm for a time comprised between 15 and 30 minutes, thus obtaining a solid residue; (ii) adding to the solid residue obtained in (i) an equal amount by weight of a solution comprising a solvent selected from ethanol, methanol and mixtures thereof, acidified with a strong acid, and stirring for a time comprised between 1 and 24 hours, thus obtaining a suspension; (iii) centrifuging the suspension obtained in (ii) at a speed comprised between 3000 and 7000 rpm for a time comprised between 15 and 30 minutes, thus obtaining a supernatant which comprises the organic dye.

Description

METHOD FOR PROVIDING PHOTOELECTROCHEMICAL CELLS WITH THE USE OF DYES EXTRACTED FROM WINEMAKING RESIDUES
The present invention relates to the extraction of an organic dye from a waste product of the winemaking process and the use of such organic dye as a sensitizing agent in photoelectrochemical cells.
The invention, furthermore, comprises a method for providing photoelectrochemical cells that comprise such dye.
State of the art
Photovoltaic cells are devices that are capable of converting solar energy to electricity and, among these, technologies based on the use of materials of organic origin are eliciting ever-increasing interest.
The most promising are photoelectrochemical solar cells with a sensitizing agent, known as“Dye Sensitized Solar Cells” (DSSC) and also as Graetzel cells, from the name of their inventor.
In the early 1990s in fact, Graetzel and O’Regan at the Lausanne Institute of Chemistry and Physics created the first Graetzel cell {A low- cost, high-efficiency solar cell based on dye-sensitized colloidal Ti02 film. Nature, 1991, Vol. 353).
These cells aim to offer an advantageous alternative to traditional silicon-based technologies, owing to their economy, their environmental- friendly construction methods which allow recycling with low environmental impact, and their high efficiency of energy conversion under cloudy skies or artificial lighting (A. Fakhamddin et al., A perspective on the production of dye-sensitized solar modules. Energy Environ. Sci. 7, 2014, 3952-3981).
A Graetzel cell can be considered as a multi-layer structure, in which each layer must meet determined chemical/physical requirements as it has a specific and well-defined function in the process of generation of electric current. Graetzel cells are generally constituted by a negative electrode, called a photoanode, which comprises a matrix of glass or other material transparent to solar radiation, which has a spectral range comprised between near-UV and near-infrared, and which is made electrically conducting by a thin layer of indium oxide and tin oxide, Sn02/In20r3 (also known as indium oxide doped with tin) (ITO), or by tin dioxide doped with fluorine, Sn02:F (FTO).
Semiconductor nanocrystals of titanium oxide or zinc oxide are deposited on this base, forming a matrix on which a sensitizing agent, in the form of a dye, is adsorbed.
The dye acts by capturing sunlight and injecting electrons into the semiconductor on which it is adsorbed.
The dyes that can be used can be organic dyes, derived from extracts of plant foods like blueberries, blackcurrants, aubergines (G. Calogero et ah, 2012. Anthocyanins and betalains as light-harvesting pigments for dye- sensitized solar cells. Solar Energy, 86, 1563-1575 and G. Calogero et al, 2015 Vegetable-based Dye-Sensitized Solar Cells. Chem. Soc. Rev., 44, 3244-3294), or high-efficiency artificial dyes, which are usually based on ruthenium like N3 or N719 (Ruthenium-based dyes for Dye-sensitized Solar Cells - Sigma Aldrich).
Artificial dyes can be organic or inorganic.
Although they offer high energy yields, inorganic dyes however have several drawbacks, such as for example high production costs, a certain toxicity that also affects the waste products deriving from their preparation, and low environmental sustainability, since they are neither recyclable nor biodegradable.
Furthermore, for application in photoelectrochemical cells, only inorganic dyes ensure stability of operation for periods of the order of several decades, while artificial organic dyes are not as stable and efficient.
The use of synthetic dyes further presents the disadvantage of making any disposal of the cells more difficult.
On the other hand, the use of solutions containing natural dyes and/or derivatives thereof is subject to a number of limitations: for example they offer low quantum efficiency of conversion of light to electric current, with consequent low energy efficiency yield.
The aim of the present invention is to provide an environmentally sustainable organic dye for providing DSSC photoelectrochemical solar cells.
Within this aim, an object of the present invention is to provide a method for extracting the dye from a waste material of the agrifood sector.
Another object of the present invention is to provide a method for providing a DSSC photoelectrochemical cell which enables the renewable and sustainable production of electricity.
Summary of the invention
This aim and these and other objects which will become better apparent hereinafter are achieved by a method for extracting an organic dye from a waste product of a winemaking process, which comprises the steps of:
(i) centrifuging the waste product of a winemaking process at a speed comprised between 3000 and 7000 rpm for a time comprised between 15 and 30 minutes, thus obtaining a solid residue;
(ii) adding to the solid residue obtained in (i) an equal amount by weight of a solution comprising a solvent selected from ethanol, methanol and mixtures thereof, acidified with a strong acid, and stirring for a time comprised between 1 and 24 hours, thus obtaining a suspension;
(iii) centrifuging the suspension obtained in (ii) at a speed comprised between 3000 and 7000 rpm for a time comprised between 15 and 30 minutes, thus obtaining a supernatant which comprises the organic dye.
The objects of the present invention are also achieved by an organic dye obtainable by way of the method according to the invention, wherein said organic dye comprises:
- anthocyans in a quantity comprised between 6.0 and 15.0 g/L;
- catechins in a quantity comprised between 150 and 250 mg/L;
- tannins in a quantity comprised between 3.0 and 5.0 g/L; and
- polyphenols in a quantity comprised between 4.0 and 6.0 g/L.
The objects of the present invention are also achieved by a method for providing a photoelectrochemical cell, which comprises the steps of:
(a) extracting an organic dye from a waste product of the winemaking process by way of the method according to the invention;
(b) immersing an electrode comprising a titanium dioxide film in a solution of the organic dye extracted in step (a) for a time comprised between 12 and 24 hours, thus impregnating the titanium dioxide film with the organic dye.
The objects and advantages of the present invention are finally achieved by a photoelectrochemical cell, which comprises:
- an electrode which comprises a titanium dioxide film impregnated with an organic dye according to the invention;
- a backing electrode which is coated by a platinum film,
wherein said electrode and said backing electrode are assembled in a structure which comprises an electrolytic solution in the free space between them.
Further characteristics and advantages of the invention will become better apparent from the detailed description that follows and from the accompanying Figures 1-6.
Description of the figures
Figure 1 is a schematic diagram of a Graetzel cell according to the known art which comprises: conductive glass (1), nanocrystalline semiconductor film (2), dye (3), electrolyte (4), backing electrode (5).
Figure 2 shows a physisorption isotherm of N2 at -196°C of a sample of titanium dioxide prepared according to Example 2.
Figure 3 shows an X-ray diffractogram of dust (XRD) in the range 10- 80° 20 of a sample of titanium dioxide.
Figure 4 shows the variation of absorbance over time of a diluate of dye extracted according to the method of the present invention, using various different solvents.
Figure 5 shows the characterization of dyes extracted from winemaking lees with various different solvents.
Figure 6 shows the curve of the current density and power density of the cell as a function of voltage.
Detailed description of the invention
A first aspect of the present invention relates to a method for extracting an organic dye from a waste product of a winemaking process, which comprises the steps of:
(i) centrifuging a waste product of a winemaking process at a speed comprised between 3000 and 7000 rpm for a time comprised between 15 and 30 minutes, thus obtaining a solid residue;
(ii) adding to the solid residue obtained in (i) an equal amount by weight of a solution comprising a solvent selected from ethanol, methanol and mixtures thereof, acidified with a strong acid, and stirring for a time comprised between 1 and 24 hours, thus obtaining a suspension;
(iii) centrifuging the suspension obtained in (ii) at a speed comprised between 3000 and 7000 rpm for a time comprised between 15 and 30 minutes, thus obtaining a supernatant which comprises the organic dye.
In a preferred embodiment of the extraction method according to the invention, the waste product of the winemaking process is a winemaking lees.
At the end of the process of winemaking and of clarification of the wine, the deposit that remains is called the lees, which is substantially composed of yeast cells, bacteria, plant residues and, to a large extent, bentonite.
Bentonite is a phyllosilicate clay and is used by wine-growers and wine-producers to reduce protein instability and to precipitate the suspended solids responsible for clouding the wine over time (Lira E., Salazar F. N., Rodriguez-Bencomo J. J., Vincenzi S., Curioni A., Lopez F., 2014. Effect of using bentonite during fermentation on protein stabilisation and sensory properties of white wine. Int. J. of Food Science and Technology, 49, 1070- 1078).
Bentonite furthermore slightly discolors red and white wines, because it retains the molecules responsible for the color of wines, such as anthocyans, tannins, catechins and polyphenols.
The deposit that is formed following the process of winemaking and clarification of the wine is therefore a suspension of clarification adjuvants, macromolecules deriving from grapes and from yeast, and wine.
In the wine industry, this deposit is centrifuged to extract the wine still contained in it, leaving a red solid which is constituted mainly by clarification residues, polyphenols, polysaccharides and yeasts, which are treated as waste for disposal.
The method of the present invention therefore makes it possible to recover the principal waste product of a winemaking company and reinsert it into the production circuit, by extracting the organic dye necessary for the operation of DSSC photovoltaic cells.
The extraction method according to the invention comprises the step of mixing the solid residue, or winemaking lees, with a solution of ethanol, methanol and mixtures thereof, acidified with a strong acid.
Preferably the strong acid is concentrated hydrochloric acid (HC1).
Preferably the solvent is selected from ethanol and methanol.
In an embodiment, the solution of ethanol or methanol is acidified by adding concentrated HC1 in a quantity comprised between 0.5 and 5.0% by volume. In an embodiment, in step (ii) the mixture is stirred for a time comprised between 1 and 8 hours.
In another embodiment, in step (ii) the mixture is stirred for a time comprised between 2 and 6 hours.
A second aspect of the present invention relates to an organic dye obtainable by way of the method of the invention in any of the embodiments described above, wherein said organic dye comprises:
- anthocyans in a quantity comprised between 6.0 and 15.0 g/L;
- catechins in a quantity comprised between 150 and 250 mg/L;
- tannins in a quantity comprised between 3.0 and 5.0 g/L; and
- polyphenols in a quantity comprised between 4.0 and 6.0 g/L.
As will be clear to the person skilled in the art, the above mentioned quantities of anthocyans, catechins, tannins and polyphenols can vary as a function of the quality of the grape harvest.
A third aspect of the present invention relates to a method for providing a photoelectrochemical cell, which comprises the steps of:
(a) extracting an organic dye from a waste product of the winemaking process by way of the method according to the invention;
(b) immersing an electrode comprising a titanium dioxide film in a solution of the organic dye extracted in step (a) for a time comprised between 12 and 24 hours, thus impregnating the titanium dioxide film with the organic dye.
A fourth aspect of the present invention relates to a photoelectrochemical cell, which comprises:
- an electrode which comprises a titanium dioxide film impregnated with an organic dye according to the invention;
- a backing electrode which is coated by a platinum film, wherein the electrode and the backing electrode are assembled in a structure which comprises an electrolytic solution in the free space between them.
In a preferred embodiment the electrolytic solution comprises an iodide/tri-iodide (I /I3 ) redox system.
In another preferred embodiment of the photoelectrochemical cell according to the invention, the electrode and/or the backing electrode comprise a conducting and transparent oxide layer.
Preferably the conducting and transparent oxide is selected from indium oxide doped with tin (SnCk/hhCh) and tin dioxide doped with fluorine (Sn02:F).
As the following non-limiting examples show, in practice it has been found that the present invention provides an extraction method that makes it possible to recover a waste product material produced in great quantities, such as winemaking lees, producing a dye that can be advantageously used in photoelectrochemical cells.
Use of the dye in the present invention provides a solution that is extremely environmentally sustainable and has a low environmental impact for the generation of electric power, thus converting an agrifood waste product into a resource and improving the environmental index of wine growing and wine-making companies.
EXAMPLES
EXAMPLE 1 : Extraction of the dve present in the lees
Various extractions are carried out with various different solvents which are considered“green”, monitoring the concentration of the extracted dye over time with a UV-Vis spectrophotometer, through the following method:
I. An aliquot of raw lees is taken and centrifuged at a speed comprised between 3000 and 7000 rpm for 15-30 minutes so as to separate the solid fraction from the supernatant, then the liquid is eliminated and the solid part obtained is weighed.
II. A solution of solvent acidified with concentrated HC1 is prepared.
III. The acidified solution is added to the solid part that was centrifuged previously, keeping the solid: solution ratio 1 : 1 by weight. IV. The solution is sonicated for 5-15 minutes in a water bath at ambient temperature.
V. The whole is stirred with a magnetic stirring rod and at ambient temperature.
VI. After 2-6 hours a dye concentration value is reached of approximately 98% with respect to the extraction conducted for 24 hours.
VII. The suspension is taken and centrifuged, after which the dye obtained is placed in a container in darkness and in a refrigerator.
This method is used to test the solvents ethanol, methanol, water and an ethanol/water mixture in various different ratios, comprised between 1 :0.5 and 1 :2 weight/weight, monitoring the dye concentration trend over time.
Suspension aliquots were taken at increasing times, centrifuging the extracted suspension to separate the dye from the solid part.
The dye was conveniently diluted with deionized water so as to be able to register the UV-Vis spectra, considering the maximum of absorption at a wavelength of 525 nm. As shown in Figure 4, extractions with methanol and ethanol result in a similar yield which is greater than the extraction conducted using the water: ethanol mixture.
The dyes obtained were characterized using various methods: anthocyans (Ribereau Gayon and Stonestreet, 1965); catechins (Zironi et al., 1992); total tannins; total polyphenols (Glories, 1978).
As shown in Figure 5, extractions with methanol and ethanol result in a similar yield in anthocyans, greater than the extraction conducted using the water: ethanol mixture.
EXAMPLE 2: Synthesis via sol- gel process of titanium dioxide fTiC nanostructured with a high surface area and ordered mesoporositv
A titanium dioxide was obtained by following the following synthesis:
I. Deionized water is added to a solution of titanium isopropoxide (TTIP), acetic acid and polyethylene glycol phenyl ether in ethanol, in a molar ratio TTIP:H20 comprised between 1.0:0.5 and 1.0:5.0.
II. The solution is left to age for 12-24 hours. Subsequently it is heated until the solvent is completely eliminated and is replaced with water, obtaining a dispersion.
III. The dispersion obtained is transferred to an autoclave for a hydrothermal treatment at 140-200 °C at autogenous pressure for 12-24 hours.
IV. The solid obtained is centrifuged and washed with deionized water and ethanol.
V. Finally it is dried in a stove.
The samples obtained are characterized by X-ray diffraction (XRD) (Figure 3), physisorption of nitrogen at -196°C (Figure 2), and scanning electronic microscope (SEM).
The nanoparticles present titanium dioxide in anatase phase, with average dimensions of 20-50 nm.
The specific surface area is equal to 130-190 m2/g and the average diameter of the pores is less than 20 nm.
EXAMPLE 3 : Preparation of a titanium dioxide paste
A viscous paste of titanium dioxide is prepared by grinding an aliquot of synthesized titanium dioxide with a mortar, adding glacial acetic acid and deionized water. The compound obtained is dispersed with ethanol (Ti02:EtOH 1 : 10 weight/weight) and sonicated for 10-25 minutes.
Then a terpene alcohol is added as a dispersing agent, an alcoholic solution containing an alkylated cellulose is added, and proceed with sonication for 10-25 minutes.
Finally the excess ethanol is evaporated.
EXAMPLE 4: Provision of a photovoltaic cell IDS SCI using an organic dve
A photoelectrochemical cell according to the invention was provided by assembling the following layers in succession:
I. Transparent electrode based on dye/titanium dioxide.
A transparent photoanode (FTO glass) is conveniently covered with a blocking layer of titanium dioxide provided by deposition with the spray pyrolysis method followed by treatment at a temperature comprised between 400 and 550°C.
A layer of nano structured mesoporous titanium dioxide is then screen-printed on this glass, using the viscous titanium dioxide paste obtained in Example 2 and heat-treating the electrode until the deposited titanium dioxide is completely sintered.
The final thickness of the deposited oxide is measured with a stylus profilometer, and is comprised between 5 and 30 pm.
In this way an electrode is obtained which is then immersed in an aqueous solution of TiCE, heated to a temperature comprised between 350 and 550°C and subsequently impregnated with the dye of the invention.
The impregnation occurs by completely immersing the electrode in the extracted dye, at ambient temperature and in darkness for a time comprised between 12 and 24 hours.
II. Platinum backing electrode.
The backing electrode is provided by way of the spray pyrolysis method, depositing on FTO glass an alcoholic solution of hexachloroplatinic acid (H2PtCl6), and subsequently heat-treating it.
The electrode based on titanium dioxide/dye and the platinum backing electrode are assembled and sealed with ionomeric resin in a “sandwich” structure, introducing an electrolytic solution into the internal free space, preferably containing an iodide/tri-iodide (I /I3 ) redox system.
EXAMPLE 5: Characterization of the photoelectrochemical cell
The power of the cell and the photocurrent generated were measured using a solar simulator (Sunlight Solar Simulator, 100 W Xenon arc lamp, Abet Technologies) as a light source, so as to approximate the solar spectrum at sea level, and a multimeter (Tektronix Keithley 2410) connected directly to the cell.
The characteristic current/voltage curves I-V were registered.
By way of example, below one of the I-V curves is shown (Figure 6), using the dye extracted from winemaking lees of Cabernet-Merlot red wine for impregnation, from which the efficacy of the cell in the production of electricity can be seen.
The disclosures in Italian Patent Application No. 102019000006939 from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A method for extracting an organic dye from a waste product of a winemaking process, which comprises the steps of:
(i) centrifuging a waste product of a winemaking process at a speed comprised between 3000 and 7000 rpm for a time comprised between 15 and 30 minutes, thus obtaining a solid residue;
(ii) adding to the solid residue obtained in (i) an equal amount by weight of a solution comprising a solvent selected from ethanol, methanol and mixtures thereof, acidified with a strong acid, and stirring for a time comprised between 1 and 24 hours, thus obtaining a suspension;
(iii) centrifuging the suspension obtained in (ii) at a speed comprised between 3000 and 7000 rpm for a time comprised between 15 and 30 minutes, thus obtaining a supernatant which comprises the organic dye.
2. The method according to claim 1, wherein said waste product is winemaking lees.
3. The method according to any one of the preceding claims, wherein in said step (ii) the mixture is stirred for a time comprised between 1 and 8 hours.
4. The method according to any one of the preceding claims, wherein said strong acid is concentrated hydrochloric acid.
5. An organic dye obtainable by way of the method according to any of claims 1 to 4, wherein said organic dye comprises:
- anthocyans in a quantity comprised between 6.0 and 15.0 g/L;
- catechins in a quantity comprised between 150 and 250 mg/L;
- tannins in a quantity comprised between 3.0 and 5.0 g/L; and
- polyphenols in a quantity comprised between 4.0 and 6.0 g/L.
6. A method for providing a photoelectrochemical cell, which comprises the steps of:
(a) extracting an organic dye from a waste product of a winemaking process by way of the method according to any one of claims 1-4;
(b) immersing an electrode comprising a titanium dioxide film in a solution of the organic dye extracted in step (a) for a time comprised between 12 and 24 hours, thus impregnating the titanium dioxide film with the organic dye.
7. A photoelectrochemical cell, which comprises:
- an electrode which comprises a titanium dioxide film impregnated with an organic dye according to claim 5 ;
- a backing electrode which is coated by a platinum film,
wherein said electrode and said backing electrode are assembled in a structure which comprises an electrolytic solution in the free space between them.
8. The photoelectrochemical cell according to claim 7, wherein said electrolytic solution comprises an iodide/tri-iodide (I /I3 ) redox system.
9. The photoelectrochemical cell according to claim 7 or 8, wherein said electrode and/or said backing electrode comprise a conducting and transparent oxide layer.
10. The photoelectrochemical cell according to claim 9, wherein said conducting and transparent oxide is selected from indium oxide doped with tin (Sn02/In203) and tin dioxide doped with fluorine (Sn02:F).
PCT/EP2020/063367 2019-05-17 2020-05-13 Method for providing photoelectrochemical cells with the use of dyes extracted from winemaking residues WO2020234092A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2628122A1 (en) * 2008-04-14 2009-10-14 Michel English Photosynthesis twin tube solar cell
WO2010044122A1 (en) * 2008-10-16 2010-04-22 Giuseppe Calogero Photoelectrochemical solar cell comprising sensitizing anthocyanin and betalain dyes of vegetal or synthetic origin, or mixtures thereof technical field of the invention
JP2011076791A (en) * 2009-09-29 2011-04-14 Yaegaki Hakko Giken Kk Photoelectric conversion element, and optical power generating device using the photoelectric conversion element
WO2016063226A1 (en) * 2014-10-22 2016-04-28 Nishati S.R.L. Photoelectrochemical cell and process for the production of said cell

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2628122A1 (en) * 2008-04-14 2009-10-14 Michel English Photosynthesis twin tube solar cell
WO2010044122A1 (en) * 2008-10-16 2010-04-22 Giuseppe Calogero Photoelectrochemical solar cell comprising sensitizing anthocyanin and betalain dyes of vegetal or synthetic origin, or mixtures thereof technical field of the invention
JP2011076791A (en) * 2009-09-29 2011-04-14 Yaegaki Hakko Giken Kk Photoelectric conversion element, and optical power generating device using the photoelectric conversion element
WO2016063226A1 (en) * 2014-10-22 2016-04-28 Nishati S.R.L. Photoelectrochemical cell and process for the production of said cell

Non-Patent Citations (9)

* Cited by examiner, † Cited by third party
Title
"A low-cost, high-efficiency solar cell based on dye-sensitized colloidal Ti0 film", NATURE, vol. 353, 1991
A. FAKHARUDDIN ET AL.: "A perspective on the production of dye-sensitized solar modules", ENERGY ENVIRON. SCI., vol. 7, 2014, pages 3952 - 3981
CALOGERO G ET AL: "Red Sicilian orange and purple eggplant fruits as natural sensitizers for dye-sensitized solar cells", SOLAR ENERGY MATERIALS AND SOLAR CELLS, ELSEVIER SCIENCE PUBLISHERS, AMSTERDAM, NL, vol. 92, no. 11, 20 June 2008 (2008-06-20), pages 1341 - 1346, XP024522870, ISSN: 0927-0248, [retrieved on 20080620], DOI: 10.1016/J.SOLMAT.2008.05.007 *
CALOGERO GIUSEPPE ET AL: "Absorption spectra, thermal analysis, photoelectrochemical characterization and stability test of vegetable-based dye-sensitized solar cells", OPTICAL MATERIALS, vol. 88, 6 November 2018 (2018-11-06), pages 24 - 29, XP085607379, ISSN: 0925-3467, DOI: 10.1016/J.OPTMAT.2018.11.005 *
CHEREPY N J ET AL: "Ultrafast Electron Injection: Implications for a Photoelectrochemical Cell Utilizing an Anthocyanin Dye-Sensitized TiO" Nanocrystalline Electrode", JOURNAL OF PHYSICAL CHEMISTRY. B, MATERIALS, SURFACES, INTERFACES AND BIOPHYSICAL, WASHINGTON, DC, US, vol. 101, no. 45, 6 September 1997 (1997-09-06), pages 9342 - 9351, XP002116793, ISSN: 1089-5647, DOI: 10.1021/JP972197W *
G. CALOGERO ET AL.: "Anthocyanins and betalains as light-harvesting pigments for dye-sensitized solar cells", SOLAR ENERGY, vol. 86, 2012, pages 1563 - 1575, XP055664199, DOI: 10.1016/j.solener.2012.02.018
G. CALOGERO ET AL.: "Vegetable-based Dye-Sensitized Solar Cells", CHEM. SOC. REV., vol. 44, 2015, pages 3244 - 3294
LIRA E.SALAZAR F. N.RODRIGUEZ-BENCOMO J. J.VINCENZI S.CURIONI A.LOPEZ F.: "Effect of using bentonite during fermentation on protein stabilisation and sensory properties of white wine", INT. J. OF FOOD SCIENCE AND TECHNOLOGY, vol. 49, 2014, pages 1070 - 1078
TENNAKONE K ET AL: "EFFICIENT PHOTOSENSITIZATION OF NANOCRYSTALLINE TIO2 FILMS BY TANNINS AND RELATED PHENOLIC SUBSTANCES", JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY, A: CHEMISTRY, ELSEVIER SEQUOIA, LAUSANNE, CH, vol. 94, no. 2/03, 8 March 1996 (1996-03-08), pages 217 - 220, XP001151971, ISSN: 1010-6030, DOI: 10.1016/1010-6030(95)04222-9 *

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