Description:These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
In some embodiments of the present invention, to find the probable solution for both these problems is the high cost of petrol and minimizing carbon footprint from the atmosphere, we have designed a process for the electrocatalytic reduction of CO2 in ethanol (biofuel) which can be used in blended petrol. For this, we have developed a technique for CO2 capture, electro-catalytic reduction of CO2 followed by conversion of CO2 into biofuel (ethanol) for use in blended fuel. The product ethanol formed will be separated from aqueous electrolyte and then concentrated, purified, and stored for further use in blended petrol.
In some embodiments of the present invention, the KOH electrolyte used in electro-reduction will be regenerated for reuse in another electro-reduction process. The electricity used in electro-catalytic reduction will be used from solar panels and rechargeable batteries hence the use of green energy. The CuO catalyst used as a cathode further speeds up the process of reduction of carbon dioxide to ethanol. This electrocatalytic reduction is supported by both an electric field as well a catalyst.
In some embodiments of the present invention, CO2 needs to be captured from industrial processes, power plants, or directly from the atmosphere from the actual source of pollution. This will involve techniques like absorption of CO2 from atmosphere using high affinity substance like Zeolites (Physio sorption), amine-based materials (Chemisorption), and metal-organic frameworks (MOFs) assisted Physio sorption.
In some embodiments of the present invention, ambient air rich in CO2 is drawn into the carbon capture system. The air is filtered to remove particulate matter (suspended solids) and other impurities before it comes into contact with the adsorbent material (Zeolites, and MoFs). The CO2 rich air passes through a contactor where the selected adsorbent material Zeolites and MoFs are located. CO2 molecules in the air are captured by the adsorbent material's surface through a process called chemisorption or physio sorption.
In some embodiments of the present invention, after the adsorbent material becomes saturated with CO2, it needs to be desorbed (regenerated) for reuse. This involves releasing the captured CO2 molecules from the material. The process of desorption was typically achieved by raising the temperature or reducing the pressure.
In some embodiments of the present invention, the CO2-rich gas released during desorption is then processed to further concentrate the captured CO2. This step is important to produce a concentrated stream of CO2 that can be more easily stored or utilized. The concentrated CO2 stream is compressed to increase its density, making it suitable for storage or conversion into other products.
A process for Carbon capture, its electro-catalytic reduction, and conversion to biofuel for blended petrol comprising the steps of:
absorbing CO2 from the atmosphere passes through a contactor using high affinity substances like Zeolites (Physio sorption), amine-based materials (Chemisorption), and metal-organic frameworks (MOFs) (3) assisted Physio sorption;
Desorbing (regenerated) the adsorbent material by raising the temperature or reducing the pressure, after it becomes saturated with CO2 for reuse;
processing the CO2-rich gas released during desorption to further concentrate the captured CO2, to produce a concentrated stream of CO2; and
doing electro-catalytic reduction (7) of CO2 into biofuel (ethanol) by electro-catalytic cell and electrodes (at cathode (8)) supported with metal catalysts like CuO, and AgO, which uses green electricity (solar panel) to drive the reaction.
The process as claimed in Claim 1, wherein the concentrated CO2 stream is compressed to increase its density, making it suitable for storage or conversion into other products.
The process as claimed in Claim 1, wherein desorption (regeneration) of adsorbed CO2 is done by switching on the circular heater (4) and suction pump (5) simultaneously and collecting in a cylinder (6).
The process as claimed in claim 1, wherein the electrolyte solution used was 1.0 M KOH that enables the transfer of ions between the anode and cathode compartments.
The process as claimed in claim 1, wherein the potential (voltage) ?0.51 V w.r.t. reference electrode was applied across the cathode and anode to initiate the reduction reactions.
EXAMPLE 1
Detailed methodology
We have developed a technique for CO2 capture, electro-catalytic reduction followed by conversion into biofuel (ethanol) for use in blended fuel. Different sequential steps followed are as under:
Step 1: Carbon Dioxide (CO2) Capture:
CO2 needs to be captured from industrial processes, power plants, or directly from the atmosphere from the actual source of pollution. This will involve techniques like absorption of CO2 from the atmosphere using high-affinity substances like Zeolites (Physio sorption), amine-based materials (Chemisorption), and metal-organic frameworks (MOFs) assisted Physio sorption. Ambient air rich in CO2 is drawn into the carbon capture system. The air is filtered to remove particulate matter (suspended solids) and other impurities before it comes into contact with the adsorbent material (Zeolites, and MoFs). The CO2-rich air passes through a contactor where the selected adsorbent material Zeolites and MoFs are located. CO2 molecules in the air are captured by the adsorbent material's surface through a process called chemisorption or physio sorption.
After the adsorbent material becomes saturated with CO2, it needs to be desorbed (regenerated) for reuse. This involves releasing the captured CO2 molecules from the material. The process of desorption was typically achieved by raising the temperature or reducing the pressure. The CO2-rich gas released during desorption is then processed to further concentrate the captured CO2. This step is important to produce a concentrated stream of CO2 that can be more easily stored or utilized. The concentrated CO2 stream is compressed to increase its density, making it suitable for storage or conversion into other products.
Step 2: Electro-catalytic Reduction of CO2:
The electro-catalytic reduction of CO2 into biofuel (ethanol) involves electro-catalytic cells and electrodes supported with metal catalysts like CuO, and AgO, which uses green electricity (solar panel) to drive the reaction. The entire process takes place in an electrolytic cell equipped with a cathode (CuO) and an anode. The electro-catalytic reduction of CO2 to ethanol occurs at the surface of the cathode. Setting up an electrolytic cell requires two compartments separated by an ion-conductive membrane. The anode and cathode are placed in separate compartments. The cathode is where the reduction of CO2 to ethanol will take place. Copper oxide (CuO) was used as cathode material due to its ability to facilitate the formation of Ethanol from CO2 as a product.
The electrolyte solution used was 1.0 M KOH that enables the transfer of ions between the anode and cathode compartments. The KOH electrolyte is highly conductive and allow for the migration of CO2 and other ions involved in the reduction process. The potential (voltage) ?0.51 V w.r.t. reference electrode was applied across the cathode and anode to initiate the reduction reactions.
Then, we introduced CO2 into the cathode compartment. The CO2 gas well-dissolved in the electrolyte (KOH) to enhance its interaction with the cathode surface.
At the cathode, CO2 molecules undergo catalytic reduction through a series of electrochemical reactions. The main reduction reaction involves the sequential electro-catalytic reduction of CO2 to form ethanol are:
i) Electrolytic reduction of CO2:
CO2 (g) + 2e- ? CO (g)
ii) CO Reduction:
CO + 2e- ? C (adsorbed)
iii) Catalytic hydrogenation:
C (adsorbed) + 4H+ + 4e- ? CH3CHO (Acetaldehyde)
iv) Formation of ethanol from acetaldehyde:
CH3CHO + H+ + e- ? C2H5OH (Ethanol)
Overall reaction is
2CO2 + 12H+ + 12e- CH3CH2OH + 3H2O E0 = ?0.67 V
Here, CuO catalysts are essential for speeding up the reaction and promoting product formation (ethanol).
Step 3: Product Separation and Purification:
After the conversion of CO2 to biofuel, the resulting products contain ethanol, electrolytes along other by-products. Efficient separation and purification techniques were used to isolate pure ethanol from the mixture. Ethanol and other reaction products formed at the cathode were collected from the electrolytic solution using the following sub-steps:
i. Electrolyte removal: Before starting the separation process, the electrolysis cell or system was turned off, and the electrochemical reactions halted. After that electrolyte containing ethanol was collected in a beaker.
ii. Filtration and pre-treatment: Any solid particles or impurities in the electrolyte were separated by performing a preliminary filtration. This was done using filter paper, and wire mesh filtration methods.
iii. Ethanol extraction: The separation of ethanol was achieved through liquid-liquid extraction. This method exploits the difference in solubility between ethanol and the KOH solution. The following steps were followed for ethanol extraction:
a. A non-polar solvent (ethyl acetate, diethyl ether, or hexane) was added to the KOH electrolyte. Ethanol is more soluble in non-polar solvents than in the KOH solution.
b. The solution was mixed well to allow for the transfer of ethanol from the KOH solution to the non-polar solvent.
c. The mixture was allowed to settle, the two phases get separated. The non-polar solvent layer containing ethanol floated on top of the KOH solution.
d. Carefully collect the non-polar solvent layer, which contains the extracted ethanol.
e. Removal of non-polar solvent: The non-polar solvent used for extraction needs to be separated from the ethanol. This was achieved through simple distillation or evaporation. Ethanol has a lower boiling point than most non-polar solvents, allowing for its selective removal.
f. Ethanol purification: The extracted ethanol might still contain traces of impurities. For higher purity, distillation was used. Fractional distillation can separate ethanol from remaining solvent and impurities based on their different boiling points.
g. Recovery of KOH electrolyte: After the ethanol extraction, the KOH solution that remains can be collected and recycled for use in the electrolysis process.
h. Ethanol storage: Store the purified ethanol in appropriate containers, ensuring that it is sealed and kept away from sources of ignition.
4. Energy Source: For electro-catalytic reduction of carbon dioxide to ethanol, a clean energy source like renewable electricity (from solar, rechargeable batteries, etc.) is crucial to ensure that the overall process is environmentally friendly and sustainable.
, Claims:1. A process for Carbon capture, its electro-catalytic reduction, and conversion to biofuel for blended petrol comprising the steps of:
a) absorbing CO2 from atmosphere passes through a contactor using high affinity substance like Zeolites (Physio sorption), amine-based materials (Chemisorption), and metal-organic frameworks (MOFs) (3) assisted Physio sorption;
b) desorbing (regenerated) the adsorbent material by raising the temperature or reducing the pressure, after it becomes saturated with CO2 for reuse;
c) processing the CO2-rich gas released during desorption to further concentrate the captured CO2, to produce a concentrated stream of CO2; and
d) doing electro-catalytic reduction (7 and 8) of CO2 into biofuel (ethanol) by electro-catalytic cell and electrodes (at cathode (8)) supported with metal catalyst like CuO, and AgO, which uses green electricity (solar panel) to drive the reaction.
2. The process as claimed in claim 1, wherein the concentrated CO2 stream is compressed to increase its density, making it suitable for storage or conversion into other products.
3. The process as claimed in claim 1, wherein desorption (regeneration) of adsorbed CO2 is done by switching on the circular heater (4) and suction pump (5) simultaneously and collecting in a cylinder (6).
4. The process as claimed in claim 1, wherein the electrolyte solution used was 1.0 M KOH enables the transfer of ions between the anode (7) and cathode (8) compartments.
5. The process as claimed in claim 1, wherein the potential (voltage) ?0.51 V w.r.t. reference electrode was applied by potentiostat (9) across the cathode and anode to initiate the reduction reactions connected to solar panel for green energy (11).
6. The process claimed in claim 1, the ethanol formed as a product (10) get separated from electrolyte (Chemical separation), purified and stored.