2. INTRODUCTION
CO2 is a greenhouse gas.
It is mainly responsible for the global warming and ocean
acidification.
The methods for reduction is classified as:
a. Artificial
b. Natural
Various chemicals and fuels are produced by co2 reduction.
4. FUTURE CHALLENGES
A recent report on the future
of carbon dioxide (Co2)
emission predicts that in the
coming few decades (2010-
2060), ~496 gigatonnes of
Co2 will be produced because
of fossil fuels combustion by
existing infrastructure.
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.slideshare.net%2FRabiaAziz6%2Frabia-aziz-bs-iv-reducation-of-co2-and-its-application-to-environment-ppt-
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5. SOLUTION TO THE PROBLEM
Co2 can be artificially converted into fuel or
commodity chemicals.
The Co2 conversion methodology not only
addresses the potential solution for
controlling the Co2 concentration level in the
environment but also offers an alternative
approach for conversion of renewable energy
to a chemical fuel or product.
So far, various noble metals (Ag, Au, Cu, Pt
and so on) and metal complexes are used as
heterogeneous catalysts (as electrodes ) for
Co2 reduction. However, the rising cost of
noble metals is the main hindrance towards
their large scale practical applications.
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16f7hA&ust=1649655978304000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCPi6xenliPcCFQAAAAAdAAAAABAD
6. Attempts at Co2 Reduction
Radiochemical
Chemical reduction
Thermochemical
Photo chemical
Electrochemical
Biochemical
Bio photochemical
Photo electrochemical
Bio electrochemical
Bio photoelectrochemical
7. ELECTROCHEMICAL REDUCTION
The electrochemical reduction of
carbon dioxide is the conversion
of carbon dioxide(Co2) to more reduced
chemical species using electrical
energy.
Electrochemical reduction of carbon
dioxide represents a possible means of
producing chemicals or fuels,
converting carbon dioxide (CO2) to
organic feedstocks such as formic acid
(HCOOH),carbon monoxide
(CO), methane (CH4), ethylene (C2H4)
and ethanol (C2H5OH).
Among the more selective metallic
catalysts in this field are tin for formic
acid, silver for carbon monoxide
and copper for methane, ethylene or
ethanol.
https://en.wikipedia.org/wiki/Electrochemical_reduction_of_carbon_dioxide#:~:text=The%20electrochemical%20reduction%20of%20carbon,of%20the%20most%20promising%20approaches.
12. CATALYTIC CO2 REDUCTION
SABATIER REACTION FOR METHANE PRODUCTION
o Electrolysis of water produces H2.
o The H2 is combined with captured CO2, compressed and reacts over a catalyst at a
moderate temperature and pressure(≈225˚C, ≈5MPa) to produce methanol and water.
CO2 + 4H2 CH4 + 2H2O
13. CALVIN CYCLE
The Calvin cycle is a process that plants and algae use to turn carbon dioxide from the air
into sugar, the food autotrophs need to grow.
Every living thing on Earth depends on the Calvin cycle.
Plants depend on the Calvin cycle for energy and food.
The primary function of the Calvin cycle is to make organic products that plants need using
the products from the light reactions of photosynthesis (ATP and NADPH).
The products formed after a single turn of the Calvin cycle are 3 ADP, 2 glyceraldehyde-3-
phosphate (G3P) molecules, and 2 NADP+.
16. Merits and De-Merits
MERITS
More affordable way to reduce Co2 levels by
directly converting the gas into useful
products.
Convert molecules in more stable forms.
Very low environmental impact , doesn’t
produce harmful emissions.
DE-MERITS
Efficiency is low.
Lack of efficient catalysts of water
oxidation & Co2 reduction.
