528
sequestration by burying in sub-surface environments is being explored, a better
alternative would be to convert the carbon dioxide to value added materials. In theory, carbon dioxide (CO 2 ) can be converted into several chemicals and fuels.
However, the relative unreactivity and very low Gibbs energy of carbon dioxide
makes it energetically unfavourable to convert CO 2 into fuel and chemical products
of higher value. The large volumes of CO 2 emitted also pose a challenge at doing
this at the scales to be dealt with. However, the need to reduce CO 2 emissions to the
atmosphere demands that CO 2 be treated as a commodity chemical instead of a
waste. This perspective will transform CO 2 into an asset as it is considered a primary feedstock to the chemical industry. This chapter provides a background and
challenges associated with this proposition. As human exploration of other planets
and outer space continues, we also propose the utilization of carbon dioxide by
reforming on extra- terrestrial planets, especially Mars.
1.1 Climate Challenges with CO 2
In 2018, the globally averaged carbon dioxide (CO 2 ) concentration at the earth surface was 407.4 ppm which is a 46% increase of CO 2 levels since pre-industrial times
[1]. Over the past decade, CO 2 concentration in the atmosphere increased at the rate
of 2 ppm/year, resulting in serious global threats to human life and the environment—global warming and the concomitant effects of climate change [2, 3]. The
International Energy Agency’s (IEA), global energy and CO 2 status report indicates
that there has been a 1 °C increase in global average annual surface temperature
above pre-industrial levels [4].
The emissions of CO 2 influence the climate causing global warming via the
greenhouse effect. The greenhouse effect is the trapping of solar radiation in the
earth’s atmosphere as heat by greenhouse gases. Solar radiation, with wavelengths
ranging from 0.3 to 5 μm, incident on earth surface is radiated back into space during the night with wavelengths at the infra-red region. The natural frequency of the
bonds of the greenhouse gases is within the infra-red frequency of the re-radiated
energy, thereby causing resonance in the greenhouse gas molecules. The increased
vibration due to resonance heats up the greenhouse gas molecules. Furthermore, the
heat is transferred to other gases in the atmosphere, effectively trapping the reradiated energy as heat in the atmosphere [5].
Major greenhouse gases in the atmosphere include CO 2 , water (H 2 O) vapour,
methane (CH 4 ), dinitrogen oxide (N 2 O) and chlorinated hydrocarbons. Water vapour
has been shown to be a more effective greenhouse gas than CO 2 , and its concentration in the atmosphere is orders of magnitude higher than carbon dioxide. However,
the concentration of water vapour is controlled by temperature. An increase in CO 2
in the atmosphere will increase the atmosphere’s temperature slightly which is
enough to increase the concentration of water vapour in the atmosphere by evaporation from the oceans. It is this feedback mechanism that has the greatest influence
on global temperature. In a sense, paradoxically, the concentration of CO 2 acts as a
O. Okonkwo and P. Biswas
sequestration by burying in sub-surface environments is being explored, a better
alternative would be to convert the carbon dioxide to value added materials. In theory, carbon dioxide (CO 2 ) can be converted into several chemicals and fuels.
However, the relative unreactivity and very low Gibbs energy of carbon dioxide
makes it energetically unfavourable to convert CO 2 into fuel and chemical products
of higher value. The large volumes of CO 2 emitted also pose a challenge at doing
this at the scales to be dealt with. However, the need to reduce CO 2 emissions to the
atmosphere demands that CO 2 be treated as a commodity chemical instead of a
waste. This perspective will transform CO 2 into an asset as it is considered a primary feedstock to the chemical industry. This chapter provides a background and
challenges associated with this proposition. As human exploration of other planets
and outer space continues, we also propose the utilization of carbon dioxide by
reforming on extra- terrestrial planets, especially Mars.
1.1 Climate Challenges with CO 2
In 2018, the globally averaged carbon dioxide (CO 2 ) concentration at the earth surface was 407.4 ppm which is a 46% increase of CO 2 levels since pre-industrial times
[1]. Over the past decade, CO 2 concentration in the atmosphere increased at the rate
of 2 ppm/year, resulting in serious global threats to human life and the environment—global warming and the concomitant effects of climate change [2, 3]. The
International Energy Agency’s (IEA), global energy and CO 2 status report indicates
that there has been a 1 °C increase in global average annual surface temperature
above pre-industrial levels [4].
The emissions of CO 2 influence the climate causing global warming via the
greenhouse effect. The greenhouse effect is the trapping of solar radiation in the
earth’s atmosphere as heat by greenhouse gases. Solar radiation, with wavelengths
ranging from 0.3 to 5 μm, incident on earth surface is radiated back into space during the night with wavelengths at the infra-red region. The natural frequency of the
bonds of the greenhouse gases is within the infra-red frequency of the re-radiated
energy, thereby causing resonance in the greenhouse gas molecules. The increased
vibration due to resonance heats up the greenhouse gas molecules. Furthermore, the
heat is transferred to other gases in the atmosphere, effectively trapping the reradiated energy as heat in the atmosphere [5].
Major greenhouse gases in the atmosphere include CO 2 , water (H 2 O) vapour,
methane (CH 4 ), dinitrogen oxide (N 2 O) and chlorinated hydrocarbons. Water vapour
has been shown to be a more effective greenhouse gas than CO 2 , and its concentration in the atmosphere is orders of magnitude higher than carbon dioxide. However,
the concentration of water vapour is controlled by temperature. An increase in CO 2
in the atmosphere will increase the atmosphere’s temperature slightly which is
enough to increase the concentration of water vapour in the atmosphere by evaporation from the oceans. It is this feedback mechanism that has the greatest influence
on global temperature. In a sense, paradoxically, the concentration of CO 2 acts as a
O. Okonkwo and P. Biswas