CDU can contribute to the reduction of CO 2 accumulation in the atmosphere
through the “industrial innovation” that will require less use of natural fossil
resources (raw materials diversification), and will be based on more efficient processes with recycling of carbon, implementing the “industry clustering” concept.
Moving apart from the fossil-C based energy frame, the big change will require
the extended use of largely available and free perennial energy sources. SWGH
exploitation, coupled with CO 2 conversion, will bring in the system several
advantages in terms of use of existing infrastructures and logistics, with economic
benefits. The direct injection of PV- or wind-generated electrons into the
electric-grid avoids the penalty (ca. 30% of energy loss) typical of the use of
electricity for producing hydrogen for the chemical conversion of CO 2 into
chemicals. This is a point that many people take in favor of the direct use of
electricity. But electricity cannot solve all problems, in the short–medium term. Let
us use hydrogen, then! This is the second point against CO 2 conversion, but the
direct use of hydrogen rises several problems, such as storage, transportation,
change of vehicle engines, safety, and new infrastructure. They will demand a
tremendous economic effort and large investments, which will not be affordable in
some areas of the planet. Especially safety issues require much attention. The direct
use of PV-electricity will be possible for some applications, especially in
low-density operation. Some sectors such as avio-transport, navy, and heavy-road
transport will not be able to run on PV in the short–medium term and liquid
(gaseous) fuels will be necessary for a long time. However, the use of non-fossil H 2
for converting CO 2 into fuels (liquid and gaseous) has a sense from the economic
and safety point of view and for guaranteeing the continued utilization of existing
and improved infrastructures for the benefit of less advanced countries. As we have
already said, intensive energy applications can be only partially de-fossilized and
human life cannot be decarbonized. Electricity production for Industries and
megalo-polies and heavy-transport will be based on fossil-C derivatives (diesel),
which are the highest density energy carriers, still close to the end of this century.
Human life will need C-based goods and food forever.
There is not a single technology that can solve the CO 2 problem. Such complex
problem needs an integrated solution and CDU is part of the solution package.
How much carbon dioxide can, thus, be used and avoided, suppose that all options
described in previous chapters are exploited at their best? We recall that “used” and
“avoided” are not synonyms. The former term refers to the amount of CO 2 used in a
synthesis (dictated by the stoichiometry), the latter to the amount of CO 2 not
emitted (with respect to existing conventional processes) while using CO 2 in
syntheses. In an average case, for an “innovative” procedure based on CO 2 carried
out in most effective conditions, the ratio “avoided/used” ranges around 2.8. This
means that per each tonne of used CO 2 , 2.8 are avoided.
We make now an attempt to size the amount of CO 2 that will be used per each
class of compounds. Table 12.1 presents the actual and perspective (2040) use of
CO 2 in the synthesis of some classes of chemicals, summarizing what has been
presented in Chap. 9.
12.2 The Carbon Dioxide Revolution
223
through the “industrial innovation” that will require less use of natural fossil
resources (raw materials diversification), and will be based on more efficient processes with recycling of carbon, implementing the “industry clustering” concept.
Moving apart from the fossil-C based energy frame, the big change will require
the extended use of largely available and free perennial energy sources. SWGH
exploitation, coupled with CO 2 conversion, will bring in the system several
advantages in terms of use of existing infrastructures and logistics, with economic
benefits. The direct injection of PV- or wind-generated electrons into the
electric-grid avoids the penalty (ca. 30% of energy loss) typical of the use of
electricity for producing hydrogen for the chemical conversion of CO 2 into
chemicals. This is a point that many people take in favor of the direct use of
electricity. But electricity cannot solve all problems, in the short–medium term. Let
us use hydrogen, then! This is the second point against CO 2 conversion, but the
direct use of hydrogen rises several problems, such as storage, transportation,
change of vehicle engines, safety, and new infrastructure. They will demand a
tremendous economic effort and large investments, which will not be affordable in
some areas of the planet. Especially safety issues require much attention. The direct
use of PV-electricity will be possible for some applications, especially in
low-density operation. Some sectors such as avio-transport, navy, and heavy-road
transport will not be able to run on PV in the short–medium term and liquid
(gaseous) fuels will be necessary for a long time. However, the use of non-fossil H 2
for converting CO 2 into fuels (liquid and gaseous) has a sense from the economic
and safety point of view and for guaranteeing the continued utilization of existing
and improved infrastructures for the benefit of less advanced countries. As we have
already said, intensive energy applications can be only partially de-fossilized and
human life cannot be decarbonized. Electricity production for Industries and
megalo-polies and heavy-transport will be based on fossil-C derivatives (diesel),
which are the highest density energy carriers, still close to the end of this century.
Human life will need C-based goods and food forever.
There is not a single technology that can solve the CO 2 problem. Such complex
problem needs an integrated solution and CDU is part of the solution package.
How much carbon dioxide can, thus, be used and avoided, suppose that all options
described in previous chapters are exploited at their best? We recall that “used” and
“avoided” are not synonyms. The former term refers to the amount of CO 2 used in a
synthesis (dictated by the stoichiometry), the latter to the amount of CO 2 not
emitted (with respect to existing conventional processes) while using CO 2 in
syntheses. In an average case, for an “innovative” procedure based on CO 2 carried
out in most effective conditions, the ratio “avoided/used” ranges around 2.8. This
means that per each tonne of used CO 2 , 2.8 are avoided.
We make now an attempt to size the amount of CO 2 that will be used per each
class of compounds. Table 12.1 presents the actual and perspective (2040) use of
CO 2 in the synthesis of some classes of chemicals, summarizing what has been
presented in Chap. 9.
12.2 The Carbon Dioxide Revolution
223