I attended last year and also in January two ASHRAE conferences about the use of CO2 as refrigerant in the chillers. I shared the subject in the form of a scheme that highlights the idea of captation of emitted anthropogenic CO2 and reuse as refrigerant. As I did not get feed back from Ashrae members and connexions, I made a slight research to have an idea about how much worldwide chillers can absorb anthropogenic CO2. The estimation brought me to 0.034% for 2006 !
So for 2006 we have the following datas:
The total estimated installed quantity of refrigerants is 2.8 M tonnes.
The inventory of estimated global CO2 emissions are is 8200 M Tonnes.
Ignoring the social, financial and technical constraints to converge to CO2 refrigerant from all other kinds, and making a coarse simplification assuming that 1 tonne of CO2 is equivalent to 1 tonne of any other refrigerant, we’ll be talking about 0.034% of emitted CO2 that can be injected in the refrigeration equipments, which is extremely negligible.
However, the convergence from actual refrigerants to CO2 is still seducing if we take into account the tremendous values of GWP of all the refrigerants (specially the HFC & CFC) which highlights the outstanding values of their radiative forcing capacity in comparison to CO2.