How Molecular Modelling Tools Can Help …
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more dependent on renewable energy sources and more efficient energy utilisation
systems, the dependency on fossil fuels as primary energy sources are likely to
remain intact at least for several years for safeguarding future energy availability due
to the growing global energy demand [7, 9, 10]. One of the most viable options to
alleviate the effects of increased anthropogenic CO 2 emissions in the short-medium
term is by capturing and separating CO 2 from diluted point sources, such as effluents
emitted from fossil fuel consumption and other industrial processes [11], in order
to use it for industrial applications, or to permanently store it. This technology is
known as carbon capture, utilisation and storage (CCUS). CO 2 can be used as raw
material, in marketable products such as the carbonation of beverages, as a solvent in
extraction processes using supercritical CO 2 , for making construction materials or for
enhanced oil recovery or alternatively, it can be transported and stored in permeable
and geologically stable underground layers or in deep saline aquifers [12].
A plethora of CO 2 capture and separation technologies have been explored [13],
such as chemical absorption via amine scrubbing, separation by adsorption [14–
16], membrane separation [17] and calcium chemical looping [18]. Nowadays, the
utmost popular method used in industry is the absorption with amines, where CO 2
is counter-currently contacted with an aqueous amine solution, and amines are typically regenerated in a regeneration column by increasing the temperature. However,
this technology suffers from several drawbacks, among them: (1) the degradation
of the amines at a relatively low temperature, especially in the presence of oxygen
in the inlet flue gas stream, (2) special care is required with respect to equipment
corrosion [19], and (3) the utilisation of aqueous solvents adds a parasitic energy
penalty of approximately 30% of the energy produced in the power plant [20].
Owing to the wide variety of potential amines, as along with the factors related
to the source of the flue gas (CO 2 purity, presence of other gases, water content,
etc.), there is still room for improvement. As such, is it essential to use accurate
thermodynamic models capable of reproducing the physicochemical behaviour of
complex fluids, while predicting a wide range of different thermodynamic properties
and phase behaviour of the pure fluids and their multi-component mixtures involved
under several thermodynamic conditions. Conversely, solid adsorbent-based systems
have received significant attention in the past years with the arrival of novel materials,
showing high CO 2 capacities and high selectivities, thus demonstrating potential for
greater versatility and less-energy intensive processes than solvent-based processes
in specialised applications [21, 22].
In addition to CCUS, other technologies need to be developed or improved in
order to mitigate climate change, among them, the development of environmentally
friendly refrigerants. By the mid-1980s, it was found that traditionally used refrigerants such as hydrochlorofluorocarbons (HCFC) and chlorofluorocarbons (CFC)
were ozone depleting. With the Montreal Protocol in 1987, it was globally decided to
phase-out ozone depleting substances. Consequently, over the past decades, the application of hydrofluorocarbons (HFC) as a substitute for refrigeration units expanded.
Yet, it remains known that HFCs are GHGs with considerable high GWP, thousands of times higher than carbon dioxide [19]. Kigali’s Amendment to the Montreal
Protocol [8], a global deal coming into effect in 2019, legally binds the world’s
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more dependent on renewable energy sources and more efficient energy utilisation
systems, the dependency on fossil fuels as primary energy sources are likely to
remain intact at least for several years for safeguarding future energy availability due
to the growing global energy demand [7, 9, 10]. One of the most viable options to
alleviate the effects of increased anthropogenic CO 2 emissions in the short-medium
term is by capturing and separating CO 2 from diluted point sources, such as effluents
emitted from fossil fuel consumption and other industrial processes [11], in order
to use it for industrial applications, or to permanently store it. This technology is
known as carbon capture, utilisation and storage (CCUS). CO 2 can be used as raw
material, in marketable products such as the carbonation of beverages, as a solvent in
extraction processes using supercritical CO 2 , for making construction materials or for
enhanced oil recovery or alternatively, it can be transported and stored in permeable
and geologically stable underground layers or in deep saline aquifers [12].
A plethora of CO 2 capture and separation technologies have been explored [13],
such as chemical absorption via amine scrubbing, separation by adsorption [14–
16], membrane separation [17] and calcium chemical looping [18]. Nowadays, the
utmost popular method used in industry is the absorption with amines, where CO 2
is counter-currently contacted with an aqueous amine solution, and amines are typically regenerated in a regeneration column by increasing the temperature. However,
this technology suffers from several drawbacks, among them: (1) the degradation
of the amines at a relatively low temperature, especially in the presence of oxygen
in the inlet flue gas stream, (2) special care is required with respect to equipment
corrosion [19], and (3) the utilisation of aqueous solvents adds a parasitic energy
penalty of approximately 30% of the energy produced in the power plant [20].
Owing to the wide variety of potential amines, as along with the factors related
to the source of the flue gas (CO 2 purity, presence of other gases, water content,
etc.), there is still room for improvement. As such, is it essential to use accurate
thermodynamic models capable of reproducing the physicochemical behaviour of
complex fluids, while predicting a wide range of different thermodynamic properties
and phase behaviour of the pure fluids and their multi-component mixtures involved
under several thermodynamic conditions. Conversely, solid adsorbent-based systems
have received significant attention in the past years with the arrival of novel materials,
showing high CO 2 capacities and high selectivities, thus demonstrating potential for
greater versatility and less-energy intensive processes than solvent-based processes
in specialised applications [21, 22].
In addition to CCUS, other technologies need to be developed or improved in
order to mitigate climate change, among them, the development of environmentally
friendly refrigerants. By the mid-1980s, it was found that traditionally used refrigerants such as hydrochlorofluorocarbons (HCFC) and chlorofluorocarbons (CFC)
were ozone depleting. With the Montreal Protocol in 1987, it was globally decided to
phase-out ozone depleting substances. Consequently, over the past decades, the application of hydrofluorocarbons (HFC) as a substitute for refrigeration units expanded.
Yet, it remains known that HFCs are GHGs with considerable high GWP, thousands of times higher than carbon dioxide [19]. Kigali’s Amendment to the Montreal
Protocol [8], a global deal coming into effect in 2019, legally binds the world’s