Resumen del producto

The increasing emissions of gaseous pollutants of anthropogenic origin, such as
carbon dioxide (CO2), which causes global warming, have raised great interest in
developing and improving processes that allow their mitigation. Among them,
adsorption on porous materials has been proposed as a sustainable alternative. This
work presents a study of CO2 equilibrium adsorption at low temperatures (0, 10, and
20 °C) over a wide range of low pressures, on activated carbon derived from
Eucalyptus (ES) and Patula Pine (PP) forest waste, and carbonaceous material
derived from Waste Tires (WT). The precursors of these materials were previously
prepared, and their physicochemical properties were characterized. ES and PP were
thermochemically treated with phosphoric acid and WT was oxidized with nitric acid.
Additionally, these materials were used to obtain monoliths using uniaxial compaction
techniques and different binding agents, with better results obtained with
montmorillonite. A total of six adsorbent solids had their textural and chemical
properties characterized and were tested for CO2 adsorption. The highest specific
surface area (1405 m2 g-1), and micropore properties were found for activated carbon
derived from Eucalyptus whose highest adsorption capacity ranged from 2.27 mmol g-
1 (at 0 °C and 100 kPa) to 1.60 mmol g-1 (at 20 °C and 100 kPa). The activated
carbon monoliths presented the lowest CO2 adsorption capacities, however, the
studied materials showed high potential for CO2 capture and storage applications at
high pressures. The isosteric heats of adsorption were also estimated for all the
materials and ranged from 16 to 45 kJ mol-1 at very low coverage explained by the
energetic heterogeneity and weak repulsive interactions among adsorbed CO2
molecules.

Abstract del producto

The increasing emissions of gaseous pollutants of anthropogenic origin, such as
carbon dioxide (CO2), which causes global warming, have raised great interest in
developing and improving processes that allow their mitigation. Among them,
adsorption on porous materials has been proposed as a sustainable alternative. This
work presents a study of CO2 equilibrium adsorption at low temperatures (0, 10, and
20 °C) over a wide range of low pressures, on activated carbon derived from
Eucalyptus (ES) and Patula Pine (PP) forest waste, and carbonaceous material
derived from Waste Tires (WT). The precursors of these materials were previously
prepared, and their physicochemical properties were characterized. ES and PP were
thermochemically treated with phosphoric acid and WT was oxidized with nitric acid.
Additionally, these materials were used to obtain monoliths using uniaxial compaction
techniques and different binding agents, with better results obtained with
montmorillonite. A total of six adsorbent solids had their textural and chemical
properties characterized and were tested for CO2 adsorption. The highest specific
surface area (1405 m2 g-1), and micropore properties were found for activated carbon
derived from Eucalyptus whose highest adsorption capacity ranged from 2.27 mmol g-
1 (at 0 °C and 100 kPa) to 1.60 mmol g-1 (at 20 °C and 100 kPa). The activated
carbon monoliths presented the lowest CO2 adsorption capacities, however, the
studied materials showed high potential for CO2 capture and storage applications at
high pressures. The isosteric heats of adsorption were also estimated for all the
materials and ranged from 16 to 45 kJ mol-1 at very low coverage explained by the
energetic heterogeneity and weak repulsive interactions among adsorbed CO2
molecules.

Palabras clave

Activated carbons, CO2 adsorption, Pyrolysis, Chemical activation, Monoliths, Lignocellulosic precursor, Waste tires