4. Conclusions
The preparation of a series of activated carbons with superior
properties was demonstrated in the present study. Activated carbon
materials were produced by dry chemical activation of gelatin
and starch. They were mixed and carbonized together to get the
porous material. The experimental results illustrated significant
improvements in the specific surface area SBET, CO2 capture for
activated carbon materials when gelatin and starch are mixed
together compared to when they were prepared individually under
similar experimental conditions. The improvement in the porosity
is because of heteroatoms (O and N) present in the precursor material.
A large CO2 capture (4.74–7.49 mmol g1 at 0 C and 3.28–
3.8 wt% at 25 C) was observed for these samples (GSK0.5-700,
GSK1-700 GSK2-700), respectively. Moreover, ACs showed a good
CO2/N2 adsorption ideal selectivity (up to 98/1) at 273 K and
200 mmHg. The highest heat of adsorption observed for the sample
GSK1-700 (62.9–27.6 kJ mol1
) may be attributed to the amount of
residual hydroxyl groups and the ratio of non-carbon elements
such as O and N retained in the activated carbon material.
Furthermore, a higher concentration of the activating agent was
found to enhance the porous structure in resulting activated
carbon materials.