Thai researchers used microwave-assisted KOH activation to convert low-rank Mae Moh lignite into activated carbon with 1,349 m2/g surface area. Under 15% CO2 at 1 atm, equilibrium capacity was 47.34 mg/g at 298 K and declined with temperature. Performance remained stable over six laboratory cycles, but process sustainability and economics remain unproven.
Key findings
- BET area reached 1,349 m2/g and pore volume 0.78 cm3/g, 165- and 78-fold above raw lignite. CO2 capacities were 47.34, 34.37 and 21.34 mg/g at 298, 328 and 353 K. Avrami, FL-PFO and general-order fits gave R² 0.9994-0.9998; mesopore diffusion was rate limiting. ΔG° was -24.20 to -26.87 kJ/mol, ΔH° -9.42 kJ/mol and activation energy 9.11 kJ/mol, consistent with physisorption.
Why this matters globally
Regenerable solid sorbents could capture CO2 from hard-to-abate flue gas with less solvent burden. Real performance depends on moisture, contaminants, pressure drop, cycle life and regeneration energy under industrial gas.
Thai researcher contribution
The University of Phayao, NSTDA's National Energy Technology Center and Mahasarakham University linked Mae Moh feedstock with surface science, pore engineering and carbon-capture testing.
Limitations to consider
Only six cycles and clean simulated gas were tested, without steam, SOx/NOx, dust or long-term ageing. Capacity needs like-for-like benchmarks. No mass/energy balance, KOH and washing cost, waste treatment or life-cycle assessment was reported, and lignite feedstock may conflict with decarbonisation goals.
Verify the original sources
International Journal of Molecular SciencesRead the original article↗DOI: 10.3390/ijms27146123