{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T19:11:17Z","timestamp":1790881877207,"version":"4.1.0"},"reference-count":49,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T00:00:00Z","timestamp":1783468800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Lignite-derived activated carbon (L-AC) was fabricated via a microwave-assisted KOH activation process using a low-rank Mae Moh lignite and explored its potential as an adsorbent solid for post-combustion CO2 capture. Optimization of the KOH ratio, microwave irradiation power, and activation time gave rise to a product with a BET surface area of 1349 m2 g\u22121 and total pore volume of 0.78 cm3 g\u22121, which represented 165 times and 78 times enhancement compared with that of the initial lignite, respectively. Scanning electron microscope (SEM) images proved the formation of a hierarchical macropore\u2013mesopore\u2013micropore structure, whereas Raman (ID\/IG = 1.83) and Fourier-transform infrared spectroscopy analyses revealed a graphitic-like structure rich in defects with the existence of C=O and C\u2013O\u2013C functional groups involved in the Lewis acid\u2013base interaction between L-AC and CO2 molecules. Dynamic fixed-bed breakthrough tests performed at temperatures of 298, 328, and 353 K under post-combustion relevant conditions (CO2 concentration: 15%, pressure: 1 atm) yielded CO2 equilibrium uptake capacities of 47.34, 34.37, and 21.34 mg g\u22121, respectively, with outstanding cyclic stability achieved after six consecutive adsorption\u2013desorption cycles of temperature swing adsorption\u2013desorption at 393 K. Among the seven nonlinear kinetic models, the Avrami, FL-PFO, and general-order models exhibited the highest fitting accuracy (R2 = 0.9994\u20130.9998), suggesting that CO2 adsorption onto L-AC proceeds through heterogeneous, multi-stage adsorption kinetics. A Weber\u2013Morris intra-particle diffusion analysis identified a three-stage sequential transport mechanism in which mesopore diffusion constitutes the primary rate-limiting step. Thermodynamic parameters confirmed spontaneous (\u0394G\u00b0 = \u221224.20 to \u221226.87 kJ mol\u22121), exothermic (\u0394H\u00b0 = \u22129.42 kJ mol\u22121), and entropy-assisted adsorption (\u0394S\u00b0 = +49.93 J mol\u22121 K\u22121) consistent with a physisorption mechanism, corroborated by a low activation energy of 9.11 kJ mol\u22121. These findings demonstrate the viability of low-rank lignite as a low-cost precursor for the scalable synthesis of high-performance carbonaceous CO2 adsorbents for post-combustion capture applications.<\/jats:p>","DOI":"10.3390\/ijms27146123","type":"journal-article","created":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T17:27:31Z","timestamp":1783531651000},"page":"6123","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Microwave-Assisted Conversion of Low-Rank Lignite into Hierarchical Activated Carbon: Molecular Insights into Efficient Post-Combustion CO2 Capture"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3161-0915","authenticated-orcid":false,"given":"Anusorn","family":"Boonpoke","sequence":"first","affiliation":[{"name":"School of Energy and Environment, University of Phayao, Phayao 56000, Thailand"},{"name":"Atmospheric Pollution and Climate Change Unit (APCC), School of Energy and Environment, University of Phayao, Phayao 56000, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-7055-4036","authenticated-orcid":false,"given":"Sirasit","family":"Meesiri","sequence":"additional","affiliation":[{"name":"School of Energy and Environment, University of Phayao, Phayao 56000, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1149-1277","authenticated-orcid":false,"given":"Saksit","family":"Imman","sequence":"additional","affiliation":[{"name":"School of Energy and Environment, University of Phayao, Phayao 56000, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Boonyawan","family":"Yoosuk","sequence":"additional","affiliation":[{"name":"Clean Fuel Technology and Advanced Chemistry Research Team, National Energy Technology Center, National Science and Technology Development Agency, Pathum Thani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wajussakorn","family":"Kanjana","sequence":"additional","affiliation":[{"name":"Faculty of Engineering, Mahasarakham University, Khamriang, Maha Sarakham 44150, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5687-4562","authenticated-orcid":false,"given":"Surachai","family":"Wongcharee","sequence":"additional","affiliation":[{"name":"Faculty of Engineering, Mahasarakham University, Khamriang, Maha Sarakham 44150, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,8]]},"reference":[{"key":"ref_1","unstructured":"Rahimpour, M.R., Farsi, M., and Makarem, M.A. (2020). 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