Lignin holds great promise for fabricating multifunctional carbon materials, yet it is hindered by the difficulty of simultaneous pore structure regulation and heteroatom doping. To address this challenge, we propose a novel molten KCl-thiourea synergistic strategy for the scalable synthesis of N/S co-doped lignin-derived porous carbons without additional chemical activators. Molten KCl provides a growing environment to inhibit carbon agglomeration, guiding the formation of a hierarchical micropore-mesopore structure. Thiourea serves as a multi-role precursor: it crosslinks lignin-derived fragments to prevent structural collapse, acts as an in-situ N/S source, and reacts with residual Na+in lignin to form water-soluble salts for in-situ desalination. The optimal sample exhibits a high surface area of 1802 m2⋅g 1, a balanced pore size distribution, and a heteroatom content of N/S for CO2 adsorption (5.7 mmol⋅g 1) and supercapacitor applications (345F⋅g 1 at 0.1 A⋅g 1 and 98% capacitance retention after 10,000 cycles). This work not only provides a sustainable and cost-effective route for lignin valorization but also reveals the synergistic mechanism of molten salts and heteroatom precursors in regulating carbon structures. The resulting carbons exhibit great potential for practical applications in carbon capture and electrochemical energy storage.

An accurate viscosity prediction model is essential for the intelligent design and industrial scaling of ionic liquid (IL)-based technologies. This study presents a novel hybrid residual modeling strategy that leverages machine learning to identify and capture systematic deviations in physical modeling. The model was developed using experimental viscosity data for 159 ILs and seven quantum chemical descriptors determined from first-principle. A physics-based viscosity model (COSMO-RS) provides prior knowledge as one example, where systematic deviations follow a power law distribution (n_cosmo = An_exp^B) identified in this work. The proposed model with systematic deviations demonstrates excellent performance compared to the model with random deviations and also outperforms the conventional hybrid and data-driven models, achieving superior predictive accuracy on the test set (R² = 0.993, MAE = 0.04) and reducing the average absolute relative deviation from 52.42 % to 4.49 %. Feature importance results reveal the key descriptors contributing to the systematic deviations: A = f(Polarity), B = f(Sigma, AdE).

The century-old Murray’s law, originally formulated to describe optimal transport in biological vascular systems, continues to inspire the design of hierarchical nanomaterials. However, at the nanoscale, its fundamental assumptions of fluid homogeneity and negligible interfacial slip no longer hold, limiting its validity. In this work, Murray’s law is extended to incorporate nanoscale effects, including slip boundary conditions and confinement-induced variations in fluid density and viscosity. Quantitative calculations reveal a transition from traditional viscous flow dominance at larger scales to interfacial slip-driven transport in microporous channels, leading to significant deviations from the original predictions of Murray’s law. Furthermore, the physical foundation of the nanoscale-adapted Murray’s law, namely minimum energy dissipation in nonequilibrium thermodynamics, is restated as a generalized resistance matching principle, offering a practical framework for designing hierarchical structures. This principle is experimentally validated in two structurally diverse nanosystems─biological-skeleton carbon and zeolite molecular sieves─demonstrating its broad applicability. The work provides a generalizable theoretical foundation and a practical benchmark for the rational engineering of advanced hierarchical nanomaterials. By bridging a century-old biological principle with modern nanofluidics, the proposed resistance-matching principle is expected to influence fields such as heterogeneous catalysis, membrane technology, and energy storage.

Oxygen mass transfer in non-Newtonian fluids represents a key rate-limiting step in aerobic biopolymer fermentations. To enhance mass-transfer performance, a novel chaotic reactor (CHR) featuring tri-axial impellers was proposed and optimized using validated computational fluid dynamics (CFD) modeling. The impacts of pumping mode, impeller rotational speeds, and chaotic flow characteristics on the volumetric mass-transfer coefficient (kLa) and power consumption (P) were systematically investigated. The CFD model demonstrates average relative deviations of 5.7% and 12.6% in predicting bubble coalescence/breakup behavior and kLa-P relationships. The optimized CHR, configured with down-pumping operation for both bottom and top pitched-blade impellers, achieved 131% higher process efficiency than that of the conventional coaxial reactor when processing 1.0% carboxymethyl cellulose solution. The mechanism is attributed to the formation of a large-scale horizontal vortex and effective chaotic flow at Reynolds numbers (Re) exceeding 17.5. These findings provide new insights for rational optimization in aerobic bioprocess fermentations.

Upgrading clean energy fuels, such as biogas, natural gas, and shale gas, requires the capture of CO2 to enhance their heating value. Ionic liquids (ILs) are promising absorbents for this purpose, but the vast number of available ILs necessitates an efficient screening method. The Comparative Absorption Factor (CAF) developed in our previous study can estimate the total annual cost (TAC) of CO2 capture from biogas, which is a key advantage over alternative screening methods. However, CAF does not consider the effects of operating conditions such as CO2 concentration, pressure, and temperature. To address this limitation, a modified CAF (CAFmodified) that incorporates these factors was proposed. Given the linear relationship between the original CAF and TAC, three representative ILs ([C10mpy][DCA], [C1mim][tfo], and [C1py][tfo]) were selected from 490 ILs based on their melting point, viscosity, and original CAF values. Subsequently, process simulations for these ILs were conducted using Aspen Plus, considering a wider range of operating conditions: CO2 concentrations of 30–50 vol%, temperatures of 303.15–318.15 K, and pressures of 7–15 bar. These simulations were used to determine the Aspen Plus-derived TAC, which served as the basis for proposing CAFmodified. Finally, data for Aspen Plus-derived TAC from the previous study and for 6 additional ILs over a broad range of operating conditions were used to compare with the TAC values estimated by CAFmodified. The results showed an average relative deviation of 16%, indicating that CAFmodified is effective for screening ILs for CO2 capture under varying operating conditions.

The hybrid sorbent, combining ionic liquid and activated carbon, offers an innovative pathway for CO₂/CH₄ separation. This study prepared three single-step steam activated bamboo carbons (SBCs), and developed the hybrid sorbents of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Hmim][NTf₂])/SBCs/water (H₂O). The gas solubility and sorption rate in the hybrid sorbent were measured, and the Henry's constant, selectivity, and liquid-phase mass-transfer coefficient were calculated. Additionally, a self-developed index was utilized to estimate the CO₂/CH₄ separation cost using the hybrid sorbents. The results showed that the hybrid sorbent containing SBCs prepared by the steam activation at 1073.2 K and 120 min (S812) exhibited the most efficient CO2/CH4 separation performance owing to its optimal microporous structure and oxygen-containing functional groups. Consequently, the hybrid sorbent of [Hmim][NTf₂]/S812-H₂O (w_{[Hmim][NTf2]/S812}=3.0 wt%) demonstrated a 3.2 times intensification on the comprehensive CO₂/CH₄ separation performance as well as a 53.8 % reduction of separation cost compared to the commercial technology. 

Deep eutectic solvent (DES)-based systems have recently emerged as promising alternatives to conventional liquid sorbents for CO2 capture due to their tunable properties and potential for enhanced mass transfer. In this work, two DES-based slurry systems previously developed for CO2 capture, one aqueous and one non-aqueous, were further evaluated under conditions relevant to industrial operation. Their performance was investigated using pure CO2 as well as the CO2/N2 and CO2/CH4 gas mixtures up to 1.5 MPa to elucidate the effects of operating pressure and non-reactive gas components typically present in industrial gas streams. It shows that the species other than CO2 revealed a negligible impact on CO2 uptake. Subsequently, to assess the practical applicability of the slurry systems, CO2 capture was performed using conditioned flue gas after the biomass combustion at the Smurfit WestRock industrial site in Piteå, Sweden. The slurries demonstrated stable performance, with the aqueous slurry exhibiting higher uptake.

Deep eutectic solvents (DESs) have attracted considerable attention as promising alternatives to conventional solvents for mitigating CO2 emissions due to their tunable structures, low volatility, and promising physicochemical properties. In this work, a series of [Triz]Cl/amine DESs were designed and synthesized and then formulated as 30 wt% aqueous solutions (30 wt% DES + 70 wt% H2O) to systematically investigate how the type of hydrogen bond donor (HBD) affects their physicochemical properties, thermal stability, and CO2 capture performance, and to identify the most effective solvent; their CO2 absorption capacity, absorption rate, thermal stability, and desorption efficiency were determined experimentally, and a novel stepwise evaluation strategy was employed for identification. [Triz]Cl/DETA was identified, exhibiting significantly enhanced performance, with CO2 absorption capacity, absorption rate, thermal stability, and cyclic loading increased by 34%, 12%, 114%, and 39%, respectively, when compared with the conventional monoethanolamine (MEA). Its viscosity (both before and after CO2 absorption), oxidative stability, and corrosion resistance were further studied, confirming the superior performance, and the reaction mechanism was also elucidated. This work provides valuable insights into the structure–property relationships of DESs and establishes [Triz]Cl/DETA-based solvents as promising candidates for efficient and sustainable CO2 capture applications.

The development of advanced absorbents for effectively capturing carbon dioxide is crucial in mitigating greenhouse gas emissions. This study introduced a series of deep eutectic solvents (DESs) for CO2 capture and identified the most promising DESs with the stepwise screening method based on their absorption capacity, absorption rate, thermal stability, desorption efficiency, and apparent activation energy. Consequently, compared to the monoethanolamine (MEA), in the 30 wt% aqueous solutions, [1,2,3-Triazolium chloride][diethylenetriamine] ([TrizCl][DETA]) and [Piperazinium chloride][diethylenetriamine] ([PzCl][DETA]) improved the CO2 absorption capacities by 31% and 34%, absorption rates by 12% and 30%, and the amounts of CO2 desorbed by 42% and 23%, as well as reduced the apparent activation energies by 9% and 28%, respectively. Meanwhile, their thermal stabilities (degradation onset temperatures, Tonset) were enhanced by 101% and 32%, respectively. The FTIR and NMR analyses were conducted to provide deeper insights into the chemical absorption mechanism of CO2 by the DESs. 

Amine sorbent technology offers transformative low-energy potential for both direct air capture (DAC) and post-combustion carbon capture (PCC); its viability is severely undermined by the poor heat and mass transfer of conventional solid sorbents. Herein, we report a rationally designed core-shell microwave-responsive composite support that synergistically integrates a highly graphitized carbon nanotube (CNT) core and a mesoporous silica (MS) shell for ultra-low-energy carbon capture. The CNT core not only provides efficient microwave-to-thermal conversion but also constructs a loose fibrous skeleton that prevents silica agglomeration and creates hierarchical mass transfer pathways. The MS shell, synthesized via a dual-template method, enables uniform dispersion of polyethyleneimine (PEI) even at 70 wt% loading and enhances heat transfer from the CNT core to active amine sites. The optimized PEI70-MS/CNT06 adsorbent delivers exceptional CO2 adsorption capacities of 3.28 mmol·g−1 under PCC and 2.64 mmol·g−1 under DAC conditions. Importantly, it realizes ultra-fast regeneration under 20 W microwave irradiation for only 15 s, with regeneration energy consumptions of 1.64 MJ·kg−1 CO2 (PCC) and 3.28 MJ·kg−1 CO2 (DAC), which are 60–70% lower than conventional thermal swing adsorption (TSA). The adsorbent retains 76% of its initial capacity after 50 consecutive cycles, outperforming both PEI/CNT and TSA-regenerated counterparts. This work explores microwave-assisted regeneration for high-performance DAC systems and further establishes a universal design principle for the fabrication of microwave-responsive solid amine adsorbents toward efficient dilute CO2 capture.