AIChE Journal最新文献

We address the identification of the actual stoichiometric network in reacting systems using composition measurements, extending our previous work (Fromer et al. I&ECR 2023). We generalize this algorithm for scenarios where not all species are measured and back-calculate the missing concentrations through the reaction extents of the candidate network. In addition to the prior global accuracy comparison among candidate reaction networks, we introduce a species-by-species F-test accuracy comparison between the most accurate reaction networks from the global assessment. We examine two case studies involving 7 and 11 species participate in 4 or 8 reactions, respectively. In the second case study, the 8 reactions are linearly dependent, presenting an additional challenge. The enhanced algorithm successfully identifies the actual reaction network as the most accurate, even with 4 of the 11 species not measured.

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, T_onset) 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.

Partial hydrogenolysis of dimethyl oxalate (DMO) to methyl glycolate (MG) is a central step in biodegradable polyglycolic acid (PGA) production. However, it remains a great challenge for efficient and selective DMO hydrogenolysis under mild temperature (<100°C). In this work, we demonstrate an outstanding DMO hydrogenolysis by employing alkaline (Na, K) metal-doped Ru catalysts. Na presents a stronger promotional effect than K. The highest yield of MG is achieved at 90.2% at 85°C in 15 h of reaction on 3Ru-0.4Na/SiO₂ and the catalyst can be directly reused more than 10 times without any additional regeneration. The doping of Na effectively enables smaller Ru nanoparticle size, larger capacity of H₂ adsorption via a hydrogen pool (includes surface hydride, i.e., Na-H^δ−) on Ru–Na interface, stronger strength of DMO adsorption. It is further revealed that there is a linear relation between the content of surface Ru⁰ + Ru³⁺ + Ru^δ− and MG yield. Finally, an optimal ratio of Ru³⁺ + Ru^δ−/Ru⁰ of 1.26 is achieved.

Combining CO₂ capture with sustainable salt recovery in biofuel production is a promising strategy to address environmental and economic challenges in biorefinery. This study demonstrates a closed-loop system that utilizes K₂CO₃ as a bifunctional agent for both separation and purification of acetone–1-butanol–ethanol (ABE) solution and CO₂ capture from biofuel fermentation. Salt reuse and CO₂ sequestration were achieved by reacting CO₂ with salted K₂CO₃-rich aqueous phase to form KHCO₃. The experimental results showed that K₂CO₃ could achieve efficient ABE separation (>99% recovery of 1-butanol at 500 g/kg) and CO₂ utilization reached 88% under optimal conditions (stirring rate of 1100 r/min, gas flow rate of 40 mL/min). Salt recovery stabilized at 84%, which was limited by KHCO₃ solubility and ionic strength. This research provides a scalable blueprint for sustainable biofuel production by addressing the twin challenges of resource waste and carbon emissions.

Water gas shift (WGS) reaction is crucial for removing CO impurity in industrial hydrogen production. Noble-metal-free Co-based species mainly serve as a support rather than dominant sites for this reaction. Here, a bulk Co₄N nanospheres (Co₄N-NS) catalyst is prepared via temperature programmed nitriding using Co₃O₄ nanosphere precursor for low-temperature WGS reaction. It is found that the CO conversion can achieve 97.6% at 240°C, and the thermodynamic equilibrium conversion is reached at 250°C, which is unprecedentedly reported for Co-based catalysts. Moreover, the reaction rate reaches 19.84 mmol_CO g_cat⁻¹ h⁻¹ with a better stability, 4.5 times higher than that on Co₄N-C from commercial Co₃O₄ precursor. The characterizations and kinetic studies show that Co₄N-NS enhances the H₂O activation and promotes the CO adsorption, which renders a lower activation energy compared to Co₄N-C for the WGS reaction. This study offers insights for designing cost-effective WGS catalysts with transition metal nitrides.