•The diffusion and mass-transfer coefficients of CO2 in the hybrid absorbents depend on the viscosity.•The reaction rate constant of CO2 in the hybrid absorbent is sensitive to temperature.•The ...addition of PEG200 can weaken the CO2 absorption rate in the hybrid absorbent.•30 wt% ChoPro/H2O + PEG200 is promising for CO2 separation.
Understanding the mass-transfer kinetics of CO2 in novel hybrid absorbents with physical and chemical contributions is essential for process design and evaluation. In this study, the liquid-side mass-transfer coefficients (kL) and second-order reaction rate constants (k2) of CO2 in hybrid absorbents (namely, choline-2-pyrrolidine-carboxylic acid salt/polyethylene glycol/water (ChoPro/PEG200/H2O)) were determined. The kL values for the hybrid absorbents were obtained from the CO2 diffusion coefficients (DCO2) and the kL values in PEG200/H2O. The DCO2 value was calculated from the density and viscosity of the hybrid absorbents, whereas the kL values in PEG200/H2O were measured experimentally. The k2 values of CO2 in the hybrid absorbents were estimated according to the reaction mechanism, the enhancement factor, and the kL values, and compared with those of other commercialized absorbents. The results showed that 30 wt% ChoPro + 70 wt% H2O had the highest kL and k2 values at atmospheric pressure, whereas the values of kL and k2 of CO2 in 30 wt% ChoPro/H2O + PEG200 were comparable to those in diethanolamine aqueous and amino-functionalized ILs. The hybrid absorbent of ChoPro/PEG200/H2O could be promising for CO2 separation considering its thermodynamic and kinetic properties.
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•MDEA/Im-EG (molar ratio = 1:1) achieved a capture capacity of 0.446 SO2/g absorbent at 2000 ppm SO2 and 293.2 K.•The desorption enthalpy of SO2 in MDEA/Im-EG (molar ratio = 1:1) is ...only −40.67 kJ·mol−1.•The hybrid absorbent has a slightly lower SO2 capture capacity and a substantially lower viscosity than that of DES.
Deep eutectic solvents (DESs) are considered as the highly effective absorbents for sulfur dioxide (SO2) capture. However, the high viscosity of DESs and the resulting slow absorption rate as well as low absorption capacity at low SO2 concentration seriously hinder their industrial application. In this study, DES of N-methyldiethanolamine (MDEA) and imidazole (Im) is simply blended with ethylene glycol (EG) forming a hybrid absorbent, namely MDEA/Im-EG, which exhibits extremely high SO2 capture capacity at low concentration. In particular, SO2 capture capacity in MDEA/Im-EG (molar ratio = 1:1) reaches 0.446 g SO2/g absorbent at 293.2 K with SO2 concentration of 2000 ppm. Moreover, the corresponding desorption enthalpy is only −40.67 kJ/mol. To well understand the results, thermodynamic analysis of SO2 capture is performed and the SO2 capture mechanism is speculated by nuclear magnetic resonance and Fourier transform infrared spectroscopy.
Developing novel hybrid absorbents is essential for CO 2 separation. In this study, the density and viscosity of a hybrid absorbent (choline-2-pyrrolidine-carboxylic acid/polyethylene glycol/water ...(ChoPro/PEG200/H 2 O)) were measured experimentally, and its CO 2 solubility was also determined. The excess mole volume and excess Gibbs energy of activation of the hybrid absorbent were further estimated to understand the molecular structure and interactions between ChoPro/PEG200 and H 2 O. The CO 2 solubilities in ChoPro/PEG200 and ChoPro/H 2 O were analyzed and described using the Redlich–Kwong non-random-two-liquid (RK-NRTL) model. Furthermore, the CO 2 solubility in the hybrid absorbent was predicted using the RK-NRTL model and was compared with the new experimental results for verification. The effect of H 2 O on the CO 2 absorption performance was further analyzed. The performance and cost of the hybrid absorbent were compared with those of other commercialized CO 2 absorbents. In addition, the recyclability of the hybrid absorbent for CO 2 separation was studied. The results of this study indicated that the hybrid absorbent could be promising for CO 2 separation.
Background
T-type calcium channels, characterized as low-voltage activated (LVA) calcium channels, play crucial physiological roles across a wide range of tissues, including both the neuronal and ...nonneuronal systems. Using in situ hybridization and RNA interference (RNAi) techniques in vitro, we previously identified the tissue distribution and physiological function of the T-type calcium channel α
1
subunit (
DdCα1G
) in the plant-parasitic nematode
Ditylenchus destructor
.
Methods and results
To further characterize the functional role of
DdCα1G
, we employed a combination of immunohistochemistry and fungus-mediated RNAi and found that DdCα1G was clearly distributed in stylet-related tissue, oesophageal gland-related tissue, secretory-excretory duct-related tissue and male spicule-related tissue. Silencing
DdCα1G
led to impairments in the locomotion, feeding, reproductive ability and protein secretion of nematodes. To confirm the defects in behavior, we used phalloidin staining to examine muscle changes in
DdCα1G
-RNAi nematodes. Our observations demonstrated that defective behaviors are associated with related muscular atrophy.
Conclusion
Our findings provide a deeper understanding of the physiological functions of T-type calcium channels in plant-parasitic nematodes. The T-type calcium channel can be considered a promising target for sustainable nematode management practices.
•The ChoPro + K2CO3 solution was studied as a novel absorbent for CO2 capture.•The ChoPro can improve the absorption rate of the aqueous K2CO3 solution.•A tradeoff was noticed between the apparent ...absorption rate constant and equilibrium absorption amount.•The highest apparent desorption rate constant was achieved for the aqueous 20 wt.% ChoPro + 10 wt.% K2CO3 solution.•The desorption Ea of the 20 wt.% ChoPro + 10 wt.% K2CO3 absorbent is 56.6 kJ/mol.
In this work, an aqueous (2-hydroxyethyl)-trimethyl-ammonium (S)-2-pyrrolidinecarboxylic acid salt (ChoPro) + K2CO3 solution was studied as a novel absorbent for CO2 capture, and the kinetics and mechanism of the CO2 absorption/desorption process were systematically investigated. Adding ChoPro to the aqueous K2CO3 solution improved the absorption rate of the solution during the initial stage, and the apparent CO2 absorption rate increased as the concentration of ChoPro increased. Meanwhile, equilibrium was reached faster when ChoPro was added, and a tradeoff was noticed between the apparent absorption rate constant and equilibrium absorption amount. The desorption rates of the CO2-rich aqueous ChoPro + K2CO3 solutions were higher than that of the aqueous ChoPro solution at 363.15 K, and the highest apparent desorption rate constant was achieved for the aqueous 20 wt.% ChoPro + 10 wt.% K2CO3 solution. A further study on the aqueous 20 wt.% ChoPro + 10 wt.% K2CO3 solution indicated that the desorption amount increased with the increase in the temperature from 348.15 to 365.15 K. Moreover, with further increase in temperature, the desorption amount exhibited a lower increasing rate when temperature was higher than 361.15 K. The 20 wt.% ChoPro + 10 wt.% K2CO3 absorbent exhibited more stable regeneration performance after 7 cycles and lower desorption activation energy than the aqueous 30 wt.% monoethanolamine (MEA) and 30 wt.% ChoPro solutions as well as higher working capacity compared to the aqueous 30 wt.% ChoPro solution.
The splitting behavior and structural transformation process of K₂Ti₆O₁₃ whiskers in various hydrothermal solutions were investigated by the X-ray diffraction technique, scanning electron microscopy, ...transmission electron microscopy, and atomic force microscopy. TiO₂ (B) particle aggregates and rutile twinned crystals were produced respectively in diluted and concentrated HCl solutions via “dissolution-precipitation” mechanism, while no changes were observed in deionized water. In contrary to the chemical inertia of K₂Ti₆O₁₃ whiskers in KOH solution, trititanate nanowires were synthesized by splitting the bulk K₂Ti₆O₁₃ whiskers in NaOH solution. The driving force for the formation of nanowires originated from the intrinsic strain induced by the phase transition from K₂Ti₆O₁₃ with a tunnel structure to layered trititanate.
To develop polyethylene glycol 200 (PEG200) and aqueous PEG200 solutions (PEG200/H2O) as solvents for CO2 separation, in this study, the available thermo-physical properties of PEG200 and PEG200/H2O ...measured experimentally were surveyed, evaluated, and correlated with empirical equations. The solubility of CO2 in PEG200 was also surveyed, evaluated and described with the Henry's law with the Poynting correction, while the solubilities of CH4 and N2 in PEG200 were determined experimentally and then described with the Henry's law. The CO2, CH4 and N2 solubilities in PEG200/H2O were measured and described with the Redlich–Kwong Nonrandom-Two-Liquid (RK-NRTL) model. In addition, the performances of PEG200, PEG200/H2O and other commercialized physical solvents for CO2 separation were discussed based on the properties, and the biogas upgrading was chosen as the example to quantitatively evaluate the performances of PEG200 and PEG200/H2O with process simulation and compared with the high pressure water scrubbing (HPWS). It shows that the total energy usage and the amount of recirculated solvent for biogas upgrading can decrease by 9.1% and 26.5%, respectively, when H2O is replaced by PEG200 completely.
Understanding the mass-transfer kinetics of CO 2 in novel hybrid absorbents with physical and chemical contributions is essential for process design and evaluation. In this study, the liquid-side ...mass-transfer coefficients ( k L ) and second-order reaction rate constants ( k 2 ) of CO 2 in hybrid absorbents (namely, choline-2-pyrrolidine-carboxylic acid salt/polyethylene glycol/water (ChoPro/PEG200/H 2 O)) were determined. The k L values for the hybrid absorbents were obtained from the CO 2 diffusion coefficients (D CO2 ) and the k L values in PEG200/H 2 O. The D CO2 value was calculated from the density and viscosity of the hybrid absorbents, whereas the k L values in PEG200/H 2 O were measured experimentally. The k 2 values of CO 2 in the hybrid absorbents were estimated according to the reaction mechanism, the enhancement factor, and the k L values, and compared with those of other commercialized absorbents. The results showed that 30 wt% ChoPro+70 wt% H 2 O had the highest k L and k 2 values at atmospheric pressure, whereas the values of k L and k 2 of CO 2 in 30 wt% ChoPro/H 2 O+PEG200 were comparable to those in diethanolamine aqueous and amino-functionalized ILs. The hybrid absorbent of ChoPro/PEG200/H 2 O could be promising for CO 2 separation considering its thermodynamic and kinetic properties.
Deep eutectic solvents (DESs) are considered as the highly effective absorbents for sulfur dioxide (SO2) capture. However, the high viscosity of DESs and the resulting slow absorption rate as well as ...low absorption capacity at low SO2 concentration seriously hinder their industrial application. In this study, DES of N-methyldiethanolamine (MDEA) and imidazole (Im) is simply blended with ethylene glycol (EG) forming a hybrid absorbent, namely MDEA/Im-EG, which exhibits extremely high SO2 capture capacity at low concentration. In particular, SO2 capture capacity in MDEA/Im-EG (molar ratio = 1:1) reaches 0.446 g SO2/g absorbent at 293.2 K with SO2 concentration of 2000 ppm. Moreover, the corresponding desorption enthalpy is only −40.67 kJ/mol. To well understand the results, thermodynamic analysis of SO2 capture is performed and the SO2 capture mechanism is speculated by nuclear magnetic resonance and Fourier transform infrared spectroscopy.
Supported ionic liquid (IL) sorbents for CO2 capture were prepared by impregnating tetramethylammonium glycinate (N1111Gly) into four types of porous materials in this study. The CO2 adsorption ...behavior was investigated in a thermogravimetric analyzer (TGA). Among them, poly(methyl methacrylate) (PMMA)-N1111Gly exhibits the best CO2 adsorption properties in terms of adsorption capacity and rate. The CO2 adsorption capacity reaches up to 2.14 mmol·g−1 sorbent at 35 °C. The fast CO2 adsorption rate of PMMA-N1111Gly allows 60 min of adsorption equilibrium time at 35 °C and much shorter time of 4 min is achieved at 75 °C. Further, Avrami's fractional-order kinetic model was used and fitted well with the experiment data, which shows good consistency between experimental results and theoretical model. In addition, PMMA-N1111Gly remained excellent durability in the continuous adsorption–desorption cycling test. Therefore, this stable PMMA-N1111Gly sorbent has great potential to be used for fast CO2 adsorption from flue-gas.
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