Experimental studies of air-blast atomization on the CO_(2)capture with aqueous alkali solutions

In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concentration on the CO2 removal efficiency(η)and the volumetric overall mass transfer coefficient(KGav)were investigated.The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance.For the aqueous MEA and Na OH solutions,the experimental results show that theηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G.The effects on KGavare more complicated than those forη.When the CO2 concentration is low(3 vol%),KGavincreases with increasing gas flow rate while decreases with increasing L/G.However,when the CO2 concentration is high(9.5 vol%),as the gas flow rate and L/G increases,KGavincreases first and then decreases.The aqueous MEA solution achieves higherηand KGavthan the aqueous Na OH solution.The air-blast atomizing column shows a good performance on CO2 capture.

Light weight, mechanically strong and biocompatible α-chitin aerogels from different aqueous alkali hydroxide/urea solutions

Light weight and mechanically strong α-chitin aerogels were fabricated using the sol-gel/self-assembly method from α-chitin in different aqueous alkali hydroxide(KOH, Na OH and Li OH)/urea solutions. All of the α-chitin solutions exhibited temperature-induced rapid gelation behavior. 13 C nuclear magnetic resonance(NMR) spectra revealed that the aqueous alkali hydroxide/urea solutions are non-derivatizing solvents for α-chitin. Fourier transform infrared(FT-IR), X-ray diffraction(XRD) and cross-polarization magic angle spinning(CP/MAS) 13 C NMR confirmed that α-chitin has a stable aggregate structure after undergoing dissolution and regeneration. Subsequently, nanostructured α-chitin aerogels were fabricated by regeneration from the chitin solutions in ethanol and then freeze-drying from t-Bu OH. These α-chitin aerogels exhibited high porosity(87% to 94%), low density(0.09 to 0.19 g/cm^3), high specific surface area(419 to 535 m^2/g) and large pore volume(2.7 to 3.8 cm^3/g). Moreover, the α-chitin aerogels exhibited good mechanical properties under compression and tension models. In vitro studies showed that m BMSCs cultured on chitin hydrogels have good biocompatibility. These nanostructured α-chitin aerogels may be useful for various applications, such as catalyst supports, carbon aerogel precursors and biomedical materials.

Design strategies for rechargeable aqueous metal-ion batteries

Rechargeable aqueous metal-ion batteries(AMBs)have attracted extensive scientific and commercial interest due to their potential for cost-effective,highly safe,and scalable stationary energy storage.However,their limited output voltage,inadequate energy density,and poor reversibility of ambiguous electrode reactions in aqueous electrolytes strongly limit their practical viability.This review aims to elucidate the challenges of existing AMBs from the material design to whole device applications.We summarize the emerging electrochemistry,fundamental properties,and key issues in interfacial behaviors of various classes of prevailing AMBs,including aqueous alkali metal-ion batteries and multivalent-ion batteries,and present an appraisal of recent advances for addressing the performance deficiency.Specifically,the progress of zinc-ion batteries is highlighted to provide a ubiquitous guideline for their commercialization in the grid-scale energy storage.Finally,we figure out the dominating general challenges for achieving high-performance AMBs,laying out a perspective for future breakthroughs.