Enthalpy Of Absorption Research Articles

Thermodynamic Modeling of an Aqueous N, N-Dimethyldipropylenetriamine and Benzylamine Blend for Efficient CO2 Capture.

This study evaluates the carbon dioxide (CO2) capture capabilities of a novel aqueous blend of N,N-dimethyldipropylenetriamine (DMDPTA) and benzylamine (BA). The solvent properties such density, vapor- liquid equilibrium (VLE) of CO2 in the solvent, CO2 absorption enthalpy are evaluated experimentally for solvent composition of (5 mass % DMDPTA+25 mass % BA), (10 mass % DMDPTA+20 mass % BA), and (15 mass % DMDPTA+15 mass % BA). Solvent density were measured in the temperature range of 303 K-333 K and correlated using Redlich-Kister excess molar volume model, with a low average absolute relative deviation (AARD) of 0.014. VLE data was measured using a custom-made stirred VLE cell, within CO2 partial pressure range of 2-200 kPa and at temperatures 313 K, 323 K and 333 K. Equilibrium CO2 solubility data were correlated using a modified Kent-Eisenberg model, achieving an AARD of 1.5 %. Enthalpy of CO2 absorption was measured at 313 K using a Meter Toledo reaction calorimeter. Results indicated that under similar process conditions and solvent composition, (DMDPTA+BA) blends exhibited significantly higher CO2 loading and low absorption enthalpy compared to aqueous BA and monoethanolamine solvent alone indicating the potential of (DMDPTA+BA) blend as efficient CO2 capture solvent.

Synergistic inhibition kinetics and mechanisms of polyethylene glycol – citric acid on non-caking coal oxidation at low temperature

ABSTRACT Focused on the insufficient efficacy of conventional flame retardants in mitigating coal spontaneous combustion (CSC), a novel composite flame retardant synthesized from polyethylene glycol (PEG) 2000 and citric acid (CA) is proposed. Through Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR) experiments, the inhibitory kinetics and mechanisms were conducted. By enhancing heat absorption rate and enthalpy, with a significant increase by 90 kJ·mol−1 of activation energy, CSC resistance is improved. CA-metal ion interaction raises activation energy to inhibit methyl/methylene oxidation, while PEG disrupts aromatic oxidation by generating H ions upon hydration. This composite retardant offers a promising avenue for CSC mitigation in coal, enhancing coal fire safety.

Dihydroxyl-Cooperative 1,2,4-Triazole-Based Ionic Liquid for Robust Reversible CO2 Absorption.

The development of aqueous absorbents for CO2 capture is significantly important to reduce global industrial gas emissions through high regeneration efficiency and low energy consumption. Herein, we newly designed and prepared a dihydroxylated ionic liquid (IL) bis(2-hydroxyethyl)dimethylammonium 1,2,4-triazole ([N1,1,2OH,2OH][TZ]) for highly efficient CO2 absorption through anion-cation cooperative interactions. A superior capacity of 1.33 mol of CO2 per mol of IL and excellent reversibility have been achieved by the introduction of dihydroxy sites on the ammonium-based Tz IL. 1H and 13C nuclear magnetic resonance, Fourier transform infrared, and quantum chemical calculations demonstrate bihydroxyl-cooperative absorption of CO2 via hydrogen bond interaction between the cation and anion of the IL. The theory calculation shows that IL displays a superlow reactive absorption enthalpy, favorable to the reversible CO2 absorption, which can maintain an initial absorption capacity of 98.5% with the cycle numbers of 100, implying the facile regeneration and superlow energy consumption. Thus, the functionalized ILs toward group cooperative gas absorption and excellent reversibility may open a door to designing new materials for enhancing CO2 absorption and utilization.

Investigation of hydrogen storage properties on the Mg-La-Ni alloy compounded with C@Pr2O3 composite catalyst

To explore the effect of C@Pr2O3 on the hydrogen storage performance of Mg-La-Ni alloy. In experiment, a nanostructured composite catalyst C@Pr2O3 was prepared using chemical blowing carbonization. The microstructures of the catalyst and alloy powder were characterized using techniques such as transmission electron microscope, high-resolution transmission electron microscopy, scanning electron microscope, and selective region electron diffraction. Hydrogen storage properties of the alloy were evaluated using Pressure-composition-temperature equipment, and it was observed that the addition of the catalyst significantly enhanced the hydrogen kinetics of the alloys. At 320 ℃, the two-minute hydrogen saturation ratio of Mg96NiLa3 +5 wt% C@Pr2O3 was 80.65 %, Mg96NiLa3 +7 wt% C@Pr2O3 releases 3 wt% H2 at 340 °C for 6 min. This can be attributed to the addition of nanoscale C and catalyst Pr2O3, which improved the hydrogen kinetics of the alloys. The dehydrogenation activation of Mg96NiLa3 +5 wt%C@Pr2O3 is 85.2 kJ/mol, enhancing the rate of hydrogen release while simultaneously reducing the activation energy required for dehydrogenation of the alloy. The enthalpy of hydrogen absorption of Mg96NiLa3 +5 wt% C@Pr2O3 was 72 KJ/mol. However, the thermodynamic properties of the alloy were still not satisfied with the requirements of practical application.

Physicochemical properties of starch of four varieties of native potatoes

The limited industrial use of indigenous varieties of native potatoes has caused a decrease in its cultivation, restricting it to the self-consumption of the Andean population. The present study analyzed the physicochemical, thermal, and structural properties of the starches extracted from four of these varieties Aq'hu Pukucho, Yurakk Kkachun Wakkachi, Yurac Anca, and Huarmi Mallco, as a potential source of be used in industries such as food, pharmaceutical and, bioplastics. The percentage yield in wet extraction ranged between 14.53 and 20.26 %. The luminosity L* and whiteness index (WI) values were observed in ranges of 90.75–92.71 and 90.05–91.50, respectively. The Finding revealed various techno-functional properties, since the level of amylose varied between 36.29 and 43.97 %, an average zeta potential of −22 mV, and a maximum viscosity between 19,450–14,583 cP. The starches showed consistent thermal behavior since the TGA curves showed three stages with gelatinization temperatures that ranged between 54.9 and 59.75 °C, an enthalpy of 3.60–6.62 J/g, and various shapes of particles such as circular, elliptical, and oval. In conclusion, the relationships between variables such as water absorption index, swelling power, viscosity, crystallinity, enthalpy, and gelatinization temperature reveal different characteristics of each type of starch, which can influence its use.

Synthesis and Properties of the Helium Clathrate and Defect Perovskite [He2-x □ x ][CaNb]F6.

The defect double perovskite [He2-x □ x ][CaNb]F6, with helium on its A-site, can be prepared by the insertion of helium into ReO3-type CaNbF6 at high pressure. Upon cooling from 300 to 100 K under 0.4 GPa helium, ∼60% of the A-sites become occupied. Helium uptake was quantified by both neutron powder diffraction and gas insertion and release measurements. After the conversion of gauge pressure to fugacity, the uptake of helium by CaNbF6 can be described by a Langmuir isotherm. The enthalpy of absorption for helium in [He2-x □ x ][CaNb]F6 is estimated to be ∼+3(1) kJ mol-1, implying that its formation is entropically favored. Helium is able to diffuse through the material on a time scale of minutes at temperatures down to ∼150 K but is trapped at 100 K and below. The insertion of helium into CaNbF6 reduces the magnitude of its negative thermal expansion, increases the bulk modulus, and modifies its phase behavior. On compressing pristine CaNbF6, at 50 and 100 K, a cubic (Fm3̅m) to rhombohedral (R3̅) phase transition was observed at <0.20 GPa. However, a helium-containing sample remained cubic at 0.4 GPa and 50 K. CaNbF6, compressed in helium at room temperature, remained cubic to >3.7 GPa, the limit of our X-ray diffraction measurements, in contrast to prior reports that upon compression in a nonpenetrating medium, a phase transition is detected at ∼0.4 GPa.

Hydrated carboxylate ionic liquids as chemical CO2 sorbents of high capacity and moderate enthalpy of absorption

Tetralkylphosphonium carboxylate ionic liquids are herein presented as efficient carbon dioxide chemisorbents in the presence of water. The ionic liquids tetrabutylphosphonium formate and acetate, tributylmethylphosphonium formate and a series of triethylalkylphosphonium formates and acetates, have been prepared by various synthetic procedures either from hydroxide or methylcarbonate precursors, or via multiple steps starting from the parent triethylphosphine. Their physicochemical properties, namely melting or glass transition temperatures, thermal decomposition behaviour, densities and viscosities have been determined. As dry substances, they are viscous liquids or low-melting solids, whereas they show little tendency to solidify in their hydrated forms. They were used mostly as monohydrates in CO2 solubility measurements, exhibiting highest capacities (3 mol L−1, i.e. ≈ 0.9 molCO2 molIL−1, at 5 bar, 25 °C) at equimolar H2O/ionic liquid ratios, approaching those of commercial aqueous amine sorbents. Carbon dioxide chemisorption into hydrogencarbonate takes place, as demonstrated by infrared spectroscopy with isotopic labelling. CO2 absorption isotherms were recorded at various temperatures and the data used to estimate the heat of absorption according to three different thermodynamic models. Enthalpies of CO2 absorption depended heavily on the model used. Rationalisation of this was done on the grounds of the expected relevance of physical and chemical sorption processes. Average heats of CO2 absorption lie between −40 and −45 kJ mol−1, in accordance with mild chemical absorption albeit significantly lower than those for typical chemical sorbents such as amines. This reinforces the feasibility of hydrated carboxylate ionic liquids for CO2 capture technologies of low regeneration energies.

Carbon Dioxide Solubility in Three Bis Tri (Fluromethylsulfonyl) Imide-Based Ionic Liquids.

This study delves into the necessity of mitigating carbon dioxide (CO2) emissions, focusing on effective capture methods to combat global warming by investigating the solubility of CO2 in three ionic liquids (ILs), 1-Decyl-3-MethylimidazoliumBis (Trifluromethylsulfonyl Imide) [IL1], 1-Hexadecyl-3-Methyl imidazoliumBis (Trifluromethylsulfonyl Imide) [IL2] and Triethytetradecyl Ammonium Bis (Trifluromethylsulfonyl Imide) [IL3]. Solubility experiments were conducted at (30, 50 and 70) °C with pressures up to 1.5 MPa. The research shows [IL2] as the superior candidate for CO2 capture, with its longer alkyl chain, and is confirmed by its lower Henry's Law constant. Utilizing the Peng Robinson equation of state, the study correlates well with the solubility measurements using three mixing rules. The study reveals promising results for IL1, IL2 and IL3 surpassing all other published ionic liquids including Selexol/Genesorb 1753, except for 1-Methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide. Insights into the enthalpy and entropy of absorption underscore the significant impact of IL structure on CO2 solubility, emphasizing the potential of tailored ILs for advanced carbon capture strategies. In summary, this research highlights [IL2] as the optimal choice for CO2 capture, offering valuable contributions to the ongoing efforts in combating climate change.

Hydride ion diffusion along grain boundaries in titanium nitride

Density functional theory (DFT) simulations are utilized to study the absorption and diffusion of hydride ions along four types of titanium nitride grain boundaries: open and compact structures of Σ5 (210)[001] and Σ5 (310)[001]. The absorption energy into bulk vacancies ranges from approx. −0.7 eV in TiN0.7 to −0.38 eV for a single vacancy in TiN, and shows a minor dependence on the hydrogen content in the structure. The absorption energy for vacancy sites at the grain boundaries ranges from −0.44 eV to −0.66 eV. Hydrogen absorption into interstitial sites at the grain boundaries is less favourable, in part due to a positive and fairly large zero-point energy contribution, with absorption enthalpies between −0.09 eV and 0.06 eV. The interstitial diffusion barriers are 1.34 eV and 0.83 eV in the open Σ5 (310) and Σ5 (210) grain boundaries, respectively. In the compact grain boundaries, the migrating hydrogen species changed oxidation state from a hydride ion (H0.5−) to a proton (H0.3+) at the transition state as it formed bonds to nitrogen along the diffusion path. The diffusion barriers are larger than in the corresponding open structures: 1.75 eV and 1.02 eV in the compact Σ5 (310) and Σ5 (210) structures, respectively. The considered grain boundaries and diffusion pathways cannot explain the fast interfacial hydride ion transport reported for hydrogen separation membranes based on TiNx thin films with columnar microstructure.

Effects of Mn and Fe elements on the electrochemical hydrogen storage properties of the A5B19-type La-Y-Mg-Ni-Al alloy for nickel metal hydride battery

Rare earth–Mg–Ni-based alloys with superlattice structures are novel anode materials for nickel metal hydride batteries, wherein A5B19-type alloys have been regarded as the replacement of the current commercialized A2B7-type alloys due to the superior discharge ability at high rates and cycling stability. However, it is still a challenge to further improve the hydrogen storage properties of the A5B19-type alloys in a low-cost approach. Herein, we select low-cost Mn and Fe elements to substitute Ni to further reduce the cost of an A5B19-type La0.72Y0.13Mg0.15Ni3.70Al0.15 alloy and focus on their effects on the alloy's structure and hydrogen storage properties. Results show that the La0.72Y0.13Mg0.15Ni3.65Al0.15Fe0.05 alloy features increased intrinsic gas-solid hydrogen storage ability of 1.44 wt% and hydrogen absorption enthalpy change of −22.9 kJ mol–1, which have been altered by 0.21 wt% and 7.3 kJ mol–1 in contrast to the La0.72Y0.13Mg0.15Ni3.70Al0.15 alloy, respectively. Furthermore, the Fe substitution benefits capacity retention during electrochemical cycling compared to Mn, which maintains 87.5% and 62.4% after cycling 100 and 500 times. The Mn substitution results in superior rate capability compared to the alloy containing Fe. The work provides guidance for designing hydrogen storage alloys with superlattice structures to improve the electrochemical performance.

Thermodynamic Analysis of the Absorption of Common Refrigerants in Fluorinated Deep Eutectic Solvents

The potential to decrease the negative environmental impact of greenhouse gases in terms of global warming potential (GWP) is a current challenge. Apart from CO2, fluorinated greenhouse gases (F-gases), which are human-made chemicals used in refrigeration and other industrial applications, have a huge environmental impact due to their high GWPs. In this regard, the design of units to capture and recover these gases would contribute to their reuse, avoiding the negative impact of their final emission or incineration. Fluorinated Deep Eutectic Solvents (FDESs) have been considered as promising solvents for the absorption and the selective separation of F-gases. However, the complex and expensive experimental labour to fully characterize FDESs delays its study and development. In this work, a computational approach is applied to develop accurate thermodynamic models of the gas solubility of several F-refrigerants in DESs. The molecular-based equation of state (EoS) soft-SAFT is used to assess the absorption of three F-gases (1,1,1,2-tetrafluoroethane (R-134a), difluoromethane (R-32), and pentafluoroethane (R-125)) at different temperatures in five DESs derived from fluorinated salts and perfluorinated acids. New molecular models are developed through the soft-SAFT approach for FDESs in good agreement with experimental data, and the solubility of F-gases is also calculated at varying temperatures with high accuracy. Then, an in-depth analysis of the characteristics of the refrigerants, and of the FDESs affecting the F-gases absorption is performed, and the enthalpy and entropy of absorption and the selectivity are calculated. It has been encountered that the best FDESs for each particular F-gas separation can be obtained by modifying the composition of DES and the operating temperature. Finally, an assessment based on the selectivity obtained from the soft-SAFT model is carried out to choose the most adequate solvent to separate the studied F-gases.

Biphasic solvents based on dual-functionalized ionic liquid for enhanced post-combustion CO2 capture and corrosion inhibition during the absorption process

To reduce the energy consumption for solvent regeneration and mitigate the corrosiveness of saturated solvents, dual-functionalized ionic liquid (IL) [DMAPA][TZ] was synthesized as a primary absorbent, and mixed with a phase separation accelerator poly (ethylene glycol) dimethyl ether (NHD) or propylene carbonate (PC) as biphasic solvents, to achieve high efficiency, energy savings, and corrosion inhibition of post-combustion CO2 capture. The results demonstrated a transition from a homogeneous solvent to a biphasic system upon CO2 absorption, with the majority of CO2 being concentrated in the rich phase, which is related to the formation of hydrogen bonds. Molecular dynamics analysis showed that interaction between the IL and PC is significantly stronger than that with NHD, resulting in a reduced absorption capacity of IL-PC relative to IL-NHD, while NHD effectively suppressed the formation of HCO3−/CO32−. At 373 K, both solvents exhibited efficient regeneration of their respective rich phases within 10 min. The calculated absorption enthalpies for IL-NHD and IL-PC are remarkably low at 0.662 and 0.772 GJ·t−1, respectively, and the regeneration energy consumption of IL-NHD was lower to 1.387 GJ·t−1. Notably, the phase separation accelerator exerts a significant influence on the phase-transition behavior and absorption products of biphasic solvents. Furthermore, ILs effectively inhibited corrosion through the adsorption-passivation mechanism; specifically, the corrosion rate of the CO2-rich phase in IL-NHD relative to 20# carbon steel was only 0.1896 mpy, which is only 1/865 of the rate of the saturated 5 M MEA solution.

Effects of different extrusion temperatures on the physicochemical properties, edible quality and digestive attributes of multigrain reconstituted rice.

Multigrain reconstituted rice, as a nutritious and convenient staple, holds considerable promise for the food industry. Furthermore, highland barley, corn, and other coarse cereals are distinguished by their low glycemic index (GI), rendering them effective in mitigating postprandial blood glucose levels, thereby underscoring their beneficial physiological impact. This study investigated the impact of extrusion temperature on the physicochemical properties, edible quality, and digestibility of multigrain reconstituted rice. The morphology revealed that starch particles that are not fully gelatinized in multigrain reconstituted rice are observed at an extrusion temperature range of 60 °C-90 °C. As the extrusion temperature increased, the degree of gelatinization (DG) increased, while the contents of water, protein, total starch, and amylopectin decreased substantially. Concurrently, the relative crystallinity, orderliness of starch, and heat absorption enthalpy (ΔH) decreased significantly, and water absorption (WAI) and water solubility (WSI) increased markedly. Regarding edible quality, sensory evaluation displayed an initial increase followed by a decrease. In terms of digestibility, the estimated glycemic index (eGI) increased from 61.10 to 70.81, and the GI increased from 60.41 to 75.33. In addition, the DG was significantly correlated with both eGI (r = 0.886**) and GI (r = 0.947**). The results indicated that the ideal extrusion temperature for multigrain reconstituted rice was 90 °C. The findings underscored the pivotal role of optimal extrusion temperatures in the production of multigrain reconstituted rice, which features low GI and high nutritional quality.

Effect of industrial grade raw materials and its associated impurities on first hydrogenation of BCC solid solution alloys

This study explores the effects of using industrial-grade raw materials on the hydrogen storage properties of body-centered cubic (BCC) solid solution alloys. Industrial scrap metals were chosen as the raw material, and the desired alloys were synthesized using a vacuum arc melting furnace. Instead of using pure vanadium (V), different inexpensive industrial substitutes such as low-grade vanadium (V), vanadium nitride (VN), vanadium oxide (VO), and ferrovanadium (FeV) were utilized. The crystal structure, morphology, first hydrogenation, thermodynamics, and cyclability of the prepared alloys were analyzed by using XRD, SEM-EDS, and XPS methods. The crystal structure and morphology analysis revealed multiphase alloys in all the prepared alloys and a Ti rich third phase in the VN sample, which was absent otherwise. The first hydrogenation was performed at room temperature under a hydrogen pressure of 2 MPa without any prior heat treatment. The VO alloy displayed negligible hydrogen absorption during first hydrogenation, while the V, VN, and FeV alloys showed maximum hydrogen storage capacities of 3.49 wt%, 2.47 wt%, and 2.18 wt%, respectively. The presence of oxygen hinders the activation of the VO alloy and requires two activation cycles to activate the sample. A short-term cyclability analysis showed a reversible hydrogen storage capacity of 2 wt%. The change in enthalpy of hydrogen absorption and desorption for V alloy were calculated to be −36.73 ± 8.6 and 57.34 ± 8.3 kJ/mol H2, respectively. One of the prominent advantages of utilizing scrap raw materials was the substantial reduction in overall raw material costs, which saw an impressive 95% decrease when compared to using pure raw materials. These results highlight the economic benefits of incorporating recovered industrial scrap into hydrogen storage alloys.

Microstructure and hydrogen storage properties of MgH2/MIL-101(Cr) composite

In this paper, a new hydrogen storage composite based on magnesium hydride and metal-organic framework MIL-101(Cr) (an acronym for Material Institute Lavoisier) has been mechanically synthesized and investigated. The hydrogen sorption and desorption behavior in the composite was investigated for the temperature and pressure ranges of (593−653) K and (0−3) MPa, respectively. According to the pressure-composition-temperature isotherms of hydrogen sorption/desorption, the MgH2–5 wt%MIL-101(Cr) composite starts to absorb hydrogen at a lower pressure at 593 K. In addition, the hydrogen release peak for composite shifts to lower temperatures by about 140 K compared to the pure milled MgH2 during temperature programmed desorption at a heating rate of 6 K/min. The activation energy of hydrogen desorption from the composite is 120 ± 2 kJ/mol, which is 36% lower than the activation energy of hydrogen desorption from magnesium hydride (189 ± 2 kJ/mol). The enthalpy of hydrogen absorption was found to be 73 kJ/mol H2 and 60 kJ/mol H2 for milled MgH2 and MgH2–5 wt%MIL-101(Cr) composites, respectively. It is showed that the MIL-101(Cr) MOF structures decompose during ball milling and the chromium oxide nanoparticles form a core-shell structure with MgH2 particles. Thus, composite has better sorption and desorption properties than pure magnesium/magnesium hydride due to the nanoconfinement of MgH2. The chromium oxide nanoparticles act as active sites on the surface of the magnesium particles and facilitate the dissociative chemisorption or recombinative desorption of hydrogen. The main regularities of the phase transition in the magnesium-hydrogen system for the composite and magnesium hydride during dehydrogenation have been studied for temperatures in the range of 298–750 K. The in situ analysis of the phase transitions during the dehydrogenation of MgH2 and MgH2–5 wt%MIL-101(Cr) composite indicates a pronounced catalytic effect of the addition of MIL-101(Cr) to the Mg/MgH2. Based on the experimental results and ab initio calculations, a mechanism for the sorption and desorption of hydrogen by the composite has been proposed.

Novel amino acid ionic liquids as messenger of multi-tertiary-amines solutions for highly efficient capture of CO2

Carbon capture, utilization, and storage (CCUS) are among the key technologies to achieve large-scale carbon emission reduction globally. Amino acid ionic liquids (AAILs) featuring biodegradability and biological activity are capable as eco-friendly absorbents for CO2 capture. Herein, a series of novel AAILs are proposed via one-step hydrolysis of cheap lactams, which can act as messengers to facilitate aqueous solution of multi-tertiary-amines fast and pronounced absorption of CO2. Dynamic absorption experiments were carried out to indicate that [N1111][Maba]-PMDETA-50 % showed a larger apparent absorption rate constant (0.282 min−1) than that of MDEA solution (0.043 min−1), demonstrating the activated role of AAILs. [N1111][Maba]-PMDETA-50 % shows the exceptional absorption capacity of 0.162 g (1.0 bar) or 0.095 g (0.1 bar) of CO2 per g absorbent at 313.2 K, respectively, surpassing all the reported formulated solution. The facilitated absorption mechanism is also illuminated from the NMR spectra. The regeneration heat (equal to absorption enthalpy) was calculated to be − 55.7 kJ·mol−1 from absorption isotherm of three different temperatures. The recyclability was evaluated from the vacuum regeneration (ten consecutive absorption–desorption cycles) and dynamic thermal regeneration, achieving the regeneration efficiency of more than 95 % and 99 %, respectively. All these experimental data indicate that the AAIL-based multi-tertiary-amines aqueous solution may be good candidate absorbent in terms of rapid efficient capture of CO2.

Aminoalkyl organosilicon with dual chemical sites for SO2 absorption and analysis of site-specific absorption entropy and enthalpy

Wet flue gas desulfurization is widely used for its high efficiency, however, the low absorption capacity, high viscosity and poor thermal stability of absorbents remains an open question. Herein, a low viscosity and high thermal stability SO2 absorbent with dual interacting sites was synthesized by introducing phenyl into organic silicon. The thermal stability of 1,5-bis (diethylamino)− 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane (BADPS) is comparable to ILs, while its viscosity is much lower than that of ILs. For the first time, we use a variant of the pseudo-first-order reaction rate equation obtained the reaction rate constant and the saturation absorption capacity. In addition, the optimal absorption and desorption temperatures were obtained based on an objective function. Mostly importantly, the absorption enthalpy change (ΔH) and entropy change (ΔS) of BADPS absorption reaction show the highest absolute values of SO2 absorbents reported so far. These results indicated that the prepared amine alkyl organosilicon could serve as a promising desulfurizing agent with low-energy consumption.

Correlation between absorbed acetylene spectral characteristic and nature of ionic liquids studied by in situ ATR-FTIR spectroscopy

Ionic liquids (ILs) are believed to be a prospective replacement for molecular solvents and are suggested to be used for storing and/or purifying acetylene. Systematic studies of the nature of the interaction between acetylene and different ILs may be necessary to predict new types of ionic liquids. Therefore, in order to investigate the absorption of acetylene by ionic liquids, in situ ATR-FTIR spectroscopy has been applied for the first time. Two series of ILs, such as [C2‍–‍10MIM][BF4] and ILs based on imidazolium with various anions, have been considered. A detailed analysis of the spectra of absorbed acetylene is given, with special attention being paid to the basicity of IL anions as well as the influence of the cation alkyl chain length. It has been found that the magnitude of the band shift associated with the CH stretching vibration and the antisymmetric CH bending vibration of absorbed acetylene correlates well with the change in the Kamlet-Taft β parameter of the ILs. Moreover, neither the free volume nor the IL polarity plays a key role in acetylene solubility. In addition, the enthalpy and entropy of absorption have been calculated for several ILs.

Absorption characteristics, model, and molecular mechanism of hydrogen sulfide in morpholine acetate aqueous solution

Absorption characteristics, model, and molecular mechanism of hydrogen sulfide in morpholine acetate aqueous solution

Trifunctional composite thermal barrier mitigates the thermal runaway propagation of large-format prismatic lithium-ion batteries

With the increasing energy density and capacity of lithium ion batteries (LIB), the safety problems caused by thermal runaway propagation (TRP) has become the most predominant hazard for electric vehicles (EVs) and energy storage systems (ESSs). Mitigating the TRP is significant for large-format LIB application. This study proposed a novel thermal barrier with nano-ceramic fiber, phase change materials (PCM) and mica cross skeleton. A 3 mm thermal barrier can effectively prevent the TRP behavior of a 153 Ah Li(Ni0.5Co0.2Mn0.3) (NCM523) battery module. The enthalpy of heat absorption of PCM is 1958 J/g. Besides, the mica skeleton can resist the extrusion pressure from the batteries, and the remaining nano-ceramic fiber provides insulation capacity. Moreover, the thermal barrier still maintains desirable heat insulation under pressure and high temperature operations, exhibiting high compressive strength. Furthermore, the thermal barrier can reduce the maximum temperature of the battery by about 10 °C during 2C charging and discharging conditions. This study guides the safety design of thermal barrier for large capacity LIB systems, contributing to the potential safety protection of next-generation EVs and ESSs.