Adsorption Of 1-butene Research Articles

Effect of ambient temperature on the adsorption performance of automotive activated carbon: An experimental and molecular simulation study

The ambient temperature is a non-negligible factor when evaluating the adsorption performance of automobile activated carbon. In this study, dynamic tests of butane adsorption on activated carbon were carried out at ambient temperatures of 293 K, 313 K, and 333 K. In addition, molecular simulation method was used to analyze the influence mechanism of temperature on the adsorption performance of activated carbon. The results show that the working capacity of automotive activated carbon decreases by 15.9% to 20.2% and the butane breakthrough time is shortened by 21.4% to 37.5%, as the ambient temperature is increased from 293 K to 333 K. In the high temperature environment, the thermal movement of the gas molecules is more intense so that the kinetic energy and diffusion coefficient of the butane molecules are increased. When activated carbon adsorbs multilayer butane molecules, the temperature increase mainly reduces the adsorption sites after the first adsorption layer (around 5.5 Å).

Micropatterning MXene/TiO2 Nanocomposite Ink for Gas Sensing

This work describes the preparation, characterization, and micropatterning of MXene(Ti3C2)/TiO2 nanocomposite inks. MXene nanopowder was oxidized to form MXene/TiO2 nanocomposite powder using an air-aging method. The MXene/TiO2 inks were prepared using deionized water (H2O) as the solvent/dispersant and polyvinylpyrrolidone (PVP) as the surfactant. Various techniques were utilized to characterize the MXene/TiO2 nanocomposite material, and the BET results showed the preferential adsorption of butane of the MXene/TiO2 coating. Utilizing an ultrasonic dispersion printer in conjunction with a stencil mask, the MXene/TiO2 nanocomposite ink was successfully printed onto a 10mm*10mm gold-plated silicon substrate. This process achieved millimeter-level precision control, enabling the printing of fine lines with a width of 1μm and a spacing of 0.05mm. Furthermore, this technique demonstrated the ability to render various complex patterns, thus exemplifying the potential of MXene/TiO2 nanocomposite ink in the field of micro- and nano-manufacturing.

Preparation and characterization of pitch-derived activated carbon pellet for butane adsorption

Preparation and characterization of pitch-derived activated carbon pellet for butane adsorption

Tailoring the Selectivity of 1,3-Butadiene versus 1-Butene Adsorption on Pt(111) by Ultrathin Ionic Liquid Films

Tailoring the Selectivity of 1,3-Butadiene versus 1-Butene Adsorption on Pt(111) by Ultrathin Ionic Liquid Films

Tailoring 3D Printed Micro‐Structured Carbons for Adsorption

AbstractThe manufacture of tailored carbon‐based adsorbent structures with exceptionally low‐pressure drops and improved kinetics using stereolithographic 3D printing is presented. Adsorbent structures are printed from commercial resins with square, circular, and hexagonal cross‐sectional microchannels. These structures can reduce energy use by 50–95% compared to conventional carbon‐packed beds. The activated 3D printed carbon achieves Brunauer–Emmett–Teller surface areas over 1000 m2 g−1 and shows outstanding butane adsorption capacities, over twice the capacity of a commercial carbon and a comparable capacity to phenolic‐based carbons. The structures also show excellent uptakes of cyclohexane, up to 0.62 g g−1 in a saturated feed. The introduction of complex axial geometries including spirals and chevrons enable superior adsorption kinetics and premature breakthrough of contaminants at high gas flow rates. These results demonstrate the success of intelligent manufacturing of low‐pressure drop, high‐capacity micro‐structured adsorbents, allowing for the development of gas separation technologies for applications such as greenhouse gas removal and respiratory protection.

Influence of 1-Butene Adsorption on the Dimerization Activity of Single Metal Cations on UiO-66 Nodes.

Grafting metal cations to missing linker defect sites in zirconium-based metal-organic frameworks, such as UiO-66, produces a uniquely well-defined and homotopic catalytically active site. We present here the synthesis and characterization of a group of UiO-66-supported metal catalysts, M-UiO-66 (M = Ni, Co, Cu, and Cr), for the catalytic dimerization of alkenes. The hydrogen-deuterium exchange via deuterium oxide adsorption followed by infrared spectroscopy showed that the last molecular water ligand desorbs from the sites after evacuation at 300 °C leading to M(OH)-UiO-66 structures. Adsorption of 1-butene is studied using calorimetry and density functional theory techniques to characterize the interactions of the alkene with metal cation sites that are found active for alkene oligomerization. For the most active Ni-UiO-66, the removal of molecular water from the active site significantly increases the 1-butene adsorption enthalpy and almost doubles the catalytic activity for 1-butene dimerization in comparison to the presence of water ligands. Other M-UiO-66 (M = Co, Cu, and Cr) exhibit 1-3 orders of magnitude lower catalytic activities compared to Ni-UiO-66. The catalytic activities correlate linearly with the Gibbs free energy of 1-butene adsorption. Density functional theory calculations probing the Cossee-Arlman mechanism for all metals support the differences in activity, providing a molecular level understanding of the metal site as the active center for 1-butene dimerization.

CsxCo/Na-MOR Coating on Ceramic Monoliths for Co-Adsorption of Hydrocarbons Mixture and Selective Catalytic Reduction of NOx

In this work, ceramic monoliths were coated with powders based on exchanged Cs and/or Co cations in Na-mordenite (MOR) zeolite. SEM images showed that zeolite particles fill the macropores of cordierite walls and form a continuous layer of approximately 40 µm with good adherence. XPS analysis revealed that Co and Cs are present on the film surface solely as Co2+ and Cs+ at exchange positions in zeolite. The monolithic structures were evaluated for the butane-toluene co-adsorption and SCR of NOx with hydrocarbon mixture as the reducing agent. The presence of alkali metal cations in the zeolitic lattice favored the adsorption capacity of both hydrocarbons, while cobalt cations provoked a decrease in the adsorbed amounts due to its weak interaction with the HCs. Breakthrough curves of butane adsorption showed a roll-up phenomenon, associated with a competitive adsorption effect generated from toluene presence. In the desorption process, it was observed that adsorbed toluene hindered the butane diffusion through mordenite channels, which released at higher temperatures (above 250 °C). Cs2CoM and Cs7CoM monoliths were more active than the CoM monolith for NO-SCR. The presence of Cs cations close to Co cations increased the hydrocarbons concentration around active sites at high temperatures, according to TPD results, promoting the reduction activity of NO.

Sulfur-doped silicon carbide nanotube as a sensor for detecting liquefied petroleum gas at room temperature

Sensing behaviors of sulfur-doped silicon carbide nanotube (S-SiCNT) to propane and butane gases, which are parts of Liquefied Petroleum Gas (LPG), are investigated by calculations of adsorption energy, electronic band structure, density of states (DOS), sensitivity and charge transfer using first principle calculations based on density functional theory. Adsorption of propane or butane undergoes spontaneous exothermic reactions, resulting in chemisorptions. Propane or butane adsorption on S-SiCNT induces notable alteration of electronic structure of the nanotube, which causes electron transfer from the nanotube to the propane or butane (hole-doping). The sensitivity to propane is found much higher than that to butane of S-SiCNT. The calculated sensitivities to propane and butane of S-SiCNT and charge transfer analyses underscore the significant sensor properties of S-SiCNT to detect LPG at room temperature.

Experimental and Numerical Investigation into the Heat- and Mass-Transfer Processes of n-Butane Adsorption on Activated Carbon.

In this work, the adsorption parameters of n-butane vapor on an absorbent were tested following the fixed-bed method. According to the corresponding experiments, the maximum adsorption capacity and breakthrough time of activated carbon (AC) are 0.2674 g·g–1 and 924 min, respectively. According to the two-energy-state model formula and the classical adsorption heat formula, the values of theoretical and actual adsorption heat of AC adsorbing n-butane are 5.48 and 5.56 kJ·mol–1, respectively. The model for adsorption of n-butane by an AC fixed bed is based on the analytical solutions to the mass, momentum, and energy conservation equations. The model is built using porous media zone in ANSYS Fluent, the implementation of the model into ANSYS Fluent under user-defined functions (UDFs) is also described, the mass source term Si and energy source term ST are loaded into Fluent through UDF, and then the mass- and heat-transfer processes of AC in the absorption of n-butane are simulated. Furthermore, the predictions by ANSYS Fluent are compared with in situ experimental data, and the deviation rate of breakthrough time and temperature of six monitoring points is less than 5%. The results verify the accuracy and feasibility of computational fluid dynamics (CFD). Therefore, the model can be used to predict the engineering application of the adsorption of organic gases by various porous media.

A Hydrogen‐Bonded yet Hydrophobic Porous Molecular Crystal for Molecular‐Sieving‐like Separation of Butane and Isobutane

AbstractPorous molecular crystals sustained by hydrogen bonds and/or weaker connections are an intriguing type of adsorbents, but they rarely demonstrate efficient adsorptive separation because of poor structural robustness and tailorability. Herein, we report a porous molecular crystal based on hydrogen‐bonded cyclic dinuclear AgI complex, which exhibits exceptional hydrophobicity with a water contact angle of 134°, and high chemical stability in water at pH 2–13. The seemingly rigid adsorbent shows a pore‐opening or nonporous‐to‐porous type butane adsorption isotherm and complete exclusion of isobutane, indicating potential molecular sieving. Quantitative column breakthrough experiments show slight co‐adsorption of isobutane with an experimental butane/isobutane selectivity of 23, and isobutane can be purified more efficiently than for butane. In situ powder/single‐crystal X‐ray diffraction and computational simulations reveal that a trivial guest‐induced structural transformation plays a critical role.

A Hydrogen-Bonded yet Hydrophobic Porous Molecular Crystal for Molecular-Sieving-like Separation of Butane and Isobutane.

Porous molecular crystals sustained by hydrogen bonds and/or weaker connections are an intriguing type of adsorbents, but they rarely demonstrate efficient adsorptive separation because of poor structural robustness and tailorability. Herein, we report a porous molecular crystal based on hydrogen-bonded cyclic dinuclear AgI complex, which exhibits exceptional hydrophobicity with a water contact angle of 134°, and high chemical stability in water at pH 2-13. The seemingly rigid adsorbent shows a pore-opening or nonporous-to-porous type butane adsorption isotherm and complete exclusion of isobutane, indicating potential molecular sieving. Quantitative column breakthrough experiments show slight co-adsorption of isobutane with an experimental butane/isobutane selectivity of 23, and isobutane can be purified more efficiently than for butane. In situ powder/single-crystal X-ray diffraction and computational simulations reveal that a trivial guest-induced structural transformation plays a critical role.

Experimental study of butane adsorption on coconut based activated carbon for different gas concentrations, temperatures and relative humidities

ABSTRACT In this paper, the adsorption behaviour of activated carbon was investigated experimentally for changing butane concentration, temperature and relative humidity. Throughout the study, the coconut-based activated carbon was used. During the tests applied for butane concentration of 2, 4, 8, 20, 40 and 80 ppm, the temperature was taken as 15, 23 and 33°C for a relative humidity of 50, 70 and 90%. The results showed that butane concentration had a direct relationship with adsorption. However, temperature and adsorption were inversely proportional. As a result of the adsorption between activated carbon and butane, it led to physical adsorption as one of the most important types of adsorption due to Van der Waals forces among molecules. To create physical adsorption, lower temperature ranges were more convenient. The relative humidity of the air reduced the time to reach the maximum saturation rate. The increased relative humidity also reduced the amount of butane adsorbed. Also, 50% relative humidity range was an important turning point. Relative humidity affected the adsorption of butane at a relative humidity of 50%. However, the relative humidity at 70 and 90% significantly reduced butane adsorption; on the other hand, it considerably increased the adsorption of moisture.

Thermodynamic Separation of 1-Butene from 2-Butene in Metal-Organic Frameworks with Open Metal Sites.

Most C4 hydrocarbons are obtained as byproducts of ethylene production or oil refining, and complex and energy-intensive separation schemes are required for their isolation. Substantial industrial and academic effort has been expended to develop more cost-effective adsorbent- or membrane-based approaches to purify commodity chemicals such as 1,3-butadiene, isobutene, and 1-butene, but the very similar physical properties of these C4 hydrocarbons make this a challenging task. Here, we examine the adsorption behavior of 1-butene, cis-2-butene, and trans-2-butene in the metal-organic frameworks M2(dobdc) (M = Mn, Fe, Co, Ni; dobdc4- = 2,5-dioxidobenzene-1,4-dicarboxylate) and M2(m-dobdc) (m-dobdc4- = 4,6-dioxidobenzene-1,3-dicarboxylate), which all contain a high density of coordinatively unsaturated M2+ sites. We find that both Co2(m-dobdc) and Ni2(m-dobdc) are able to separate 1-butene from the 2-butene isomers, a critical industrial process that relies largely on energetically demanding cryogenic distillation. The origin of 1-butene selectivity is traced to the high charge density retained by the M2+ metal centers exposed within the M2(m-dobdc) structures, which results in a reversal of the cis-2-butene selectivity typically observed at framework open metal sites. Selectivity for 1-butene adsorption under multicomponent conditions is demonstrated for Ni2(m-dobdc) in both the gaseous and the liquid phases via breakthrough and batch adsorption experiments.

Influence of acidity on the performance of silica supported tungsten oxide catalysts assessed by in situ and Operando DRIFTS

The types of acidity on WOx/SiO2 catalysts prepared with different tungsten loadings (5 and 9 wt.% W) and pretreatment atmospheres (N2 and H2) were clarified by using the in situ diffuse reflectance infrared Fourier transform spectroscopy with temperature-programmed desorption (in situ DRIFTS-TPD) technique. Ammonia (NH3) acted as probe molecules that could block Lewis acid site type II (1620 cm−1) on the studied catalysts. The reactant feed containing 2% trans-2-butene or mixed feed of 2% trans-2-butene and 4% ethylene were used to investigate the reaction pathway on the WOx/SiO2 catalysts. Combining the Operando DRIFTS with gas chromatography-flame ionization detector (Operando DRIFTS-GC-FID) technique and in situ DRIFTS-TPD led to more deeply understanding of the correlation of acid sites and the primary cross metathesis reaction as the main reaction with isomerization of trans-2-butene as the side reaction. The adsorption energy of pulse chemisorption of 1-butene on catalyst by in situ DSC, confirmed the presence of the Lewis acid site type II related to the opportunity of 1-butene adsorption. The results confirmed that the Lewis acid site at 1620 cm−1 was crucial for the secondary metathesis reaction of 1-butene.

Effects of Pore Structure on n-Butane Adsorption Characteristics of Polymer-Based Activated Carbon

In this study, the correlation between n-butane adsorption characteristics and pore characteristics of activated carbons (ACs) was investigated by activated polymer-based hard carbons (APHCs) using a carbon dioxide activation method. The structural characteristics of the ACs were observed by X-ray diffraction and Raman spectroscopy. The N2 adsorption isotherm characteristics at 77 K were confirmed by Brunauer–Emmett–Teller, Barrett–Joyner–Halenda, and nonlocal density functional theory equations. From the results, specific surface areas and total pore volume of the ACs were determined to be 1020–2440 m2/g and 0.42–1.30 cm3/g, respectively. As the activation time increased, the fraction of micropores decreased from 85% to about 40%. On the other hand, the porosity of the mesopores increased to about 60% from a ratio of about 10%. The specific power adsorption has been increased with the development of the mesopores and exhibited 20 960 sK/g at APHC-10–5 (540% higher compared to that of APHC-10–2). It was c...

Selective hydrogenation of 1,3-butadiene catalyzed by a single Pd atom anchored on graphene: the importance of dynamics.

The active-site structure, reaction mechanism, and product selectivity of the industrially important selective hydrogenation of 1,3-butadiene are investigated using first principles for an emerging single-atom Pd catalyst anchored on graphene. Density functional theory calculations suggest that the mono-π-adsorbed reactant undergoes sequential hydrogenation by Pd-activated H2. Importantly, the high selectivity towards 1-butene is attributed to the post-transition-state dynamics in the second hydrogenation step, which leads exclusively to the desorption of the product. This dynamical event prevails despite the existence of energetically preferred 1-butene adsorption on Pd, which would eventually lead to complete hydrogenation to butane and be thus inconsistent with experimental observations. This insight underscores the importance of dynamics in heterogeneous catalysis, which has so far been underappreciated.

Thermodynamics of adsorption of light hydrocarbons on microporous active carbons at supercritical temperatures

Methods for describing adsorption isotherms and the thermodynamic characteristics of adsorption of methane, ethylene, propane, and butane on active carbons are considered in a wide range of temperatures below and above the critical ones.

6-4-3 シリカ添着法による吸着材のブタン吸着性能改善に関する研究(6-4 分散システム要素技術・開発,Session 6 省エネルギー,研究発表)

6-4-3 シリカ添着法による吸着材のブタン吸着性能改善に関する研究(6-4 分散システム要素技術・開発,Session 6 省エネルギー,研究発表)

Adsorption and dehydrogenation of ethane, propane and butane on Rh13 clusters supported on unzipped graphene oxide and TiO2(110) - a DFT study.

The catalytic activity for the adsorption and dehydrogenation of alkanes (CnH2n+2, n = 2, 3, 4) on a low-symmetry Rh13 cluster (Rh13-Ls) is compared with a system consisting of the same cluster (Rh13-Ls) supported on either an unzipped graphene-oxide (UGO) sheet (Rh13-Ls/UGO) or a TiO2(110) surface (Rh13-Ls/TiO2). The adsorption energies of these alkanes, calculated using density-functional theory, follow the order Rh13-Ls/TiO2 ≈ Rh13-Ls/UGO > Rh13-Ls. Our proposed reaction path for the dehydrogenation of ethane, propane and butane on Rh13-Ls/UGO has first barrier heights of 0.21, 0.22 and 0.16 eV for the dissociation of a terminal C-H bond to form -C2H5, -C3H7 and -C4H9, respectively. Compared with the barriers on Rh13-Ls and Rh13-Ls/TiO2, the barrier on Rh13-Ls/UGO is the lowest for all alkanes. The calculated data, including the electronic distribution and the density of states of alkanes adsorbed on Rh13-Ls/UGO, Rh13-Ls and Rh13-Ls/TiO2, to support our results are presented.

Adsorption separation for high purity propane from liquefied petroleum gas in a fixed bed by removal of alkanes

Abstract The process for high purity propane production via adsorption separation of propane from liquefied petroleum gas (LPG) was investigated at ambient temperature and atmospheric pressure under dynamic conditions in a fixed bed. Breakthrough curves for LPG adsorption on 4A, 5A, 13X and NaY zeolite pellets and granular activated carbon were measured. The length of unused bed (LUB) values for isobutane and butane adsorption in fixed beds with different adsorbent samples were determined by analyzing breakthrough curves. Effects of bed height (5–10 cm) and flow rate (60–100 mL/min) on adsorption characteristics of propane, isobutane and butane onto activated carbon were also examined. Among all these five adsorbent samples, activated carbon exhibited the highest adsorption capacity and the best separation performance, and the concentration of propane in the outlet gas could reach as high as 99.7% (volume fraction). Besides, the LUB value of activated carbon fixed bed was the smallest, which indicated that activated carbon fixed bed was more suitable for adsorption separation of propane from LPG. Adsorption dynamics also showed that relatively lower flow rate and relatively longer bed length were favorable for removal of isobutane and butane from LPG. The Yoon–Nelson model provided a good fit to the experimental data and there was a nice agreement between the numerical simulations and the corresponding data obtained from experiments. All the correlation coefficients in fitted equations exceeded 0.98, indicating a good confidence level for the fit.