Few-layered hexagonal boron nitride nanosheets stabilized Pt NPs for oxidation promoted adsorptive desulfurization of fuel oil

A few-layered hexagonal boron nitride nanosheets stabilized platinum nanoparticles(Pt/h-BNNS)is engineered for oxidation-promoted adsorptive desulfurization(OPADS)of fuel oil.It was found that the few-layered structure and the defective sites of h-BNNS not only are beneficial to the stabilization of Pt NPs but also favor the adsorption of aromatic sulfides.By employing Pt/h-BNNS with a Pt loading amount of 1.19 wt%as the active adsorbent and air as an oxidant,a 98.0%sulfur removal over dibenzothiophene(DBT)is achieved along with a total conversion of the DBT to the corresponding sulfones(DBTO_(2)).Detailed experiments show that the excellent desulfurization activity originates from the few-layered structure of h-BNNS and the high catalytic activity of Pt NPs.In addition,the OPADS system with Pt/h-BNNS as the active adsorbent shows remarkable stability in desulfurization performance with the existence of different interferents such as olefin,and aromatic hydrocarbons.Besides,the Pt/h-BNNS can be recycled 12 times without a significant decrease in desulfurization performance.Also,a process flow diagram is proposed for deep desulfurization of fuel oil and recovery of high value-added products,which would promote the industrial application of such OPADS strategy.

Characterization of adsorptive capacity and mechanisms on adsorption of copper, lead and zinc by modified orange peel

A novel adsorbent was prepared by modifying orange peel with sodium hydroxide and calcium chloride. The morphological and characteristics of the adsorbent were evaluated by infrared spectroscopy （IR）, scanning electron microscopy （SEM） and N2-adsorption techniques. The adsorption behavior of Cu^2＋, Pb^2＋ and Zn^2＋ on modified orange peel （SCOP） was studied by varying parameters like pH, initial concentration of metal ions. Equilibrium was well described by Langmuir equation with the maximum adsorption capacities for Cu^2＋, Pb^2＋ and Zn^2＋ of 70.73, 209.8 and 56.18 mg/g, respectively. Based on the results obtained in batch experiments, breakthrough profiles were examined using a column packed with SCOP for the separation of small concentration of Pb^2＋ from an excess of Zn^2＋ followed by elution tests. Ion exchange with Ca^2＋ neutralizing the carboxyl groups of the pectin was found to be the predominant mechanism.

Aspen Adsorption在气体吸附过程模拟方面的应用

Aspen Adsorption是一款吸附模拟软件,常用于气体吸附分离过程的模拟计算,对操作条件优化、设计优化、吸附材料性能评价等方面具有一定的指导作用。简要介绍了Aspen Adsorption软件的应用、模型参数和各种衡算方程,总结了其在穿透曲线计算方面的模拟计算和应用,归纳了利用循环控制器Cycle Organizer针对各种类型的变压吸附PSA(Pressure Swing Adsorption)和变温吸附TSA(Temperature Swing Adsorption)过程进行模拟的情况。此外,针对Aspen Adsorption与其他软件结合使用的案例也进行了简要介绍。最后对Aspen Adsorption的未来发展进行了展望。

Efficient desulfurization of gasoline fuel using ionic liquid extraction as a complementary process to adsorptive desulfurization

The extractive desulfurization of a model gaso- line containing several alkyl thiols and aromatic thiophenic compounds was investigated using two imidazolium-based ionic liquids （ILs）, 1-butyl-3-methylimidazolium tetrachloroaluminate, and 1-octyl-3-methylimidazolium te- trafluoroborate, as extractants. A fractional factorial design of experiments was employed to evaluate the effects and possible interactions of several process variables. Analysis of variance tests indicated that the number of extraction steps and the IL/gasoline volume ratio were of statistically highly significant, but none of the interactions were significant. The results showed that the desulfurization efficiency of the model gasoline by the ILs could reach 95.2 % under the optimal conditions. The optimized conditions were applied to study the extraction of thiophenic compounds in model gasoline and several real gasoline samples; the following order was observed in their separation： benzothio- phenc 〉 thiophcne 〉 3-methylthiophene 〉 2-methylthiophene, with 96.1% removal efficiency for benzothiophene. The IL extraction was successfully applied as a complementary process to the adsorptive desulfurization with acti- vated Raney nickel and acetonitrile solvent. The results indicated that the adsorptive process combined with IL extraction could provide high efficiency and selectivity, which can be regarded as a promising energy efficient desulfurization strategy for production of low-sulfur gasoline.

Adsorptive desulfurization over hierarchical beta zeolite by alkaline treatment

Hierarchical beta zeolites with SiO2/Al2O3 molar ratios of 16 to 25 were obtained by alkaline treatment in NaOH solution. The effects of treatment temperature on crystallinity, textural properties and chemical composites were studied by XRD, N2 sorption, FT-IR and XRF techniques. The desulfurization performance of parent and alkaline-treated beta zeolites was investigated by static absorption in four model fuels, containing four sulfur compounds of different molecular sizes like thiophene （TP）, 3-methylthiophene （3-MT）, benzothiophene （BT） and dibenzothiophene （DBT）, respectively. The crystallinity was observed to be successfully maintained when the treatment temperature was below 50 ℃. Mesoporosity of beta zeolite was evidently developed with alkaline treatment. The formation of mesopore remarkably improved the desulfurization performance for TP, 3-MT, BT and DBT, especially for DBT with larger molecular diameter. Though the addition of toluene in the model fuels resulted in a significant drop of the desulfurization performance of mesoporous beta zeolite, the introduction of cerium ions to some extent mitigated the effect of toluene, which means that both the adsorbent’s porous structure and the adsorption mode are responsible for the desulfurization performance. The adsorbent of cerium ion-exchanged mesoporous beta showed about 80% recovery of desulfurization after the first regeneration.

Regeneration of Ag_XO@SBA-15 for reactive adsorptive desulfurization of fuel

Adsorbent regeneration is critical for a continuous adsorption–regeneration process and often underestimated. In this work,the regeneration of bifunctional AgXO@SBA-15 for [O]-induced reactive adsorptive desulfurization of liquid fuel is reported and further investigated. The spent AgXO@SBA-15 was regenerated in various types of solvents followed by calcination and tested in multiple desulfurization–regeneration cycles. The effects of regenerate solvents were also compared systematically. The original and regenerated AgXO@SBA-15 was characterized by X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Nadsorption, X-ray photoelectron spectroscopy and atomic absorption spectrometry. The recovery of desulfurization capacity using various solvents follows the order of acetonitrile [ acetone [ ethanol [ methanol [ water. Owing to the complete reduction of silver species to Ag~0 and severe agglomeration of Ag~0, the bifunctional AgXO@SBA-15 demonstrating [ 85%(2.60 mg-S/g) of sulfur removal dramatically reduced to \ 46%(1.56 mg-S/g) after only 1 st-cycle regeneration. It is suggested that polar organic species strongly adsorbed(or residual) on the spent AgXO@SBA-15, in that case, after solvent wash may contribute to the accelerated decomposition of Ag~+ to Ag~0 in the following calcination step. The desulfurization capacity decreased rather mildly in the later regeneration runs. Cautious choice of regeneration conditions and strategies to rational design stabilized adsorbents is required to avert the adsorbent deactivation.

Adsorptive removal of nitrogen-containing compounds from fuel by metal-organic frameworks

The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,quinoline and indole were used as model NCCs in fuels to study the adsorption mechanism.The physicochemical properties of the adsorbents were characterized by XRD,N2physical adsorption,FT-IR spectrum and Hammett indicator method.The metal-organic frameworks(MOFs),especially the MIL-101(Cr)containing Lewis acid sites as well as high specific surface area,can adsorb large quantities of NCCs from fuels.In addition,the adsorptive capacity over MIL-101(Cr)will be different for NCCs with different basicity.The stronger basicity of the NCC is,the more it can be absorbed over MIL-101(Cr).Furthermore,pore size and shape also affect the adsorption capacity for a given adsorbate,which can be proved by the adsorption over MIL-53(Al)and MIL-96(Al).The pseudo-second-order kinetic model and Langmuir equation can be used to describe kinetics and thermodynamics of the adsorption process,respectively.Finally,the regeneration of the used adsorbent has been conducted successfully by just washing it with ethanol.

Adsorptive Properties of Dyes to Cellulosic Sheet and Discoloration of Dye Solution by UV-ray Irradiation

The adsorptive properties and selectivity of dyes and water molecules to cellulosic sheet, dependence of adsorptive properties of dyes on the concentration of dye solution, and discoloration of the dye solution due to the UV-ray irradiation were determined for 18 kinds of commercial dyes. The results are as follows： 1） the adsorptive properties of dyes to cellulose sheet differed greatly, but did not depend on the dye types such as acidic, basic and so on; 2） adsorptive properties of dyes to cellulosic sheet de- pended on the concentration of dye solution and were classified into 4 types： concentration-independent, increasing or decreasing with dye concentration, and having a maximum. This classification was irrelevant to the dye types; 3） the irradiation of UV-ray did not cause significant discoloration of dye solution itself, which suggested that wood components as well as dye molecules influence the discoloration of wood.

Trace Determination of Zirconium(Ⅳ) by Anodic Adsorptive Voltammetry at a Carbon Paste Electrode

A new sensitive adsorptive voltammetric method was described for the determination of zirconium at a carbon paste electrode (CPE) in the presence of alizarin complexone (ALC). Optimal analytical conditions are: 1.0?0-6 or 5.0?0-7 mol/L ALC, 0. 20 mol/L HAC-NaAc (pH 4.3), accumulation for 60 s at 0 V (vs. SCE), and linear scanning from 0 V to 1.0 V at 250 mV/s. The peak potential of the complex is at 0.81 V. By using a model JP-303 polarographic analyzer, 2.0?0-10 mol/L (S/N=3) zirconium can be detected with a 90 s accumulation, when the 2nd-order derivative linear sweep technique is used, and the linear range is 6.0?0-10-2.0?0-8 mol/L (5.0?0-7 mol/L ALC) and 2.0?0-8-2.0?0-7 mol/L (1.0?0-6 mol/L ALC), respectively. The developed method was applied to the determination of trace zirconium in the ore samples with satisfactory results.

Determination of trace amounts of morphine in human plasma by anodic adsorptive stripping differential pulse voltammetry

New adsorptive anodic differential pulse stripping voltammetry method for the direct determination of morphine at trace levels in human plasma of addicts is proposed.The procedure involves an adsorptive accumulation of morphine on a HMDE,followed by oxidation of adsorbed morphine by voltammetry scan using differential pulse modulation.The optimum conditions for the analysis of morphine are pH 10.5,Eacc of -100 mV（vs.Ag/AgCl）,and tacc of 120 s.The peak current is proportional to the concentration of morphine,and a Linear calibration graph is obtained at 0.01-3.10μg mL^-1.A relative standard deviation of 1.06%（n=5）was obtained,and the limit of detection was 3 ng mL^-1.The capabiLity of the method for the analysis of real samples was evaluated by the determination of morphine in spiked human plasma and addicts human plasma with satisfactory results.

Protein-derived nitrogen and sulfur co-doped carbon for efficient adsorptive removal of heavy metals

A nitrogen and sulfur co-doped carbon has been synthesized employing egg white as a sustainable protein-rich precursor.According to CHNS elemental analysis,N,S and O heteroatoms accounted for mass fractions of 3.66%,2.28%and 19.29%respectively,and the types of surface functionalities were further characterized by FT-IR and XPS measurements.Although the carbon possessed a smaller surface area(815 m2·g-1)compared to a commercial activated carbon(1100 m2·g-1),its adsorption capacity towards Co2+reached 320.3 mg·g-1,which was over 8 times higher compared to the limited 34.0 mg·g-1 over the activate carbon.Furthermore,the carbon was found to be an efficient adsorbent towards a series of metal ions including VO2+,Cr3+,Ni2+,Cu2+and Cd2+.Combined with its environmental merits,the protein derived carbon may be a promising candidate for heavy metal pollution control.

Comparison on Adsorptive Separation of n-Paraffins Based on Binderless and Binder-containing Zeolite 5A Pellets

Binderless zeolite is considered to be a potential alternative for binder-containing zeolite in the industrial applications of adsorptive separation process. Synthesized binderless zeolite and commercial binder-containing product were used in adsorptive separation of n-paraffins from a model oil, with their performance compared. It is indicated that the binderless zeolite exhibits by 25%-35% higher in saturated adsorption capacity and by 115%-130% more adsorption amount at the breakthrough point with much shorter length of mass-transfer zone. Adsorptive separation of n-paraffins from naphtha was carried out in a fixed-bed adsorber containing the synthesized binderless zeolite 5 A under the operating conditions covering a feed space velocity of 90 h-1 and an adsorption temperature of 573 K. As compared to original naphtha, the raffinate shows by 34 units more in research octane number and by around 10% more of potential aromatic content, while the desorption oil exhibits by 13.3% more ethylene yield and by 11.7% higher in total olefins yield.

Research on Optimized Utilization of Naphtha Resources Based on Adsorptive Separation with Zeolite

By means of molecular scale management, the technology of separating normal paraffins from naphtha through adsorption using 5A molecular sieves was studied with the purpose of optimizing the utilization of naphtha. The raw materials used in steam cracking and catalytic reforming processes could be allocated properly. During the adsorption process, the separation efficiency of the normal paraffins was above 99.9% with the purity of normal paraffins in the desorption oil exceeding 98.2%. With the use of the desorption oil as the feedstock of steam cracking, the ethylene yield increased from 29.7%-35.0% to 41.4%- 49.2% compared to that of the naphtha in the existing plant under similar operation conditions. The potential aromatic content of the raffinate oil rose from 30.6% to 43.5% compared to that in naphtha. The research octane number of the raffinate oil reached more than 85 with an increase of 20 units compared to that of naphtha, so the raffinate oil is more suitable for use as a blending component for high-octane clean gasoline.

Adsorptive Recovery of Uranium from Nuclear Fuel Industrial Wastewater by Titanium Loaded Collagen Fiber

Effective recovery of UO2+2 from wastewater is essential for nuclear fuel industry and related industries.In this study,a novel adsorbent was prepared by loading titanium(Ti4+) onto collagen fiber(TICF),and its physical and chemical properties as well as adsorption to UO2+2 in nuclear fuel industrial wastewater were investigated.It is found that TICF can effectively recover UO2+2 from the wastewater with excellent adsorption capacity.The adsorption capacity is 0.62 mmol·g-1 at 303 K and pH 5.0 when the initial concentration of UO2+2 is 1.50 mmol·L-1.The adsorption isotherms can be described by the Langmuir equation and the adsorption capacity increases with temperature.The effect of co-existed F on the adsorption capacity for UO2+2 is significant,which can be eliminated by adding aluminum ions as complexing agent,while the other co-existed ions in the solutions,including HCO-3,Cl-,NO-3,Ca2+,Mg2+ and Cu2+,have little effect on the adsorption capacity for UO2+2.The saturated TICF after UO2+2 adsorption can be regenerated by using 0.2 mol·L-1 nitrate(HNO-3) as desorption agent,and the TICF can be reused at least three times.Thus the TICF is a new and effective adsorbent for the recovery of UO2+2 from the wastewater.

Safety and clinical efficacy of granulocyte and monocyte adsorptive apheresis therapy for ulcerative colitis

Active ulcerative colitis （UC） is frequently associated with infiltration of a large number of leukocytes into the bowel mucosa. Therefore, removal of activated circulating leukocytes by apheresis has the potential for improving UC. In Japan, since April 2000, leukocytapheresis using Adacolumn has been approved as the treatment for active UC by the Ministry of Health and Welfare. The Adacolumn is an extracorporeal leukocyte apheresis device filled with cellulose acetate beads, and selectively adsorbs granulocytes and monocytes/macrophages. To assess the safety and clinical efficacy of granulocyte and monocyte adsorptive apheresis （GMCAP） for UC, we reviewed 10 open trials of the use of GMCAP to treat UC. One apheresis session （session time, 60 min） per week for five consecutive weeks （a total of five apheresis sessions） has been a standard protocol. Several studies used modified protocols with two sessions per week, with 90-min session, or with a total of 10 apheresis sessions. Typical adverse reactions were dizziness, nausea, headache, flushing, and fever. No serious adverse effects were reported during and after GMCAP therapy, and almost all the patients could complete the treatment course. GMCAP is safe and well-tolerated. In the majority of patients, GMCAP therapy achieved clinical remission or improvement. GMCAP is a useful alternative therapy for patients with steroid-refractory or -dependent UC. GMCAP should have the potential to allow tapering the dose of steroids, and is useful for shortening the time to remission and avoiding re-administration of steroids at the time of relapse. Furthermore, GMCAP may have efficacy as the first-line therapy for steroid-naive patients or patients who have the first attack of UC. However, most of the previous studies were uncontrolled trials. To assess a definite efficacy of GMCAP, randomized, doubleblind, sham-controlled trials are necessary. A serious problem with GMCAP is cost; a single session costs ￥145 000 （$1 300）. However, if this treatment prevents hospital admission, re-administration of steroids and surgery, and improves a quality of life of the patients, GMCAP may prove to be cost-effective.

Ultra-deep adsorptive removal of thiophenic sulfur compounds from FCC gasoline over the specific active sites of CeHY zeolite

Adsorption desulfurization performance of Na Y,HY and Ce HY zeolites is evaluated in a miniature fixedbed flow by model gasoline containing with thiophene,tetrahydrothiophene,2-methylthiophene,benzothiophene or mixed sulfur compounds.The structural properties of adsorbents are characterized by XRD,N2-adsorption and XPS techniques.Adsorption desulfurization mechanisms of these sulfur compounds over the specific active sites of adsorbents as a major focus of this work,have been systematically investigated by using in situ FT-IR spectroscopy with single and double probing molecules.Desulfurization experimental results show that the Ce HY adsorbent exhibits superior adsorption sulfur capacity at breakthrough point of zero sulfur for ultra-deep removal of each thiophenic sulfur compound,especially in the capture of aromatic 2-methylthiophene(about ca.28.6 mgS/gadsorbent).The results of in situ FT-IR with single probing molecule demonstrate an important finding that high oligomerization ability of thiophene or 2-methylthiophene on the CeHY can promote the breakthrough adsorption sulfur capacity,mainly resulting from the synergy between Br?nsted acid sites and Ce(III)hydroxylated species active sites located in the supercages of Ce HY.Meanwhile,the result of in situ FT-IR with double probing molecules further reveals the essence of oligomerization reactions of thiophene and 2-methylthiophene molecules on those specific active sites.By contrast,the oligomerization reaction of benzothiophene molecules on the active sites of Ce HY cannot occur due to the restriction of cavity size of supercages,but they can be adsorbed on the Br?nsted acid sites via protonation,and on Ce(III)hydroxylated species and extra-framework aluminum hydroxyls species via direct"S-M"bonding interaction.As to the tetrahydrothiophene,adsorption mechanism is similar to that of benzothiophene,except in the absence of protonation.The paper can provide a new design idea of specific adsorption active sites in excellent desulfurization adsorbents for elevating higher quality of FCC gasoline in the future.

Effective adsorptive denitrogenation from model fuels over yttrium ion-exchanged Y zeolite

The adsorption removal of indole and quinoline in octane with and without toluene over zeolites NaY and Yttrium Ion-exchanged Y(YY)using batch adsorption experiments was studied at 25℃and 0.1 MPa.YY was prepared by treating NaY with Y(NO3)3 solution twice via liquid ion-exchange method.NaY and YY were both characterized by XRD,SEM,N2 adsorption,XRF,NH3-TPD,and pyridine-FTIR techniques.Adsorption isotherms of indole,quinoline and toluene in octane were conducted at 25.0℃to explain the influence of toluene on nitrogen removal over NaY and YY.The partial destruct of the crystalline structure of NaY was observed after the introduction of yttrium ion,which led to an evident decline in BET surface area and pore volume of YY.Strong Br?nsted acidity and medium Lewis acidity were introduced by yttrium ion-exchange.Though the specific surface area and pore volume of YY were much lower than those of NaY,YY exhibited equivalent adsorption capacities for indole and quinoline as NaY in model fuels without toluene.In the presence of 20 vol%toluene,however,YY exhibited much higher adsorption capacities for indole and quinoline than NaY,especially in the case of quinoline.The improved toluene-tolerant of YY was ascribed to the strong acid–base interaction between YY and quinoline and the decreased adsorption strength between YY and toluene.

Study of Adsorptive Ethylene/Ethane Separation with Ag^+-Exchanged Resins via π-Complexation

Ag^+-exchanged resins are prepared and studied for ethylene/ethaneseparation by adsorption. On Ag^+-exchanged S9, at 25 deg. C and0.1013 Mpa, the equilibrium adsorbed amount for C_2H_4 is 0.992 mmol·g^-1, and The adsorption ratio for C_2H_4/C_2H_6 is 3.56. Theadsorption capacity can be restored almost completely at 25 deg. CAnd 75 deg. C, and the desorption residual amount is less than 0.01mmol·g^-1. For the adsorption consisting of physical Adsorption andπ-complexation with energy heterogeneity, the equilibrium data arecorrelated with Langmuir- Freundlich isotherm equation.

Enhanced adsorptive removal of Cr(VI)in aqueous solution by polyethyleneimine modified palygorskite

Polyethyleneimine(PEI)modified palygorskite(Pal)was used for the adsorption of Cr(VI)in aqueous solution.The absorbent was characterized by Fourier transform infrared spectroscopy(FT-IR)and thermogravimetric analysis(TGA).Characterized results confirmed that the Pal has been successfully modified by PEI.The modification of PEI increased the Cr(VI)adsorption performance of the Pal by the adsorption combined reduction mechanism,and amino groups of the adsorbent play the main role in the enhanced Cr(VI)adsorption.The maximum adsorption capacity was 51.10 mg·g^-1 at pH4.0 and 25°C.The adsorption kinetics of Cr(VI)on the adsorbent conforms to the Langmuir isotherm model.The maximum adsorption occurs at pH3,and then the adsorption capacity of PEI-Pal was decreased with the increase of p H values.The adsorption kinetics of Cr(VI)on PEI-Pal was modeled with pseudo-second-order model.The addition of Cl^-,SO4^2-and PO4^3-reduced the Cr(VI)adsorption by competition with Cr(VI)for the active sites of PEI-Pal.The Cr(VI)saturated PEI-Pal can be regenerated in alkaline solution,and the adsorption capacity can still be maintained at 30.44 mg·g^-1 after 4 cycles.The results demonstrate that PEI-Pal can be used as a potential adsorbent of Cr(VI)in aqueous solutions.

Adsorptive Removal of Copper Ions from Aqueous Solution Using Cross-linked Magnetic Chitosan Beads

The performance of cross-linked magnetic chitosan, coated with magnetic fluids and cross-linked with ePichlorohydrin, was investigated for the adsorption of Copper （Ⅱ） from aqueous solutions. Infrared spectra of chitosan before and after modification showed that the coating and cross-linking are effective. Experiments were performed at different pH of solution and contact time, and appropriate conditions for the adsorption of Cu（Ⅱ） were determined. Experimental equilibrium data were correlated with Langmuir and Freundlich isotherms for determination of the adsorption potential. The results showed that the Langmuir isotherm was better compared with the Freundlich isotherm, and the uptake of Cu（Ⅱ） was 78.13 mg·g^- 1. The kinetics of adsorption corresponded with the first-order Langergren rate equation, and Langergren rate constants were determined.