Hydrodynamics of air–kerosene bubble column under elevated pressure in homogeneous flow regime

A multiphase computational fluid dynamics(CFD) model coupled with the population balance equation(PBE) was developed in a homogeneous air–kerosene bubble column under elevated pressure(P). The specific pressure drop(DP/L), gas holdup(a_G), and Sauter mean diameter(d_(32)) were experimentally measured in the bubble column with 1.8 m height and 0.1 m inner diameter, which was operated at a superficial gas velocity of 12.3 mm·s~(-1), and P = 1–35 bar(1 bar = 10~5 Pa). A modified drag coefficient model was proposed to consider the effect of bubble swarm and pressure on hydrodynamics of the bubble column.The Luo breakage model was modified to account for liquid density, viscosity, surface tension and gas density. The DP/L, a_G, and d_(32) obtained from the CFD model were compared with experimental data,and the gas density-dependent parameters of the CFD model were identified. With increasing P from 1 to 35 bar, the aGvaried from 5.4% to 7.2% and the d_(32) decreased from 2.3 to 1.5 mm. The CFD-PBE model is applicable to predict hydrodynamics of pressurized bubble columns for gas–organic liquid in the homogeneous regime.     

Spray-drying assisted layer-structured H2TiO3 ion sieve synthesis and lithium adsorption performance

A spray-drying assisted solid-state method to prepare spherical layer-structured H₂TiO₃ ion sieve (LSTIS) particles is reported herein. The effects of synthesis parameters (calcination temperature, calcination time, and the lithium-titanium molar ratio) on adsorption–desorption performance (the delithiation ratio, titanium dissolution loss, and the adsorption capacity) were investigated. The as-prepared LSTIS exhibited an equilibrium adsorption capacity of 30.08 mg·g^-1 (average of 25.85 mg·g^-1 over 5 cycles) and ultra-low titanium dissolution loss of less than 0.12% (average of 0.086% over 5 cycles). The LSTIS showed excellent selectivity toward Li⁺ in Na⁺, K⁺, Mg²⁺, and Ca²⁺ coexisting saline solutions where its adsorption capacity reached 27.45 mg·g^-1 and the separation factors of Li⁺ over the coexisting cations exceeded 100. The data suggests that the LSTIS is promising to competitively enrich Li⁺ from saline solutions.     

离子交换树脂对D-甘油酸的吸附热力学和动力学

D-甘油酸是一种重要的甘油衍生物,具有解酒护肝的功能。关于D-甘油酸生产方法的研究已有不少,但对其分离方法及分离机理的研究却鲜见报道。通过静态吸附实验,研究了D-甘油酸在201×7阴离子交换树脂上的等温热力学和动力学特性。结果表明,D-甘油酸在201×7阴离子交换树脂上的最大平衡吸附容量随pH的增加而降低,其吸附等温线符合Freundlich模型。在293~308 K下,吸附焓变为14.77 kJ·mol^-1,表明该吸附过程为吸热过程。升高温度有利于提高吸附速率,但对最大平衡吸附容量影响不大。同时,采用动边界模型描述D-甘油酸在该树脂上的交换行为,分别考察了料液浓度、树脂粒径和温度对交换过程的影响。交换过程的吸附速率随D-甘油酸浓度和温度的增加而增大,但随树脂粒径的增大而减小。研究表明该离子交换过程的速率控制步骤为颗粒扩散过程,交换过程的反应速率常数k₀为1.22×10^-3,反应级数a为0.631,表观活化能E_a为14.90 kJ·mol^-1,并得到了动力学总方程。     

不同晶型纳米二氧化锰制备及对亚甲基蓝吸附性能

以高锰酸钾（KMnO₄）为氧化剂、硫酸亚铁铵[（NH₄）₂Fe（SO₄）₂]为还原剂,用水热氧化还原反应制备了层状δ-二氧化锰和隧道型α-二氧化锰纳米材料。用X射线衍射（XRD）、扫描电镜（SEM）和氮气吸-脱附技术对产物的晶型、形貌及孔结构进行了表征。实验结果表明,δ-二氧化锰呈花状微球形貌,具有介孔结构（平均孔径为3.4 nm）,BET比表面积为219 m²/g;α-二氧化锰呈纳米线束形貌,具有部分介孔结构（平均孔径为35.7 nm和154.6 nm）,BET比表面积为26 m²/g。研究了不同晶型纳米二氧化锰对亚甲基蓝的吸附性能。实验结果表明,在相同条件下α-二氧化锰的吸附性能优于δ-二氧化锰,且在碱性环境下吸附效果较好。当反应时间达到120 min时,α-二氧化锰和δ-二氧化锰对亚甲基蓝的去除率分别为84.4%和82.9%。     

Removal of Reactive Red 198 from aqueous solution by combined method multi-walled carbon nanotubes and zero-valent iron:Equilibrium,kinetics, and thermodynamic

Dyes often include toxic,carcinogenic compounds and are harmful to humans' health.Therefore,removal of dyes from textile industry wastewater is essential.The present study aimed to evaluate the efficiency of the combination of zero valent iron(ZVI) powder and multi-walled carbon nanotubes(MWCNTs) in the removal of Reactive Red 198(RR198) dye from aqueous solution.This applied research was performed in a batch system in the laboratory scale.This study investigated the effect of various factors influencing dye removal,including contact time,p H,adsorbent dose,iron powder dose,initial dye concentration,and temperature.The equilibrium adsorption data were analyzed using three common adsorption models:Langmuir,Freundlich and Temkin.Besides,kinetic and thermodynamic parameters were used to establish the adsorption mechanism.The results showed,in pH =3,contact time = 100 min,ZVI dose = 5000 mg·L~(-1),and MWCNTs dose = 600 mg·L~(-1)in 100 mg·L~(-1)dye concentration,the adsorption efficiency increased to 99.16%.Also,adsorption kinetics was best described by the pseudo-second-order model.Equilibrium data fitted well with the Freundlich isotherm(R2= 0.99).The negative values of ΔG0and the positive value of ΔH0(91.76) indicate that the RR198 adsorption process is spontaneous and endothermic.According to the results,the combination of MWCNTs and ZVI was highly efficient in the removal of azo dyes.     

氨基改性苯乙烯树脂的合成及其对铼的吸附

离子交换法因适于低浓度物质的分离富集而被广泛应用于湿法冶金行业,新型高效吸附材料的合成与应用成为该领域的发展趋势。针对铀矿中伴生铼这一稀缺资源需要同步回收的现状,根据新近研发的氨基改性苯乙烯阴离子交换树脂(LSC-Re),通过静态和动态吸附解吸试验,系统考察了溶液酸度、初始浓度、吸附时间、吸附温度等因素对吸附性能的影响,结果表明：在室温(25℃)下,铼溶液初始浓度为100 mg·L^-1,该树脂6 h达到吸附平衡,酸度对该树脂吸附铼的影响不大,树脂在pH=1.5时铀铼分离效果最佳,分离系数可达到41.68;树脂的饱和吸附容量达到129.3 mg·g^-1;从热力学和动力学角度分析,吸附过程符合Langmuir吸附等温模型和准二级动力学模型,且吸附是自发的吸热过程。动态吸附解吸试验中,控制溶液流速0.5 ml·min^-1,动态饱和吸附容量达到76.17 g·L^-1,饱穿比为2.35,用1 mol·L^-1 氨水进行解吸铼效果较好,8个树脂床体积可将其解吸完全,由此可见富集倍数接近70倍,具有良好的工业应用前景。     

木薯淀粉磁性微球的结构表征及其对溶菌酶的吸附性能

磁性微球是高分子材料与磁性物质通过一定作用复合而成的一类具有特殊功能的磁性高分子微球。以木薯淀粉为原材料,复合共沉淀法制备的改性磁流体Fe₃O₄,采用两步法(化学交联法)制备木薯淀粉磁性微球。利用傅里叶变换红外光谱仪、X射线衍射仪、同步热分析仪、扫描电镜、激光粒度仪、磁天平等对其性能及结构进行表征并研究其对溶菌酶的吸附行为。通过单因素法考察磁性微球用量、溶液pH值、吸附温度、吸附时间对吸附率的影响,并采用准一级动力学模型和准二级动力学模型研究其吸附动力学。结果表明:制备的木薯淀粉磁性微球Fe₃O₄含量为19.71%,D₅₀(中位径)为15.40μm,磁化率为1.571×10^-3cm³/g,形貌规整;在微球用量为1.25g,溶液pH=10,吸附温度为25℃,吸附时间为80min时,微球对溶菌酶的吸附率最高,达到84.67%。以相关系数R²为参考,准二级动力学模型(R²=0.99993)较准一级动力学模型(R²=0.99174)、颗粒内扩散模型(R²=0.69996)能更好描述木薯淀粉磁性微球对溶菌酶的吸附行为。     

改性超细煤粉对甲基橙的吸附行为研究

The adsorption of methyl orange onto ultrafine coal powder (UCP) and modified ultrafine coal powder (MUCP) from aqueous solutions were studied, in which the influence of contact time, dosage, temperature, pH, and methyl orange concentration in the solution were investigated. The adsorption kinetics of methyl orange by UCP and MUCP can be described by the Lagergren first-order and pseudo second-order kinetic models, respectively. The adsorption isotherms of methyl orange onto MUCP at 303, 313 and 323 K follow the Freundlich and Langmuir isotherm equation. Values of G0 for methyl orange adsorption onto MUCP are -22.55, -23.10 and -23.79 kJ•mol－1 at 303, 313, and 323 K, respectively. The values of ΔH0 and ΔS0 are -3.74 kJ•mol－1 and 61.99 J•mol－1, respectively. The adsorption process is spontaneous and exothermic.     

中煤级煤甲烷饱和吸附量的数值模拟计算

根据表征中煤级煤（镜质组最大反射率R_o,max=0.65%～2.50%）的系列等温吸附（20℃、30℃、40℃和50℃这4个实测温度）“煤变质程度-压力-吸附量”的三变量数学方程,建立一组“煤变质程度-温度-压力-吸附量”这4个共同存在并相互影响的四变量数学方程。该四变量数学方程用于预测1200m以浅的中煤级煤甲烷饱和吸附量。这种数学转换的平均相对误差在7.28%～9.49%之间。有处理中煤级煤甲烷饱和吸附量的数值模拟的软件著作。只要将5个实测数据：镜质组最大反射率R_0,max、温度梯度、压力梯度、埋深和恒温层温度,输入相应可编辑文本框中,就可以输出5个值：饱和吸附量V、温度-压力-吸附量方程中的参数（A、B、Δ、β）。还可以输出在自己感兴趣的镜质组最大反射率R_0,max、温度梯度、压力梯度、埋深和恒温层温度下,“R_0,max值时温压吸附曲面”和“吸附量随埋深变化图”。     

Adsorption equilibrium for Z-ligustilide on C18-bonded silica from supercritical carbon dioxide

Adsorption equilibrium is of great importance for the preparative supercritical fluid chromatography(pre-SFC) in defining supercritical adsorption behavior and the industrial amplification.This paper presents adsorption isotherms of Z-ligustilide from supercritical carbon dioxide(SC-CO_2) on C18-bonded silica.Adsorption behavior was studied at 305.15 K,313.15 K and 323.15 K with SC-CO_2 density varying from 0.687 g·cm~(-3) to0.863 g·cm~(-3) with the elution by characteristic points(ECP) method.The adsorption amount of Z-ligustilide from SC-CO_2 on C18-bonded silica decreased with the increasing density of the mobile phase as well as the increasing temperature.Adsorption equilibrium data were fitted by Langmuir and Freundlich isotherm models,and the Langmuir isotherm model performed better for describing the whole adsorption process on the column.The monolayer saturation adsorption capacity of Z-ligustilide is in the range of 3.0 × 10~(-4) mg·cm~(-3) to5.5 × 10~(-4) mg·cm~(-3) with an average value of 4.0 × 10~(-4) mg·cm~(-3).     

Selective extraction of In(III), Ga(III) and Zn(II) using a novel extractant with phenylphosphinic acid

A new extractant, [N,N-di(2-ethylhexyl)amino]methylphenylphosphinic acid (DEAPP), was synthesized to de-velop the mutual separation techniques of In(III), Ga(III) and Zn(II). The extraction selectivity for In(III), Ga(I I) and Zn(II) with DEAPP was higher than that of the commercial phosphorus acid extractants such as D2EHPA and PC-88A. The extraction selectivity for metal ions in 1 mol·L?1 aqueous ammonium nitrate solution with DEAPP was in the following order:In(III) N Ga(III) N Zn(II). These selective extraction behaviors indicate that the amino moiety of DEAPP plays an important role in the mutual separation of In(III), Ga(III) and Zn(II). The extraction equilibria of In(I I), Ga(II ) and Zn(II) with DEAPP (=HR) were expressed by the following reactions:In3++2eHRT2?InR3eHRT+3H+, Ga3++1.5eHRT2+NO3??GaR2eHRTeNO3T+2H+, and Zn2++2eHRT2?ZnR2eHRT 2 + 2H+. The extraction equilibrium constants of In(III), Ga(III) and Zn(II) with DEAPP were determined to be Kex,M=1.7 × 104 [dm3·mol?1], 4.17 [(dm3·mol?1)0.5], and 1.55 x 10?2 [–], respectively.     

亲水基团性质对双亲性壳聚糖衍生物单分子膜性能的影响

制备了双亲性O-磺化-N,N-双十二烷基壳聚糖(HSDLCS)、O-季铵化-N,N-双十二烷基壳聚糖(QADLCS)和O-羟丙基-N,N-双十二烷基壳聚糖(HPDLCS),研究了不同亲水基团对产物单分子膜性能的影响。结果表明,与N,N-双十二烷基壳聚糖(DLCS)相比,引入亲水基团后的产物其单分子膜具有较高的崩溃压(π_c)和最大压缩模量(C_s^-1,_max),凝聚性更好。与非离子型产物HPDLCS相比,离子型产物具有较大的π_c和C_s^-1,_max,其中阴离子型产物HSDLCS单分子膜的π_c(44.64mN/m)和C_s^-1,_max(84.27mN/m)最大,阳离子型产物QADLCS(π_c,42.01mN/m;C_s^-1,_max,82.99mN/m)次之,HSDLCS单分子膜具有较强的凝聚性和抗形变能力。     

Facile synthesis of metal-organic frameworks embedded in interconnected macroporous polymer as a dual acid-base bifunctional catalyst for efficient conversion of cellulose to 5-hydroxymethylfurfural

5-Hydroxymethylfurfural (5-HMF), as a key platform compound for the conversion of biomass to various biomass-derived chemicals and biofuels, has been attracted extensive attention. In this research, using Pickering high internal phase emulsions (Pickering HIPEs) as template and functional metal-organic frameworks (MOFs, UiO-66-SO₃H and UiO-66-NH₂)/Tween 85 as co-stabilizers to synthesis the dual acid-base bifunctional macroporous polymer catalyst by one-pot process, which has excellent catalytic activity in the cascade reaction of converting cellulose to 5-HMF. The effects of the emulsion parameters including the amount of surfactant (ranging from 0.5% to 2.0% (mass)), the internal phase volume fraction (ranging from 75% to 90%) and the acid/base Pickering particles mass ratio (ranging from 0:6 to 6:0) on the morphology and catalytic performance of solid catalyst were systematically researched. The results of catalytic experiments suggested that the connected large pore size of catalyst can effectively improve the cellulose conversion, and the synergistic effect of acid and base active sites can effectively improve the 5-HMF yield. The highest 5-HMF yield, about 40.5%, can be obtained by using polymer/MOFs composite as catalyst (Poly-P12, the pore size of (53.3 ±11.3) μm, the acid density of 1.99 mmol·g^-1 and the base density of 1.13 mol·g^-1) under the optimal reaction conditions (130 ℃, 3 h). Herein, the polymer/MOFs composite with open-cell structure was prepared by the Pickering HIPEs templating method, which provided a favorable experimental basis and theoretical reference for achieving efficient production of high added-value product from abundant biomass.     

污泥含炭吸附剂的制备及其吸附模拟烟气中汞蒸汽的应用(英文)

The carbonaceous adsorbent was prepared from mixtures of dewatered sludge and sawdust with enhanced ZnCl2 chemical activation.Characteristics of the adsorbent were studied using scanning electron microscope(SEM) ,Fourier transform infrared spectroscopy(FT-IR) ,and adsorption of nitrogen.The surface analysis showed that the carbonaceous adsorbent had good specific surface and porosity(394 m 2 ·g-1of BET surface,0.12 and 0.10 ml·g-1of microporous and mesoporous volume,respectively) .The oxygen functional groups such as OH,C O and C O were found on the surface by FTIR and XPS(X-ray photoelectron spectroscopy) .The adsorption of elemental mercury(Hg0) on the carbonaceous adsorbent was studied in a fixed bed reactor.The dynamic adsorption capacity of carbonaceous adsorbent increased with influent mercury concentration,from 23.6μg·g-1at 12.58μg·m-3to 87.9μg·g-1at 72.50μg·m-3,and decreased as the adsorption temperature increased,from 246 μg·g-1 at 25°C to 61.3μg·g-1 at 140°C,when dry nitrogen was used as the carrier gas.The carbonaceous adsorbent presented higher dynamic adsorption capacity than activated carbon,which was 81.2μg·g-1and 53.8μg·g-1respectively.The adsorption data were fitted to the Langmuir adsorption model.The physical and chemical adsorption were identified on the adsorbent.     

Efficient CO2 adsorption and mechanism on nitrogen-doped porous carbons

In this work, nitrogen-doped porous carbons (NACs) were fabricated as an adsorbent by urea modification and KOH activation. The CO₂ adsorption mechanism for the NACs was then explored. The NACs are found to present a large specific surface area (1920.72– 3078.99 m²·g⁻¹) and high micropore percentage (61.60%–76.23%). Under a pressure of 1 bar, sample NAC-650-650 shows the highest CO₂ adsorption capacity up to 5.96 and 3.92 mmol·g⁻¹ at 0 and 25 °C, respectively. In addition, the CO₂/N₂ selectivity of NAC-650-650 is 79.93, much higher than the value of 49.77 obtained for the nonnitrogen-doped carbon AC-650-650. The CO₂ adsorption capacity of the NAC-650-650 sample maintains over 97% after ten cycles. Analysis of the results show that the CO₂ capacity of the NACs has a linear correlation (R² = 0.9633) with the cumulative pore volume for a pore size less than 1.02 nm. The presence of nitrogen and oxygen enhances the CO₂/N₂ selectivity, and pyrrole-N and hydroxy groups contribute more to the CO₂ adsorption. In situ Fourier transform infrared spectra analysis indicates that CO₂ is adsorbed onto the NACs as a gas. Furthermore, the physical adsorption mechanism is confirmed by adsorption kinetic models and the isosteric heat, and it is found to be controlled by CO₂ diffusion. The CO₂ adsorption kinetics for NACs at room temperature and in pure CO₂ is in accordance with the pseudo-first-order model and Avramís fractional-order kinetic model.     

萃取-吸附法处理辛醇废碱液

辛醇废碱液中含有大量有机物,为此开展了萃取-大孔树脂吸附法处理辛醇废碱液、高效回收有机物的实验研究,实验结果表明:当辛醇废碱液的ρ(COD)为104651mg/L时,以辛醇为萃取剂,在pH=3、辛醇与辛醇废碱液的体积比为0.5、萃取级数为2等条件下,出水ρ(COD)可降至6453mg/L以下,COD去除率达到93.8%以上,萃取剂辛醇可以通过精馏再生循环利用;采用HYA-106大孔吸附树脂对辛醇二级萃取出水进行吸附处理,HYA-106大孔吸附树脂较佳的吸附流速为1BV/h、温度为40℃,此时出水ρ(COD)平均在155~183mg/L之间,COD去除率在97.1%~97.4%之间,单位体积树脂的废水处理量为34BV以上,树脂吸附量在213~215mgCOD/mL树脂之间,吸附-解吸效果稳定;萃取-吸附工艺的COD总去除率达到99.8%以上,最大程度地实现了辛醇废碱液中有机物的回收。     

纳米γ-氧化铁的制备及其吸附性能研究

以硝酸铁和十二烷基三甲基溴化铵为原料,采用固相法制备了γ-氧化铁纳米粒子。通过X射线衍射、氮气吸附-脱附、磁性测试等手段对γ-氧化铁样品进行了表征。研究了γ-氧化铁对有机染料直接耐酸大红4BS的吸附性能。结果表明,制备的γ-氧化铁样品为γ-氧化铁纳米粒子,平均晶粒尺寸为18.5 nm;γ-氧化铁的比表面积为83.2 m ²/g,孔容为0.25 cm ³/g,最可几孔径为3.8 nm,属于介孔范围;γ-氧化铁的最大饱和磁化强度为63.7 A·m ²/kg;介孔γ-氧化铁对直接耐酸大红4BS的吸附过程符合准二级吸附动力学模型;γ-氧化铁对直接耐酸大红4BS的吸附符合Langmuir吸附等温式,极限吸附量为113.3 mg/g;将γ-氧化铁脱附处理后可重复使用。     

Comparative study on pressure swing adsorption system for industrial hydrogen and fuel cell hydrogen

In order to improve the design of PSA system for fuel cell hydrogen production, a non-isothermal model of eight-bed PSA hydrogen process with five-component (H₂/N₂/CH₄/CO/CO₂=74.59%/0.01%/4.2%/2.5%/18.7% (vol)) four-stage pressure equalization was developed in this article. The model adopts a composite adsorption bed of activated carbon and zeolite 5A. In this article, pressure variation, temperature field and separation performance are stimulated, and also effect of providing purge (PP) differential pressure and the ratio of activated carbon to zeolite 5A on separation performance in the process of producing industrial hydrogen (CO content in hydrogen is 10 μl·L^-1) and fuel cell hydrogen (CO content is 0.2 μl·L^-1) are compared. The results show that Run 3, when the CO content in hydrogen is 10 μl·L^-1, the hydrogen recovery is 89.8%, and the average flow rate of feed gas is 0.529 mol·s^-1; When the CO content in hydrogen is 0.2 μl·L^-1, the hydrogen recovery is 85.2%, and the average flow rate of feed gas is 0.43 mol·s^-1. With the increase of PP differential pressure, hydrogen recovery first increases and then decreases, reaching the maximum when PP differential pressure is 0.263 MPa; With the decrease of the ratio of activated carbon to zeolite 5A, the hydrogen recovery increases gradually. When the CO content in hydrogen is 0.2 μl·L^-1 the hydrogen recovery increases more obviously, from 83.96% to 86.37%, until the ratio of activated carbon to zeolite 5A decreases to 1. At the end of PP step, no large amount of CO₂ in gas or solid phase enters the zeolite 5A adsorption bed, while when the CO content in hydrogen is 10 μl·L^-1, and the ratio of carbon to zeolite 5A is less than 1.4, more CO₂ will enter the zeolite 5A bed.     

海胆状Fe3O4@TiO2磁性纳米介质对Pb2+的选择吸附特性

耦合溶胶-凝胶技术与水热法,制备具有核壳结构的海胆状Fe₃O₄@TiO₂磁性纳米介质（sea urchin magnetic nanoparticles,SUMNPs）。采用TEM、SEM等方法对SUMNPs的形貌等性质进行表征,证实该材料呈现出以Fe₃O₄为核,以TiO₂为壳的海胆状结构,壳层直径约400 nm,比表面积高达236.082 m²·g^-1,表面孔径约6.274 nm。SUMNPs对重金属离子选择吸附的结果表明,基于Pb²⁺离子半径大、电子层数多等物化特点,在Pb²⁺、Cu²⁺、Ni²⁺、Zn²⁺、Cd²⁺ 5种金属离子混合体系中,SUMNPs可以高容量、高选择性快速吸附Pb²⁺,而对其他4种重金属离子几乎无吸附活性。单一Pb²⁺吸附可在5 min内快速平衡,平衡吸附容量为283 mg·g^-1。吸附过程符合Langmuir等温吸附模型,SUMNPs对Pb²⁺的最大饱和吸附容量为458.72 mg·g^-1。经EDTA二钠解吸,NaOH再生后的SUNMPs可以重复使用8次以上。SUMNPs对Pb²⁺具备优异的选择性吸附性能,在处理水体铅污染、恢复水体生态领域具有良好的应用前景。     

Shear-rate dependence of first normal stress difference of poly(isoprene-b-styrene) in solution near the order-disorder transition temperature

Viscoelastic properties of poly(isoprene-b-styrene) in dioctylphthalate under steady shear flow were measured near the order—disorder transition temperature. In ordered states, first normal stress difference N₁ is proportional to shear rate at low region, but becomes proportional to at the high region, similar to the N₁ behaviour of polymer blends undergoing shear-induced homogenization. Because the existence of microdomains was confirmed at the high region by the flow birefringence method, it is concluded that the above N₁ behaviour is not caused by shear-induced homogenization, but is probably caused by the shear-induced alignment of the microdomain structure.