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1.
Amine-functionalized mesoporous silica was prepared by using lauric acid and N-stearoyl-l-glutamic acid as structure directing agents via the SN+-I mechanism and applied to CO2 adsorption at room temperature. With γ-aminopropyltriethoxysilane as co-structure directing agent and due to the direct electrostatic interaction with anionic surfactant, most of the amino groups were uniformly distributed at the inner surface of pores and the performance was stable. The amine-functionalized mesoporous silica was characterized by Fourier transform infrared spectrometer, X-ray diffraction, nitrogen physisorption and thermogravimetric analysis. The CO2 adsorption capacity was measured by digital recording balance. At the room temperature and under the atmospheric pres-sure, the adsorption capacity of LAA-AMS-0.2 for CO2 and N2 is 1.40 mmol•g1 and 0.03 mmol•g1, respectively, indicating high separation coefficient of CO2/N2. 相似文献
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The adsorption equilibrium of a fluoride solution on 1-2 mm granular activated alumina modified by Fe2(SO4)3 solution was investigated. The experiments were conducted using a wide range of initial fluoride concentrations (0.5 to 180 mg8226;L61485;1 at pH ~7.0) and an adsorbent dose of 1.0 g8226;L61485;1. The application of Langmuir and Freundlich adsorption isotherm models (linear and nonlinear forms) generally showed that a single Langmuir or Freundlich equation cannot fit the entire concentration gap. Experimental data on low equilibrium concentrations (0.1 to 5.0 mg8226;L61485;1) was in line with both Langmuir and Freundlich isotherm models, whereas that of high equilibrium concentrations (5.0 to 150 mg8226;L61485;1) was more in line with the Freundlich isotherm model. A new Langmuir- Freundlich function was used for the entire concentration gap, as well as for low and high concentrations. 相似文献
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Considering limited success in target-hitting discharge from alcohol industry, our attention was directed toward a recycling use of distillery spentwash (DS) in cassava bioethanol production by using a two-stage up-flow anaerobic sludge blanket bioremediation (TS-UASBB). With the TS-UASBB, , COD, N and P in the effluent from the DS degraded significantly and their concentrations were kept at 0.2 g•L1, 2.0 g•L1, 1.0 g•L1 and 15 mg•L1, respectively, in 13 batch processes for water-recycled ethanol fermentation. With the effluent used directly as dilution water, no heat-resistant bacteria were found alive. The thirteen-batch ethanol production individually achieved 10% after 48 h fermentation. The starch utilization ratio and total sugar consumption were 90% and 99.5%, respectively. The novel water-recycled bioethanol production process with ethanol fermentation and TS-UASBB has a considerable potential in other starchy and cellulosic ethanol production. 相似文献
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The CuO/γ-Al2O3/cordierite catalyst, after being sulfated by sulfur dioxide (SO2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH3) at 573-723 K. The intrinsic kinetics of SCR of NO with NH3 over CuO/γ-Al2O3/cordierite catalyst has been measured in a fixed-bed reactor in the absence of internal and external diffusions. The experimental results show that the reaction rate can be quantified by a first-order expression with activation energy of 94.01 kJ•mol1 and the corresponding pre-exponential factor of 3.39×108 cm3•g1•s1 when NH3 is excessive. However, when NH3 is not enough, an Eley-Rideal kinetic model based on experimental data is derived with Ea of 105.79 kJ•mol1, the corresponding A of 2.94×109 cm3•g1•s1, heat of adsorption ΔHads of 87.90 kJ•mol1 and the corresponding Aads of 9.24 cm3•mol1. The intrinsic kinetic model obtained was incorporated in a 3D mathematical model of monolithic reactor, and the agreement of the prediction with experimental data indicates that the present kinetic model is adequate for the reactor design and engineering scale-up. 相似文献
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Farshid Ghorbani Shahna Faride Golbabaei Javad Hamedi Hossein Mahjub Hossein Reza Darabi Seyed Jamaladdin Shahtaheri 《中国化学工程学报》2010,18(1):113-121
A novel bioactive foam emulsion bioreactor for benzene, toluene and xylene (BTX) contaminated air streams treatment has been developed. The gas-liquid interfacial area by biocompatible foam and driving force for mass transfer by a water immiscible organic phase were increased in this reactor. The effect of several parameters such as gas residence time, oxygen content, and organic phase concentration on bioreactor performance was studied. Experimental results showed an average elimination capacity (EC) of 220 g&;#8226;m-3&;#8226;h-1 with removal efficiency (RE) of 89.59% for BTX inlet concentration of 1 g&;#8226;m-3 at 15 s gas residence time in the bioreactor. The statistical developed model predicted that the maximum elimination capacity of the reactor for BTX could be reached to 423.45 g&;#8226;m-3&;#8226;h-1. Continues operation of the bioreactor with high EC and RE was demonstrated by optimizing the operational parameters of the bioreactor. Overall the results suggest that the bioreactor developed can be very effective systems to treat BTX vapors. 相似文献
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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 61508;G0 for methyl orange adsorption onto MUCP are -22.55, -23.10 and -23.79 kJ8226;mol-1 at 303, 313, and 323 K, respectively. The values of ΔH0 and ΔS0 are -3.74 kJ8226;mol-1 and 61.99 J8226;mol-1, respectively. The adsorption process is spontaneous and exothermic. 相似文献
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Recombinant Escherichia coli BL21 is used to produce human-like collagen. The key constituents of media are optimized using response surface methodology (RSM). Before thermal induction, the highest biomass production and the lowest production of some hazardous by-products, especially acetic acid, were obtained in the media containing 0.085 mol∙L1 glucose and 0.019 mol∙L1 nitrogen (carbon-nitrogen ratio, 4.47︰1). After thermal induction, when the concentrations of glucose and nitrogen in the media were 0.065 mol∙L1 and 0.017 mol∙L1, respectively (carbon-nitrogen ratio, 3.82︰1), the productivity of human-like collagen per cell was the highest while that of acetic acid was the lowest. The extended analysis showed that the production of lactic acid and propionic acid increased while that of some intermediate acids of the tricarboxylic acid cycle decreased if the dose of glucose in-creased. 相似文献
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A versatile peroxidase (VP-Peco60-7) was generated and purified from the liquid culture of Pleurotus eryngii. The purification procedure included ammonium sulfate precipitation, ion exchange chromatography, and gel chromatography. The molecular weight and isoelectric point (pI) of VP-Peco60-7 were determined to be approximately 40 kDa and 4.1, respectively. By N-terminal sequence determination and peptide mapping analysis, VP-Peco60-7 was found to be similar to the versatile peroxidase isoenzyme VPL1, which was previously isolated from liquid cultures of the same species. However, the molecular weight and pI of VP-Peco60-7 were different from those of versatile peroxidases of liquid cultures, implying that the VP-Peco60-7 in this study is of a novel type. With 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a substrate, the maximal enzyme activity was obtained at 50 °C and pH 3.0. The catalysis of ABTS by VP-Peco60-7 was expressed by the Michaelis-Menten equation. At 50 °C and pH 3.0, the maxi-mum velocity (Vmax) was 188.68 U•mg1 and the michaelis constant (Km) was 203.09 mmol•L1. 相似文献
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Pervaporation has attracted considerable interest owing to its potential application in recovering biobutanol from biomass acetone-butanol-ethanol (ABE) fermentation broth. In this study, butanol was recovered from its aqueous solution using a polydimethylsiloxane (PDMS)/ceramic composite pervaporation membrane. The effects of operating temperature, feed concentration, feed flow rate and operating time on the membrane pervaporation per-formance were investigated. It was found that with the increase of temperature or butanol concentration in the feed, the total flux through the membrane increased while the separation factor decreased slightly. As the feed flow rate increased, the total flux increased gradually while the separation factor changed little. At 40 C and 1% (by mass) butanol in the feed, the total flux and separation factor of the membrane reached 457.4 g•m2•h1 and 26.1, respec-tively. The membrane with high flux is suitable for recovering butanol from ABE fermentation broth. 相似文献
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The separation of Eu3+ is studied with a dispersion combined liquid membrane (DCLM), in which polyvinylidene fluoride membrane (PVDF) is used as the liquid membrane support, dispersion solution containing HCl solution as the stripping solution, and 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (P507) dissolved in kerosene as the membrane solution. The effects of pH value, initial concentration of Eu3+ and different ionic strength in the feed phase, volume ratio of membrane solution to stripping solution, concentration of HCl solution, concentration of carrier, different stripping agents in the dispersion phase on the separation are investigated. The optimum condition for separation of Eu3+ is that concentration of HCl solution is 4.0 mol8226;L61485;1, concentration of carrier is 0.16 mol8226;L61485;1, and volume ratio of membrane solution to stripping solution is 30︰30 in the dispersion phase, and pH value is 4.2 in the feed phase. The ionic strength has no significant effect on separation of Eu3+. Under the optimum condition, when the initial concentration of Eu3+ is 0.8×1061485;4 mol8226;L61485;1, the separation percentage of Eu3+ is 95.3% during the separation time of 130 min. The kinetic equation is developed in terms of the law of mass diffusion and the theory of interface chemistry. The diffusion coefficient of Eu3+ in the membrane and the thickness of diffusion layer between feed phase and membrane phase are obtained and their values are 1.48×1061485;7 m28226;s61485;1 and 36.6 μm, respectively. The results obtained are in good agreement with literature data. 相似文献
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利用环氧氯丙烷活化法将甘氨酸固定于SephadexG-25凝胶上制备弱酸性阳离子交换树脂。通过树脂对水中Ca2+和Mg外的静态吸附、动态吸附和解吸等实验,探讨了金属离子溶液初始浓度、树脂pH值和流速等对树脂吸附Ca2+和Mg2+的影响以及再生条件。结果表明,环氧氯丙烷活化法固定甘氨酸制备阳离子交换树脂的偶联率为12mg·g-1;树脂对Ca2+和Mg2+有良好的吸附/解吸性能,室温下,对Ca件和Mg抖的静态饱和吸附量分别为7.59mg·g-1和6.16mg·g-1,而动态饱和吸附量则分别达到10.83mg·g-1和8.80mg·g-1。该树脂交换柱较好的操作条件如下:以pH值为8.5的0.05mol·L2+ Tris—HCl溶液作为平衡液,上样流速1mL·min-1;以pH值为1.5的1mol·L-1 NaCl-HCl溶液作为洗脱液,流速0.5mL·min2+。该树脂性能稳定,再生效果好,可重复多次使用。 相似文献
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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。 相似文献
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为减少甲烷排放,实现低浓度煤层气有效资源化利用,探究了使用规整复合吸附剂真空变压吸附富集低浓度煤层气的工艺。采用静态容积法测定了甲烷、氮气在规整复合吸附剂上的吸附等温线,同时建立了包括质量、热量和动量守恒在内的严格吸附床数学模型,设计了三塔连续进料的真空变压吸附工艺并进行模拟。分析了工艺达到循环稳态后吸附床层轴向温度分布和压力变化,并且探究了进料量、解吸压力、原料气中甲烷浓度和吸附压力对纯度、回收率、工艺能耗和吸附剂产率等工艺性能的影响。模拟结果表明,在进料量为100 L·min-1,解吸压力为0.1 bar(1 bar=0.1 MPa),原料气甲烷浓度为30%,吸附压力为3 bar时可以生产纯度为59.07%,回收率为93.64%的富CH4产品气,同时单位能耗为18.70 kJ·mol-1,吸附剂产率为4.56 mol·h-1·kg-1。表明规整吸附剂对CH4/N2具有良好的吸附分离效果,能够实现低浓度煤层气中甲烷高效富集。 相似文献
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研究了超声波对活性炭吸附/脱附Cr(Ⅵ)的影响,结果表明:有无超声波作用下,活性炭对Cr(Ⅵ)的吸附率均随pH值的升高而减小,相对于无超声作用体系,超声作用下的相平衡向吸附量减小的方向移动,且pH值越大,其减小的幅度越大;当Cr(Ⅵ)初始浓度由20 mg·L-1增至110 mg·L-1时,超声波作用下的Cr(Ⅵ)去除率由99.9%降至79.8%,平衡吸附量则由3.3 mg·g-1增至15.0 mg·g-1,与无超声波作用下的效果接近,但无超声波作用时的吸附率持续上升至平衡,而超声波作用下的吸附率先快速增加至近平衡,再出现小幅下降后又缓慢增至平衡。脱附实验发现,无论有无超声作用,活性炭表面Cr(Ⅵ)在蒸馏水中的脱附率均很小;添加NaOH可显著改善脱附效果,脱附率随NaOH用量的增加而增加,且超声场中NaOH对脱附的促进作用显著高于非超声场中的效果。 相似文献
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研究了超声波对活性炭吸附/脱附Cr(Ⅵ)的影响,结果表明:有无超声波作用下,活性炭对Cr(Ⅵ)的吸附率均随pH值的升高而减小,相对于无超声作用体系,超声作用下的相平衡向吸附量减小的方向移动,且pH值越大,其减小的幅度越大;当Cr(Ⅵ)初始浓度由20 mg·L-1增至110 mg·L-1时,超声波作用下的Cr(Ⅵ)去除率由99.9%降至79.8%,平衡吸附量则由3.3 mg·g-1增至15.0 mg·g-1,与无超声波作用下的效果接近,但无超声波作用时的吸附率持续上升至平衡,而超声波作用下的吸附率先快速增加至近平衡,再出现小幅下降后又缓慢增至平衡。脱附实验发现,无论有无超声作用,活性炭表面Cr(Ⅵ)在蒸馏水中的脱附率均很小;添加NaOH可显著改善脱附效果,脱附率随NaOH用量的增加而增加,且超声场中NaOH对脱附的促进作用显著高于非超声场中的效果。 相似文献
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The enrichment of low concentration coalbed methane using adsorption process with activated carbon adsorbent was studied in this work.Adsorption isotherms of methane,nitrogen and carbon dioxide on activated carbon were measured by volumetric method,meanwhile a series of breakthrough tests with single component,binary components and three components feed mixture has been performed for exploring dynamic adsorption behaviors.Moreover,a rigorous mathematical model of adsorption bed containing mass,energy,and momentum conservation equation as well as dual-site Langmuir model with the Linear driving force model for gas-solid phase mass transfer has been proposed for numerical modeling and simulation of fixed bed breakthrough process and vacuum pressure swing adsorption process.Furthermore,the lumped mass transfer coefficient of methane,nitrogen and carbon dioxide on activated carbon adsorbent has been determined to be 0.3 s~(-1),1.0 s~(-1) and 0.06 s~(-1) by fitting the breakthrough curves using numerical calculation.Additionally,a six bed VPSA process with twelve step cycle sequence has been proposed and investigated for low concentration coalbed methane enrichment.Results demonstrated that the methane molar fraction in feed mixture ranged from 10% to 50% could be enriched to 32.15% to 88.75% methane in heavy product gas with a methane recovery higher than 83%under the adsorption pressure of 3 bar(1 bar=10~5 Pa) and desorption pressure of 0.1 bar.Energy consumption of this VPSA process was varied from 0.165 kW·h·m~(-3) CH_4 to 0.649 kW·h·m~(-3) CH_4.Finally,a dual-stage VPSA process has been successfully developed to upgrade a low concentration coalbed methane containing 20% methane to a target product gas with methane purity higher than 90%,meanwhile the total methane recovery was up to 98.71% with a total energy consumption of 0.504 kW·h·m~(-3) CH_4. 相似文献