Henry's law constants and thermodynamic properties of gases and vapours in bitumens

Solubilities for 13 gases and vapours (CO₂, alkanes from ethane to n-octane, benzene, toluene, xylene, dichloromethane, and methanol) in two Alberta bitumens (Athabasca and Wolf Lake) have been measured at several temperatures (30-150°C), using gas-liquid chromatography (GLC). The GLC method yields accurate solubilities and Henry's law constants for moderately soluble gases, but is not applicable to less soluble gases such as CH₄ and H₂. Results have been used for calculations of ΔH_o and ΔC^o_p for processes of the type Solute Substance (gas) = Solute Substance (in bitumen). Correlations of Henry's law constants and ΔH^o values with carbon number for alkanes have been observed and used for predictions of CH₄ solubilities in bitumens.     

四氟化碳中痕量气体杂质的气相色谱分析

采用配有放电离子化检测器的气相色谱仪分析高纯四氟化碳中痕量气体杂质。研究了分析四氟化碳中氧气、氮气、一氧化碳、二氧化碳和六氟化硫等气体杂质的操作参数,确定了高纯四氟化碳中痕量气体杂质的分析方法。     

同时测定乙烯中烃类杂质及CO、CO_2方法探讨

采用1台气相色谱仪、双阀双通道、双氢火焰检测器一次进样同时完成乙烯中微量CO、CO2及烃类杂质的全分析。通过考察载气流速、柱温、升温速率、分流比对实验结果的影响,确定了最佳实验条件,同时对该方法进行了精密度、准确度和最小检测限考察。结果表明该方法是乙烯中杂质含量测定的一种简单快捷、准确可靠的分析方法。     

磷化氢在改性13X分子筛上的吸附行为

为回收工业废气中的磷化氢(PH3)并资源化,采用浸渍法制备了一种CaCl2改性13X分子筛吸附剂,通过容积法研究了25—70℃PH3气体在改性13X分子筛上的等温吸附行为。结果表明,在实验条件范围内25,40,55,70℃下PH3的饱和吸附量(质量分数)分别为2.528,1.901,1.591,0.925mg/g。Freundlich吸附等温方程很好地模拟了改性13X分子筛对PH3的等温吸附,Langmuir和Henry吸附等温方程对吸附平衡数据的拟合效果不佳表明了改性13X分子筛表面吸附位的不均匀分布。当初始吸附量为0.10mg/g时,等量吸附热值最大,为17.81353kJ/mol,即等量吸附热不超过18kJ/mol,过程为物理吸附,便于PH3气体的解吸。     

异丙醇对合成13X分子筛的结构和吸附性能的影响

利用XRD、SEM、BET、ICP-AES等手段,对常规水热13X分子筛合成体系中加入不同量异丙醇合成的分子筛进行表征。结果发现,随着合成体系中异丙醇量的增加,分子筛的相对结晶度、晶粒尺寸以及分子筛硅铝比均减小;分子筛的孔容、孔径均增大。将分子筛样品在含1×10-3(mol/mol)二甲醚(DME)的乙烯原料以1 500h-1体积空速下,应用于乙烯中甲醇、二甲醚等含氧化合物的脱除实验表明,小晶粒、大孔容分子筛样品表现出更好的吸附性能。在合成体系中加入15%(质量分数)异丙醇的分子筛样品吸附性能更好,其单程寿命达到280min,单位时间(h)内的积炭量0.71%。     

异丙醇对合成13X分子筛的结构和吸附性能的影响

利用XRD、SEM、BET、ICP-AES等手段,对常规水热13X分子筛合成体系中加入不同量异丙醇合成的分子筛进行表征。结果发现,随着合成体系中异丙醇量增加,分子筛的相对结晶度、晶粒尺寸、以及分子筛硅铝比均减小;分子筛的孔容、孔径均增大。将分子筛样品在含1000ppm二甲醚（DME）的乙烯原料以1500h-1体积空速下,应用于乙烯中甲醇、二甲醚等含氧化合物的脱除实验表明,小晶粒、大孔容分子筛样品表现出更好的吸附性能。在合成体系中加入15wt%异丙醇的分子筛样品吸附性能更好,其单程寿命达到280min,单位时间（h）内的积炭量0.71%。     

Adsorption of mercaptan from model gasoline on 13X loaded with Zn2+

Adsorption of mercaptan on 13X loaded with Zn²⁺ from model gasoline was studied at different concentration and temperatures. The results indicate that high temperature and low concentration favour the removal of mercaptan from the model gasoline. The adsorptive amount of the untreated adsorbents loaded with Zn²⁺ is less than the treated with heat obviously, but the adsorbed amount is not enhanced distinctly by the way of increasing the treating temperature. A pseudo‐first‐order mechanism has been proposed to describe the adsorption in the model gasoline system. The desulphurizing capability increases due to the Zn²⁺ impregnated. With the concentration of Zn²⁺ higher, the adsorptive amount for ethanethiol increases. Adsorption mechanism shows that it is a chemical adsorption. Two different methods of regeneration were investigated.     

Behaviour and mechanism of enhanced phosphate sorption on loess modified with metals: equilibrium study

BACKGROUND: Phosphate is one of the main contaminants responsible for the eutrophication of surface waters. In developing countries, algae blooming in lakes have threatened the quality of drinking water due to the lack of proper management of phosphate‐containing wastewaters from mining sites and industry. MAJOR RESULTS: The sorption behaviour of phosphate on loess modified by metals (Zn(II), Cu(II) and Pb(II)) was investigated in this paper. Zn(II) and Cu(II) sorption on the loess was attributed to the constituent silicate minerals while the sorption of Pb(II) was assigned to natural carbonate in the loess. The sorption affinity of phosphate towards the modified sorbent was as follows: Pb(II) (221.3–832.2 L g⁻¹) > Cu(II) (20.26 L g⁻¹) > Zn(II) (0.77–1.90 L g⁻¹) > loess (0.11 L g⁻¹) with regard to the partition coefficient. The sorption isotherms were well fitted by an extended Henry's law with multi‐linearity. Several factors including metal loading, pH, sorbent dosage and temperature were investigated and all were found to correlate positively with phosphate sorption. The enthalpy and entropy changes during phosphate sorption on Pb(II) loaded loess were predicted as 14.32 kJ mol⁻¹ and 128.45 J mol⁻¹ K⁻¹, respectively. The sorption mechanism for phosphate on Pb(II) doped loess was investigated by FT‐IR spectra from which the sorption was attributed to chemical bonding with lead carbonate and physisorption with surface adsorbed phosphate as well as diffusion through micropores into the sorbent. CONCLUSIONS: Pb(II) loaded loess shows the best performance for phosphate removal from aqueous solution. The optimum conditions for sorption were pH = 9.5, lead modified loess sorbent dosage = 10 g L⁻¹, temperature = 35 °C and Pb(II) loading 295 mg g⁻¹. Copyright © 2008 Society of Chemical Industry     

壳聚糖对痕量重金属离子铅、铬、镍的吸附研究

本文研究了重金属捕集剂壳聚糖对痕量重金属Pb2 、Cr3 、Ni2 离子的吸附作用。实验结果表明,壳聚糖对痕量重金属的吸附率与壳聚糖的用量、pH值、吸附时间、壳聚糖的脱乙酰度有关。在常温下,0.2 g的脱乙酰度为80%的CS在pH=7时,对Pb(Ⅱ)、Cr(Ⅲ)、Ni(Ⅱ)的吸附率分别为94.2%,54.3%,90.6%。     

超声法制备Ce^4＋/13X分子筛的吸附脱硫性能

采用在离子交换过程中引入超声的方法制备了Ce4 /13X分子筛,考察了超声法对分子筛的制备及脱硫性能的影响,并考察了静态吸附条件对Ce4 /13X在低硫模型汽油(硫含量为23 mg/kg)中的脱硫性能影响。结果表明,超声法可显著缩短分子筛离子交换平衡的时间,提高离子交换度,且能有效地提高活性组分Ce在分子筛表面的含量,脱硫实验结果也显示吸附容量有明显的提高。常温常压,吸附时间为2.5 h,剂油质量比为0.0072的条件下,Ce4 /13X对噻吩的脱硫效果最好,吸附量为0.07653mmol/g,脱硫率可达到76.5%。Freundlich等温式能很好地关联噻吩在Ce4 /13X上的吸附平衡数据。450℃空气气氛中焙烧4 h的方法,可较好地再生Ce4 /13X。     

低湿CO2/H2O混合气体吸附特性实验

CO₂捕集、封存及利用是实现“双碳”目标的重要途径,为将碳捕集后的低湿CO₂/H₂O进行CO₂提纯和资源化利用,采用动态吸附实验研究了不同温度（303K、313K）、H₂O含量（0.7%~3.0%）的CO₂/H₂O在活性炭、活性氧化铝、分子筛3A和13X四种吸附剂上的动态吸附穿透曲线、吸附床温度分布、吸附量,分析了CO₂/H₂O分离系数和吸附热。结果表明,在CO₂/H₂O动态吸附过程中,吸附床温度与各组分浓度随时间变化趋势相同。H₂O饱和时间随进气温度升高而缩短;H₂O含量增加,抑制CO₂吸附;活性炭和氧化铝中H₂O的饱和时间随H₂O含量增加而增长,但分子筛3A和13X饱和时间缩短。H₂O吸附量随H₂O含量增加而增加,吸附热随吸附量增加而减小,CO₂则相反。分子筛3A对CO₂吸附量最小且CO₂/H₂O分离系数最大。H₂O含量小于1%时,CO₂吸附量最大的分子筛13X分离系数大于活性氧化铝,分子筛3A和13X适合分离低湿CO₂/H₂O。     

Adsorption behavior of poly(vinylpyrrolidone) toward fuller's earth suspensions

The adsorption of poly(vinylpyrrolidone) (PVP) onto Fuller's earth surface was studied at fixed pH (4.2) and room temperature (27 ± 0.2°C). The kinetics of the adsorption process was monitored and various adsorption and kinetic parameters such as the adsorption coefficient, the rate constants for adsorption and desorption, the diffusion constant, and the penetration constant were evaluated. The effects of various experimental factors such as the pH and the presence of inorganic and organic anions or aliphatic alcohols were also studied on the adsorbed amounts of PVP. The role of temperature was also investigated and various thermodynamic parameters such as the standard Gibb's free energy, enthalpy, and entropy were also evaluated. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2122–2133, 2000     

沼气变压吸附剂吸附性能比较

研究了工程上常用的3种吸附剂CO2吸附剂硅胶、13X分子筛和碳分子筛在高压(0.1~1 MPa)下对CO2和CH4的吸附容量、稳定性和选择性,以确定其在沼气变压吸附分离中应用的可行性. 结果表明,硅胶的吸附稳定性非常好,0.1 MPa时吸附选择性系数为8~10,能有效分离CH4?CO2;13X分子筛对CH4和CO2吸附容量最高、吸附选择性最好,重复使用5次CO2的吸附容量略有下降;以CH4的损失率作为评价标准时,13X分子筛吸附CH4的损失率最低. 降压不能使被碳分子筛吸附的CH4完全解吸,吸附位不能充分释放,不适用于CH4与CO2的分离.     

The solubility of ethane in n-methylpyrrolidinone

The solubility of ethane in N-methylpyrrolidinone (NMP) has been measured at ?10, 25, 40, 50, 70, 75, 100, and 120°C at pressures up to 7.1 MPa. The solubility data obtained are compared with those of ethane in other physical solvents. The results were correlated with the Peng-Robinson (1976) equation of state and the interaction parameters were obtained. Henry's constants were also determined.     

13X分子筛对烟气中低分子醛酮的选择性吸附研究

为降低卷烟烟气中有害成分低分子醛酮化合物的含量和研究X型分子筛在卷烟减害中的应用,将13X型分子筛添加到卷烟嘴棒中,分析其对主流烟气中八种低分子醛酮化合物含量的影响。结果显示13X分子筛对低分子醛酮有明显的脱除作用。通过进一步研究13X分子筛对烟气中苯酚和苯并(α)芘的吸附作用,揭示了13X分子筛对低分子醛酮的选择性吸附与其因表面静电引力优先吸附极性物质的特性以及低分子醛酮的低熔沸点密切相关。烟气三项指标分析表明,13X分子筛对烟气中的焦油和烟碱含量影响不大,这有利于保持卷烟的香气。     

Adsorption performance of nickel and cadmium ions onto brewer's yeast

The brewer's yeast was used as adsorbent for the removal of Ni(II) and Cd(II) metal ions from aqueous solution. The surface of the brewer's yeast had three main functional groups of sulfonate, carboxyl, and amine groups. The pH of solution played an important role on the uptake of metal ions, and optimum adsorption was obtained at pH 6. Acid solution (pH 3) was efficient for the desorption of Ni(II) and Cd(II) ions from loaded brewer's yeast and the desorption efficiency was higher than 90%. The rate of metal ions adsorption onto brewer's yeast was rapid with short contact time. The kinetics of the adsorption process was found to follow the pseudo‐second‐order kinetic model. Langmuir and Freundlich isotherm models were used to fit the experimental data with Langmuir isotherm model having a better fit. The maximum uptakes of Ni(II) and Cd(II) by brewer's yeast were estimated to be 5.34 and 10.17 mg/g, respectively.     

Solubility measurements of N2 and CO2 in polypropylene and ethene/octene copolymer

In this set of experiments a magnetic suspension balance (MSB) was employed to measure the apparent solubilities of N₂ and CO₂ in polypropylene (PP) and ethene/octene copolymer melts, while the swollen volume predicted by the Sanchez–Lacombe (SL) equation of state (EOS) was used to account for the buoyancy effect. The swollen volume of the polymer/gas mixture, as well as the gas solubilities for both PP and the ethene/octene copolymer, are discussed. It was observed that the branched molecular structure limited the molecular movement, and therefore the volume swelling of the polymer/gas mixture. In a similar context, the solubility of both N₂ and CO₂ were less in the branched polymer (ethene/octene copolymer) than in the linear PP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2945–2953, 2007     

Dynamic Adsorption of CO2 from Methane: Studies on Mass and Heat Transfer

Three‐dimensional computational fluid dynamics studies related to dynamics adsorption of CO₂ from natural gas is found to be limited. 3D analyses for dynamics adsorption are substantially crucial to give a better prediction on the adsorption process by considering the actual fluid flow behavior within the packed‐bed porous media. A kinetic adsorption model has been integrated in a commercial fluid dynamics simulator to simulate the 3D hydrodynamics and adsorption phenomenon in a zeolite‐filled packed column for a CO₂‐methane separation system. The effects of various parameters such as Reynolds number, CO₂ feed concentration, feed temperature, and column dimension on CO₂ adsorption efficiency have been investigated. A correlation for adsorption efficiency based on the CO₂ concentration profiles has been developed and validated.     

CTMAB-13X分子筛的制备及对水中甲基橙的吸附

用十六烷基三甲基溴化铵(CTMAB)对13X分子筛进行改性制备CTMAB-13X分子筛,研究了不同条件下CTMAB-13X分子筛对废水中甲基橙的吸附性能、影响因素及动力学过程.结果表明:CTMAB-13X分子筛投加量为0.1 g/L,吸附时间10 min后对甲基橙吸附可达平衡,此时去除率达到88.9％.CTMAB-13X分子筛吸附容量为275mg/g,高于活性炭的182 mg/g.Zeta电位分析说明经阳离子表面活性剂CTMAB改性的13X分子筛表面带正电,对水中带负电的酸性染料甲基橙有较强的吸附效果.由红外吸收光谱(FTIR)看出CTMAB的特征峰出现在CTMAB-13X分子筛中,说明CTMAB接枝改性到13X分子筛表面.分析X-射线图谱得出CTMAB改性剂没有破坏13X分子筛自身的晶体结构,进一步证明CTMAB是接枝在分子筛表面.从扫描电镜(SEM)可以看出改性后的CTMAB-13X分子筛更为分散,因此可以为染料分子提供更多的吸附点位.激光粒度测定结果表明CTMAB-13X分子筛平均粒径Dav由17.45 μm下降到12.41 μm,比表面积(S/V)由5143.69 cm2/cm3增大到7752.48 cm2/cm3,与SEM分析结果一致.