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研究了改性活性炭(7%碳酸钠溶液浸渍)吸附硫化氢(H2S)气体的影响因素.利用改性后的活性炭考察氧含量、反应温度、空速等对活性炭吸附硫化氢的影响.结果表明,在反应条件下低氧含量时活性炭的吸附容量随氧含量增加而增加,但氧含量增加到3.5%后,氧含量对吸附容量的影响越来越小;在20~70℃范围内物理吸附发生主要作用,70~95℃化学吸附占主导作用,随着温度的增加,物理吸附逐渐向化学吸附转化,所以吸附容量先减小后增大;随着空速的增加,改性炭的吸附容量减小;改性后活性炭吸附H2S适宜的操作条件为氧含量2%,温度95℃,空速1000~2000 h-1. 相似文献
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《应用化工》2022,(4):703-707
采用微波辐照与氧化剂浸泡对椰壳活性炭进行改性研究。通过BET、SEM、FTIR对其表面物理化学性质进行表征。结果表明,微波与氧化改性均能丰富活性炭表面孔隙结构;活性炭改性后表面O—H、C—O、CO等含氧官能团含量增加,微波与K2Cr2O7浸泡共同改性样品的增加最为明显。脱硫实验结果表明,椰壳活性炭改性后,SO2吸附能力明显提高,微波与K2Cr2O7浸泡共同改性效果最佳,在60℃、烟气流量0.4 L/min时吸附量为33.31 mg/g;在烟气流量0.41 L/min之间,活性炭的吸附量随烟气流量的增加而减少;在601 L/min之间,活性炭的吸附量随烟气流量的增加而减少;在60120℃,随着温度升高,活性炭的初始吸附速率和吸附量均减小。 相似文献
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MnO-Ag/CaAl2O4乙烯脱氧剂性能 总被引:1,自引:0,他引:1
比较了还原温度对MnO/CaAl2O4和MnO-Ag/CaAl2O4乙烯脱氧剂脱氧容量的影响;考察了反应温度、反应压力、乙烯空速、乙烯中氧含量对MnO-Ag/CaAl2O4脱氧容量和脱氧后乙烯中残余氧含量的影响以及该脱氧剂重复再生使用时脱氧容量的变化.实验结果表明,MnO-Ag/CaAl2O4脱氧剂的还原再生温度比MnO/CaAl2O4低180℃;MnO-Ag/CaAl2O4脱氧刺在温度25-150℃,压力0.50~3.0MPa,空速1200~8000h-1反应条件下,可以将乙烯中氧含量从50~1000μL/L几净化至小于0.050μL/L;脱氧容量与反应温度呈正比例关系,在25℃和80℃其脱氧容量分别大于7.0mL氧/g脱氧剂和11.0mL氧/g脱氧剂;MnO-Ag/CaAl2O4脱氧剂能够反复再生使用,不会引起乙烯发生聚合、氧化等副反应. 相似文献
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采用微波辐照与氧化剂浸泡对椰壳活性炭进行改性研究。通过BET、SEM、FTIR对其表面物理化学性质进行表征。结果表明,微波与氧化改性均能丰富活性炭表面孔隙结构;活性炭改性后表面O—H、C—O、CO等含氧官能团含量增加,微波与K2Cr2O7浸泡共同改性样品的增加最为明显。脱硫实验结果表明,椰壳活性炭改性后,SO2吸附能力明显提高,微波与K2Cr2O7浸泡共同改性效果最佳,在60℃、烟气流量0.4 L/min时吸附量为33.31 mg/g;在烟气流量0.4~1 L/min之间,活性炭的吸附量随烟气流量的增加而减少;在60~120℃,随着温度升高,活性炭的初始吸附速率和吸附量均减小。 相似文献
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以煤质颗粒活性炭为原料,先采用浸渍法将KMn O4浸渍在活性炭上,再经热处理制得负载Mn O2活性炭。利用Mn O2的催化氧化和活性炭的吸附强化对甲醛进行去除。结果表明活性炭最佳制备条件:KMn O4浸渍液的浓度为0.079 mol/L、焙烧温度为600℃,负载Mn O2改性活性炭吸附甲醛用Langmuir线性吸附等温方程式描述最为合适。最佳吸附条件:吸附温度为35℃、p H为7。用Na OH溶液进行活性炭再生试验,最经济的再生条件为再生温度60℃、时间6~12 h。 相似文献
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以石油焦为原料经高温炭化和水蒸气活化处理制备出石油焦基活性炭,经硝酸氧化处理后,采用静态吸附法测试了2-甲基噻吩在石油焦基活性炭上的吸附性能。研究结果显示,制备的活性炭比表面积高于800 m2·g-1,孔容大于0.45 cm3·g-1,经硝酸处理后比表面积和总孔容有所下降。样品经硝酸处理后,对2-甲基噻吩的饱和吸附量显著增加,硝酸处理40 min得到的活性炭对2-甲基噻吩的饱和吸附量最大。2-甲基噻吩在石油焦基活性炭上的吸附动力学均遵循拟二级动力学模型,饱和吸附量随吸附温度的增加而减小,热力学上表现为放热,熵减且是自发进行的过程。 相似文献
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通过分析活化条件对γ-Al2O3膜/污泥活性炭表面孔结构和酸碱性的影响,研究了活化温度和活化时间对γ-Al2O3膜/污泥活性炭吸附脱硫性能影响的机理,探讨提高γ-Al2O3膜/污泥活性炭脱硫性能的活化条件.用BET(BRUNAUER-Emett-Teller)分别对γ-Al2O3膜/污泥活性炭的孔结构进行了研究,用化学法研究了γ-Al2O3膜/污泥活性炭表面的酸碱性.结果表明:随着活化温度升高,γ-Al2O3膜/污泥活性炭的BET比表面积增大,增强了物理吸附SO2气体的能力,超过600℃,γ-Al2O3膜/污泥活性炭的BET比表面积有所减少;碱性官能团的浓度随活化温度升高而显著地增加,有利于酸性气体SO2的化学吸附.随着活化时间的延长,γ-Al2O3膜/污泥活性炭的BET比表面积呈递减的变化趋势,碱性官能团呈现先增后减的变化趋势,使得吸附脱硫性能发生了相应的改变. 相似文献
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采用不同浓度硝酸氧化联合热处理的方法对活性炭(AC)进行表面化学改性,并研究了改性之后活性炭的Cr(VI)的吸附性能以及溶液初始浓度、pH、温度和时间等因素对其吸附性能的影响。研究发现,在空气氛围下,经20wt%的沸腾的硝酸溶液氧化3 h,450℃条件下马弗炉热处理2h后活性炭(MAC-20)的Cr(VI)的吸附性能最好,饱和吸附容量为34.89mg·g~(-1),比AC增加了10.77mg·g~(-1)。溶液pH是MAC-20的Cr(VI)吸附性能的主要影响因素,pH=2,MAC-20达到最大吸附值。MAC-20的Cr(VI)吸附规律符合Lagergren准二级反应速率模型,Cr(VI)在MAC-20表面的吸附行为主要以化学吸附为主。 相似文献
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A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases. 相似文献
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ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l/3为氧气,2/3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中:A一混… 相似文献
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面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。 相似文献
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P. P. Budnikoff 《Journal of the American Ceramic Society》1924,7(11):817-820
The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO3 and determination of CaO by KMnO4 titration, the SO3 by Andrews method of titration of BaCrO4 has been found to give very reliable results with the least consumption of time. 相似文献
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用两个形状指数表征粉煤灰颗粒形貌的研究 总被引:5,自引:0,他引:5
引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。 相似文献
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A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.
Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology. 相似文献
Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology. 相似文献
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本文以三种典型煤的碳燃烧为研究对象,分别采用简单一维沉降燃烧方式和等温加热燃烧方式,实验研究了煤在快速加热条件下,其碳的初期和中,后期燃烧过程。以实验为基础,建立了煤的碳燃烧模型,变工况数值模拟了煤的碳燃烧过程,揭示了煤不同条件下的单颗粒碳燃烧特性。 相似文献
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提出了有双官能团酸相对分子质量调节剂存在时己内酰胺水解聚合过程动力学模型 ,并进行了实验验证 .对不同温度下聚合产物组成和各影响因素对数均聚合度的影响进行了模拟 .结果表明 ,数均聚合度随进料中水、氨基己酸及相对分子质量调节剂浓度的增加而减小 ,其中水的浓度影响较显著 ,且在考察浓度范围内相对分子质量调节剂浓度 [R]0 ≤ 0 0 0 68mol·kg- 1 时数均聚合度基本不变 ,而 [R]0 >0 0 0 68mol·kg- 1 时数均聚合度则显著减小 .无氨基己酸及相对分子质量调节剂时数均聚合度亦随水浓度增加而减小 . 相似文献
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ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES 总被引:5,自引:0,他引:5
Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log10 viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log10 viscosity as a function of soda content are smooth up to 50% Na2O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO2, 2Na2O) due to Molecular Substitution of CaO, MgO and Al2O3 for Na2O The effect is clearly brought out by plotting (from the results of English) the change of log10η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature Ta. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log10η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A12O3) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al2O3) per 100°. At the aggregation temperature the change of log10η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al2O3. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log10η due to substitution of an oxide for Na2O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na2O-CaO-SiO2. Change of Viscosity of Glass (4SiO2, 2Na2O) due to of Substitution of B2O3 for SiO2 The change of log10η (from the results of English) is plotted as a function of temperature, and also the change of log10η per per cent B2O3. The curves are more complex than for the substitution for Na2O. 相似文献
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