共查询到18条相似文献,搜索用时 140 毫秒
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主要研究应用微波辐射再生高聚物吸附树脂.论述了微波加热的优点和微波脱附的原理,以乙醇为吸附质研究了吸附和微波辐射再生吸附剂过程.进行了正流微波辐射脱附和逆流微波辐射脱附实验,测定了微波脱附流出曲线和床层的温升曲线,并与传统的热脱附流出曲线和在不同加热速率下得到的床层温升曲线进行比较.实验结果表明:微波脱附比热脱附脱附速度更快,效率更高;高聚物吸附树脂类吸附剂对微波是半透明的,它对微波的吸收能力随着温度的升高而下降,因此,在微波辐射下,吸附剂床层吸收微波的能力也随着床层温度的升高和吸附质的脱附而减弱,床层最终温度不超过84℃,可使吸附剂的结构和性能不会被破坏和受影响,这有利于吸附剂的循环使用.微波在脱附和吸附剂再生中有很好的应用前景. 相似文献
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采用程序升温脱附技术研究了升温速率对CO2在13X上脱附性能的影响,基于Polanyi?Wigner方程在无假定条件的情况下计算了不同升温速率下的脱附活化能(Ed). 结果表明,13X分子筛在常温下吸附CO2后,脱附时会产生两个脱附峰(低温峰和高温峰);改变升温速率?会影响Ed,随?升高,低温峰的脱附活化能Ed,L呈对数规律减小,高温峰的脱附活化能Ed,H基本不变,且Ed,L>Qd,H;物理吸附与化学吸附作用力的差异造成两峰吸脱附机理存在根本差别. 相似文献
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以重庆市某炼铁厂地块复合污染土壤为试样,采用真空管式电阻炉进行热脱附试验,探究复合污染土壤中汞和多环芳烃在不同脱附温度和时间下的脱附效果。结果表明:(1)土壤样品中的汞多以难降解有机质及某些硫化物结合态、残渣态或晶格态等形式存在;(2)汞含量较低初始浓度(10~20 mg/kg)和较高初始浓度(20~40 mg/kg)的土样脱附温度宜分别不低于400℃和450℃;(3)低浓度多环芳烃(超标倍数≤5)、中等浓度多环芳烃(5<超标倍数<50)和高浓度多环芳烃(超标倍数≥50)的试样,脱附温度宜分别设置为400℃、500℃和550℃;(4)对汞和多环芳烃复合污染土壤的脱附温度选择关键取决于多环芳烃;(5)脱附温度相比脱附时间对污染物脱附效果的影响更大。 相似文献
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低挥发性有机物脱附活化能估算模型 总被引:1,自引:0,他引:1
提出了一种新的低挥发性有机物程序升温脱附(TPD)活化能估算模型.与经典 TPD 模型相比,所提出的新的 TPD理论模型不仅考虑了脱附过程中存在的吸附质分子再吸附现象的影响,而且还考虑了脱附分子在吸附剂孔内扩散的影响.通过 TPD 实验,运用所建立的活化能估算模型,技术测定了二苯并呋喃在 Norit RB1、Monolith 和 Chemviron三种活性炭上的脱附活化能.结果表明经典TPD 模型所估算出来的二苯并呋喃的活化能要比非线性 TPD 模型估算结果偏高约8.2%~9.6%,这表明脱附过程中存在吸附质分子再吸附现象和内扩散过程对脱附活化能有一定的影响. 相似文献
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以吸附过程本征动力学模型为基础,提出了一种新的TPD非线性活化能估算模型.与经典TPD模型相比,这种新的TPD理论模型考虑了脱附过程中存在的吸附质分子再吸附现象的影响,更接近实际的脱附过程.采用TPD实验技术测定了二苯并呋喃在Norit RB1、Monolith和Chemviron 3种活性炭上、不同升温速率下的程序升温脱附图谱.以这些TPD图谱为基础,分别采用经典TPD模型和TPD非线性模型计算了二苯并呋喃在3种活性炭上的脱附活化能.结果表明,经典TPD模型所估算出来的二苯并呋喃的活化能要偏高TPD非线性模型估算结果约8%~12%,脱附过程中存在吸附质分子再吸附现象对脱附活化能有较大的影响. 相似文献
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在太阳能吸附制冷循环解吸过程中传质性能受到非稳定热源温度的限制,而压力调节可作为强化传质的有效补偿手段。通过构建活性炭-甲醇工质对的恒温解吸理论模型给出了解吸率、解吸速率的表达式,对变压强化传质效果进行计算,揭示了温度与压力变化对解吸率的影响规律。计算结果显示系统压力降低10 kPa可等效于热源温度升高了6~8℃。搭建了以活性炭-甲醇为工质对的吸附单元管吸附制冷平台,实验结果显示当解吸温度分别为90、100和110℃时,系统压力降低14 kPa后,解吸率分别提高了20.5%、15.1%和12.1%,平均解吸速率分别提高了49.3%、44.6%和37.1%,与理论计算吻合较好。得出了温度与压力对解吸性能影响的耦合关系,并对实际太阳能吸附制冷系统变压解吸方法给出建议。 相似文献
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Ali Izadbakhsh Fatholah Farhadi Farhad Khorasheh Zi-Feng Yan 《Journal of Porous Materials》2009,16(5):599-603
Comparison of the traditional linear heating method of TPD with an original stepwise heating scheme was reported for the first time. Stepwise heating TPD was carried out by keeping the temperature constant as soon as ammonia desorption signal rises until the signal returns to the baseline. More ammonia desorption peaks on a SAPO-34 catalyst were identified using TPD with stepwise heating. The effect of temperature ramp on desorption peak broadening in TPD curve was also addressed. The more distinct ammonia desorption peaks in stepwise TPD indicates that ammonia adsorbs in about five or six different ways on SAPO-34, and attribution of different adsorptions may be explained considering some known features of SAPO’s acidity; including adsorption on the bridge hydroxyl groups Brønsted acid sites with different acid strength resulting from different silicon environment of SAPO molecular sieves, adsorption on terminal hydroxyl groups Brønsted acid sites, and by multiple adsorption of ammonia on acid sites. 相似文献
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在静态条件下,用强碱性阴离子交换纤维分离纯化银杏叶中的黄酮。采用正交实验法研究了不同条件对吸附的影响,并分别研究了解吸剂配比、调节荆酸度和温度对解吸的影响。结果表明,离子交换纤维对银杏叶黄酮具有良好的分离纯化效果,最佳吸附条件为:溶剂为20%乙醇溶液,.黄酮浓度为0.4045mg/mL,温度为70℃,pH值为4,浴比为I:300;最佳解吸条件为:解吸剂为70%乙醇溶液,温度为70℃,酸度调节荆为3mol/L的盐酸,且酸度调节剂与解吸荆的体积比为1:4。 相似文献
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The desorption process of volatile organic compounds(VOC) from a polymer adsorbent in counter-current multistage fluidized bed was studied. And a mathematical model considering the mass transfer dynamics was developed, which was validated from experiment data. The gaseous ethyl acetate mass transfer was discussed, and the limiting step is the intraparticle mass transfer of the desorption process. The value of intraparticle mass transfer coefficient is between 1.85 × 10~(-6) and 1.38 × 10~(-5) m·s~(-1) under temperature of 100–160 °C. Experiments under different operating conditions were carried out. The effects of operating conditions such as gas–solid flow ratio,gas inlet temperature and total stage number of multistage fluidized bed on outlet VOCs concentration and desorption efficiency were discussed. The maximum outlet VOCs concentration and corresponding desorption efficiency of the multistage fluidized bed desorber was calculated under different gas inlet temperatures and total stage numbers. 相似文献
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腐植酸对氮、磷、钾的吸附和解吸特性研究 总被引:9,自引:0,他引:9
通过研究风化煤腐植酸在不同pH值下对氮、磷、钾的吸附和解吸特性,得出结论:(1)在供试的各种pH值(4~8)条件下,随着氮、磷、钾初始处理浓度的增加,腐植酸对其吸附量和解吸量均呈上升趋势,但解吸率均呈下降趋势。(2)在不同pH值的介质溶液中,腐植酸对氮、磷、钾的吸附和解吸特性不尽相同。其中,在碱性条件下,腐植酸对氮的吸附和解吸作用较强;在酸性条件下,腐植酸对磷的吸附和解吸作用较强,而腐植酸对钾的吸附和解吸作用在中性条件下更易发生。(3)腐植酸对氮、磷、钾的等温吸附可用Linear、Langmuir和Freundlich 3个吸附方程来拟合,相关性达显著或极显著水平,但以Freundlich方程为最优。 相似文献
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The adsorption and desorption performances of CI Acid Red 18 and CI Acid Red 88 on an anion exchange membrane were studied. The effects of temperature, time, pH value and inorganic salt on the adsorption were investigated. The results showed that temperature and pH value had nearly no influence on the dye adsorption. The addition of inorganic salt (sodium sulphate) in the dye solution had a definite influence on the adsorption. The adsorption of the two acid dyes was in accordance with the pseudo‐second order dynamics model. The Langmuir adsorption model could describe the adsorption processes well. The membrane was more effective on CI Acid Red 18, which has three sulphonic groups. In the desorption process, different solutions were applied to investigate the desorption performance of the two acid dyes. The desorption percentage could reach ca. 90% using a mixture of ethanol, sodium chloride and water as the desorption solution. The anion exchange membrane could be reused. 相似文献