Adsorption Performance of Activated Carbon Prepared from Corn Stalks

[Objective] This study aimed to study the adsorption performance of activated carbon prepared from corn stalks. [Methed] With granular activated carbon prepared from corn stalks as research object, adsorption performance simulation test equipment was set up to investigate the adsorption performance of the prepared activated carbon for methanol by static weight method. In addition, the effects of adsorption bed structure, activated carbon particle size in adsorption bed, addition amount of graphite powder in activated carbon and modified activated carbon on systematic adsorption performance were studied. [Result] Under conditions of same activated carbon and same adsorption temperature, the adsorption performance of new adsorption bed A （installed with finned diaphragm adsorbate tubes） was signifi- cantly better than that of unmodified adsorption bed B. Compared with adsorption bed B, adsorption bed A took 5 min shorter to reach the adsorption amount of 0.22 g/g. Under the same adsorption temperature, the adsorption performance of bed loaded with different-particle size activated carbon was significantly better than that loaded with same-particle size activated carbon. The bed loaded with different-particle size activated carbon took 16 min shorter to reach the adsorption capacity of 0.22 g/g compared with the bed loaded with same-particle size activated carbon. Adding proper amount of graphite powder in activated carbon could enhance the thermal conductivity and strengthen the adsorption properties. The optimum addition amount of graphite powder was 20% of the total amount of activated carbon. Com- pared with that of the control, the adsorption performance of activated carbon soaked by weak acidic solution was significantly improved. It took 3 min shorter to reach 87.1% of the equilibrium adsorption amount. [Conclusion] This study will provide reference for optimizing structural design of adsorption bed and adsorption refrigeration system.

An Adsorption Kinetic Model for Sulfur Dioxide Adsorption by ZL50 Activated Carbon

A semi-empirical adsorption kinetic model was proposed with the time compensation method to describe the chemisorption of SO2 in flue gas by carbon adsorbents for flue gas purification.The change in adsorption capacity and adsorption rate with time at different water vapor concentrations and different SO2 concentrations was studied.The model was in good agreement with experimental data.The surface reaction was probably the rate controlling step in the early stage for SO2 adsorption by ZL50 activated carbon.The parameters m and n in the nth order adsorption kinetic model were related to the magnitude of the time compensation and adsorption driving force,respectively.The change of parameter n with water vapor concentrations and sulfur dioxide concentrations was studied and some physical implications were given.The sum of square errors was less than 1.0 and the average absolute percentage deviations ranged from 0.5 to 3.2.The kinetic model was compared with other models in the literature.

Theoretical and Experimental Study on the Adsorption and Desorption of Methane by Granular Activated Carbon at 25℃

A theoretical and experimental study was conducted to accurately determine the amount of adsorption and desorption of methane by various Granular Activated Carbon （GAC） under different physical conditions. To carry out the experiments, the volumetric method was used up to 500 psia at constant temperature of 25℃. In these experiments, adsorption as well as desorption capacities of four different GAC in the adsorption of methane, the major constituent of natural gas, at various equilibrium pressures and a constant temperature were studied. Also, various adsorption isotherm models were used to model the experimental data collected from the experiments. The accuracy of the results obtained from the adsorption isotherm models was compared and the values for the regressed parameters were reported. The results shows that the physical characteristics of activated carbons such as BET surface area, micropore volume, packing density, and pore size distribution play an important role in the amount of methane to be adsorbed and desorbed.

Effect of preparation methods on the adsorption property of municipal solid waste-based carbon materials

Three different preparation methods including steam physical activation, catalytic carbonation and KOH chemical activation methods were used to prepare municipal solid waste- based carbon materials. The methylene blue （MB） adsorption value was applied to evaluate the adsorption capabilities of the prepared carbon materials. The effects of preparation methods on adsorption capability and yield of products were investigated. The yield of carbon materials with the catalytic carbonation method is the highest, and the KOH activation method is the second level. Considering the adsorption performance, the KOH activation method is much more favorable. Among the different components of municipal solid waste-based carbon materials, the adsorption properties of the single component of paperboard, the double components of tire and paperboard, the triple components of tire, paperboard and polyvinyl chloride （PVC）, and the multi-component mixtures are better than those of other single-, double-, triple- and multi-component mixtures, respectively.

Preparation and photocatalytic activity of TiO_2-coated granular activated carbon composites by a molecular adsorption-deposition method

TiO2 nanoparticle-coated granular activated carbon (GAC) composite photocatalysts (CPs) were suc-cessfully prepared by a molecular adsorption-deposition (MAD) method. The CPs were detected by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), BET surface area and UV-Vis adsorption spectroscopy, and their photoactivity was evaluated by methyl orange (MO) photodegradation. The results show that small-sized TiO2 nanoparticles were dispersed well, deposited on the surface of GAC, and showed slight blue shift in comparison with pure TiO2. With the increase in TiO2 content, the CPs showed band gaps in lower energy, smaller surface areas and the higher content of Ti3+ ions. Compared with pure TiO2 and others CPs samples, CPs-382 sample showed the highest photoactivity due to the optimum TiO2 content and surface area besides the synergic effect of photocatalytic degradation of TiO2 and adsorptive property of GAC. In addition, the CPs could be very easily reclaimed, recycled and reused for methyl orange removal while high photoactivity is pre-served.

Multiscale Simulation Starting at the Molecular Level for Adsorption Process Development

This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.

一步炭化-活化法制备球形活性炭及其储氢性能研究

氢能是一种清洁高效的能源,但缺乏高效的氢气储运方式,因而制约了氢能产业的发展。以强酸性聚苯乙烯树脂为原料,KOH为活化剂,通过一步炭化-活化法制备了多孔树脂基球形活性炭,并对样品进行了表征和储氢性能研究。实验结果表明,KOH质量分数为30%、炭化温度为750℃时,制备的球形活性炭比表面积为2158m^(2)/g,总孔容为1.12cm^(3)/g。该样品综合储氢性能最优,在温度-196℃、压力1MPa条件下,质量储氢密度可达3.14%,体积储氢密度为11.47kg/m^(3)。

载铁活性炭对酸性嫩黄G的吸附机理

为获得高效处理酸性嫩黄G(AYG)废水方法,采用浸渍法制备载铁活性炭(Fe-AC)作为吸附剂,并采用傅里叶红外光谱、扫描电镜及比表面积方法对改性前后活性炭进行表征分析。研究采用Box-Behnken Design响应面分析了各因素及其交互作用对AYG的去除影响,并探讨了Fe-AC吸附处理AYG的机理。结果表明:3个因素对AYG去除影响的显著顺序为Fe-AC投加量>处理时间>pH。最佳处理条件:Fe-AC投加量为9.51g/L、处理时间为40.79 min、pH值为4.23。Fe-AC吸附AYG遵循准二级动力学模型,反应速率常数为0.0102~0.6193 g/(mg·min),吸附过程符合Temkin吸附等温模型。机理分析结果表明,Fe-AC含氧官能团增加,表面粗糙,比表面积及单点吸附总孔容增加,裂缝、凹陷丰富,存在多层吸附现象,为其吸附AYG提供了更多结合位点,更利于其与吸附质结合,增加其对AYG吸附量。

油气回收装置活性炭更换过程及要点分析

对吸附法油气回收装置活性炭更换的过程及要点进行了介绍和分析,从油气回收装置的工艺流程和活性炭吸附机理出发,结合石油库油气回收装置活性炭实际更换情况分析出在选型、更换、钝化、投用等过程中要点,为石油库更换油气回收装置活性炭提供了参考。

超高纯氢低温提纯工艺研究

氢能是正在大力发展的重要清洁能源,在使用过程中对氢气纯度有较高的要求。随着燃料电池和半导体行业的迅速发展,本文基于大型氢液化装置在液氢制备和液氢加注过程中回收的纯度99%以上的氢气提纯需求,对于氢气纯度的要求更加苛刻,一般纯度需求为5N~6N级别,这对于氢气高效提纯工艺提出了更大的挑战。对低温吸附法、变压吸附法、钯合金扩散法(膜分离)以及金属吸氢法等4种氢提纯工艺进行了对比分析;实验研究了液氮温区大颗粒活性炭对氢气和氮气的吸附效果;同时采用低温吸附方法设计了99%以上纯度向超高纯氢气(6N)的提纯工艺,并利用数值模拟软件对低温吸附流程工艺进行了建模分析与优化,目的在于探索和开发适用于工业生产的大流量、高纯度、稳定可靠以及经济高效的超高纯氢提纯工艺。

活性炭复合材料对有毒工业气体吸附性能的研究进展

活性炭复合材料结合了活性炭与多种功能材料的优点,在有毒气体治理领域展现出了巨大应用潜力。本文综述了活性炭与分子筛、金属有机骨架材料、金属氧化物、矿物聚合物等进行复合的方法,并详细探讨了这些复合材料用于有毒工业气体吸附的研究进展。通过对比分析,总结了活性炭复合材料在吸附性能上的优势与不足,并展望了其未来的发展方向。

响应面法优化制备巨菌草基高比表面积活性炭

以巨菌草作为原料,化学活化法制备高比表面积活性炭,在单因素考察基础上,采用响应面分析法对活化温度、活化时间、碱炭比等影响因素进行了条件优化.通过模型分析确定了最佳制备工艺条件为活化温度920℃、活化时间50 min、碱炭比4∶1,该条件下制备的巨菌草基活性炭实际碘吸附值与预测值相近,证明响应面法模型优化分析结果可靠.通过BET、IR和SEM等进行表征,表明所制备的巨菌草基活性炭表面官能团种类丰富,孔隙结构发达,达到了超级活性炭的标准,为巨菌草基活性炭的开发应用提供了制备工艺参数及材料性能参考.

吸附剂对选矿废水中丁基黄药的吸附性能研究

为高效解决选矿废水残余浮选药剂浓度高的问题,将活性炭和钙基膨润土分别作为吸附剂,系统探究了吸附剂用量、吸附时间、反应温度、溶液初始pH值等因素对废水中丁基黄药吸附性能的影响。试验结果表明:活性炭对丁基黄药的吸附量和去除率最大值分别为6.55mg/g和98.32%,而钙基膨润土对丁基黄药的吸附量和去除率最大值分别为2.73 mg/g和40.95%。通过X射线衍射(XRD)和傅里叶红外光谱(FTIR)对吸附材料吸附前后的结构变化进行对比表明,活性炭和钙基膨润土对丁基黄药的去除机制主要为物理吸附。

活性炭纤维对SO_(2)饱和吸附量的测定方法改进

“绿色化学”是当前化学实验教学中重要的课程思政元素,“活性炭纤维对SO_(2)饱和吸附量的测定”作为综合性实验具有现实意义。而传统的对SO_(2)吸附量的测定方法存在仪器昂贵、操作复杂、危险性等问题,不适合应用于实验教学,同时也不适用于一些硬件设施有限的中小型实验室中进行科学研究。通过参考国家环境保护总局标准HJ/T56-2000《固定污染源排气中二氧化硫的测定.碘量法》并进行方法及装置的改进,可以有效的测定活性炭纤维材料对SO_(2)的饱和吸附量。新方法操作简单、安全、成本较低,为实验室开展相关教学及中小型实验研究具有参考意义。

活性炭吸附原子吸收法测金含量时铅的干扰与消除

采用活性炭吸附原子吸收法测金含量时,铅对检测结果有极大干扰,针对铅对活性炭吸附原子吸收法测金的影响,通过实验探讨温度、酸度、Na_(2)SO_(4)加入量对检测结果影响,并提出改进方法,有效消除了铅的干扰,提高了检测结果的准确性及精密度。

大型油田含油污泥无害化处理技术及其应用研究

为了减少或消除污泥对环境和人体健康的危害,并实现对其资源化、能源化或再利用,提出大型油田含油污泥无害化处理技术。首先,在预处理阶段,将含油污泥进行破碎和混合均匀。破碎的目的是使污泥中的原油和水分尽可能均匀地分散在每个颗粒中,混合则是为了使污泥中的各种成分充分混合在一起。然后,借助化学氧化处理、活性炭吸附处理、生物处理方式,分别降低含油污泥中固体杂质、含油量,以及有机物质含量。最后,采用深度处理方法,如高温焚烧方法,对生物处理后的含油污泥进行减量化和资源化处理。在测试结果中,含油污泥的含油量下降幅度为5.01%,水分含量的下降幅度为6.61%,固体杂质含量的下降幅度为6.00%。

三乙烯二胺改性活性炭纤维对气态甲基碘吸附研究

气态甲基碘是核设施运行过程中难以处理的放射性气态产物之一。本文通过水热法制备了三乙烯二胺(TEDA)改性高比表面积粘胶基活性炭纤维材料,并开展了改性材料气态甲基碘吸附研究,通过BET、SEM-EDS、FT-IR、TGA、放射性测试方法对材料进行了表征和吸附性能分析。静态气态碘吸附结果表明,水热改性材料对单质碘吸附量提高了36%,达到1.84 g/g,甲基碘吸附量达到400 mg/g。甲基碘动态吸附实验表明,改性材料具有较高的吸附效率;随着温度和湿度的增加,吸附效率略有降低;环境湿度对气态甲基碘的吸附性能影响较大。温度30℃、相对湿度95%条件下的穿透测试表明,材料在12 h内未出现穿透,改性材料展现出优异的甲基碘吸附性能。放射性甲基碘吸附实验显示,水热改性材料吸附效率接近95%,超过未改性材料的3倍;TEDA改性活性炭纤维明显提高了对气态甲基碘的化学吸附能力。水热法TEDA改性粘胶基活性炭纤维材料表现出优异气态甲基碘吸附性能。

臭氧氧化-活性炭吸附联合法处理苯酚废水研究

使用臭氧氧化-活性炭吸附联合法处理苯酚废水,分别考察了活性炭投加量、苯酚废水溶液pH值和活性炭吸附反应时间等因素对苯酚模拟废水处理效果的影响。结果表明,室温条件下,废水溶液的pH值为9,臭氧通入时间为25 min,活性炭投加量2.5 g/L,活性炭吸附反应时间为50 min的实验条件下,初始浓度为100.0 mg/L的苯酚模拟废水经过处理,苯酚去除率为95.0%。

活性炭+THF溶液体系中CO_(2)水合物生成特性研究

水合物法捕集CO_(2)具有储气量大、生成条件温和等显著优点,应用前景广阔。提高水合物生成速率和CO_(2)气体消耗量是该方法需解决的关键问题。在活性炭+THF溶液体系中开展了CO_(2)水合物生成特性研究,探究了THF溶液浓度(物质的量分数,下同)、THF溶液饱和度对CO_(2)气体消耗量的影响,并通过可视显微实验研究了活性炭+THF溶液体系中CO_(2)水合物的生长形貌特征。研究结果表明,相比于THF溶液浓度为5.56%的体系,活性炭+THF溶液体系(THF溶液浓度为5.56%、溶液饱和度为100%)的CO_(2)气体消耗量增加了59%;当THF溶液饱和度为100%时,提高THF溶液浓度可以有效促进水合物生长,在THF溶液浓度为5.56%的条件下,CO_(2)气体消耗量达到总CO_(2)气体消耗量90%所需的时间(t90)最短(106.67min)。活性炭+THF溶液体系中的CO_(2)水合反应由气体吸附和水合物生长两个阶段组成,水合物最初形成于活性炭颗粒/溶液界面并逐渐填充活性炭颗粒间隙;当THF溶液浓度为5.56%时,CO_(2)气体消耗量随THF溶液饱和度增加而降低,在THF溶液饱和度为40%的条件下的CO_(2)气体消耗量最大,对应的t90最短(23.5min)。

化学活化法制备重质沥青基活性炭的研究

以重质沥青为原料,采用化学活化法制备重质沥青基活性炭,探究空气预氧化与硝酸钾预氧化、不同碱炭比及不同活化时间和活化温度对重质沥青基活性炭性能的影响,并采用碘吸附值与二氧化硫吸附量来确定活性炭的吸附性能。结果表明:在硝酸钾预氧化及碱炭比为4∶1的条件下,活化时间80min、活化温度850℃时制备的重质沥青基活性炭具有较为发达的微孔结构,碘吸附值为1052.2mg/g,二氧化硫吸附量为319.1mg/g。其性能优于物理活化法制备的活性炭,有望应用于吸附脱硫环保领域。