• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.233-239
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• 2013

A quartz crystal microbalance (QCM) system coated with poly (isobutylene), polystyrene, and poly (methyl methacrylate) has been prepared to measure the adsorption amounts of benzene, toluene, and p-xylene at very low pressures. The resonant frequency shift of the QCM system is proportional to the increase in pressure in all experiments. The Henry's constants for all adsorbates on the polymer films are obtained from experimental data and compared with the minimum adsorption potential energies between adsorbates and the polymer films. In general, there is an explicit correlation between adsorption amount and the minimum adsorption potential energy.

• Journal of the Korean Vacuum Society
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• v.21 no.2
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• pp.106-112
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• 2012

New equipment for quantitative and qualitative adsorption of volatile organic compound was set up, and using this equipment, adsorption behaviors of various carbob-based nanomaterials and $TiO_2$ thin films prepared by atomic layer deposition were compared. We could conclud that $TiO_2$ thin films can show higher adsorption capacity of toluene comparing to the carbon-based nanostructures due to higher affinity of the surface OH groups of $TiO_2$ towards toluene adsorption. We also demonstrate that our method allows to discriminate reversible and irreversible adsorptions at a given temperature.

• Journal of the Korean Society of Safety
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• v.34 no.6
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• pp.22-28
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• 2019

In South Korea, the enact of Korean Coast Guard Act-1 manages physical and chemical oil-dispersants. Oil snare, which is made of polypropylene, is newly added to the aforementioned act, and it has advantage on the ease of recovery compare to other adsorbents. This study synthesized bunker B-oil with diesel-oil and bunker C-oil to perform an adsorption test based on three samples which were manufactured in South Korea. As a result, adsorption test revealed 5.2 g/g more adsorption than the previous results from the act. Additional toluene test revealed that all the samples satisfied 90.0%, however coloured samples could release its pigment on the marine environment. Thus, colorless samples are recommended on the risk management of marine accidents. The study on the basic direction of the calculation of the test items and the standard value for the quality control of the oil snare was also carried out.

• Journal of the Korean Applied Science and Technology
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• v.17 no.2
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• pp.83-88
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• 2000

The VOCs(Volatile Organic Compounds) is one of the major cause for the atmosphere pollution. Breakthrough behavior of benzene and toluene in adsorption bed packed with activated carbon was experimentally studied. Composition and temperature of the gas flowing in the bed was measured and breakthrough curves for each component was obtained. Breakthrough time of benzene was earlier than that of toluene due to relatively weak adsorptivity. The relationship between breakthrough time and flow rate was obtained. The shape of temperature change with time was dependent on the position in the bed. Temperature changed faster and sharper in the inlet than in the outlet. It was noted that breakthrough behavior could be affected by the heat transfer properties.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.2
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• pp.122-132
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• 2009

Adsorption of toluene by activated carbon fiber (ACF) coated with dielectric heating element and desorption by applying microwave were investigated. In order to prepare adsorbent so that VOC can be desorbed by microwave heating, fine dielectric heating element with nano size was coated on the surface of the ACF using hybrid binder. Eight adsorbents (ACF-DHE, Activated Carbon Fiber coated with Dielectric Heating Element) were prepared with different amount of dielectric heating element, kinds of hybrid binder, and solvent. In order to investigate adsorption characteristics, BET surface area, pore volume, and average pore size were measured for each adsorbent including ACF. Breakthrough experiments with toluene concentration, flow rate, bed length using fixed bed reactor were performed to investigate adsorbality of adsorbent, and results were compared with that of the ACF. Desorption reactor was constructed with modified microwave oven to investigate heating effect on ACF-DHE by applying microwave power. Each adsorbent saturated with toluene were put into desorption reactor. Composition of desorbed gas generated by applying controlled microwave power to reactor was measured. Up to now, hot air desorption method has been used. Experimental results showed that desorption method with new adsorbent prepared by coating dielectric heating element on ACF can be used for industrial application.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.313-317
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• 2023

In this study, the physicochemical characterization and adsorption performance of air pollutants (VOCs, SO₂, and CO₂) were evaluated for the recycling of zeolite used in the ion exchange process. The surface characteristics of the zeolite used were confirmed through Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) analysis, and the composition and specific surface area were measured through X-Ray Fluorescence (XRF) and Brunauer-Emmett-Teller (BET). There was no change in the surface properties of the used zeolite, but the content of potassium and calcium increased and the specific surface area decreased. The toluene, sulfur oxides, and carbon dioxide adsorption performance of the used zeolite was evaluated, and it was confirmed that the performance was improved compared to the fresh zeolite. In particular, for toluene and sulfur oxides, the adsorption amount increased by 2.6 times and 2.3 times, respectively, which might be due to the enhancement of the polymerization reaction and the increase of the base point, according to the composition of the used zeolite.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.382-390
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• 2015

Poly(methyl methacrylate) (PMMA) supports and amine additives were investigated to adsorb $CO_2$. PMMA supports were fabricated by using different ratio of pore forming agents (porogen) to control the BET specific surface area, pore volume and distribution. Toluene and xylene are used for porogens. Supported amine sorbents were prepared by wet impregnation of tetraethylenepentamine (TEPA) on PMMA supports. So we could identify the effect of the pore structure of supports and the quantity of impregnated TEPA on the adsorption capacity. The increased amount of toluene as pore foaming agent resulted in the decreased average pore diameter and the increased BET surface area. Polymer supports with huge different pore distribution could be fabricated by controlling the ratio of porogen. After impregnation, the support with micropore structure is supposed the pore blocking and filling effect so that it has low $CO_2$ capacity and kinetics due to the difficulty of diffusing. Macropore structure indicates fast adsorption capacity and low influence of amine loading. In case of support with mesopore, it has high performance of adsorption capacity and kinetics. So high surface area and meso-/macro- pore structure is suitable for $CO_2$ capture.

• Environmental Engineering Research
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• v.11 no.1
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• pp.1-13
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• 2006

In this study, conventional biofilters packed with flexible synthetic polyurethane (PU) foam carriers were operated to remove toluene from a contaminated air stream. PU foams containing various adsorbents (e.g., zeolite, sepiolite, dolomite and barite) were synthesized for the biofilter media and their adsorption characteristics of toluene were determined. Adsorption capacity of PU-adsorbent foam was in the order of PU-dolomite ${\approx}$ PU-zeolite > PU-sepiolite > PU-barite. During the biofiltration experiment, influent toluene concentration was in the range of 0-160 ppm and EBRT (i.e., empty bed residence time) was 45 seconds. Pressure drop of the biofilter bed was 4-5 mm $H_2O/m$ column height. The maximum removal capacity was in the order of PU-dolomite > PU-zeolite > PU-sepiolite > PU-barite, while the complete removal capacity was in the order of PU-dolomite > PU-sepiolite > PU-zeolite > PU-barite. The better biofiltration performance in PU-dolomite foam was because PU-dolomite foam had lower density and higher porosity than the others providing favorable conditions for microbial growth. The results of biodegradation kinetic analysis showed that PU-dolomite foam had higher maximum removal rate ($V_m\;=\;11.04\;g$ toluene/kg dry material/day) and saturation constant ($K_s\;=\;26.57\;ppm$) than the other PU foams. This supports that PU-dolomite foam was better than the others for biofilteration of toluene.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.5
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• pp.316-325
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• 2012

In this study, we suggested adequate control technology by analyzing emission process and main chemical of VOC/HAPs generated from four paint factories in Busan area. And we estimated whether Kapok fiber, which is a natural material, can be commercially used for an absorbent by testing adsorption ability. As a result of this sturdy, above 60% of VOC/HAPs was volatilized and dispersed inside the working place without conducting control system of facilities during manufacturing paints. Concentration profile of VOC/HAPs, which is volatile naturally outside the factories, is surveyed above 70% at Toluene, Ethylbenzene, and Xylene. And a result of evaluation of odor attribution level about the component whose Odor Threshold is known, it is estimated that major cause material of A, B, C factories is Toluene and that of D factory is m/p-Xylene. And that result presented design arguments such as facilities specifications, activated carbon filling volume, and replace cycle of activated carbon as control technology. Also, that result presented emission process improvement such as adsorption of central-controlled ventilation device, installation of inlet flenge, and potable cleaning process. The rate of pollutant adsorption of Kapok fiber, which is natural material, is indicated about 91.9%, 66.7%. That result validated the possibility as replacement of activated carbon.

• Journal of the Korean Institute of Gas
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• v.14 no.3
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• pp.35-40
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• 2010

This study is to develop of an adsorbent for the removing of human body harmful benzene, toluene, and p-xylene as VOCs. Thus, this study researched the adsorption efficiency of the commercial ACF and the reactivated ACF by KOH/ACF to molar 1: 1. As the results, the effects have shown to enlarge with the increasing of VOCs concentration for adsorptive breakthrough time and breakthrough percentage on each substance. Also, the study have investigated as a similar tendency in case of desorption efficiency for toluene and p-xylene at constant concentration as 125PPM and 0.5$\ell$/min volume flow rate. But in case of benzene, it has been investigated to have rather lower desorption efficiency re-activation ACF than commercial ACF.