Papers by Keyword: Volatile Organic Compound (VOC)

Abstract: A new measurement system has been introduced to perform real-time measurements of molecular air contaminants at different location in a clean room down to a concentration of approximately 0.1 ppb. The system consists of an air sampling unit coupled to a proton transfer mass spectrometer and a Cavity Ring-Down Spectrometer. The measurements show that the time average concentrations of more than 10 different volatile impurity molecules exceed 1 ppb.

Abstract: The use of thermoplastic elastomers (TPE) in making parts of the vehicle such as a weather strip at the door and car window, floor mat, and dashboard is widespread. The commonly being used as in automotive parts manufacturing is styrene based TPE. Styrene based TPE released harmful gas, volatile organic compound (VOC) to the environment when it expose to the high temperature. Therefore, the new material with properties of thermoplastic elastomers is made from Natural rubber blend with local Tacca leontopetaloides starch and silica extracted from rice husk (as filler). Investigation on the mechanical properties by using Universal Testing Machine (UTM) found that the green material produced has potential to replace the existing floor mat used in automotive production. Indeed, when the starch was plasticized by glycerol and the volume of Natural rubber was varies, the value of tensile strength of green material produced was higher compared with existing floor mat. The VOCs released when its expose to the high temperature was much lower than the existing floor mat used. On top of that, Tacca leontopetaloides starch has potential to create low cost of new green materials in manufacturing of automotive parts.

Abstract: Eight volatile organic compounds (VOCs) in melon seeds printing and packaging materials have been analyzed by a headspace gas chromatography and mass spectrometry method. The results of external standard method show that PET and aluminum foil as raw materials of melon seeds plastic bags contain less VOCs, but PE contains much more VOCs. There are more VOCs in printing inks. Red ink has the most amount of VOCs (2777.27 mg/kg). The binder contains 143.574 mg/kg of VOCs. PE and printing inks may be the main sources of VOCs in the melon seeds plastic bags. Residues of benzenes in the front plastic bag materials exceed national standards. The amount of VOCs and benzenes in the back plastic bag materials all exceed national standards.

Abstract: Room temperature fluorescence gas sensor was developed based on TiO₂ nanoparticles coated with porphyrin dye thin films. The porphyrin dye used for this experiment were Iron (III) meso-tetraphenylporphine chloride (IMTPPCl) and Manganase (III) 5,10,15,20 tetra (4-pyridyl)-21H, 23H porphine chloride tetrakis (metachloride). The sensing sensitivity was due to the changes of the emission spectra produce by the thin film when expose to the organic vapors from volatile organic compounds; ethanol, acetone and 2-propanol. Both thin films show good response toward volatile organic vapors. However, TiO₂ nanoparticles with porphyrin; IMTPPCl thin film shows pronounced interaction, marked fluorescence spectra and more selective property, hence useful for chemical identification purpose.

Abstract: Three surfactant, sodium dodecyl sulfate (SBS), sodium dodecylbenzene sulfonate(SDBS), Polyoxyethylene Sorbitan Monolaurate(Tween 20), Turkey red oil sodium salt(TROS), were prepared and tested as composite adsorbents to remove chlorinated volatile organic component from exhaust gas. A gas–liquid absorption equipment was used to evaluate the performance of composite adsorbents. It is found that the three composite adsorbents could all effectively remove chlorobenzene but their absorption abilities were rather different. The maximum removal efficiency of chlorobenzene is composite absorbent TROS with low surface tension, reached as high as 85%, much greater than those of Tween 20 and SDBS (38% and 65%, respectively).

Abstract: Tightness, dynamic back pressure and air to liquid volume ratio (A/L) of vapor recovery system of gasoline filling stations were detected, VOCs was analyzed by GC, in-station diagnostic operation status was inspected by site investigation. The results denoted that the modification of gasoline filling stations was not complete and the installed vapor recovery systems didn’t operate under normal state. Insufficient understanding on vapor recovery control, poor management and unsuitable regulations resulted in these problems. Some solutions such as enhancing the propaganda, making preferential policies, holding training for the connected staffs, maintenance in time, and revising the unsuitable regulations were proposed. This study has positive significance in promoting vapor recovery control developed in China.

Abstract: Kaohsiung and Pintung are the first regions were set into action of total quantity control zones for air quality in Taiwan. Cap and trade programs have built for the particle matters (PM10), sulfur oxides (SOx), nitrogen oxides (NOx) and Volatile Organic Compounds (VOCs) in 2010. The offset ratio was designed as 1.0 or 1.2 various on the offset sources. The fixed offset ratio setting is suitable for PM10, SOx, and NOx since their characters are unitary. However, VOCs include a variety of chemicals, some of which may have short- or long-term adverse health effects. Even the same pollutant trading amount cannot guarantee the same health risk or environmental impacts. It would induced the highly uncertainty of air quality for the fixed offset ratio system. This study therefore tried to create a new methodology based on the pollutant impact strength of health and environment for determining the offset ratio of VOCs. An equation for calculating the offset ratio of VOCs was proposed and evaluated by case study. The elasticity of weighting determination was remained to the decision makers for confronting the various environmental improving targets.

Abstract: Bake-out exhaust method was used to significantly accelerate the release of VOCs from building materials. This paper studies the bake-out technology with dilution ventilation for indoor air pollution by experimental works. The baking effectiveness of formaldehyde, benzene, toluene and xylene ranged from 3 to 7.6, 7.6 to 25, 5.1 to 17 and 6 to 22 for the six cases, respectively. Baking effectiveness would become higher at longer baking time and higher baking temperature for formaldehyde and VOCs released from decorative materials. However, considering the possible deformation of building materials, 40°C and 10 hr would be the best choice for a suitable bake-out.

Abstract: Eight volatile organic compounds (VOCs) in the four disposable food packages at refrigeration temperature, room temperature and heating temperature have been analyzed by a headspace gas chromatography and mass spectrometry method. The results of external standard method show that the amount of VOCs in the four disposable packages at different temperatures are arranged in the following order: black plastic lunch box, white plastic lunch box, paper cup, paper bowl. Under the three types of temperature for an hour, the amount of VOCs in the black plastic lunch box at heating temperatures is higher (1.2382 mg/m² at 90 °C), room temperature has smaller content (0.6682 mg/m² and 0.9105 mg/m² at 20 °C and 30 °C, repectively). Content of VOCs in the white plastic lunch box increases gradually with temperature rising.

Abstract: Experimental investigations using granular activated carbon (GAC) adsorption and then desorpted with microwave irradiation for toluene abatement are reported in this paper. The results indicated that For different kinds of catalysts, Cu_0.33Mn_0.67O_x/γ-Al₂O₃ had the highest catalytic activity. For toluene combustion, the temperature required for 99% toluene conversion was lower than 300°C. In combination process of microwave desorption with catalytic combustion, the toluene conversion was ranged from 92% to 99% and the optimum volume flow rate ratio of carrier and air was 1:1.