Production of Pelletized Fuel from Biodiesel-Production Wastes: Oil Palm Fronds and Crude Glycerin

Biomass from agricultural residue is regarded as an important source of renewable energy in Thailand due to tremendous annual production. One of the country's largest and most available crop residues is obtained from oil palm plantations. The residue is mainly used for biodiesel feedstock. Thus, this study was aimed to investigate the potential of using oil palm fronds to produce pelletized fuel. To improve the calorific property of the fuel, crude glycerin obtained from biodiesel-processing production was combined with ground fronds as a biomass binder. The glycerin content, ranging from 19 to 45% (by weight), enhanced the heating value of the oil palm fronds from 17.2 MJ/kg (no addition of glycerin) to 17.8-20.4 MJ/kg. The fuel properties, which were examined by the proximate and ultimate analyses, comply with the quality demands of pelletized fuel suggested by the European Biomass Industry Association. Although the combustion ash content was found to be higher than the criterion, the ash chemical composition was found to be suitable for being used as a cement-replacement material. The result of preconditioning the crude glycerin with pH adjustment indicated that the preconditioning did not appear to have the effect on the fuel quality of the palm frond pellets

Investigation of Formaldehyde in Gross Anatomy Laboratory: Area-Based and Exposure Levels, Ventilation, Health Risk and Clinical Symptoms

Formaldehyde is commonly used in embalming solution in medical fields to preserve tissues. Formaldehyde vapor released from cadavers during dissection practice can adversely affect students and instructors in gross anatomy laboratories. Therefore, this study investigated formaldehyde concentrations in a gross anatomy laboratory of Mahasarakham University, Thailand. Area-based sampling was conducted for three scenarios: (1) a laboratory cleaning period, (2) three periods of teaching classes and (3) a non-teaching class period. Personal samples were also collected for five consecutive working days from two anatomy lab instructors and a non-lab instructor. Measurements were conducted during May to October 2016 using cartridges filled with dinitrophenylhydrazine coated silica gel. Samples were desorbed and analyzed by high performance liquid chromatography. Results showed that the average area-based concentrations during the dissection classes ranged from 9.3 to 17.6 ppb, while the non-teaching class concentration was 5.5 ppb. The concentration increased to 3.1×103 ppb during the laboratory cleaning. The five-day average exposure concentrations were 7.6 ppb and 4.7 ppb for the two lab instructors and 1.1 ppb for the non-lab instructor. The lifetime cancer risk estimates were 5.8×10-6, 2.9×10-6 and 8.1×10-7, respectively. The three most reported clinical symptoms by the gross anatomy students were associated with formaldehyde concentrations above 16 ppb at the significance level of 0.05. These included unpleasant odor, general fatigue or fatigue after awakening and dizziness with response rates of 57.5 %, 38.5 % and 33.1 %, respectively. Improvement of the ventilation and source control measures are essential for reducing formaldehyde emissions in the gross anatomy laboratory

The Influence of Ammonia and Carbon Dioxide on the Sorption of a Basic Organic Pollutant to a Mineral Surface

Indoor surfaces have a sorptive capacity for organic pollutants which may be significantly influenced by other gases and the pH of the surface. in this research, we examine the influence of a common indoor gaseous acid, CO2, and base, NH3, on the adsorption of a volatile organic base, trimethylamine (TMA), to a mineral surface, zirconium silicate beads. Varying ammonia and CO2 within concentration ranges of indoor relevance substantially influences the sorptive capacity of this mineral surface. Increasing the CO2 mixing ratio to 1000 p.p.m. enhances surface capacity of TMA by 40-50%; increasing the NH3 mixing ratio to 10 p.p.m. decreases the TMA surface capacity by ~5-80% depending on relative humidity. the phenomena of dissolution of TMA into bulk surface water and acid-base chemistry in the surface water do not adequately describe equilibrium adsorption on this surface. Instead, adsorption to the dry solid or to adsorbed water layers appears to dominate. Reduction in the equilibrium partition coefficient, ke, in the presence of NH3 is due to a competition between TMA and ammonia molecules for adsorption sites. Site competition appears to follow the Langmuir competitive model and most ke values range from 0.003-0.045 m

Variation of VOCs Inside a New Car during the First Year and Their Relationship to Temperature

Passenger exposure to volatile organic compounds (VOCs) emitted from vehicle interiors has increasingly drawn public concern over their potential health risks. This study aimed to investigate ambient levels of in-cabin VOCs in a new car over the period of one year after first delivery. The relationship between VOC concentrations and in-cabin temperature was also studied. Seventeen active air samplings inside a parked new car were conducted from February 2012 to February 2013 using sorbent tubes. Six VOCs were measured with first-month average concentrations of 215 µg m-3 for benzene, 65.6 µg m-3 for toluene, 151 µg m-3 for 1,2,3-trimethylbenzene, 806 µg m-3 for ethyl acetate, 183 µg m-3 for formaldehyde, and 28.2 µg m-3 for acetone. The concentration profiles of all VOCs except formaldehyde declined, falling below the detection limits towards the end of the 1-year monitoring period. Formaldehyde concentrations were found to be directly proportional to in-cabin temperature at a significance level of p = 0.05 during the first five months

Rapid Measurement of Indoor Mass-Transfer Coefficients

Indoor air pollutant concentrations can be influenced by how rapidly species are transported to and from surfaces. Consequently, a greater understanding of indoor transport phenomena to surfaces improves estimates of human exposure to indoor air pollutants. Here, we introduce two methods of rapidly and directly measuring species fluxes at indoor surfaces, allowing us to evaluate the transport-limited deposition velocity, vt (a mass-transfer coefficient). The deposition velocity sensor (DeVS) method employs a small microbalance coated with a pure hydrocarbon, preferably octadecane. We quantify flux (or evaporation rate) of the hydrocarbon into a room by observing the rate of mass loss on the microbalance. The transport-limited deposition velocity, vt, octadecane, is then obtained by combining the flux with the vapor pressure of the hydrocarbon. Simultaneously, vt, ozone is quantified using the depostion velocity of ozone (DeVO) method, which acts as a standard to caliberate ans evaluate DeVS. Specifically, DeVO evaluates ozone transport to surfaces by quantifying the conversion by ozone of nitrate on a glass fiber filter. Simultaneous laboratory chamber experiments demonstrates that vt for octadecane and ozone are strongly correlated, with the values for ozone ~1.5 times greater than that for octadecane. In an office experiments, the DeVS method responds within minutes to step changes in conditions such as occupancy, activities and ventilation. At present, the results are in order-of-magnitude agreement with predicted indoor mass-transfer coefficients

The influence of ammonia and carbon dioxide on the sorption of basic (alkaline) organic pollutants onto indoor surfaces

Sorptive interactions with indoor surfaces strongly influence indoor exposure to organic pollutants. The surface capacity of a volatile amine, a basic compound, is influenced by a common indoor gaseous acid, CO₂, and base, NH₃. Experimental results show that CO₂ tends to cause a mineral surface (zirconium silicate) and carpet to store more amine, but NH₃ tends to decrease the surface capacity of zirconium silicate, carpet and latex-painted gypsum board. Hypotheses testing along with the studies of surface characterizations and molecular interactions with an amine suggests that sorption of an amine to these indoor materials is primarily a surface phenomenon. However, dissolution of an amine and acid-base chemistry in the bulk surface water may also contribute to the overall sorptive capacity of carpet at high relative humidity. This fundamental research is a first step towards better understanding indoor exposures to amines such as nicotine, pyridine, etc. --Abstract, page iii

Influence of Ammonia and Carbon Dioxide on the Sorption of a Basic Organic Pollutant to Carpet and Latex-Painted Gypsum Board

Sorptive interactions with indoor surfaces strongly influence indoor exposure to organic pollutants. Adsorption itself may be influenced by indoor levels of common indoor gases such as CO2, NH3, and H2O. We quantified sorption characteristics of trimethylamine (TMA) on carpet and painted wallboard, while challenging the surface with gas-phase CO2, NH3 and H2O. We show that the capacity of the carpet to sorb TMA, doubles when the CO2 mixing ratio is increased from 0 to 1000 ppm CO2 at 90% relative humidity. In contrast, NH3 decreases the surface capacity of both carpet and latex paint. Sorption of TMA to these indoor materials is primarily caused by interactions at one or more interfaces. Dissolution of TMA and aqueous acid−base chemistry appear to also contribute to the overall sorptive capacity of carpet at high relative humidity. The reduction in the distribution coefficient, ke, in the presence of NH3 is explained by competition between TMA and NH3 molecules for sites on the substrates at low-to-medium relative humidity conditions

Characterization of Total Volatile Organic Compound Emissions from Finished Solid Wood Using an Environmental Chamber

Solvent-based finishes used for solid wood furniture involve exposure of workers and customers to volatile organic compounds. This study was to characterize emission parameters of total volatile organic compounds from five different types of solid wood products: urethane-coated, lacquer-coated, acrylic-coated, gloss white-painted, and matte white-painted. Emission experiments were conducted using a 10-liter environmental test chamber, and all test finished wood samples were prepared by professional furniture-workers. Emission parameters were quantified by fitting the experimental time-dependent concentrations to the two-decaying sources model using a non linear regression method. The quantified emission rate constants of the fast-decaying phase were 5.09, 5.09, 6.84, 4.71, and 0.43 1/h for the urethane-coated, lacquer-coated, acrylic-coated, gloss white-painted, and matte white-painted products, respectively, while the emission rate constants for the slow-decaying phase were 3.12x10-2, 2.23x10-2, 1.48x10-2, 2.14x10-2, and 1.2x10-3 1/h, respectively. The matte white-painted wood exhibited the higher total quantities of emitted organic species than other finished wood products by 4-16 times for the fast-decaying emission and by 5-18 times for the slow-decaying emission

Characterizing the Chemical Nature of a Sorbed Amine on Indoor Surfaces Using ATR-FTIR

Sorptive interactions with indoor surfaces strongly influence indoor exposure to organic pollutants. Thus, we develop a better understanding of intermolecular interactions between an aliphatic amine and indoor surfaces using ATR-FTIR spectroscopy. The measurements are conducted at high relative humidity in the presence of CO2 and NH3, a gaseous acid and base found in indoor air. The spectral features of an amine sorbed on mineral and polyethylene surfaces are indicative of a protonated species. An amine may chemisorb to either dry surface sites or an adsorbed water surface. These contrast with the spectra of an amine sorbed on latex paint under an NH3 stream in which the peaks assigned to protonation are not observed