Thongboonchoo, Narisara

Preferred name

Alternative Name

Thongboonchoo, N.

Main Affiliation

School of Engineering

narisara.th@kmitl.ac.th

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Removal of Free Fatty Acids and Impurities from Palm Oil for Use in Bio-Transformer Oils
(2024-01-01)
Phoongen, Fariz
;
Thongboonchoo, Narisara
;
Lertweeranontharat, Chanaphat
;
Kitchaiya, Prakob
;
Mantree, Nattapong
This research aims to study the removal of free fatty acids (FFA) in palm oil to make it suitable for use as transformer oil using the adsorption method. The adsorbent used in this study is hydrogels of amorphous silica. The experiments were conducted by varying the following conditions: adsorbent modification, adsorbent type, adsorbent dosage, temperature, and adsorption time. The adsorption kinetics and equilibrium were studied. The equation for estimating the required amount of adsorbent at different temperatures was developed. It was found that 3 grams of adsorbent per 100 grams of oil were required to reduce the FFA content from 691.64 to 44.53 ppm at room temperature (30°C) and an adsorption time of 1 hour and 30 minutes. This achieved the desired target of reducing the FFA content to below 50 ppm. The analysis of the chemical composition of each fatty acid before and after adsorption using the HPLC technique showed that each type of FFA, including palmitic acid, stearic acid, oleic acid, linoleic acid, and eicosanoic acid, was significantly reduced. The adsorbent was equally effective in removing each type of FFA. The electrical properties of palm oil before and after adsorption were tested. It was found that the palm oil after adsorption had a breakdown voltage of 50 kV and 61.3 kV at a test gap of 2 mm, and 32.6 kV and 37.3 kV at a test gap of 1 mm, respectively. This shows that the reduction in FFA resulted in an increase in the breakdown voltage. This increase makes the use of palm oil as a liquid insulation in transformers more efficient and safer.
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Simulating the transport and chemical evolution of biomass burning pollutants originating from Southeast Asia during 7-SEAS/2010 Dongsha experiment
(2015-07-01)
Chuang, Ming Tung
;
Fu, Joshua S.
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Lin, Neng Huei
;
Lee, Chung Te
;
Gao, Yang
This study aimed to simulate the transport of biomass burning (BB) aerosol originating from Southeast Asia (SEA) during the Dongsha Experiment conducted from March 2010 to April 2010. Transport pathways were reanalyzed and steering flow in the mid-latitude areas and anticyclones in low-latitude areas were found to control the transport of BB plume after it was injected to a high atmosphere. For the 12 simulated and observed events at Mt. Lulin (2862m MSL; 23°28'07″ N, 120°52'25″ E), the 72h backward trajectories were all tracked back to southern China and northern Indochina, which were the locations of the largest BB fire activities in SEA. Chemical evolutions of BB pollutants along the moving trajectories showed that organic matter was always the dominant component in PM<inf>2.5</inf>, consistent with the observations at both near-source regions and Mt. Lulin. For nitrogen species, nearly all NO<inf>x</inf> molecules oxidized into HNO<inf>3</inf>, NO<inf>3</inf><sup>-</sup>, PAN, and PANX in fires or near fires. The synchronic consumption of NO<inf>x</inf>, SO<inf>2</inf>, and NH<inf>3</inf> explained the production of the major components of inorganic salts. In the moving BB plume, sulfate concentration increased with decreased nitrate concentration. Ratios of ammonium to PM<inf>2.5</inf> and elemental carbon to PM<inf>2.5</inf> remained nearly constant because additional sources were lacking.
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A Lagrangian model investigation of chemico-microphysical evolution of northeast Asian pollution plumes within the MBL during TRACE-P
(2007-12-01)
Song, C. H.
;
Han, K. M.
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Cho, H. J.
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Kim, J.
;
Carmichael, G. R.
In this work, we determine the major channels through which air pollutants, mainly originating in Northeast Asian mega-cities, flow out into the Northwestern Pacific atmosphere. For this purpose, comprehensive backward/forward trajectory analyses are conducted. Two important channels along which pollutants from the Northeast Asian mega-cities flow out are defined, and are labeled as "DC8 transport path" and "P3B transport path". We then comprehensively examine the chemico-microphysical transformations of the anthropogenic pollutants from the Northeast Asian mega-cities along the two major transport paths, using a new Lagrangian forward-trajectory photochemical model. In the newly developed model, state-of-the-science parameterizations for considering chemico-microphysical aging processes and atmospheric aerosol processes are incorporated. As air masses travel toward low latitudes through the marine boundary layer (MBL), the temperature increases along the trajectories and large amounts of PAN experience thermal decomposition. By this process, PAN can be an important supplier of NO<inf>2</inf> in the remote MBL. The O<inf>3</inf> productions in the remote Northwestern Pacific MBL are fueled and maintained by NO<inf>x</inf> provided from the PAN decomposition. High O<inf>3</inf> levels (>50 ppb) are observed within the remote MBL of the Northwestern Pacific Oceans from several TRACE-P DC8 and P3B measurements under the continental outflow situations. Gas-phase SO<inf>2</inf> is continuously converted into nss-sulfate via heterogeneous oxidation reaction with H<inf>2</inf>O<inf>2</inf> at a particle pH of 2-5. The Lagrangian-trajectory modeling studies also indicate that in the remote MBL of Northwestern Pacific Ocean under continental outflow situations, conditions are unfavorable for nucleation events, because of the depletion of SO<inf>2</inf>, the large aerosol surface areas available for H<inf>2</inf>SO<inf>4</inf> sink, and high temperatures. © 2007 Elsevier Ltd. All rights reserved.
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Long-term analysis of NO2, CO, and AOD seasonal variability using satellite observations over Asia and intercomparison with emission inventories and model
(2013-12-01)
Lalitaporn, Pichnaree
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Kurata, Gakuji
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Matsuoka, Yuzuru
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Thongboonchoo, Narisara
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Surapipith, Vanisa
Long-term analysis of tropospheric nitrogen dioxide (NO<inf>2</inf>) columns retrieved from GOME, SCIAMACHY, OMI and GOME-2 satellites, carbon monoxide (CO) columns from MOPITT satellite, and aerosol optical depths (AODs) from MODIS satellite was performed for Southeast Asian countries including Japan and China during 1996-2012. The results show that significant increasing levels of tropospheric NO<inf>2</inf> columns can be clearly observed during the study period, especially above the eastern regions of China. The cities located in different latitude zones present the seasonal cycle of NO<inf>2</inf> columns, CO columns, and AODs differently. For the cities located around mid-latitude zone, the maximum levels of NO<inf>2</inf> and CO columns can be observed in the winter (November-March) and the minimum in the summer (June-September). On the contrary, the maximum levels for the cities near Equator zone are revealed in dry season (June-October). In the case of AODs, the maximum peaks normally occur during biomass burning season. Ground monitoring concentrations of NO<inf>2</inf>, CO, and PM<inf>10</inf> were also comparably analyzed with satellite NO<inf>2</inf> columns, CO columns, and AODs, respectively. Anthropogenic and biomass burning emissions were derived to investigate the consistency with satellite retrievals. The results show that satellite observations are able to capture the trend and seasonal variability of the emissions and ground concentrations. The model simulations were conducted using CMAQ model. Generally, simulated model results agree well with those retrieved from satellite measurements for spatial distribution and seasonal pattern. However, the modeled results underestimate satellite data probably due to the inaccuracy in emission inventories, the inaccuracy of spatial and temporal allocations, and the uncertainties in the satellite retrievals. © 2013 Springer Science+Business Media Dordrecht.
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A compilation and development of spatial and temporal profiles of high-resolution emissions inventory over Thailand
(2009-01-01)
Vongmahadlek, Chatchawan
;
Thao, Pham Thi Bich
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Satayopas, Boonsong
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Thongboonchoo, Narisara
Thailand, located in Southeast Asia, has both anthropogenic and natural emission sources. It is important to develop an emission information system to provide fundamental data to support emission control strategies and air quality studies. In this research, emissions were compiled for the year 2005. Emission sources cover key anthropogenic and natural emission sources. The methodology to calculate emissions is based on the bottom-up approach using local specific data. For gaseous species, annual emission estimation is found as follows: 9465.9 Gg of carbon monoxide, 2583.1 Gg of nonmethane volatile organic compounds, 886.0 Gg of sulfur dioxide, 790.3 Gg of oxides of nitrogen, and 439.2 Gg of ammonia. For aerosol species, annual emission estimations are 1277.4 Gg of particulate matter smaller than or equal to 10 μm in aerodynamic diameter, 325.5 Gg of organic carbon, and 136.4 Gg of black carbon. The intercomparison with literature shows an acceptable agreement of annual estimation. Emissions are projected until the year 2027 based on a Business-as-Usual scenario from governmental trends. Spatial allocations with 1- by 1-km resolution and temporal (i.e., monthly, weekly, and diurnal) allocation profiles are also developed to investigate the variation of emissions. Copyright 2009 Air & Waste Management Association.

Thongboonchoo, Narisara

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