รศ.ดร.ไพรัช อุศุภรัตน์

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32 public publications

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Mass transfer of CO2 absorption in hybrid MEA-methanol solvents in packed column

Teerawat Sema, Abdulaziz Naami, Phairat Usubharatana, Xiangzeng Wang, Ruimin Gao, Zhiwu Liang, Raphael Idem, Paitoon Tontiwachwuthikul

Energy Procedia · 2013

The mass transfer performance of CO 2 absorption into three solvents (i.e., 5 M MEA in methanol, 5 M MEA in 1:1 water-methanol volume ratio, and 5 M MEA aqueous solutions) in an absorption column packed with DX structured packing at various CO 2 loading, liquid flow rate, and inert gas flow rate. The mass transfer performance was evaluated in terms of volumetric overall mass transfer coefficient (K G a v ) and mass flux. The results showed that 5 M MEA in methanol has higher mass transfer performance than those of 5 M MEA in 1:1 water-methanol volume ratio and 5 M MEA aqueous solutions, respectively. In addition, CO 2 loading and liquid flow rate had significant effect on mass transfer performance, but inert gas flow rate has insignificant effect on mass transfer performance.

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Part 5a: Solvent chemistry: NMR analysis and studies for amine–CO2–H2O systems with vapor–liquid equilibrium modeling for CO2capture processes

Huancong Shi, Zhiwu Liang, Teerawat Sema, Abdulaziz Naami, Phairat Usubharatana, Raphael Idem, Chintana Saiwan, Paitoon Tontiwachwuthikul

Carbon Management · 2012

This is Part 5a of a special review series on recent progress and new developments of the post-combustion carbon-capture technology using reactive solvents. NMR spectroscopy is an important method used in analytical chemistry to test the functional groups and molecular structures of organic compounds. This methodology has been recently applied in CCS in the field of solvent chemistry for aiding the development of novel solvents for capturing CO2. NMR has been used for testing new amines and amine–CO2–H2O systems with 1H and 13C spectra for a number of years. This paper is a comprehensive review recent research papers that have applied NMR spectroscopy in the analysis of a variety of amines and a systems for multiple purposes, mostly for vapor–liquid equilibrium model analysis, and for some other qualitative as well as kinetic analyses.

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The pH effects on cleaning of coconut milk deposits from batch pasteurizing process

Phanida Saikhwan, Nattaporn Jumwan, Pisan Thungsiabyuan, Woranee Paengjuntuek, Harnpon Phungrassami, Phairat Usubharatana

Engineering and Applied Science Research · 2011

In this paper, the effects of pH on the cleaning of a model coconut milk foulant found in batchpasteurization process were studied. The model coconut milk foulants were soaked in NaOH solution at pHrange of 7-12. Swelling rate and swelling ratio increase slightly with pH at pH < 10 and increasing pH beyondpH 10 resulted in a significant rise of both swelling rate and swelling ratio. The pH effects observed here havebeen reported by literature in the case of milk foulants. Strength studies were performed on coconut milkfoulants under 3 conditions: (i) no soaking, (ii) soaking in distilled water (pH 7) and soaking in NaOH solution(pH 12) where maximum swelling ratio was observed. It was found that soaking had weakened the strength offoulants but the effect was not significant. The shear stress observed to remove the foulants under the 3conditions were in the range of 345-472 Pa.

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Enhancement factor and kinetics of CO2 capture by MEA-methanol hybrid solvents

Phairat Usubharatana, Paitoon Tontiwachwuthikul

Energy Procedia · 2009

Although many studies have been done towards the solubility, enhancement factor and kinetic of the reaction between CO 2 and various alkanolamines, the reaction media are limited to aqueous solutions. This research focuses on study above characteristics of monoethanolamine (MEA)-methanol hybrid solvent. The objective of this research is to understand how the methanol mixed into MEA solution can enhance the CO 2 absorption. Three solvents used in this study are MEA aqueous solution, MEA in water-methanol 1:1 by volume, and MEA in methanol. The solubility of studied solvents was compared by Henry’s constant of pure solvent. The Kirkwood-Buff formalism was used to derive the Henry’s constant of CO 2 in water-methanol mixture. The bench-scale of CO 2 absorption in DX structuring column was carried out to evaluate the enhancement factor based on the film theory model. Based on zwitterions mechanism, reaction rate constant of the deprotonation step in MEA aqueous solution is the highest followed by MEA in methanol-water and MEA in methanol respectively, while the reaction rate constant of the formation step is in the reversed order. First order of reaction with respect to carbon dioxide is found for every representative solvent. The order of reaction respect to MEA ranges from 1.19 to 1.67 depending on the ratio of methanol in the solution. The reaction order is increased in the order of water, methanol-water and methanol. The result showed that higher performance of CO 2 absorption by MEA-methanol hybrid solvent is not because of improvement of kinetic reaction. On the contrary, methanol mixed in to MEA solution reduces the kinetic rate in the deprotronation step and cause the reduction of enhancement factor. It is because of the methanol mixed into MEA hybrid solvent enhances the diffusivity and solubility characteristics of the solvent that increase the CO 2 absorption rate.

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A study of monoethanolamine-methanol hybrid solvents for carbon dioxide capture by absorption.

Phairat Usubharatana

Open MIND · 2009

L'auteur a accords une licence non exclusive permettant a Ia Bibliotheque et Archives Canada de reproduire, publier, archiver, sauvegarder, conserver, transmettre au public par telecommunication ou par l'Intemet, preter, distribuer et vendre des theses partout dans le monde, a des fins commerciales ou autres, sur support microforme, papier, electronique et/ou autres formats.L'auteur conserve Ia propriete du droit d'auteur et des droits moraux qui protege cette these.Ni la these ni des extraits substantiels de celle-ci ne doivent etre imprimes ou autrement reproduits sans son autorisation.In compliance with the Canadian Privacy Act some supporting forms may have been removed from this thesis.While these forms may be included in the document page count, their removal does not represent any loss of content from the thesis.Ie. CanadaConformement a la loi canadienne sur Ia protection de la vie privee, quelques formulaires secondaires ont ete enleves de cette these.Bien que ces formulaires aient inclus dans la pagination, it n'y aura aucun contenu manquant.

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Mass Transfer Performance of CO2 Capture by Aqueous Hybrid MEA-Methanol in Packed Absorber

Phairat Usubharatana, Amornvadee Veawab, Adisorn Aroonwilas, Paitoon Tontiwachwuthikul

2006

Climate change and the emissions of greenhouse gases (GHGs) have become an important global problem. Carbon dioxide (CO2) emission from fossil fuel combustion is the primary contributor to this problem. Currently, a number of CO2capture technologies are technically feasible. Among these, gas absorption into chemical solvents is the most promising technology due to its capacity to handle a large volume of flue gas and can be operated at low temperature and pressure. One of the keys to successful operation of CO2chemical absorption process is the use of effective solvents. With hybrid solvents, mixtures of chemical and physical absorbents, the absorption capability at low partial pressure is enhanced or at least maintained. In addition, their performances at higher pressure are developed. This research was focused on the possibility of using hybrid solvent for CO2absorption. The mixture between monoethanolamine (MEA) and methyl alcohol was presented as hybrid solvent. The effects of main operating variables, such as CO2partial pressure, concentration of amine, the ratio of mixing, CO2loading, solvent flow rate and CO2gas flow rate were investigated. The performance of solvent for each operating parameter was compared by mean of mass transfer flux and overall gas-phase mass transfer coefficient of system.

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Photocatalytic Process for CO2 Emission Reduction from Industrial Flue Gas Streams

Phairat Usubharatana, Dena W. McMartin, Amornvadee Veawab, Paitoon Tontiwachwuthikul

Industrial & Engineering Chemistry Research · 2006

At present, carbon dioxide (CO 2 ) is the largest contributor among greenhouse gases. This article addresses the potential application of photocatalysis to the reduction of CO 2 emissions from industrial flue gas streams. Not only does this process remove CO 2, but it can also convert CO 2 into other chemical commodities such as methane, methanol, and ethanol. In addition, the photocatalytic process can consume less energy than conventional methods by harnessing solar energy. Given these advantages, photocatalysis is an attractive alternative for CO 2 capture. This article reviews the principle of photocatalysis; existing literature related to photocatalytic CO 2 reduction; and the effects of important parameters on process performance, including light wavelength and intensity, type of reductant, metal-modified surface, temperature, and pressure. Finally, we discuss various system configurations for UV and solar photocatalytic reactors. The advances in photocatalysis technology indicate a promising application potential for significant reductions of CO 2 emissions and a positive impact on climate change effects.

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ผลงานตีพิมพ์ทั้งหมด

Mass transfer of CO2 absorption in hybrid MEA-methanol solvents in packed column

Part 5a: Solvent chemistry: NMR analysis and studies for amine–CO2–H2O systems with vapor–liquid equilibrium modeling for CO2capture processes

The pH effects on cleaning of coconut milk deposits from batch pasteurizing process

Enhancement factor and kinetics of CO2 capture by MEA-methanol hybrid solvents

A study of monoethanolamine-methanol hybrid solvents for carbon dioxide capture by absorption.

Mass Transfer Performance of CO2 Capture by Aqueous Hybrid MEA-Methanol in Packed Absorber

Photocatalytic Process for CO2 Emission Reduction from Industrial Flue Gas Streams

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