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RISS 인기검색어
- 검색키워드
- 저자 : Nakorn Tippayawong (검색결과 19 건)
- 무료
- 기관 내 무료
- 유료
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Ethanolysis of Soybean Oil into Biodiesel : Process Optimization via Central Composite Design
Nakorn Tippayawong,Eaksit Kongjareon,Wasan Jompakdee 대한기계학회 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.10
A process for production of ethyl ester for use as biodiesel has been studied. The sodium hydroxide catalyzed transesterification of soybean oil with ethanol was carried out at different molar ratio of alcohol to oil, reaction temperature and catalyst amount for a constant agitation in two hours of reaction time. Central composite design and response surface methodology were used to determine optimum condition for producing biodiesel. It was found that ethanol to oil ratio and catalyst concentration have a positive influence on ester conversion as well as interaction effects between the three factors considered. An empirical model obtained was able to predict conversion as a function of ethanol to oil molar ratio, reaction temperature and catalyst concentration adequately. Optimum condition for soybean ethyl ester production was found to be moderate ethanol to oil ratio (10.5 : 1), mild temperature range (70℃) and high catalyst concentrations (1.0%wt). with corresponding ester conversion of 93.0%.
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Ethanolysis of Soybean Oil into Biodiesel : Process Optimization via Central Composite Design
Tippayawong Nakorn,Kongjareon Eaksit,Jompakdee Wasan The Korean Society of Mechanical Engineers 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.10
A process for production of ethyl ester for use as biodiesel has been studied. The sodium hydroxide catalyzed transesterification of soybean oil with ethanol was carried out at different molar ratio of alcohol to oil, reaction temperature and catalyst amount for a constant agitation in two hours of reaction time. Central composite design and response surface methodology were used to determine optimum condition for producing biodiesel. It was found that ethanol to oil ratio and catalyst concentration have a positive influence on ester conversion as well as interaction effects between the three factors considered. An empirical model obtained was able to predict conversion as a function of ethanol to oil molar ratio, reaction temperature and catalyst concentration adequately. Optimum condition for soybean ethyl ester production was found to be moderate ethanol to oil ratio (10.5: 1), mild temperature range ($70^{\circ}C$) and high catalyst concentrations ($1.0\%$wt), with corresponding ester conversion of $93.0\%$.
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Panich Intra,Nakorn Tippayawong 대한전기학회 2006 Journal of Electrical Engineering & Technology Vol.1 No.4
The electrical discharge and operational characteristics of needle and wire-cylinder corona charger based on current measurements for positive and negative coronas were evaluated and compared. A semi-empirical method was used to determine the ion concentrations in the charging zone and at the outlet of both chargers. Results from experimental investigation revealed that magnitudes of the charging current from the wire-cylinder charger were approximately 3.5 and 2 times smaller than those from the needle charger for the positive and negative coronas, respectively. The ion number concentrations at the outlet for positive corona of both chargers were higher than for negative corona at the same voltage. Flow and electric fields in the charging zone of both chargers were also analyzed via numerical computation. Strong electric field strength zone was identified and led to high charging and particle deposition. Effect of particle deposition on the evolution of discharge current was presented. It was shown that ions loss inside the wire-cylinder charger was higher than the needle charger. The particle deposited on the corona electrodes and on the grounded cylinder caused a great reduction in charging efficiency of both chargers.
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Brownian diffusion effect on nanometer aerosol classification in electrical mobility spectrometer
Panich Intra,Nakorn Tippayawong 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.1
A multi-channel differential mobility analyzer (MCDMA) or aerosol spectrometer is widely used for classifying and measuring nanometer aerosol particles in the size range from 1 nm to 1 µm because of its better time response than a typical differential mobility analyzer. In the present study, the effect of Brownian diffusion on electrical mobility classification and trajectory of nanometer aerosol particles in an electrical mobility spectrometer developed at Chiang Mai University has been analytically investigated. Th Brownian diffusion of particles inside the spectrometer increased with decreasing particle size and flow rates of aerosol and clean sheath air, and with increasing inner electrode voltage, and also decreased with decreasing operating pressure. The particle trajectories considering Brownian diffusion motion inside the spectrometer were found to be broader than those under no Brownian diffusion. Smaller particles were found to have higher degree of broadening of trajectory than the larger particles. Brownian diffusion effect was found to be significant for particles smaller than 10 nm.
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Performance evaluation of an electrometer system for ion and aerosol charge measurements
Panich Intra,Nakorn Tippayawong 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.2
An aerosol electrometer system for measuring ion and aerosol charge using electrostatic detection technique was developed and presented. It consists of a size-selective inlet, a particle charger, an ion trap, a Faraday cup,an electrometer, and a data acquisition and processing system. In this system, an aerosol sample first passes through the size-selective inlet to remove particles outside the measurement size range based on their aerodynamic diameter,and then passes through the unipolar corona charger that sets a charge on the particles and enters the ion trap to remove the free ions. After the ion trap, the charged particles then enter the Faraday cup electrometer for measuring ultra low current of about 1 pA induced by ion and aerosol charge collected on the filter in Faraday cup corresponding to the number concentration of ion and aerosol. Signal current is then recorded and processed by a data acquisition system. Finally, the detailed description of the operating principle of the system as well as the preliminary experimental testing results of ion and aerosol charge measurements were also introduced and discussed.
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Panich Intra,Nakorn Tippayawong 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6
A prototype of a short column electrical mobility spectrometer (EMS) for size measurement of aerosol particle was design, constructed, and experimentally characterized. The short EMS consists of a particle charger, a size classifier column, and a multi-channel electrometer. Its particle size resolution is derived from a 10 channel electrometer detector. The short EMS is capable of size measurements in the range between 10 nm to 1,000 nm with a time response of about 50 s for full up and down scan. Particle number concentration in which the short EMS can measure ranges from 1011 to 1013 particles/m3. The operating flow rate of the short EMS is set for the aerosol flow rate of 1.0- 2.0 l/min and the sheath air flow rate fixed at 10.0 l/min. The inner electrode voltage of the classifier can be varied between 500-3,000 VDC. The short EMS operates at sub-atmospheric pressure, typically at 526 mbar. Validation of the short EMS performance was performed against a scanning electron microscope (SEM). Good agreements were obtained from comparison between sizes determined from the short EMS classifier and the SEM analysis. Signal current from the detector was also analyzed to give rise to number concentration of particles. Experimental results obtained appeared to agree well with the theoretical predictions.
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Thermo-Fluidic Characterization of Flue Gas Flows Through a Packed Bed
Nat Vorayos,Nakorn Tippayawong,Bancha Thanapiyawanit 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.5
Enhancement of thermal performance in an incinerator and flue gas treatment with a randomly packed bed of uniform spheres was investigated in a custom-made experimental facility and reported in the present paper. Pressure drop, temperature evolution and heat transfer characteristics were evaluated for a range of superficial velocities, Reynolds numbers and bed geometries. Results revealed that increases in both superficial velocity and bed thickness caused a rise in pressure drop across the packed bed in similar fashion to the Ergun equation but with different coefficients at low Reynolds number between 60-300. The two constants were empirically determined to be 68.5 and 4.95. It was also found that the packed bed affects axial temperature distribution from the incinerator chamber to stack. For the same heating rate, higher temperature was achieved in the chamber with the packed bed, and peak temperature was reached at a rate of 7-10% faster than that without the packed bed during the startup period. The downstream side of the thicker bed appeared to have lower temperature than the thinner bed for the same axial position, demonstrating less flue loss during the transient state. The incinerator chamber proved to have higher temperature rising rate and reached higher maximum temperature with the presence of the packed bed.
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Intra, Panich,Tippayawong, Nakorn The Korean Institute of Electrical Engineers 2006 Journal of Electrical Engineering & Technology Vol.1 No.4
The electrical discharge and operational characteristics of needle and wire-cylinder corona charger based on current measurements for positive and negative coronas were evaluated and compared. A semi-empirical method was used to determine the ion concentrations in the charging zone and at the outlet of both chargers. Results from experimental investigation revealed that magnitudes of the charging current from the wire-cylinder charger were approximately 3.5 and 2 times smaller than those from the needle charger for the positive and negative coronas, respectively. The ion number concentrations at the outlet for positive corona of both chargers were higher than fur negative corona at the same voltage. Flow and electric fields in the charging zone of both chargers were also analyzed via numerical computation. Strong electric field strength zone was identified and led to high charging and particle deposition. Effect of particle deposition on the evolution of discharge current was presented. It was shown that ions loss inside the wire-cylinder charger was higher than the needle charger The particle deposited on the corona electrodes and on the grounded cylinder caused a great reduction in charging efficiency of both chargers.
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Approach to Characterization of a Diode Type Corona Charger for Aerosol Size Measurement
Intra Panich,Tippayawong Nakorn The Korean Institute of Electrical Engineers 2005 KIEE International Transactions on Electrophysics Vol.5C No.5
A semi-empirical method to determine the electrostatic characteristics of a diode type corona aerosol charger based on ion current measurement and electrostatic charging theory was presented. Results from mathematical model were in agreement with those from experimental investigation of the charger. Current-voltage characteristics, $N_{i}t$ product and charge distribution against aerosol size were obtained. It was shown that the space charge was significant and must be taken into account at high ion number concentration and low flow rate. Additionally, significant particle loss was evident for particles smaller than 20 nm in diameter where their electrical mobility was high. Increase in charging efficiency may be achieved by introducing surrounding sheath flow and applying AC high voltage. Overall, the approach was found to be useful in characterizing the aerosol charger.
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