Krit Somnuk
Prince of Songkla University
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Featured researches published by Krit Somnuk.
Biofuels | 2018
Krit Somnuk; Kichaphum Wijitsopa; Gumpon Prateepchaikul
ABSTRACT Static mixer was used as the continuous reactor in the biodiesel production. This study reports methyl ester and ethyl ester production from refined palm oil (RPO) using a 10 m long static mixer reactor. Alcohol content (vol.%), KOH (g.L−1), and static mixer length (m) were optimized to determine the ester purities with response surface methodology. As a result, 96.5 wt.% ester purity was substituted into the predicted models of FAME and FAEE. The appropriate conditions for methanolysis of 44.7 vol.% of methanol, 11.2 g.L−1 of KOH, and 4.8 m of static mixer length was obtained. The appropriate condition for ethanolysis were 45.3 vol.% of ethanol, 12.5 g.L−1 of KOH, and 5.1 m of static mixer length. From all statistical analysis data, KOH has a less significant effect when compared with other parameters, whereas alcohol content and static mixer length are first- and second-key, respectively. Alcohol consumption and reaction time for ethanolysis are more than for methanolysis. Regarding glycerol–ethyl ester separation, the glycerol phase of ethyl ester is more difficult than methyl ester.
Advanced Materials Research | 2014
Suhdee Niseng; Krit Somnuk; Gumpon Prateepchaikul
In this work, response surface methodology (RSM), with 5-level and 2-factor central composite design (CCD) was used to optimize the condition of base-catalyzed transesterification from refined palm oil. The two main parameters; methanol concentration and potassium hydroxide concentration, were varied to investigate the effect on the methyl ester purity. The result indicated that the KOH concentration was the most significant to produce methyl ester (the lowest p-values occurs in all response models). From excel solver, full quadratic model was obtained for predicting the response surface models. The suitable condition: 23.81 vol.% methanol and 11.80 wt.% KOH under temperature of 60°C and reaction time of 60 min, is the optimum condition.
Advanced Materials Research | 2014
Krit Somnuk; Gumpon Prateepchaikul
Biodiesel from a high free fatty acid (FFA) mixed crude palm oil (MCPO) can be produced to high fatty acid methyl ester (FAME) conversion by a two-step process. The first process is an acid-catalyzed esterification to reduce FFA in oil followed by a base-catalyzed transesterification process to produce biodiesel from esterified oil. In this study, the transesterification of esterified oil with methanol in the presence of potassium hydroxide (KOH) was performed in a 1,000 W ultrasonic homogenizer at a low frequency of 18 kHz. The use of high-intensity ultrasound to accelerate the reaction, the high surface power density of 1.62 W.mm-2 and the volumetric acoustic energy of 20 W.mL-1 were fixed. The objective of this study was to determine the various parameters (methanol concentration, KOH concentration, and initial temperature of oil) to produce the FAME conversion. The results showed that over 98 wt.% of FAME could be achieved with 5 g KOH/liter of oil, 15 vol.% of methanol, the total residence time of 20 seconds, and temperature of 30 oC. Moreover, the glycerides were rapidly converted to the FAME within reaction time of 10 seconds when the base-catalyst of 10 g KOH/liter of oil, and 20 vol.% of methanol were used. Consequently, the use of high-intensity ultrasonic irradiation can minimize the chemical cost, electricity cost, and reaction time.
Biofuels | 2017
Krit Somnuk; Natthapon Soysuwan; Gumpon Prateepchaikul
ABSTRACT Biodiesel production by a three-step batch process from palm fatty acid distillate (PFAD) that has high content of free fatty acids (FFA) was optimized with response surface methodology (RSM). Three key parameters for each step were investigated, namely methanol, catalyst and reaction time, to maximize the purity of ester. This gave the near optimal set-point at 29.46 wt.% methanol, 5.12 wt.% H2SO4 and 40 min reaction time for the first-step esterification. Similarly, 29.97 wt.% methanol, 5.94 wt.% H2SO4 and 40 min reaction time were near optimal for the second-step esterification, and 5.10 wt.% methanol, 0.50 g L−1 KOH, with 6 min reaction were near optimal for the third-step transesterification. Under these conditions the most FFA and partial glycerides in PFAD are converted to 99.822 wt.% ester. The obtained yields were: 106.53 wt.% of first-esterified oil, 108.86 wt.% of second-esterified oil, 112.34 wt.% of crude biodiesel and 93.13 wt.% of purified biodiesel. The amount of generated waste water and the total methanol consumption by this three-step process are lower than those of single-step esterification. Moreover, this three-step process provided methyl ester of higher purity than the single-step process did.
Applied Mechanics and Materials | 2014
Kichaphum Wijitsopa; Krit Somnuk; T. Theppaya; Gumpon Prateepchaikul
In this study, the commercial grade of ethanol was used to produce the biodiesel from refined palm oil (RPO) through the continuous static mixer system. The ethanol, an alternative alcohol to adopt in the ethyl ester production, can be used instead of methanol, and this alcohol is more eco-friendly than methanol. The 6-meter in length of SUS304 static mixer reactor is an essential part of mixing the RPO and solution of ethanol and potassium hydroxide to accelerate the base-catalyzed transesterification. The ethanol were varied at the volumetric flow rate of 30, 40, 50, 60 vol.%, KOH as base-catalyst was varied with the weight to volume of oil of 10,12,14 gKOH.L-1, to investigate the suitable condition which can converted the glycerides to the maximum purity of ethyl ester. The results showed that all varied conditions, the ethyl ester conversion was rapidly increased from 0 to over 95 wt.% when the flowing mixtures flowed through the 1 meter of static mixer. Furthermore, the highest purity of ethyl ester from RPO was succeeded when the condition: the 60 vol.% ethanol, the 14 gKOH.L-1 of catalyst, 5-meter of static mixer, and 75 oC temperature of RPO, was used in the continuous static mixer.
Applied Mechanics and Materials | 2013
Krit Somnuk; Gumpon Prateepchaikul
Free fatty acid (FFA) in mixed crude palm oil (MCPO) must be reduced to less than 1 wt.% or 2 mgKOH.g-1 of acid value by the acid-catalyzed esterification process when the base-catalyzed transesterification was used to produce the biodiesel for the two-stage process. This study was to investigate the effects of acid catalyst types: sulfuric acid (H2SO4), phosphoric acid (H3PO4), and hydrochloric acid (HCL) at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 vol.% of acid catalyst concentration on the reduction of acid value in MCPO by the continuous static mixer. Results indicated that H2SO4 has the most significant variable affecting the acid value in MCPO. The acid catalyst concentration of 1.0 and 1.5 vol.% H2SO4 can reduce the acid value to less than 2 mgKOH.g-1 with 15 vol.% of methanol and 5-meter in the length of static mixer, while both H3PO4 and HCL could not reduce the acid value was reduced to less than 2 mgKOH.g-1. Moreover, the results clearly indicated that HCL has the lowest significance effect on the acid value reduction in MCPO by the esterification reaction.
Energy Conversion and Management | 2013
Krit Somnuk; Pruittikorn Smithmaitrie; Gumpon Prateepchaikul
Energy Conversion and Management | 2013
Krit Somnuk; Pruittikorn Smithmaitrie; Gumpon Prateepchaikul
Energy Conversion and Management | 2014
Krit Somnuk; Suhdee Niseng; Gumpon Prateepchaikul
Fuel Processing Technology | 2009
Gumpon Prateepchaikul; Krit Somnuk; Michael Allen