KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 20

Some of the metrics are blocked by your
consent settings
Biodiesel produced from transesterification of palm oil using NaOH-treated activated carbon and pyrolytic char of used tires as catalysts
(2025-03-01)
Chana, Khulanuttha
;
Chen, Bing Hung
;
Na-Ranong, Duangkamol
Biodiesel produced from catalyzed transesterification of palm oil with methanol using NaOH-treated carbonaceous catalysts was studied and reported. Particularly, effect of the carbonaceous support, i.e. activated carbon (AC) and pyrolytic char of end-of-life used tire (TPC), on the yield of biodiesel was investigated. The resultant yield of biodiesel near 98.5 % could be attained from transesterification reactions conducted with a catalyst loading at 5 wt% of palm oil initially used, under a molar ratio of methanol/oil at 21/1, at 65°C and 180 min for reaction temperature and time. The kinetics of the transesterification reaction could be fitted satisfactorily with the pseudo first-order model. The Arrhenius behavior was observed from the temperature-dependent rate constants, leading to an activation energy at 111.2 kJ/mol if AC-supporting catalyst was used. Both AC and TPC-supporting catalysts could produce biodiesel with a yield greater than 90 % even after the fourth cycles of catalyzed transesterification reactions. Notably, the feasibility in the upcycling of TPC as catalyst support was demonstrated in this work.
Some of the metrics are blocked by your
consent settings
EFFECTS OF ACID AND ALKALINE TREATMENTS ON EFFICIENCY OF DIATOMACEOUS EARTH IN REMOVAL OF TETRACYCLINE IN AQUEOUS SOLUTION
(2023-09-01)
Sinpichai, Sarawut
;
Yuangsawad, Ratanaporn
;
Na-Ranong, Duangkamol
Contamination of tetracycline (TC) in environment may cause serious problems relating to increase of antibiotic resistance and development of new deceases. This paper focuses on TC removal by simple adsorption treatment and utilization of natural diatomaceous earth (NDE) as a cheap adsorbent. To improve efficiency of NDE, an impregnation method using acid (H2SO4) or base (KOH) was applied to modify NDE and influences of important activation parameters, concentration of reagent (Creagent), ratio of NDE weight and activating solution volume (NDE-to-Sol), temperature (Tact) and time (tact), on the efficiencies of the obtained acid and base activated diatomaceous earths (ADE and BDE) were investigated. Batch adsorption experiment was performed at the same condition to evaluate TC adsorption capacities at equilibrium (qe, TC) of NDE, ADE and BDE. It was found that acid activation negatively affected qe, TC and increases of CH2SO4, Tact and tact resulted in poorer ADE. In contrast, qe, TC was successfully enhanced through activation by KOH; Tact and tact played more significant roles on the enhancement, comparing with CKOH and NDE-to-Sol; impregnation at higher Tact and longer tact could improve efficiency of BDE and the best BDE (BDE-B) with the highest qe, TC (86.31 mg/g) was obtained at 3 M, 0.1 g/ml, 80 °C and 9 h.
Some of the metrics are blocked by your
consent settings
PREPARATION OF ACTIVATED CARBON FROM TIRE DERIVED PYROLYTIC CHAR FOR ADSORPTION OF TETRACYCLINE HYDROCHLORIDE
(2022-12-01)
Chana, Khulanuttha
;
Soisuwan, Sasit
;
Sinpichai, Sarawut
;
Chen, Bing Hung
;
Na-Ranong, Duangkamol
Effects of activation variables on performance of the obtained activated carbon (AC) were investigated for removal of tetracycline hydrochloride (TCH). Pyrolytic char derived from waste tire was chemically activated via two-step of KOH impregnation following by thermal treatment. According to regression analysis and fitting with second-degree polynomial equation, empirical models were developed to correlate performance of AC in TCH adsorption (percentage removal and adsorption capacity at equilibrium) with three activation variables: impregnation ratio (IR), activation temperature (T) and holding time of thermal treatment (t). The analysis of variance indicated that only T, T2 and IR2 were significant to the prediction of both percentage removal and adsorption capacity. According to the developed models, it is suggested that the pyrolytic char should be activated at IR = 6, T = 750 °C and t = 2 h to obtain the highest efficiency of TCH removal in the tested range of activation condition.
Some of the metrics are blocked by your
consent settings
Free sterols from acid hydrolysis of steryl glucosides
(2021-05-20)
Yuangsawad, Ratanaporn
;
Sinpichai, Sarawut
;
Sukra, Arunrot
;
Na-Ranong, Duangkamol
Steryl glucosides (SG) are a group of insoluble chemicals in biodiesel. Steryl glucosides may cause clogging in production line and even small amounts of them may also cause low storage stability of biodiesel and plugging in a diesel engine. Therefore, an additional separation step is required to remove these contaminants. Since steryl glucosides have low solubility in many organic solvents, it is difficult to utilize the solid waste generated from the separation. Transformation of steryl glucosides to the form that are more soluble in general organic solvents should increase feasibility of utilization of the solid waste. In this study, hydrolysis of steryl glucosides to free sterols (FS) was investigated using nontoxic organic acid as catalyst. The hydrolysed products obtained from citric, lactic, and acetic acids were identified using a gas chromatograph connected with a mass spectrometer (GC-MS). The amounts of steryl glucosides and free sterols were also measured to compare efficiency of the catalysts. The most suitable catalyst was selected according to conversion of steryl glucoside (XSG), selectivity to free sterols (SFS), and yield of free sterols (YFS). To determine important parameters effecting the steryl glucosides conversion, the reaction test was performed with the selected catalyst at various operating condition.
Some of the metrics are blocked by your
consent settings
Kinetics and Equilibrium Modeling of Sterol Adsorption on Styrene-Divinylbenzene Cation-Exchange Resins
(2019-04-01)
Yuangsawad, Ratanaporn
;
Sinpichai, Sarawut
;
Bhamarasuta, Thanutchaporn
;
Ladadok, Chinakrit
;
Panchanon, Surakan
The potential of recovering phytosterols from fatty acid methyl esters by an adsorption-desorption process is demonstrated using a strong-acid ion-exchange styrene-divinylbenzene resin (SA-R) as an adsorbent and ethanol as a desorbent. Since the operating cost of the overall process significantly depends on the efficiency of SA-R in the adsorption step, the behavior of SA-R in sterol adsorption is investigated in detail using a model solution of stigmasterol in n-heptane. The results indicate that stigmasterol was associatively and exothermically adsorbed on SA-R. Based on the experimental results, a simple pseudo-second-order model and a modified Langmuir isotherm with their parameters, which well predicted kinetics and adsorption capacity of SA-R, are proposed.
Some of the metrics are blocked by your
consent settings
Intensification of reactive distillation for TAME synthesis based on the analysis of multiple steady-state conditions
(2018-12-01)
Yamaki, Takehiro
;
Matsuda, Keigo
;
Na-Ranong, Duangkamol
;
Matsumoto, Hideyuki
Our previous study reported that operation in multiple steady states contributes to an improvement in reaction conversion, making it possible to reduce the energy consumption of the reactive distillation process for tert-amyl methyl ether (TAME) synthesis. This study clarified the factors responsible for an improvement in the reaction conversion for operation in the multiple steady states of the reactive distillation column used in TAME synthesis. The column profiles for those conditions, in which multiple steady states existed and those in which they did not exist, were compared. The vapor and liquid flow rates with the multiple steady states were larger than those when the multiple steady states did not exist. The effect of the duty of the intermediate condenser, which was introduced at the top of the reactive section, on the liquid flow rate for a reflux ratio of 1 was examined. The amount of TAME production increased from 55.2 to 72.1 kmol/h when the intermediate condenser was operated at 0 to -5 MW. Furthermore, the effect of the intermediate reboiler duty on the reaction performance was evaluated. The results revealed that the liquid and vapor flow rates influenced the reaction and separation performances, respectively.
Some of the metrics are blocked by your
consent settings
Kinetics, isotherm and thermodynamics of sterol adsorption on styrene-divinylbenzene anion-exchange resins
(2018-10-01)
Ladadok, Chinakrit
;
Yamaki, Takehiro
;
Matsuda, Keigo
;
Matsumoto, Hideyuki
;
Na-Ranong, Duangkamol
Phytosterols can be recovered from natural resources using molecular distillation, cold crystallization, which require large energy consumption. Adsorption was considered as a feasible alternative method. In this study, kinetics, isotherm and thermodynamics of stigmasterol adsorption on styrene-divinylbenzene with two different functional groups, strong base (SB-R) and weak base (WB-R), were investigated using a model solution of stigmasterol in n-heptane. Isothermal adsorption experiments were performed in temperature range of 298-313 K and concentration range of 0.3-6.0 mg/g<inf>sol</inf>. For both SB-R and WB-R cases, kinetics of adsorption was analysed based on pseudofirst- order and pseudo-second-order models and the results revealed that pseudo-second-order model agreed with the experimental data much better than pseudo-first-order model. Analysis of isotherm data based on Langmuir, Freundlich and linear models showed that Freundlich was the best model that could predict behaviour of sterol adsorption for both SB-R and WB-R cases. In addition, thermodynamics parameters (δG, δH andδS) indicated that the sterol adsorptions on these adsorbents were spontaneous, exothermic and favourable at low temperature.
Some of the metrics are blocked by your
consent settings
Energy-saving performance of reactive distillation process for TAME synthesis through multiple steady state conditions
(2018-08-01)
Yamaki, Takehiro
;
Matsuda, Keigo
;
Na-Ranong, Duangkamol
;
Matsumoto, Hideyuki
We have previously reported the existence of steady-state solutions where reaction conversion is improved within multiple steady states, which appear in the reactive distillation column for tert-amyl methyl ether (TAME) synthesis. In the present study, we examined the energy-saving performance of a reactive distillation process that comprises a reactive distillation column and two recovery distillation columns for multiple steady state conditions using steady-state process simulation. Bifurcation analysis revealed that the multiple steady state did not exist under a reflux ratio of 1, but existed under reflux ratios of 2, 3, and 4. The reboiler duty required to obtain high-purity TAME increased with increase in reflux ratio. The evaluation of energy consumption revealed that the reboiler duties of the second recovery column at the steady-state solutions in the multiple steady state were lower than that at the steady-state solution of reflux ratio 1. Due to the high reaction conversion and reduction of the reboiler duty in the second recovery column, the energy inputs per mole of TAME product at steady-state solutions of the multiple steady state with reflux ratios of 2, 3, and 4 reduced by 17, 12, and 6%, respectively, compared to that for reflux ratio 1.
Some of the metrics are blocked by your
consent settings
Kinetics, isotherm, and thermodynamics of adsorption of sterol on strong acid ion exchange resin
(2018-01-01)
Ladadok, Chinakrit
;
Yamaki, Takehiro
;
Matsuda, Keigo
;
Matsumoto, Hideyuki
;
Na-Ranong, Duangkamol
Kinetics, isotherm and thermodynamics of sterol adsorption on styrene-divinylbenzene based ion-exchange resin with strong acid was investigated at temperature in the range of 298 to 313 K using a model solution of stigmasterol in n-heptane with initial concentration in the range of 0.3×10-3 to 1.8×10-3 kg/kg-solution. Adsorbent (5 wt%) was added to the model solution and isothermal adsorption was performed at 3.33 rps for 7.2×103 s. Kinetics of sterol adsorption was analysed based on pseudo-first-order and pseudo-second-order models. The results revealed that pseudo-second-order model agreed with the experimental data, much better than pseudofirst- order model. At the equilibrium of adsorption, adsorption capacity (qe) decreased when the temperature was increased. This result indicated that sterol adsorption was exothermic. Analysis of adsorption isotherm data based on Langmuir, Freundlich and linear models showed that Freundlich was the best model that could predict the adsorption isotherm data. Adsorption equilibrium constants calculated based on Freundlich model at various temperatures were used to calculate Gibb's free energy change (ΔG), enthalpy change (ΔH), and entropy change (ΔS). The increase of ΔG with respect to temperature indicated that the adsorption was more favourable at lower temperatures. The negative value of ΔH indicated that the adsorption was exothermic and agreed well with the effect of temperature on adsorption capacity. The negative value of ΔS indicated associative adsorption and decrease of the randomness between the solid/liquid interfaces due to the adsorption.
Some of the metrics are blocked by your
consent settings
Synthesis of moleculary imprinted polymer originated from TFMAA and TRIM for sterol separation
(2018-01-01)
Ladadok, Chinakrit
;
Sinpichai, Sarawut
;
Nonthanasin, Nattawat
;
Binabdullah, Krittin
;
Na-Ranong, Duangkamol
Molecular imprinted polymer (MIP) was synthesized bulk polymerization using 2-(trifluoromethyl)acrylic acid (TFMAA) as a functional monomer, trimethylolpropane trimethacrylate (TRIM) as a cross-linker, benzoyl peroxide as an initiator, acetone as porogen solvent, and stigmasterol as template molecule to obtain adsorbent having high affinity and selectivity to stigmasterol for separation of stigmasterol or other sterols in liquid phase. Functional groups and the morphology of the obtained MIP were investigated by Fourier transform infrared (FTIR) and scanning electron microscope (SEM), respectively. The performance in sterol adsorption of MIPs synthesized under various conditions was investigated using a model solution of sterol mixture in n-heptane with initial concentration of 1.40×10-4 kg/kg-solution comparing with non-imprinted polymer (NIP). Adsorbent (1 wt%) was added to model solution and shaken in an orbital shaker at 3.67 rps, 303 K for 2.16×104 s. The analysis of variance (ANOVA) suggested that the cross-linker was more influential factor on the adsorption performance of MIP as compared to the template molecule and solvent. The optimization showed that MIP synthesized at 0.5×10-3 mol of cross-linker, 1.0×10-4 mol of template molecule, and 1.0×10-5 m3 of solvent had highest percentage adsorption of 57.73 % which was 1.37 times of NIP.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results