Kanokwan Ngaosuwan

Enhancing biodiesel quality to enable higher blending ratios is essential for decarbonizing the transportation sector. This study investigates partial hydrogenation of soybean oil methyl esters in continuous flow over MCM‐41‐supported metallic Ni and nickel compound catalysts (carbide, nitride, phosphide, and sulfide). The fuel properties and fatty acid methyl ester (FAME) composition were thoroughly evaluated before and after the hydrogenation process. The hydrogenation activities were ranked as follows: NiC > NiN > Ni > NiS >> NiP. Although NiC showed the highest activity and improved oxidative stability, it lacked selectivity toward cis ‐C18:1, promoting trans ‐C18:1 formation and increasing the cloud point to 20 °C, rendering the product off‐specification. In contrast, NiS achieved a superior balance between activity and selectivity, increasing oxidative stability to 4.2 h while maintaining favorable cold‐flow properties. Moreover, NiS preserved activity and product selectivity over 24 h on stream, highlighting its promise for selective biodiesel upgrading under mild conditions.

The dehydrogenation of waste glycerol (GLY) to high‐value dihydroxyacetone (DHA) presents a sustainable valorization strategy through the application of dielectric barrier discharge (DBD) plasma technology. This study utilized multiple needle‐in‐tube configurations to evaluate efficiency under atmospheric pressure and ambient temperature, aiming for a high DHA yield. Key parameters, such as working gas type, gas flow rate, plasma input power, initial GLY concentration, and reaction time, were analyzed for their effects on GLY conversion, DHA yield, and DHA selectivity. Experimental results demonstrated a maximum DHA yield of 27.2% with a corresponding selectivity of 42%, while excessive OH• radical concentrations were found to adversely affect DHA formation through competing oxidation pathways. A comprehensive techno‐economic analysis confirmed the process’s technical feasibility and economic viability, demonstrating profitability within ± 20% market price fluctuations and a discounted payback period (DPP) of under 5 years. This research establishes an innovative pathway for sustainable waste‐to‐value conversion, demonstrating the potential of plasma dehydrogenation for optimized DHA production while contributing to circular economy principles through effective waste GLY utilization.

This research examined transesterification of palm oil with methanol or methanolysis of palm oil, utilizing sodium methoxide as a catalyst. All experimental runs were fixed at a temperature of 63 ± 2°C and a agitated velocity of 500 rpm. Various factors influencing the yield of fatty acid methyl esters (FAMEs) were explored, including amount of sodium methoxide loading based on the palm oil, ranging from 0.2 to 1.4 wt.%; the moles ratio of methanol to palm oil (6:1, 9:1, and 12:1); and the reaction time from 0 to 60 min. The concentration of synthesized FAMEs was determined using gas chromatograph. The results indicated that using 0.6 wt.% sodium methoxide, with a methanol-to-oil moles ratio of 9:1 and a reaction time of 30 min can produce the maximum yield of FAMEs, reaching 95.59%. The influence of the FAMEs (bio-diesel) followed in according to ASTM standard including API gravity, kinematic viscosity at 40°C, free fatty acids, and flash point with the value of 0.865 m2/s, 4.653 wt.%, 0.6 and 175°C respectively.

Perfluorooctanoic acid (PFOA) contamination in water sources poses significant environmental and health concerns. The kinetic, equilibrium, and thermodynamic features of PFOA adsorption in the existence of natural organic matter (NOM) were thoroughly investigated in this work using granular activated carbon (GAC) modified by dielectric barrier discharge (DBD) plasma. The impacts of DBD plasma parameters on the adsorption process were systematically examined. The results demonstrated that GAC modified by DBD plasma exhibited enhanced adsorption performance for PFOA, even in the presence of NOM. The optimal condition for plasma-treated GAC was achieved with 20 min of plasma treatment time and 100 W of plasma power, resulting in 92% PFOA removal efficiency in deionized water (DIW) and 97% removal efficiency in Chao Phraya River water (CPRW). A kinetic investigation using the pseudo-first-order model (PFOM), the pseudo-second-order model (PSOM), and the Elovich model (EM) indicated that plasma treatment time and NOM presence influenced the adsorption capacity and rate constants of PFOA with the PSOM having emerged as the most fitting kinetic model. The Langmuir isotherm model indicates monolayer adsorption of PFOA on plasma-treated GAC, with higher maximum adsorption capacity while NOM is present. The Redlich–Peterson and Sips isotherm models indicated varying adsorption capacity and heterogeneity in the adsorption system. The Sips model was determined as the most fitting isotherm model. Furthermore, the favorable and spontaneous character of PFOA adsorption onto plasma-treated GAC was validated by thermodynamic analysis, with endothermic heat absorption during the process. Overall, this comprehensive investigation provides valuable insights into the adsorption characteristics of PFOA in the existence of NOM using GAC modified by DBD plasma.

This research investigated palm biodiesel production via solid base-catalyzed transesterification in an intensified kitchen fruit blender. Studied parameters included methanol to palm oil molar ratio, CaO catalyst loading, reaction temperature, and reaction volume. XRD analysis showed a pure CaO phase after calcination while other characteristics illustrated good functionality of the catalyst. An optimal condition was achieved with 15:1 of methanol to palm oil molar ratio, 5 wt% of CaO dosage, 60 °C of reaction temperature, and 1,000 mL of reaction volume, obtaining the highest FAME production of 97.58% and yield efficiency of 1.47 × 10 ⁻³ g/J. The FT-IR illustrated an alteration of various functional groups through a reusability experiment demonstrating exceptional activity stability. The catalyst activity was decreased by only 15.8% in the 5th consecutive cycle. Properties of produced biodiesel conformed to international standards. This proved that biodiesel production using the CaO catalyst in the intensified kitchen fruit blender provides a positive effect on reuse, reduces wastewater from the washing process, lowers production costs, and is environmentally responsible to achieve high FAME yield due to the cavitation phenomena inside the reactor to generate fine emulsion of oil and methanol which could be easier to reach the active site of the CaO catalyst.