Frontiers in Engineering Innovation Research

The study of risk factors associated with accidents in industrial factory construction projects in Chonburi province

Siripong Suttisaroj — 2026-06-17

This study aims to investigate the factors influencing construction accidents and to propose guidelines for mitigating risk factors associated with accidents in industrial construction projects in Chonburi Province. This research adopts a quantitative approach, using a questionnaire as the primary tool for data collection from personnel and construction workers in industrial factories in Chonburi Province. The sample consists of 132 respondents, including project managers (site engineers), foremen, carpenters, welders, masons, backhoe operators, and general laborers. Data were analyzed using descriptive statistics, including frequency, percentage, mean, and standard deviation. The results indicate that safety management factors have the highest influence on construction accidents (Mean = 4.10). Other contributing factors, ranked in descending order, include safety behavior in construction work, the use of surveillance technology such as closed-circuit television (CCTV) for accident prevention (Mean = 3.71), deficiencies in tools, equipment, and machinery (Mean = 3.40), and workplace environmental conditions (Mean = 3.01). The lowest-ranked factor is deficiencies in construction design and specifications (Mean = 3.00), based on the perceptions of industrial construction workers. The findings of this study contribute to the clear identification of key risk factors associated with construction accidents and can be utilized to develop effective accident prevention measures and safety management guidelines.

Valorization of glycerol via esterification of oleic acid and glycerol under microwave heating using zinc oxide as a catalyst

Puttiporn Thiamsinsangwon — 2026-06-23

This study investigated the esterification of oleic acid with glycerol for value-added glycerides production of using zinc oxide as the catalyst, with emphasis on evaluating the effects of heating mode, reactant molar ratio, and reaction temperature on oleic acid conversion and monoglyceride yield (MG yield) were evaluated. The results showed that microwave heating clearly enhanced MG yield compared with a conventional mechanically stirred reactor. The suitable condition for monoglyceride production was an oleic acid-to-glycerol molar ratio of 1:4, a ZnO catalyst loading of 0.5 wt.% based on oleic acid, a reaction temperature of 160 °C, and a reaction time of 30 min. Under this condition, oleic acid conversion, MG selectivity and MG yield were 63.1%, 75.4%, and 47.6%, respectively. In contrast, the conventional mechanically stirred reactor provided an MG yield of only 28.1% under the same condition. In addition, the oleic acid-to-glycerol molar ratio of 1:4 gave a higher MG yield than the other investigated molar ratios, indicating that an appropriate excess of glycerol promoted the formation of the target product. Although increasing the reaction temperature to 180 and 200 °C enhanced oleic acid conversion, the MG yield decreased to 40.5% and 38.9%, respectively, possibly due to the acceleration of consecutive reactions from MG to diglyceride (DG) and triglyceride (TG). Therefore, microwave-assisted esterification at a molar ratio of 1:4, 160 °C, and 30 min was identified as a suitable condition for monoglyceride production from glycerol under the investigated conditions.

Development of nickel catalysts supported on titanium dioxide derived from Thai leucoxene for hydrogen production via methane decomposition

Weerinda Mens — 2026-06-23

This study investigated the development of nickel catalysts supported on titanium dioxide derived from Thai leucoxene mineral (Ni/TiO₂-Leucoxene) for hydrogen production via methane decomposition, and compared their properties and performance with those of nickel catalysts supported on commercial titanium dioxide (Ni/TiO₂-Commercial). The catalysts were prepared by the wet impregnation method with a nickel loading of 30 wt%. Their physicochemical characteristics were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The catalysts were then tested in a fixed-bed reactor at 600 and 650 °C under atmospheric pressure, and the composition of the product gases was analyzed by gas chromatography. XRD analysis of the leucoxene-derived support revealed the presence of TiO₂ together with oxide phases of other elements, including Fe₂O₃and SiO₂. After catalyst preparation, NiO was detected in both catalysts. Scherrer analysis showed that the average crystallite size of NiO in Ni/TiO₂-Leucoxene was 11.9 nm, which was smaller than that of Ni/TiO₂-Commercial at 14.6 nm. SEM images showed that the Ni/TiO₂-Leucoxene catalyst possessed a rod-like morphology with observable interparticle voids, in contrast to the densely agglomerated particles observed for the Ni/TiO₂-Commercial catalyst. The methane decomposition results demonstrated that Ni/TiO₂-Leucoxene provided significantly higher methane conversion than Ni/TiO₂-Commercial. The maximum methane conversion of 98.7% was obtained at 650 °C after 90 min of reaction. These findings suggest that Thai leucoxene mineral has strong potential as a low-cost support material for catalysts in hydrogen production from methane.

Kinetic study of glycerol-lauric acid esterification using 12-tungstophosphoric acid as a catalyst

La-ongthip Yuwansri — 2026-06-23

This study aims to investigate the kinetics of the esterification reaction between glycerol and lauric acid using 12-tungstophosphoric acid (TPA) as a catalyst. The experiments were conducted in a 250 mL four-neck round-bottom flask, equipped with a stirring system and heated via a silicone oil bath. The effects of reaction temperature (110-170 ^oC) and molar ratio of lauric acid to glycerol (1:1–1:4) on the conversion of lauric acid were examined. The conversion was calculated based on free fatty acid (FFA) values determined by titration. The results indicated that the optimal condition was achieved at a molar ratio of 1:3, temperature of 170 ^oC, catalyst loading of 1 wt% of lauric acid, and a reaction time of 60 min, yielding a maximum lauric acid conversion of 89.2%. Kinetic analysis revealed that the reaction follows second-order kinetics, with a rate constant (k) of 0.0236 L/mol·min at 170 ^oC. The reaction rate equation is expressed as Rate = 0.0236[LA]² and an activation energy (E_a) of 67.92 kJ/mol.

Enhancing the solid fuel properties of durian peel through torrefaction under mechanical pressure

Waritsara Chaioan — 2026-06-23

This study investigated the enhancement of the solid fuel properties of durian peel through torrefaction under mechanical pressure to improve its chemical and physical characteristics prior to its use as a solid fuel and as a feedstock for biochar production. The experiments were carried out at 280, 300, 320, and 340 °C under pressures of 30, 60, 90, and 120 bar. The results showed that increasing temperature and pressure reduced the mass yield from 89.07% to 41.83%, while the carbon content, fixed carbon content, and higher heating value increased. The carbon content increased from 48.43% to 69.87%, the fixed carbon content increased from 13.97% to 41.39%, and the higher heating value increased from 18.01 to 25.52 MJ/kg. The increase in higher heating value was related to the decreases in the H/C and O/C atomic ratios, as well as the reduction of oxygen-containing functional groups in the biomass structure. However, when the energy yield was considered, the condition of 340 °C and 120 bar, although giving the highest higher heating value, resulted in an energy yield of only 59.27% and the product could not completely retain its compact pellet form. In contrast, the condition of 280 °C and 90 bar provided the highest energy yield of 104.73%. These results indicate that torrefaction under mechanical pressure can improve the solid fuel properties of durian peel. The conditions in the range of 280–300 °C under 60–90 bar appear to be more suitable in terms of the balance among fuel quality, energy yield, and the ability of the product to retain its compact form.

Sustainable conversion of coconut tree residues into activated carbon using steam activation

Chaiyan Chaiya — 2026-06-23

This study investigated the potential of five types of coconut tree residues, namely petiole base, spadix, exocarp, spathe, and rachilla, as precursors for activated carbon production through steam activation. This approach provides a sustainable pathway for valorizing agricultural residues while reducing the use of chemical activating agents in the production process. Elemental analysis revealed that the raw materials contained carbon in the range of 36.44-43.28 %, with spathe showing the highest carbon content. Proximate analysis further indicated that the raw materials were mainly composed of volatile matter, ranging from 69.41 to 72.74 %, while the fixed carbon content ranged from 15.33 to 21.34 %, reflecting the typical characteristics of lignocellulosic biomass suitable for conversion into carbon materials. After carbonization at 500 °C for 2 h, the resulting chars exhibited yields of 24.81-33.01 %, specific surface areas of 67.30-330.18 m²/g, and average pore diameters of 1.5-1.7 nm, with the exocarp-derived char showing the highest surface area at this stage. The chars were subsequently activated with steam at 500, 600, and 700 °C. The results showed that increasing the activation temperature markedly enhanced the specific surface area of the activated carbons, while the product yield decreased with increasing temperature. This trend was associated with the reaction between steam and carbon and the progressive development of porous structures. At 700 °C, the spathe-derived activated carbon exhibited the highest surface area of 778.64 m²/g, followed by rachilla, exocarp, spadix, and petiole base. In addition, increasing the activation temperature promoted pore widening, with the average pore diameter at 700 °C increasing to 1.9-2.2 nm, indicating a transition from microporous structures toward the boundary between micropores and mesopores. These findings demonstrate that spathe, rachilla, and exocarp are promising coconut tree residues for activated carbon production using steam activation and represent a sustainable route for the utilization of lignocellulosic biomass wastes.