KMITL

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

Browse

Search Results

Now showing 1 - 10 of 18

Some of the metrics are blocked by your
consent settings
Potential of advanced microporous zeolites and mesoporous materials derived from natural precursors as supports for iron phosphide catalysts in bio-jet fuel production from palm oil (Elaeis guineensis)
(2025-06-10)
Tanwongwan, Worapak
;
Sartsamai, Ruttasart
;
Kaewmeesri, Rungnapa
;
Faungnawakij, Kajornsak
;
Chollacoop, Nuwong
Iron phosphide (FeP) has emerged as an efficient catalyst for converting palm oil, a biomass-derived feedstock, into bio-jet fuel through the hydrocracking process. The catalytic performance of FeP is strongly influenced by the choice of support material. In this study, microporous MWW-type zeolites (MCM-22 and MCM-36) and mesoporous materials (MCM-41 and MCM-48) were successfully synthesized from entirely natural precursors, silica derived from rice husk and aluminosilicate gel extracted from kaolin clay, via a hydrothermal method, and employed as supports for FeP catalysts. Among these materials, MCM-22 zeolite exhibited the highest microporosity, followed by zeolite MCM-36, resulting in superior acidity compared to the mesoporous materials, MCM-41 and MCM-48. FeP supported on MCM-22 (FeP/MCM-22) demonstrated the best catalytic performance, liquid hydrocarbon yield (∼33%), and bio-jet selectivity (∼78%) were obtained, outperforming FeP/MCM-36, FeP/MCM-41, and FeP/MCM-48. This is due to its high surface area of micropores (∼187 m2 g−1) and the excellent acidity of this zeolite, which helped prevent FeP overloading and promote uniform metal distribution. Furthermore, it exhibited remarkable stability and reusability, with performance improving over three consecutive reaction cycles, LHCs yield increasing to 50% and bio-jet selectivity stabilizing at about 83%, attributed to enhanced acidity accessibility and progressive formation of the FeP active phase.
Some of the metrics are blocked by your
consent settings
NiO-YSZ anode composite material derived from mechano-chemical for solid oxide fuel cells application
(2025-06-01)
Srisuwan, Thanakorn
;
Puengjinda, Pramote
;
Kaewtrakulchai, Napat
;
Chanpee, Sirayu
;
Jadsadajerm, Supachai
This study investigates the effects of calcination time, milling duration, and sintering temperature on the properties of Nickel oxide and Yttria-stabilized zirconia (NiO-YSZ) anode composite materials for solid oxide fuel cell (SOFC) applications. NiO nanoparticles were synthesized from nickel (II) sulfate (Ni(II)SO<inf>4</inf>), with X-ray diffraction (XRD) confirming a face-centered cubic (FCC) structure. The crystallite size (21 nm) was achieved after 8 hours of calcination, while prolonged durations caused particle agglomeration. Ball-milling for 12 hours produced comparatively fine particles with an average of 706 nm, though extended milling led to grain growth and aggregation. Scanning electron microscopy (SEM) revealed nano aggregation. Sintering at 1200 °C improved the densification of the NiO-YSZ layer while increasing its porosity, which enhanced the reduction of NiO to metallic nickel (Ni). Electrochemical Impedance Spectroscopy (EIS) demonstrated lower impedance and improved electrochemical performance for cells cold-sintered at 1200 °C. These findings show the importance of optimizing processing conditions to enhance the performance of NiO-YSZ anode for SOFCs, offering valuable insights for advanced energy conversion technologies.
Some of the metrics are blocked by your
consent settings
Role of Copper Species in Copper Phyllosilicate Catalysts for the Catalytic Transfer Hydrogenation of Furfural to γ-Valerolactone
(2025-02-17)
Shoosri, Tanyarat
;
Thongratkaew, Sutarat
;
Rungtaweevoranit, Bunyarat
;
Kraithong, Wasawat
;
Faungnawakij, Kajornsak
Copper phyllosilicate (CuPS) catalysts were synthesized and evaluated for the catalytic transfer hydrogenation of furfural to γ-valerolactone (GVL). Various copper loadings (10–30 wt.%) were studied to elucidate the impact of copper species on catalytic performance. Notably, a high dispersion of copper (%D<inf>Cu</inf> ≈ 70%) and a substantial BET surface area (620 m2/g) were achieved, even at the maximum copper loading of 30 wt.%. TR-XANEs and XPS analyses identified the two geometric structures of Cu2⁺ on the CuPS catalysts; square planar and octahedral alongside Cu⁺/Cu⁰ species were formed upon reduction at temperatures exceeding 200 °C. The reduced 30% CuPS-R catalyst, enriched in metallic Cu⁰, achieved complete conversion of furfural, but exhibited low GVL selectivity (22%). Conversely, the as-synthesized 30% CuPS, predominantly composed of Cu2⁺, showed a lower furfural conversion (14%) but higher selectivity for GVL (37%). The physical mixing of 30% CuPS-R and 30% CuPS in a 50:50 ratio yielded the best catalytic performance, resulting in 100% furfural conversion and 86% GVL selectivity. The findings suggest that metallic Cu⁰ is essential for initiating the conversion of furfural, while Cu2⁺ plays a critical role in GVL formation. An optimal Lewis/Brønsted acidity (L/B) ratio of 5.7 is proposed for the mixed catalysts. The proposed reaction mechanism underscores the complex interplay between different copper species and acid sites, emphasizing the need for optimizing both metal and acid functionalities in catalyst design.
2
Some of the metrics are blocked by your
consent settings
Combination of natural silica and alumina sources for synthesis of MCM-22 zeolite
(2023-08-01)
Tanwongwan, Worapak
;
Chollacoop, Nuwong
;
Faungnawakij, Kajornsak
;
Assabumrungrat, Suttichai
;
Nakhanivej, Puritut
Zeolite has become a promising material that can potentially play a pivotal role in resolving environmental crises. Among zeolite families, MCM-22 zeolite shows outstanding intrinsic properties associated with the topology and porous structure, offering ion-exchange advantages for catalytic activity processes. The synthesis of MCM-22 zeolite becomes challenging when concerning the cost and catalytic performance. To overcome this bottleneck, we demonstrate a sustainable route of a hydrothermal process using natural resources as starting materials. Rice husk from agricultural waste was used as a silica source while natural clays (kaolin and bentonite) were applied as alumina sources. The products from natural sources were compared with the use of commercial starting materials, e.g., NaAlO<inf>2</inf> (for alumina) and Na<inf>2</inf>SiO<inf>3</inf> and TEOS (for silica), in points of crystal, compositional, and morphological views. We showed that the high purity of MCM-22 zeolite can be obtained from rice husk silica (RHS) and aluminosilicate gel (ASG) extracted from kaolin, while the use of ASG extracted from bentonite tended to be unsuitable to generate the zeolite formation. We also studied the effects of reaction time and the ratio of RHS/ASG on the crystallinity and surface area of MCM-22. The architecture and acidity of an optimal product were explored by Nuclear magnetic resonance spectroscopy and Temperature-programmed desorption of ammonia, demonstrating the success of achieving well acidity.
Some of the metrics are blocked by your
consent settings
Mechanistic investigation of Ni and NiCu for catalytic transfer hydrogenation of methyl levulinate to γ-valerolactone: A combined experimental and DFT study
(2023-06-25)
Chitpakdee, Chirawat
;
Boonyoung, Pawan
;
Pansakdanon, Chaianun
;
Suttisintong, Khomson
;
Faungnawakij, Kajornsak
Recently various supported bimetallic catalysts have been employed as effective catalysts for γ-valerolactone (GVL) production from levulinic acid or its esters. However, previous reports have shown synergetic roles of active metals and supports as important keys for superior catalytic performance. This work combines both experimental and simulation studies to focus solely on the role of bimetallic formation between nickel (Ni) and copper (Cu). The experimental results suggest that both Ni and nickel-copper alloy (NiCu) catalysts are good for hydrogenation of methyl levulinate (ML) to an intermediate species, 4-hydroxypentanoic acid (HPA). However, only NiCu has a better tendency to accelerate the conversion of HPA to GVL via cyclization process. Activation energy from experimental study of cyclization step over Ni is about two times larger than that of NiCu (E<inf>a</inf>K2 values are 121.7 and 56.0 kJ mol K−1 for Ni and NiCu, respectively) provided strong evidence of superior GVL production over NiCu catalyst. Density Functional Theory (DFT) simulation results reveal solid finding to support the high efficiency of NiCu over Ni catalyst for GVL production. The calculated energy barrier for HPA conversion to GVL over the NiCu is 1.0 eV which is lower than that of the Ni catalyst (1.54 eV). The Ni provided only one concerted pathway to transform from ML to GVL, while NiCu could provide either a concerted or nonconcerted pathway where the latter one requires lower activation energy for GVL production. The combination of these experimental and simulation results leads to a better understanding of bimetallic catalyst design for GVL production via catalytic transfer hydrogenation without any support materials.
Some of the metrics are blocked by your
consent settings
Effective Cu/Re promoted Ni-supported γ-Al2O3 catalyst for upgrading algae bio-crude oil produced by hydrothermal liquefaction
(2021-06-01)
Pongsiriyakul, Kanokthip
;
Kiatkittipong, Worapon
;
Adhikari, Sushil
;
Lim, Jun Wei
;
Lam, Su Shiung
Catalytic hydrotreating of algae bio-crude oil from hydrothermal liquefaction (HTL) of Nannochloropsis sp. was performed. Different Ni-based catalysts, including Ni/γ-Al<inf>2</inf>O<inf>3</inf>, Ni-Cu/γ-Al<inf>2</inf>O<inf>3,</inf> Ni-Re/γ-Al<inf>2</inf>O<inf>3,</inf> and Ni-Cu-Re/γ-Al<inf>2</inf>O<inf>3,</inf> (10%Ni, 5%Cu, 2.5%Re) were used in upgrading of the bio-crude oil. Most catalytic systems could effectively eliminate S and decrease the N and O contents, and enhance more than 20% improvement in the higher heating value (HHV) of the bio-oil (34 to 41–45 MJ/kg). Introducing only Cu could enhance the C[dbnd]O hydrogenation resulting in higher aromatic and alcohol compounds. While the addition of Re is effective for hydrodeoxygenation, it lowers denitrogenation due to amination reaction. Ni-Cu-Re/γ-Al<inf>2</inf>O<inf>3</inf> ternary alloy offered the best results on the overall performance, achieving the highest upgraded bio-oil yield of 58 wt% and the highest energy recovery in the upgrading process (ER<inf>upgrade</inf>) of 64.6%. As ER in HTL process (ER<inf>HTL</inf>) was ca. 71.8%, the overall ER (ER<inf>overall</inf>) from algae biomass to upgraded bio-oil of 46.4% can be achieved for Ni-Cu-Re/γ-Al<inf>2</inf>O<inf>3</inf> catalyst. Carbon efficiency approx. 47.7% can be attained as the carbon in the algae biomass feedstock was retained in the upgraded bio-oil. In addition, reaction pathways for the formation of different hydrotreated products catalyzed by mono-, bi-, and tri- metallic Ni-Cu-Re have been proposed.
Some of the metrics are blocked by your
consent settings
Parametric study on microwave-assisted pyrolysis combined KOH activation of oil palm male flowers derived nanoporous carbons
(2020-06-01)
Kaewtrakulchai, Napat
;
Faungnawakij, Kajornsak
;
Eiad-Ua, Apiluck
Oil palm male flowers (PMFs), an abundant agricultural waste from oil palm plantation in Thailand, have been utilized as an alternative precursor to develop nanoporous carbons (NPCs) via microwave-assisted pyrolysis combined potassium hydroxide (KOH) activation. The influences of relevant processing variables, such as activating agent ratio, microwave power, and activation time on the specific pore characteristics, surface morphology, and surface chemistry of PMFs derived nanoporous carbons (PMFCs) have been investigated to explore the optimum preparation condition. The optimum condition under a microwave radiation power of 700 W, activation holding time of 6 min, and activating agent ratio of 2:1 obtained the PMFC with the highest Brunauer-Emmett-Teller (BET) surface area and total pore volume approximately of 991 m2/g and 0.49 cm3/g, composed of a carbon content of 74.56%. Meanwhile, PMFCs have a highly microporous structure of about 71.12%. Moreover, activating agent ratio and microwave radiation power indicated a significant influence on the surface characteristics of PMFCs. This study revealed the potential of oil palm male flowers for the NPCs' production via microwave-assisted KOH activation with a short operating-time condition.
Some of the metrics are blocked by your
consent settings
Palm oil conversion to bio-jet and green diesel fuels over cobalt phosphide on porous carbons derived from palm male flowers
(2020-06-01)
Kaewtrakulchai, Napat
;
Kaewmeesri, Rungnapa
;
Itthibenchapong, Vorranutch
;
Eiad-Ua, Apiluck
;
Faungnawakij, Kajornsak
Porous carbon was successfully synthesized from palm male flowers (PMFs), using microwave-assisted potassium hydroxide (KOH) activation and was used as a catalyst support for the conversion of palm oil into bio-hydrocarbons, in fractions of green diesel and bio-jet fuel. Palm male flower-derived porous carbon (PC), consolidated with well dispersed cobalt phosphide (CoP) nanoparticles, was synthesized by simple wet-impregnation with subsequent thermal treatment. The physicochemical properties of the synthesized CoP/PC catalysts were evaluated by various techniques including proximate and ultimate elemental analysis, FTIR, XRD, N<inf>2</inf> sorption, SEM, TEM–EDS, and NH<inf>3</inf>-temperature programmed desorption (TPD). The effects of the pyrolysis temperatures (600−900◦ C), used for the impregnated samples before the reduction process, on catalyst properties and catalytic performance were investigated. Moreover, the effect of a liquid hourly space velocity of 0.5–1.5 h−1 and reaction temperatures of 340–420◦ C was studied in the palm oil conversion. The catalyst pyrolyzed at 600◦ C possessed the greatest particle dispersion and surface area, and showed the highest yield of liquid hydrocarbon product (C9–C18). We also found that the high pyrolysis temperature above 800◦ C partially transformed the Co<inf>2</inf> P phase into CoP one which significantly exhibited higher cracking activity and bio-jet selectivity, due to the improved acidity of the catalyst.
1
Some of the metrics are blocked by your
consent settings
Solvent-Free Hydrodeoxygenation of Triglycerides to Diesel-like Hydrocarbons over Pt-Decorated MoO2Catalysts
(2020-03-31)
Fangkoch, Sisira
;
Boonkum, Sutida
;
Ratchahat, Sakhon
;
Koo-Amornpattana, Wanida
;
Eiad-Ua, Apiluck
In the present work, the solvent-free hydrodeoxygenation of palm oil as a representative triglyceride model compound to diesel-like hydrocarbons was evaluated in a batch reactor using Pt-decorated MoO2 catalysts. The catalysts with various Pt loadings (0.5-3%) were synthesized by an incipient wetness impregnation method. The metallic Pt and MoO2 phases were detected in the XRD patterns of as-prepared catalysts after the reaction and acted as active components for the deoxygenation reactions. The XPS experiments confirmed the existence of metallic Pt and PtOx species. The XANES investigation of Mo L3-edge spectra elucidated a change in the valence state by the transformation of MoO3 into MoO2 species after the deoxygenation reaction. The TEM observation revealed the formation of Pt nanoparticles in the range of 1-3 nm decorated on MoO2 species. The number of acid sites increased with stronger metal-support interactions on increasing the Pt loading. The catalytic performance of the MoO2 catalyst significantly improved with a small amount of Pt decoration. However, the further increase in Pt loading did not relatively increase the deoxygenation activity due to the formation of the agglomerated Pt particles. The high performance of the decorated catalysts could be attributed to the moderate acidity from the Pt dispersed on MoO2 toward decarbonylation and decarboxylation reactions.
2
Some of the metrics are blocked by your
consent settings
Alternate catalyst support from microwave-assisted activation of coconut tree fiber
(2020-01-01)
Kaewtrakulchai, Napat
;
Faungnawakij, Kajornsak
;
Eiad-Ua, Apiluck
Coconut tree fiber (CTF), representing a potentials feedstock from agricultural processing, was developed to porous carbon by microwave-assisted activation. CTF was transformed into CTF char before further activation. The CTF porous carbons (CTFC<inf>s</inf>) were obtained by the microwave-assisted activation using KOH as an activating agent at 700 W microwave radiation power. To investigate the effects of KOH on specific characteristics of CTFCs, the different ratios of KOH:CTFs char (i.e. 1:1, 1:2, 1:4, 1:8 w/w) were studied. CTFCs were extensively characterized on physicochemical properties including proximate & ultimate analysis, porous characteristics, and surface morphology. The porous carbon exhibits a combination of type I/type IV sorption isotherm representing the micro/mesopores in its pore structure. The optimal condition obtained the highest SBET of 913.56 m2/g with total pore volume of 0.42 cm3/g. CTFC were potentially applied for metal catalyst support in various chemical reaction due to its high surface area and porosity to enhance the catalyst dispersion.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results