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Highly active and stable Ni–W/SiO2 catalyst derived from W incorporated on Ni phyllosilicate for deoxygenation of triglycerides into green biofuel range hydrocarbons
(2025-10-01)
Praikaew, Wanichaya
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Prameswari, Jedy
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Ratchahat, Sakhon
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Chaiwat, Weerawut
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Sakdaronnarong, Chularat
Highly active and stable Ni–W/SiO<inf>2</inf> catalyst derived from W incorporated into Ni phyllosilicate (Ni-PS) was prepared by the ammonia evaporation (AE) method, and benchmarked with the catalyst prepared by the impregnation method (IM). Their catalytic activities were evaluated for deoxygenation of triglycerides into green biofuel-range hydrocarbons. The Ni-PS structure demonstrated a large surface area with strong interaction between Ni2+ and SiO<inf>2</inf>, resulting from the incorporation of Ni2+ into the silica framework, which led to highly dispersed Ni⁰ after H<inf>2</inf> reduction. Additionally, the H<inf>2</inf> adsorption and desorption capabilities, together with a substantial quantity of Lewis acid sites, were advantageous features of Ni-PS catalysts compared to Ni-IM and 5 W/Ni-IM catalysts. Ex situ and in situ structural characterizations revealed the generation of Ni⁰ and W⁰ states, along with remaining W4+ species after H<inf>2</inf> reduction. The 5 W/Ni-AE catalyst exhibited stable performance up to 60 h on stream, producing consistent yields of 30 % jet fuel and 40 % diesel, which was attributed to its high porosity, small Ni⁰ particle sizes, enhanced H<inf>2</inf> adsorption–desorption capacities, and abundant Lewis acid sites. Consequently, the heterogeneous 5 W/Ni-AE catalyst shows significant practical relevance for generating green biofuel from oil-derived feedstock in sustainable biorefineries.
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Oil extracted from spent coffee grounds for bio-hydrotreated diesel production
(2016-10-15)
Phimsen, Songphon
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Kiatkittipong, Worapon
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Yamada, Hiroshi
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Tagawa, Tomohiko
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Kiatkittipong, Kunlanan
Oil extracted from spent coffee grounds is utilized as a renewable source for bio-hydrotreated fuel production. In the present work, oil yield up to 13% can be obtained by Soxhlet extraction with hexane as a solvent. As the extracted oil contained high content of free fatty acids (6.14%), therefore one step alkali-catalyzed for ester based biodiesel production is impractical. Hydrotreating of extracted oil was performed over two catalysts i.e. NiMo/γ-Al<inf>2</inf>O<inf>3</inf> and Pd/C with different operating parameters i.e. reaction time, operating temperature, and H<inf>2</inf>/oil. It was found that the reaction time of 2 h and the reaction temperature of 400 °C are favorable operating conditions. The liquid products mostly consisted of n-pentadecane and n-heptadecane, which contain one carbon atom shorter than the corresponding fatty acid (C<inf>n−1</inf>) i.e. palmitic and stearic acid, respectively. Unfavorable cracking of diesel product is pronounced at high temperature and prolonged reaction time. In addition, although increased H<inf>2</inf>/oil promoted overall reaction and hydrodeoxygenation activity (C<inf>n−1</inf>/C<inf>n</inf> decreased) for both catalysts, hydrocracking is enhanced over Pd/C, leading to significant increase in gasoline yield. Moreover, Pd/C gave higher olefin content in liquid product (22.3 wt%) than NiMo/γ-Al<inf>2</inf>O<inf>3</inf> (4.8 wt%). However, NiMo/γ-Al<inf>2</inf>O<inf>3</inf> shows higher isomerization activity. The amount of isoparaffins catalyzed by NiMo/γ-Al<inf>2</inf>O<inf>3</inf> and Pd/C were 10.8 and 1.7 wt%, respectively. Physiochemical analysis of the diesel fraction exhibit satisfactory properties. The density and kinematic viscosity were consistent with the specification of commercial bio-hydrogenated diesel, NExBTL, while the cetane index was much higher than conventional diesel.
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Diesel-like hydrocarbon production from hydroprocessing of relevant refining palm oil
(2013-05-22)
Kiatkittipong, Worapon
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Phimsen, Songphon
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Kiatkittipong, Kunlanan
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Wongsakulphasatch, Suwimol
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Laosiripojana, Navadol
This paper demonstrates the initiated use of relevant refining palm oil for bio-hydrogenated diesel production. The conversions of crude palm oil (CPO) and its physical refining including degummed palm oil (DPO) and palm fatty acid distillate (PFAD) to diesel fuel by hydroprocessing were studied. The effects of operating parameters (i.e. reaction time, operating temperature, and pressure) and catalyst (i.e. Pd/C and NiMo/γ-Al<inf>2</inf>O<inf>3</inf>) were examined in order to determine suitable operating condition for each feedstock. It was found that the hydroprocessing of CPO with Pd/C catalyst at 400 C, 40 bar, and reaction time of 3 h provides the highest diesel yield of 51%. When gum which contains phospholipid compounds is removed from CPO, namely DPO, the highest diesel yield of 70% can be obtained at a shorter reaction time (1 h). In the case of PFAD, which consists mainly of free fatty acids, a maximum diesel yield of 81% could be observed at milder conditions (375 C with the reaction time of 0.5 h). The main liquid products are n-pentadecane and n-heptadecane, having one carbon atom shorter than the corresponding fatty acids according to decarboxylation/decarbonylation pathways. Pd/C catalyst shows good catalytic activity for fatty acid feedstocks but becomes less promising for triglyceride feedstocks when compared to NiMo/γ-Al<inf>2</inf>O<inf>3</inf>. © 2013 Elsevier B.V.

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