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Torrefaction of durian peel in air and N2 atmospheres: Impact on chemical properties and optimization of energy yield using multilevel factorial design
(2024-09-01)
Pimsamarn, Jindarat
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Kaewtrakulchai, Napat
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Wisetsai, Awat
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Mualchontham, Jomthong
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Muidaeng, Nattawut
This study investigated the torrefaction of durian peel using air and nitrogen as carrier gases. A multilevel factorial design coupled with response surface methodology (RSM) and ANOVA analysis was employed to analyze the impact of torrefaction parameters on chemical properties and energy yield. Durian peel, an agricultural waste product, was torrefied at temperatures ranging from 200 to 320 °C for residence times between 0 and 30 min. Results showed that air torrefaction significantly enhanced thermal decomposition, reducing mass yield from 94.65 % to 30.63 % as the temperature increased from 200 °C to 300 °C with a 30-min holding time. Air torrefaction also increased the higher heating value (HHV) from 19.02 MJ/kg to 35.26 MJ/kg at 300 °C, compared to nitrogen, which achieved a maximum HHV of 32.49 MJ/kg. ANOVA analysis revealed that torrefaction temperature and carrier gas significantly affect energy yield and chemical properties. Air torrefaction positively affected HHV while reducing mass yield compared to nitrogen. Low-temperature air torrefaction showed enhanced energy yield improvement. These findings provided insights for optimizing torrefaction processes enhancing utilization wasted durian peel as a sustainable bioenergy resource.
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High Production of Cellulase and Xylanase in Solid-State Fermentation by Trichoderma reesei Using Spent Copra and Wheat Bran in Rotary Bioreactor
(2023-02-22)
Chysirichote, Teerin
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Phaiboonsilpa, Natthanon
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Laosiripojana, Navadol
The enzyme production for lignocellulose saccharification by solid-state fermentation (SSF) of a food manufacturing byproduct was successfully carried out in a 30 L rotary bioreactor. Defatted spent copra (SC) supplemented with wheat bran (WB) was used as a substrate for the SSF of Trichoderma reesei and aerated at various rates. Regression analysis showed that the carbohydrate/protein (C/P) ratio of the substrate and the supplied aeration rate were the important factors for producing the enzyme cocktail, including cellulases (FPase, CMCase, and cellobiase) and xylanase. The substrate containing SC:WB of 3:2 (or the C/P ratio of 5.4) and the aeration of 1.0 L kg-1<inf>substrate</inf> min-1 were found to enhance the production of the enzymes up to 5.68, 8.66, 29.2, and 34.44 U g-1 of dry substrate for FPase, CMCase, cellobiase, and xylanase activities, respectively. This discovery provided a promising environment for other substrates to produce multi-enzymes for lignocellulosic saccharification. Additionally, mathematical models were generated to predict the saccharifying degree of the produced enzyme for lignocellulose saccharification.
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Mechanism of CaO catalyst deactivation with unconventional monitoring method for glycerol carbonate production via transesterification of glycerol with dimethyl carbonate
(2022-02-01)
Praikaew, Wanichaya
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Kiatkittipong, Worapon
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Aiouache, Farid
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Najdanovic-Visak, Vesna
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Termtanun, Mutsee
Glycerol carbonate (GC) was synthesized by transesterification of glycerol with dimethyl carbonate (DMC) using calcium oxide (CaO) derived from eggshell as a catalyst. The best results of 96% glycerol conversion and 94% GC yield were achieved under the following reaction conditions: 0.08 mole ratio of CaO to glycerol, 1:2.5 mole ratio of glycerol to DMC, 60°C reaction temperature, and 3 hours reaction time. As expected, CaO showed deteriorated catalytic performance when recycling as observed by a rapid decrease in GC yield. This research showed that the active CaO phase first was converted to calcium methoxide (Ca[OCH<inf>3</inf>]<inf>2</inf>) and calcium diglyceroxide (Ca[C<inf>3</inf>H<inf>7</inf>O<inf>3</inf>]<inf>2</inf>) and finally to carbonate phase (CaCO<inf>3</inf>) which can be confirmed by XRD patterns. According to the phase transformation, the basicity decreased from 0.482 mmol/g to 0.023 mmol/g, and basic strength altered from strong basic strength (15.0 < H_ < 18.4) to weak basic strength (7.2 < H_ < 9.8), resulting in the lower catalytic activity of the consecutive runs. Despite the fact that the GC selectivity was almost 100%, the reaction products (methanol and GC) were not obtained in their stoichiometric ratio and their extents corresponded with that of the catalyst phase transformation to CaCO<inf>3</inf>. The mechanism of CaO catalyzed transesterification based on the condensation reaction of glycerol and catalyst was proposed, and in situ formation of water-derivative species was hypothesized as a cause of CaO transformation. CaO could react with DMC and water, generating methanol and CaCO<inf>3</inf>. This enabled unconventional monitoring of catalyst deactivation by checking if the mole ratio of methanol to GC was higher than 2:1 of its reaction stoichiometric ratio. It was also demonstrated that calcination of post-run catalyst at 900°C to CaO exhibited almost constant catalytic activity, and the mole ratio of methanol to GC was constant at its reaction stoichiometry (2:1) for at least 4 times use.
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Process and energy intensification of glycerol carbonate production from glycerol and dimethyl carbonate in the presence of eggshell-derived cao heterogeneous catalyst
(2021-07-02)
Praikaew, Wanichaya
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Kiatkittipong, Worapon
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Aiouache, Farid
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Najdanovic-Visak, Vesna
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Ngaosuwan, Kanokwan
The process and energy intensifications for the synthesis of glycerol carbonate (GC) from glycerol and dimethyl carbonate (DMC) using an eggshell-derived CaO heterogeneous catalyst were investigated. The transesterification reaction between glycerol and DMC was typically limited by mass transfer because of the immiscible nature of the reactants. By varying the stirring speed, it was observed that the mass transfer limitation could be neglected at 800 rpm. The presence of the CaO solid catalyst made the mass transport-limited reaction process more prominent. Mass transfer intensification using a simple kitchen countertop blender as an alternative to overcome the external mass transfer limitation of a typical magnetic stirrer was demonstrated. A lower amount of the catalyst and a shorter reaction time were required to achieve 93% glycerol conversion or 91% GC yield, and the turnover frequency (TOF) increased almost 5 times from 1.5 to 7.2 min−1 when using a conventional magnetic stirrer and countertop blender, respectively. In addition, using a simple kitchen countertop blender with 7200 rpm, the reaction temperature of 60◦C could be reached within approximately 3 min without the need of a heating unit. This was the result of the self-frictional heat generated by the high-shear blender. This was considered to be heat transfer intensification, as heat was generated locally (in situ), offering a higher homogeneity distribution. Meanwhile, the trend toward energy intensification was promising as the yield efficiency increased from 0.064 to 2.391 g/kJ. A comparison among other process intensification techniques, e.g., microwave reactor, ultrasonic reactor, and reactive distillation was also rationalized.
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Effective Cu/Re promoted Ni-supported γ-Al2O3 catalyst for upgrading algae bio-crude oil produced by hydrothermal liquefaction
(2021-06-01)
Pongsiriyakul, Kanokthip
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Kiatkittipong, Worapon
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Adhikari, Sushil
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Lim, Jun Wei
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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.
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Fermentation of xylose, arabinose, glucose, their mixtures and sugarcane bagasse hydrolyzate by yeast Pichia stipitis for ethanol production
(2020-02-01)
Phaiboonsilpa, Natthanon
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Chysirichote, Teerin
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Champreda, Verawat
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Laosiripojana, Navadol
Xylose, arabinose and glucose were studied their fermentabilities to ethanol by yeast Pichia stipitis. The experiments were conducted by using 1.0, 5.0, 10.0 and 20.0 g/l of mono-saccharide solutions in a close fermentation system at 30 °C with 100-rpm shaking rate for 120 h. Fermentabilities of mono-saccharides appeared to produce high ethanol yield when a low concentration of xylose and arabinose was applied. Glucose fermentability was, however, found to be preferable at high sugar concentration. The highest ethanol yields could be achieved at 106.27, 86.25, and 73.10%, reported as a relative % to its theoretical ethanol yield, by using 1.0 g/l of xylose, 1.0 g/l of arabinose, and 20.0 g/l of glucose solutions, respectively. The empirical equations were then established based on the fementabilities obtained to predict ethanol yield for a given concentration of mono-saccharides. A comparative study on fermentation of the mono-saccharide mixture and sugarcane bagasse hydrolyzate, of which xylose, arabinose and glucose concentrations were similar, were moreover conducted. It was revealed that the empirical equations provided an excellent estimation of ethanol concentration when the mono-saccharide mixture was used. The presence of furans and other compounds in sugarcane bagasse hydrolyzate besides the mono-saccharides, however, resulted in a lower ethanol fermentability compared with that calculated by the empirical equations. This is due apparently to an inhibition effect of these additional components to Pichia stipitis.
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Comparative study on liquefaction behaviors of xylan hemicellulose as treated by different hydrothermal methods
(2020-02-01)
Phaiboonsilpa, Natthanon
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Champreda, Verawat
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Laosiripojana, Navadol
Liquefaction behaviors of xylan were studied as treated by six different hydrothermal methods. As a comparative study, a xylan sample isolated from corn core was subjected to hot-compressed water, hot-compressed 0.01 and 0.1wt% H<inf>2</inf>O<inf>2</inf> solutions under pressurization of N<inf>2</inf> or CO<inf>2</inf> at 110–250 °C for 0 min in 10-ml batch-type reactor. Not only xylose and xylo-oligosaccharides, but also arabinose, glucose, and acetic acid were recovered as hydrolyzed products. In addition, decomposition compounds, i.e. furans and organic acids were found. The highest xylose yield could be attained at 210 °C in all the studied hydrothermal methods, except for only 0.1wt% H<inf>2</inf>O<inf>2</inf> solution under pressurization of CO<inf>2</inf>. By this strongly oxidative condition, where peroxy carbonic acid was formed in situ, the temperature that xylose could be highly recovered was at 190 °C. The highest xylose yield of 61.62wt% was obtained by 0.01wt% H<inf>2</inf>O<inf>2</inf> solution under pressurization of N<inf>2</inf>. Formation of furan compounds showed a preference to the treatments with pressurized CO<inf>2</inf>, while organic acids had a better recovery when N<inf>2</inf> was applied. Different results in the production of various liquefied products could be attributed to the degree of hydrolysis and oxidation reactions which altered under the different hydrothermal methods.
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Synthesis of glycerol carbonate from dimethyl carbonate and glycerol using CaO derived from eggshells
(2018-08-14)
Praikaew, Wanichaya
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Kiatkittipong, Worapon
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Kiatkittipong, Kunlanan
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Laosiripojana, Navadol
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Viriya-Empikul, Navin
Waste eggshell is proposed as a highly active catalyst for glycerol carbonate production from dimethyl carbonate (DMC) and glycerol. The effect of reaction temperature, reaction time and catalyst loading on the reaction performance were investigated in order to find a suitable operating condition. CaO derived from waste eggshell exhibits catalytic activity comparable to commercial CaO. By using CaO eggshell, glycerol conversion of 96% can be achieved within 90 min of reaction time under 2.5:1 feed molar ratio of DMC to glycerol, 0.08 mole ratio of CaO to glycerol and reaction temperature of 60°C. The catalyst was examined by XRD, TGA/DSC, SEM, N2 adsorption-desorption and Hammett indicators method. Utilization of eggshell as a catalyst for glycerol carbonate production not only provides a cost-effective and value-added of waste eggshell as a green catalyst, but also decrease amount of waste and its treatment cost which is ecologically friendly.
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Alternative Hydrocarbon Biofuel Production via Hydrotreating under a Synthesis Gas Atmosphere
(2017-11-16)
Pongsiriyakul, Kanokthip
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Kiatkittipong, Worapon
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Kiatkittipong, Kunlanan
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Laosiripojana, Navadol
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Faungnawakij, Kajornsak
Direct use of syngas, a cheaper hydrogen-rich gas, instead of pure hydrogen, as a deoxygenating agent for biohydrogenated diesel (BHD) production is presented in this study. Low-cost palm fatty acid distillate (PFAD), an inedible byproduct from refining palm oil, is used as a feedstock in the presence of a Pd/C catalyst. The results indicate that syngas can be effectively used in BHD production, while the achieved BHD yield is slightly lower than that obtained from pure hydrogen. The liquid products contain mostly n-C<inf>15</inf> and n-C<inf>17</inf>, which fall into a diesel range. Decarbonylation is a prominent pathway under both hydrogen and syngas atmospheres. It was found that CO in syngas can act as a reducing agent, which can remove an oxygen atom from fatty acid molecules to form alkenol that could be further reduced to alkene and then cyclized to cycloparaffins. After reactivation, the activity of the catalyst could be fully recovered for at least 4 reused cycles. Reaction pathways for the catalytic deoxygenation under syngas are also proposed with the underlying mechanism on the role of CO.
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Nickel sulfide, nickel phosphide and nickel carbide catalysts for bio-hydrotreated fuel production
(2017-11-01)
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
A series of nickel catalysts i.e. nickel sulfide (NiS), nickel phosphide (NiP) and nickel carbide (NiC) was investigated for hydrotreating of spent coffee oil to produce bio-hydrotreated fuel (BHF). Catalytic tests were carried out at 375–425 °C and 20–40 bar of initial H<inf>2</inf> pressure (before heating) with reaction time of 0–3 h. The activity of the catalysts are in the order of NiC > NiP > NiS; however NiC tended to promote cracking reaction resulting in high gasoline and gaseous yields. On the other hand, although NiS gives the lowest oil conversion, it is favorable to diesel yield with lowest methanation and cracking activity. Compared with decarboxylation (DCO<inf>2</inf>) and hydrodeoxygenation (HDO), decarbonylation (DCO) was the major route for deoxygenation of coffee oil for all the catalysts. The ratio of (DCO + DCO<inf>2</inf>) to HDO (as represented by C<inf>n-1</inf>/C<inf>n</inf>) decreased in the order NiS > NiC > NiP. Ketones as intermediate products (ca. 3 wt%) were detected in case of NiP. They could be generated via rearrangement of alcohol and keto-enol tautomerism. Significant amount of aromatics (4 wt%) with some isomerization products (0.9 wt%) can also be observed in NiS catalyzed liquid products while trace amount of these compounds were detected for NiP and NiC catalysts. Physiochemical analysis of the diesel fraction exhibited satisfactory properties. The density and kinematic viscosity were consistent with the specification of commercial bio-hydrogenated diesel, NExBTL. Since main products are straight chain hydrocarbons, high cetane index (>110) could be achieved.

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