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Optimization of Vanillin Production from Lignin Using Catalytic Depolymerization over a CuO/Al2O3 Catalyst
(2023-01-01)
Sangnak, Sirawit
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Neramittagapong, Arthit
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Neramittagapong, Sutasinee
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Theerakulpisut, Somnuk
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Sriprom, Pongsert
The optimal conditions for vanillin production from lignin depolymerization using CuO/Al2O3 catalysts were determined by combining Box-Behnken design (BBD) and response surface methodology (RSM). Independent variables, including temperature (80–140 °C), NaOH loading (0.5–1.5 g), time (30–90 min), and catalyst weight (0.5–1.5 g), were investigated to determine the optimal conditions, with the concentration of vanillin being the dependent variable. A CuO/Al2O3 catalyst was prepared by impregnation method. The vanillin obtained from the reaction was analyzed using high-performance liquid chromatography (HPLC). The maximum obtained vanillin concentration of 59.14 mg·L-1 was achieved with a temperature of 80 °C, a reaction time of 90 min, NaOH loading of 1.5 g, and 1.5 g of catalyst. The amount of NaOH was the most influential factor governing the obtained vanillin concentration. Regression analysis was performed to determine the formula describing the vanillin concentration in terms of the independent variables with a reasonable degree of accuracy (R2 = 0.87). This study shows that the optimal conditions for the depolymerization of lignin to vanillin over a CuO/Al2O3 catalyst can be achieved under milder conditions than those reported previously.
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Preparation of activated carbon from durian rind with difference activations and its optimization
(2021-01-01)
Sriprom, Pongsert
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Krusong, Warawut
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Assawasaengrat, Pornsawan
Durian rind wastes are an important raw material for activated carbon production due to their renewable sources and low-cost materials. The efficiency of increasing surface area and the quantity of oxygen groups on the surface of activated carbon were studied for the preparation of activated carbon. The preparation of activated carbon has been studied with the different methods as follows: activation by acid, activation by base, hydrothermal and activation by acid, and hydrothermal and activation by base. The results showed that hydrothermal and activation by acid had high iodine number which was chosen to determine the optimum condition for activated carbon preparation. The optimum condition for preparation of durian rind activated carbon was studied by Box-Behnken design. Solid/water ratio, solid/acid ratio and temperature were chosen as the important parameters for achieving the optimum reaction condition. The reaction products were analyzed by iodine number. Based on the results, the optimum condition for preparation of durian rind activated carbon was predicted using RSM. The maximum iodine number of 626.47 mg/g was expected at the optimum condition: solid/ water ratio (1:175, g/mL), solid/acid ratio (1:23, g/mL) and temperature (500°C). The preparation of durian rind activated carbon at the optimal condition was carried; the percentages of iodine number achieved (666.73 ± 6 mg/g) were close to the maximum predicted value (666.73 mg/g), thus verifying the model. At the optimum condition, the functional group on surface of durian rind activated carbon was characterized by FT-IR. The result showed that the oxygen content on surface was increased in the form of carbonyl and sulfonyl group.
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Optimizing Ammonia Adsorption Using Activated Carbon from Tamarind Pulp
(2021-01-01)
Na-Lampang, Chaiyawat
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Assawasaengrat, Pornsawan
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Phumjan, Lamphung
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Narkrugsa, Woatthichai
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Sriprom, Pongsert
Ammonia is an essential waste from fish and shrimp which has an effect on fish and shrimp transportation for export. This study aimed to remove ammonia by Activated Carbon adsorption. The activated carbon was prepared from Tamarind pulp using different methods (NaOH, H2SO4, the hydrothermal technique and activated by H2SO4 and H2SO4 hydrothermal followed by NaOH). The Activated Carbon was characterized by and Iodine number and Fourier Transform I nfrared Spectroscopy (FT-IR). The results showed that the iodine number of activated carbon prepared by the hydrothermal technique and activated by H2SO4 have the highest surface area and porosity at 537 mg/g, and the functional group on activated carbon surface is carbonyl and sulfonyl group. For ammonia adsorption, the experiments were designed by Box-Behnken design at 3 factors 3 levels including Contact time (10, 95 and 180 min), Dosage of activated carbon (0.5, 1.25 and 2.0 g) and pH of the solution (2, 6.5 and 11). The concentration of ammonia was determined by UV-Visible spectrophotometer. The result showed that the main effects and the interaction effects were found significant effect on ammonia adsorption at confidence level of 95%. However, the interaction effects between contact time and activated carbon dosage was insignificant. Finally, the optimized results suggested that 48.32 ± 0.82% of ammonia concentration could be removed by activated carbon from tamarind pulp under the following conditions: PH of 11, a contact time of 95 min, and activated carbon dosage of 2 g/100 mL. The results are believed to be of importance to fish and shrimp transportation for reduced ammonia and other similar applications.
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Production of Cellulose From Bamboo Shoot Shell Using Hydrothermal Technique
(2021-01-01)
Manamoongmongkol, Kanjana
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Suwapanich, Rachit
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Phumjan, Lamphung
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Narkrugsa, Woatthichai
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Sriprom, Pongsert
The preparation and characterization of purified cellulose from bamboo shoot shell were studied using fouriertransform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The preparation of cellulose fiber included extraction of cellulose from bamboo shoot shell by treatment with 5 % NaOH and 4 % H2O2, and purification of cellulose fiber using hydrothermal technique. The result showed that cellulose has been successfully extracted at a 32.56% yield by the 5% NaOH / 4% H2O2 treatment, and the purified cellulose was produced using autoclaving at the temperature of 120°C and pressure at 0.1 MPa for 2 h 5 min, with the % recovery of purified cellulose around 94.08. Bamboo shoot shell and cellulose sample were further characterized using FTIR technique. It was found that the 5% NaOH / 4% H2O2 treatment eliminated lignin and hemicellulose from bamboo shoot shell but did not affect cellulose. The hydrothermal technique did not affect the destruction of the cellulose structure as well. Comparison of the SEM image showed that cellulose was separated into individual microfibers after the 5% NaOH / 4% H2O2 treatment while the SEM image of purified cellulose was the small thread-like fibers with smoother surface. Therefore, hydrothermal treatment can be performed for purification of cellulose.
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Optimization of lignin conversion to phenol via partial oxidation of synthesized wastewater containing lignin
(2020-12-01)
Sriprom, Pongsert
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Leephisuth, Pornyamon
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Assawasaengrat, Pornsawan
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Neramittagapong, Arthit
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Neramittagapong, Sutasinee
This work was to optimize operating parameters for phenol production via partial oxidation. The essential settings, NaOH loading of 4–20 g/L, reaction temperatures of 140–180 °C, and time of 15–45 min, were set as the independent parameters for designing the experiments. A set of tests was generated using Box–Behnken Design (BBD) and performed in a high-pressure reactor at the constant air pressure of 2 bars. A produced phenol concentration was assigned as a response target for evaluating an optimal condition. From the results, a quadratic model of actual data was fit with high accuracy (R2 of 94.1%). A response surface methodology (RSM) was used to evaluate the operating parameters effect on the phenol formation. It showed that the temperature rising affected phenol formation due to the creation of aldehydes at low temperatures and phenol re-polymerization. The presence of NaOH plays an essential role in the production of phenol. It may increase the hydroxyl group's rate to an aromatic ring that yields a high percentage of phenol production. For the reaction time, the longer time gave a higher yield of phenol. However, it slightly increased after 30 min. The predicted optimal condition was determined at the temperature of 161 °C, the NaOH loading of 16.4 mg/L, and the reaction time of 36.2 min. Three experiments were performed at the optimal point to verify the prediction. It was found that the phenol concentration of 30 ± 1 mg/L was yielded at this condition. Moreover, the reaction temperature and the initial pressure of air were not severe. It indicates that the partial oxidation of aqueous lignin solution can produce phenol at mild conditions.
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Optimization of Lignin Conversion by Hydrothermal Method for Recovery of Vanillin
(2020-10-20)
Sriprom, Pongsert
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Leephisuth, Pornyamon
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Neramittagapong, Arthit
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Neramittagapong, Sutasinee
This work aimed to optimize lignin conversion to vanillin by hydrothermal method. An experiment was designed by Box-Benhken Design (BBD). Temperature, NaOH concentration, and reaction time were chosen as independent parameters for achieving the optimum reaction condition. The reaction products were analyzed by high-performance liquid chromatography. Based on the experimental results, the optimum condition for the hydrothermal process was predicted using the response surface method. The maximum vanillin production of 18.1 mg/L was predicted at the optimum condition given by the temperature of 142 °C, NaOH concentration of 9.2 g/L, and reaction time of 32 min. The conversion of lignin to vanillin was experimented using the predicted optimal condition to verify the prediction. It was found that the hydrothermal method at the optimum condition yielded 18.1 ± 2 mg/L of vanillin, which was in good agreement with the predicted value. It was also found that the yield of vanillin was influenced by temperature, NaOH concentration, and the interaction of both parameters, whereas the reaction time was much less influential.
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Partial oxidation of synthesized wastewater containing lignin to vanillin and phenol under mild conditions
(2020-02-01)
Sriprom, Pongsert
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Leephisuth, Pornyamon
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Neramittagapong, Arthit
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Neramittagapong, Sutasinee
Partial oxidation of synthesized wastewater containing lignin to form phenol and vanillin was investigated. The reactions were carried out in a high-pressure reactor at various temperatures in the range of 140–200 ° C and under the air atmosphere with the initial air pressure of 2 bar for 75 min. The addition of NaOH has a strong effect on the formation of vanillin and phenol. The results showed that the highest vanillin concentration of 23.4 ppm and the highest phenol production of 30 ppm were obtained at a temperature of 140 °C and 200 °C, respectively. The vanillin and phenol can be produced from the partial oxidation of wastewater containing lignin at mild conditions.

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