Search Results

Now showing 1 - 2 of 2

Some of the metrics are blocked by your
consent settings
Lignin removal from synthetic wastewater via Fenton-like reaction over Cu supported on MCM-41 derived from bagasse: Optimization and reaction intermediates
(2023-02-01)
Sriprom, Pongsert
;
Neramittagapong, Sutasinee
;
Lin, Chitsan
;
Neramittagapong, Arthit
;
Assawasaengrat, Pornsawan
Lignin degradation was performed using a Fenton-like oxidation reaction with Cu supported on MCM-41, derived from bagasse (Cu-BG-MCM-41), as the catalyst. The optimal degradation conditions required to remove a predetermined amount of lignin (95%) from an effluent were determined. Based on the literature review and preliminary tests, the critical parameters determining the operating conditions include temperature, catalyst loading, pH, H<inf>2</inf>O<inf>2</inf> concentration, and reaction time. The experimental design and working conditions were based on Box–Behnken design. The reaction products were analyzed via UV–vis and gas chromatography-mass spectrometry. Response surface methodology (RSM) was used to predict the optimum operating conditions for the Fenton-like reaction for 95% lignin degradation, which were a temperature of 80 °C, initial pH of 9, H<inf>2</inf>O<inf>2</inf> concentration of 1 mL/L, catalyst loading of 1.0 g/L, and reaction time of 30 min. These conditions were validated three times and the achieved percentage of lignin degradation was 95 ± 2%. This is close to the value of 95% used in the RSM to determine the optimum operating conditions, thus verifying the model. The catalyst was stable and functioned well under the optimum design conditions. Moreover, the reaction could be used to obtain high-value intermediate products if stopped after 5 min. Finally, lignin was degraded into vanillin, a higher-value product. As expected, the proposed Fenton-like approach expanded the pH working range from less than 4 to 5–9.
Some of the metrics are blocked by your
consent settings
Optimization of lignin conversion to phenol via partial oxidation of synthesized wastewater containing lignin
(2020-12-01)
Sriprom, Pongsert
;
Leephisuth, Pornyamon
;
Assawasaengrat, Pornsawan
;
Neramittagapong, Arthit
;
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 (R<sup>2</sup> 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.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results