Sriprom Pongsert, Neramittagapong Sutasinee, Lin Chitsan, Neramittagapong Arthit, Assawasaengrat Pornsawan
Program of Food Process Engineering, School of Food Industry, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand.
Department of Chemical Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen 40002, Thailand.
Heliyon. 2023 Jan 21;9(2):e13157. doi: 10.1016/j.heliyon.2023.e13157. eCollection 2023 Feb.
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, HO 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, HO 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.
使用以源自甘蔗渣的MCM - 41负载的铜（Cu - BG - MCM - 41）作为催化剂的类芬顿氧化反应进行木质素降解。确定了从流出物中去除预定量木质素（95%）所需的最佳降解条件。基于文献综述和初步试验，决定操作条件的关键参数包括温度、催化剂负载量、pH值、过氧化氢浓度和反应时间。实验设计和工作条件基于Box - Behnken设计。通过紫外 - 可见光谱和气相色谱 - 质谱联用对反应产物进行分析。采用响应面法（RSM）预测类芬顿反应降解95%木质素的最佳操作条件，即温度80℃、初始pH值9、过氧化氢浓度1 mL/L、催化剂负载量1.0 g/L和反应时间30分钟。这些条件经验证三次，木质素降解率达到95±2%。这接近RSM中用于确定最佳操作条件的95%的值，从而验证了该模型。催化剂在最佳设计条件下稳定且性能良好。此外，如果在5分钟后停止反应，该反应可用于获得高价值的中间产物。最后，木质素降解为香草醛，一种更高价值的产物。正如预期的那样，所提出的类芬顿方法将pH工作范围从小于4扩展到了5 - 9。
