Banca de DEFESA: IZAIAS CAMPOS DA PAIXÃO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : IZAIAS CAMPOS DA PAIXÃO
DATE: 07/02/2024
TIME: 09:00
LOCAL: videoconferência
TITLE:

Electrorefinery of high-value-added carboxylic acids and green hydrogen through electrochemical oxidation of lignina.

KEY WORDS:

Electrorefinery; Biomass; Anodic oxidation; cyclical economy

PAGES: 125
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Eletroquímica
SUMMARY:

A growing concern for issues related to environmental impacts has intensified the search for technologies in effluent remediation, renewable energies, and sustainable sources of chemical precursors. Electrochemical oxidation for promoting the reforming of organic effluents can be an alternative for obtaining high-value industrial chemical reagents. The main challenges are associated with the high energy cost of oxidative remediation processes, which can be minimized with renewable energy sources such as wind and photovoltaic. In this research, a reactor with a divided flow by an anionic ion exchange membrane was used, separating the anodic and cathodic compartments. As anodic electrodes, the following were used: Nb/BDD (Niobium/Boron-Doped Diamond) and DSA® (Ti/TiO2, RuO2, and IrO2), with a Ni-Fe mesh (Nickel-Iron) as the cathode, were used for remediating synthetic lignin effluents (a residue from the production process). The oxidative cleavage of lignin resulted in the generation of carboxylic acids in the anodic compartment and green hydrogen in the cathodic compartment. Using a BDD electrode, the best results were achieved with the following concentrations under experimental conditions of 0.5 mol L-1 NaOH and J=100 mAcm-2: oxalic acid 86.03 mg L-1, acetic acid 15.67 mg L-1, formic acid 8.64 mg L-1, and vanillic acid 0.6795 mg L-1. With a DSA electrode, the best results were obtained under similar experimental conditions: oxalic acid 53.14 mg L-1, formic acid 10.58 mg L-1, acetic acid 2.11 mg L-1, and salicylic acid 0.011 mg L-1. The best results for green hydrogen production were 2.59 L in experiments with a BDD anode under experimental conditions of 1 mol L-1 NaOH and J=100 mAcm-2, and 2.93 L in experiments with a DSA anode under experimental conditions of 0.5 mol L-1 NaOH and J=100 mAcm-2. In this context, the results obtained indicate that promoting electro-refining in lignin-based effluents is a viable alternative for obtaining value-added products, such as carboxylic acids widely used in the industry, and green hydrogen.

COMMITTEE MEMBERS:
Interna - 2140818 - AMANDA DUARTE GONDIM
Presidente - 1645110 - CARLOS ALBERTO MARTINEZ HUITLE
Externo à Instituição - JOÃO MILLER DE MELO HENRIQUE - IFSERTAO
Externa à Instituição - JUSSARA CÂMARA CARDOZO - UFRN
Externo à Instituição - MARCO ANTONIO QUIROZ ALFARO - udlap