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145 results on '"Gurgel, Leandro Vinícius Alves"'

23. Synthesis and application of sugarcane bagasse cellulose mixed esters. Part II: Removal of Co2+ and Ni2+ from single spiked aqueous solutions in batch and continuous mode

Author

Almeida, Francine Tatiane Rezende de, Elias, Megg Madonyk Cota, Xavier, Amália Luísa Pedrosa, Ferreira, Gabriel Max Dias, Silva, Isabela Almeida, Filgueiras, Jefferson Gonçalves, Azevedo, Eduardo Ribeiro de, Silva, Luis Henrique Mendes da, Gil, Laurent Frédéric, and Gurgel, Leandro Vinícius Alves

Published
2019
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36. Reduced-pressure alkaline pretreatment as an innovative and sustainable technology to extract protein from brewer's spent grain

Author

Arantes da Fonseca, Yasmim, Gurgel, Leandro Vinícius Alves, Baêta, Bruno Eduardo Lobo, Dragone, Giuliano, and Mussatto, Solange I.

Subjects
Protein, Extraction, Lignocellulosic biomass, Carbon footprint, Amino acid, Biorefinery
Abstract

One of the bottlenecks related to the extraction of protein from lignocellulosic biomass is the development of an efficient, selective, economical, and environmentally friendly process. This study investigated the reduced-pressure alkaline pretreatment (RPAP) as an innovative approach for protein extraction from brewer's spent grain (BSG). Experiments were carried out at different temperatures (30–70 °C), pressures (150–1025 mBar), times (1–7 h), and NaOH concentrations (20–180 mM) to obtain a high-yield and selective protein extraction associated with low CO2 emissions and high processing capacity per batch. Protein concentration, total CO2 emissions per protein extracted, selectivity (related to sugars), and processing capacity were the responses considered for optimization. The optimum condition (T = 70 °C; P = 455 mBar, t = 1 h, and [NaOH] = 180.00 mM) was able to extract 80% of the total protein present in BSG composition. This condition was also selective (76.8%) and had a low carbon footprint (0.43 g CO2 g protein extracted−1). Glutamic acid was the most abundant amino acid in both raw BSG (22.9%) and protein hydrolysate (23.4%), followed by leucine (9.3% and 7.0%, respectively), proline (8.3% and 11.2%, respectively), and aspartic acid (8.8% and 7.6%, respectively). RPAP was demonstrated to be an efficient and sustainable technology for protein extraction from BSG. This opens up new opportunities for BSG and other protein-rich lignocellulosic materials valorization in a biorefinery.

Published
2023

45. Oxidized Renewable Materials for the Removal of Cobalt(II) and Copper(II) from Aqueous Solution Using in Batch and Fixed-Bed Column Adsorption.

Author

Rodrigues, Josilene Aparecida Vieira, Martins, Luide Rodrigo, Furtado, Laís Milagres, Xavier, Amália Luísa Pedrosa, Almeida, Francine Tatiane Rezende de, Moreira, Ana Luísa da Silva Lage, Melo, Tânia Márcia Sacramento, Gil, Laurent Frédéric, and Gurgel, Leandro Vinícius Alves

Subjects
ADSORPTION kinetics, AQUEOUS solutions, ADSORPTION (Chemistry), ADSORPTION capacity, COBALT, COPPER
Abstract

Batch and continuous adsorption of Co2+ and Cu2+ from aqueous solutions by oxidized sugarcane bagasse (SBox) and oxidized cellulose (Cox) were investigated. The oxidation reaction of sugarcane bagasse and cellulose was made with a mixture of H3PO4‒NaNO2 to obtain SBox and Cox, with the introduction of high number of carboxylic acid functions, 4.5 and 4.8 mmol/g, respectively. The adsorption kinetics of Co2+ and Cu2+ on SBox and Cox were modeled using two models (pseudo-first-order and pseudo-second-order) and the rate-limiting step controlling the adsorption was evaluated by Boyd and intraparticle diffusion models. The Sips and Langmuir models better fitted the isotherms with values of maximum adsorption capacity Q max of 0.68 and 0.37 mmol/g for Co2+ and 1.20 and 0.57 mmol/g for Cu2+ adsorption on Cox and SBox, respectively. The reuse of both spent adsorbents was evaluated. Adsorption of Cu2+ and Co2+ on SBox in continuous was evaluated using a 22 factorial design with spatial time and initial metal concentration as independent variables and Q max and effective use of the bed as responses. The breakthrough curves were very well described by the Bohart–Adams original model and the Q max values for Co2+ and Cu2+ were 0.22 and 0.55 mmol/g. SBox confirmed to be a promising biomaterial for application on a large scale. [ABSTRACT FROM AUTHOR]

Published
2020
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47. Ethanol–water organosolv delignification of liquid hot water (LHW) pretreated sugarcane bagasse enhanced by high–pressure carbon dioxide (HP–CO2).

Author

Gurgel, Leandro Vinícius Alves, Pimenta, Maria Teresa Borges, and Curvelo, Antonio Aprigio da Silva

Subjects
*BAGASSE, *ETHANOL, *HOT water, *DELIGNIFICATION, *SUGARCANE, *PHYSIOLOGICAL effects of carbon dioxide
Abstract

Organosolv delignification assisted by high–pressure carbon dioxide (HP–CO 2 ), a low cost, non–corrosive and recoverable compound was evaluated as a potential green pretreatment technology for lignin extraction from liquid hot water (LHW) pretreated sugarcane bagasse to produce fermentable sugars in a lignocellulosic biorefinery concept. In this study, LHW pretreated bagasse (180 °C for 20 min with a liquid–to–solid ratio ( LSR ) of 9 (v/w)) was delignified with an ethanol–water mixture (1:1, v/v) and HP–CO 2 as a co–solvent at milder temperatures (111.7–168.3 °C) and times (23.8–66.2 min) at a LSR of 5 (v/w). To evaluate the effects of varying operational conditions on the lignin content and delignification extent, while preserving the glucan fraction, a 2 2 central composite design was used as a factorial planning. Solid fractions with low lignin contents (7.35% and 10.78%) and high delignification extents (82.5% and 72.2%) with good glucan preservations (84.6% and 85.3%) were obtained at 140 °C for 45 min and 111.7 °C for 45 min, respectively. These solid fractions were subjected to enzymatic hydrolysis, yielding enzymatic conversions of 60.8% and 63.7%, respectively. [ABSTRACT FROM AUTHOR]

Published
2016
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48. Activated carbons from agricultural byproducts (pine tree and coconut shell), coal, and carbon nanotubes as adsorbents for removal of sulfamethoxazole from spiked aqueous solutions: Kinetic and thermodynamic studies.

Author

Tonucci, Marina Caldeira, Gurgel, Leandro Vinícius Alves, and Aquino, Sérgio Francisco de

Subjects
*ACTIVATED carbon, *ANTIBACTERIAL agents, *CARBON nanofibers, *AQUEOUS solutions, *NANOTUBES
Abstract

In this study, four different adsorbent materials: commercial powdered activated carbon (PAC) from pine tree (PAC-I) and coconut shell (PAC-III) agricultural crop wastes, coal (PAC-II), and carbon nanotubes (CNT) were tested and compared for the removal of sulfamethoxazole (SMX) from spiked aqueous solutions. The kinetic, extrathermodynamic, and thermodynamic parameters for the adsorption of SMX on PACs and CNT were also determined. The results indicate that PAC-I was the best adsorbent for SMX adsorption. SMX adsorption was only favorable with PAC-I and CNT, leading to Gibbs free energies in the range of −39 to −44 kJ mol −1 and showing that the adsorption process was spontaneous in all temperature ranges (15–45 °C) tested. Langmuir model best described SMX adsorption on PAC-I and led to maximum adsorption capacity of ∼131 mg g −1 (at 25 °C), which was ∼4.6 times higher than that observed for CNT. The mechanism of SMX adsorption on PAC-I and CNT was suggested with basis on thermodynamic and extrathermodynamic parameters. The kinetic studies showed the pseudo-second-order model best described SMX adsorption, yielding k 2 values of 0.0035 and 0.0016 g mg −1 min −1 for PAC-I and CNT, respectively. [ABSTRACT FROM AUTHOR]

Published
2015
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49. Enhancing liquid hot water (LHW) pretreatment of sugarcane bagasse by high pressure carbon dioxide (HP-CO2).

Author

Gurgel, Leandro Vinícius Alves, Pimenta, Maria Teresa Borges, and Curvelo, Antonio Aprigio da Silva

Subjects
*HOT water, *WATER treatment plants, *SUGARCANE, *BAGASSE, *CARBON dioxide, *GREEN technology, *HEMICELLULOSE
Abstract

Highlights: [•] LHW-HP-CO2 evaluated as a potential green technology for hemicelluloses extraction. [•] At 100°C for 30min and 115°C for 60min xylan equivalent ranged 10–12g/L. [•] At 115°C for 60min, the cellulose preservation achieved 97.2%. [•] Enzymatic hydrolysis yielded 30.43g/L glucose and 41.17% cellulose conversion. [ABSTRACT FROM AUTHOR]

Published
2014
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50. Application of Raw and Chemically Modified Biomasses for Heterogeneous Cu-Catalysed Conversion of Aryl boronic Acids to Phenols Derivatives.

Author

Torres, Fernanda Guimarães, Teodoro, Filipe Simões, Gurgel, Leandro Vinícius Alves, Bourdreux, Flavien, Zayene, Olfa, Gaucher, Anne, Gil, Laurent Frédéric, and Prim, Damien

Subjects
BORONIC acid derivatives, PHENOL derivatives, BORONIC acids, CELLULOSE
Abstract

This work describes the application of raw and chemically modified cellulose and sugarcane bagasse for ipso-hydroxylation of aryl boronic acids in environmentally friendly reaction conditions. The catalytic efficiency of five support-[Cu] materials was compared in forming phenols from aryl boronic acids. Our investigation highlights that the CEDA-[Cu] material (6-deoxy-6-aminoethyleneamino cellulose loaded with Cu) leads to the best results under very mild reaction conditions. The optimized catalytic sequence, allowing a facile transformation of boronic acids to phenols, required the mandatory and joint presence of the support, Cu2O, and KOH at room temperature. CEDA-[Cu] was characterized using 13C solid-state NMR, ICP, and FTIR. The use of CEDA-[Cu] accounts for the efficacious synthesis of variously substituted phenol derivatives and presents very good recyclability after five catalytic cycles. [ABSTRACT FROM AUTHOR]

Published
2022
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