Work

Conversion of carbohydrates to organic acids in aqueous medium using aluminum nitrate as the catalyst precursor

Year: 2024

Type: article

Abstract: Fructose, glucose, and sucrose were converted to organic acids in the presence of aqueous aluminum nitrate (Al(NO3)3) to develop a technically viable route for upgrading sugarcane molasses. Reactions were carried out in a microwave reactor and a muffle oven with conventional heating (convective heat transfer) using a sealed glass tubes and a hydrothermal stainless-steel autoclave as reaction vessels, respectively. Conversion was evaluated for different reaction times and temperatures. Lactic acid predominated as the product from the retro-aldol chain splitting of fructose, reaching a 67.5 % molar yield using 2.67 mmol·L-1 Al(NO3)3 (4 wt% based on the carbohydrate dry mass) in a stainless-steel reactor with conventional heating. Sucrose required hydrolysis, glucose isomerization, retro-aldol chain splitting, dehydration, tautomerization, and 1,2-H migration to produce lactic acid in molar yields approaching those obtained from fructose (65.5 %). Besides lactic acid, formic and levulinic acids were produced in variable amounts through a fructose dehydration pathway, having 5-(hydroxymethyl)-furfural (HMF) as reaction intermediate. The use of a stepwise heating regime was a critical parameter to achieve high product yields and good lactic acid selectivity in these reaction systems.

Source: BioResources

DOI: 10.15376/biores.20.1.1037-1058

Authors: Priscila D. Fernandes, Rafael D. Lima, Gustavo R. Gomes, Daniel S. Rampon, Luiz P. Ramos

Institutions: Universidade Federal do Paraná, Universidade Estadual de Campinas (UNICAMP)

Language: English

Topic: Catalysis for Biomass Conversion

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: gold

Estimated APC paid: $1,452