Acetalization of β-citronellal Over a Renewable Carbon Catalyst Obtained from Bio-Oil Sulfonation: A Green Route to Obtain Valuable Feedstocks

• Published in: Waste and biomass valorization Vol. 15; no. 3; pp. 1369 - 1377
• Main Authors: Lopes, Neide Paloma Gonçalves, Ballotin, Fabiane Carvalho, de Carvalho Teixeira, Ana Paula, Lago, Rochel Montero, da Silva, Márcio José
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-03-2024; Springer Nature B.V
• Subjects: Acetals; Alcohol; Alcohols; Carbon; Catalysts; Citronellal; Engineering; Environment; Environmental Engineering/Biotechnology; Industrial Pollution Prevention; Oils & fats; Original Paper; Renewable and Green Energy; Room temperature; Sulfonation; Sulfuric acid; Temperature effects; Waste Management/Waste Technology; Bio-oil carbon; Acetalization; β-citronellal; Acid catalysts
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-023-02216-2

In this work, an efficient renewable carbon catalyst obtained by bio-oil
sulfonation
was used for the first time to produce terpene acetals by condensation of β-citronellal with alkyl alcohols (methyl, ethyl, propyl, butyl, isopropyl) at room temperature. The catalyst was obtained by a simple bio-oil reaction with sulfuric acid at 393 K for different times (15, 30, 60, 90, 120, and 240 min). Potentiometric titrations and FT-IR analyses showed the formation of very strong acid sites, likely -SO
3
H, with surface concentrations reaching 0.35 and 0.50 mmol/ g. catalyst, for the catalyst obtained with reactions 120 and 240 min. These catalysts were used
for
β-citronellal condensation with alkyl alcohols to acetals with conversion and selectivity higher than 90%, at room
temperature,
using
a
3.96 wt.% catalyst and 2 h reaction time. The effects of temperature, time, different alcohols, and catalyst load were evaluated. The catalyst can be recovered and reused four times without significant activity loss. The use of renewable origin solid catalysts, recyclable, and active in acetalization reactions at room temperature are positive aspects of this process.
Graphical Abstract