Biomass valorization derivatives: Clean esterification of 2-furoic acid using tungstophosphoric acid/zirconia composites as catalyst

A. ESCOBAR; A. G. SATHICQ; M. BLANCO; L. PIZZIO; G. ROMANELLI

PROCESS SAFETY AND ENVIRONMENTAL PROTECTION

INST CHEMICAL ENGINEERS

Año: 2015 vol. 98 p. 176 - 186

0957-5820

2-Furoic acid esters, which are biomass derived, are used in the flavoring and fragrance industry or as synthesis intermediates in the pharmaceutical industry. A series of zirconia samples modified with different contents of tungstophosphoric acid (TPA) and two different preparation methods (ZrPEGTPA30T100, ZrPEGTPA60T100, ZrTPA30PEGT100, and ZrTPA60PEGT100) were synthesized from zirconium propoxide via sol-gel reactions using polyethylene glycol as template. They were characterized by different physicochemical techniques (BET, FT-IR, 31P MAS NMR and potentiometric titration), and their activities were tested in the synthesis of n-butyl-2-furoate as the model compound, among which ZrTPA30PEGT100, (mesoporous acid zirconia modified catalyst) was the most active catalyst.The effect of various parameters such as catalyst loading, mole ratio of 2-furoic acid ton-butanol, and temperature was studied under optimized conditions. Several other alkyl-2-furoates were produced from esterification of 2-furoic acid with different alcohols using these catalysts, and the effect of alcohol structure over the conversion reaction was considered.The use of a solid acid catalyst made the procedure environmentally benign. The catalysts ZrPEGTPA30T100 and ZrTPA30PEGT100 were reused without appreciable loss of the catalytic activity (three runs). The methodology represents a green and efficient alternative for the conversion of bio-based 2-furoic acid into valuable esters.