Synthesis of Solketal Fuel Additive From Acetone and Glycerol Using CO2 as Switchable Catalyst

• Published in: Frontiers in energy research 2019-06, Vol.7
• Main Authors: Nascimento, Júlia A. C., Pinto, Bianca P., Calado, Verônica M. A., Mota, Claudio J. A.
• Format: Article
• Language: English
• Subjects: acetalization; CO2; design of experiments; glycerol; solketal; switchable catalyst
• ISSN: 2296-598X; 2296-598X
• DOI: 10.3389/fenrg.2019.00058

The production of solketal fuel additive was studied from the reaction of glycerol and acetone in the presence of pressurized CO2 as switchable catalyst. A design of experiments (DoE) was used to study the significance of temperature, initial pressure of CO2, glycerol/acetone molar ratio, and reaction time. The response variable was the glycerol conversion that was analyzed by GC-MS. Temperature, reaction time and initial pressure of CO2 were statistically significant whereas the molar ratio of glycerol/acetone was not. The maximum conversion at the optimal conditions (118°C, 42 bar and 5 h) was 61%. Reactions with glycerol doped with common contaminants present in the glycerin of biodiesel production was also carried out. Water has a drastic effect on the conversion, as well as the concomitant addition of water and NaCl. Reactions with a glycerin of biodiesel production, using NaOH or Ba(OH)2 as catalyst of transesterification, gave 6 and 20% conversion, respectively.