A reactive coupling process for co-production of solketal and biodiesel

• Main Authors: Al-Saadi Luma Sh., Eze Valentine C., Harvey Adam P.
• Format: Article
• Language: English
• Published: De Gruyter 2019-01-01
• Series: Green Processing and Synthesis
• Subjects: reactive coupling; biodiesel; solketal; kinetic modelling; design of experiment statistics
• Online Access: https://doi.org/10.1515/gps-2019-0020

A “reactive coupling” process for one-pot transesterification of rapeseed oil into fatty acid methyl esters (FAME) for biodiesel, and in situ acetalisation of the glycerol by-product to solketal was investigated by both an experimental and a kinetic modelling approach. The aim was to develop a process with a more valuable co-products than glycerol, and to minimise glycerol production. The results showed that a one-stage reactive coupling achieved a solketal yield of 39.5 ± 5.1% and FAME yield of 99% after 8 h at 10:7:1 of methanol: acetone: oil molar ratio. However, based on these results and the predictions of the kinetic model developed, a “two-stage” reactive coupling process was investigated, in which some of the acetone was added later in the process. The two-stage process was demonstrated to achieve up to 98 ± 0.5% FAME and 82 ± 4% solketal yields under the same operating conditions.