Abstract
Abstract For biodiesel production from waste cooking oils with high acid values, an inefficient esterification pretreatment is always conducted to convert free fatty acids (FFAs) before alkali-catalysed transesterification process. In this paper, phosphotungstic acid based poly(ionic liquid) was prepared to catalyse the esterification of palmitic acid with methanol while the required catalyst dosage was much lower than commercial Amberlyst-15. And the catalyst was characterized by 31P CP-MAS NMR, FTIR, SEM, XRF and TG. Among the three poly(ionic liquid)s prepared in this paper, phosphotungstic acid based poly(ionic liquid) was selected to be the most suitable catalyst for esterification because the catalyst could be reused for more than 5 times without significant deactivation. According to single factor analyses, the esterification yield could reach 91.6% after 8 h while the reaction temperature, methanol to acid molar ratio and catalyst dosage were 65 °C, 6 and 3% wt, respectively. Afterwards, palmitic acid was proposed to be first adsorbed on the catalyst before reacting with methanol. Finally, a palmitic acid adsorbed Eley-Rideal model was employed to analyse the reaction and the adsorption mechanism was assumed as well.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
