eprintid: 12907 rev_number: 2 eprint_status: archive userid: 1 dir: disk0/00/01/29/07 datestamp: 2023-11-10 03:27:28 lastmod: 2023-11-10 03:27:28 status_changed: 2023-11-10 01:49:50 type: article metadata_visibility: show creators_name: Nguyen, T.T. creators_name: Lam, M.K. creators_name: Uemura, Y. creators_name: Mansor, N. creators_name: Lim, J.W. creators_name: Show, P.L. creators_name: Tan, I.S. creators_name: Lim, S. title: High biodiesel yield from wet microalgae paste via in-situ transesterification: Effect of reaction parameters towards the selectivity of fatty acid esters ispublished: pub keywords: Algae; Biodiesel; Esters; Methanol; Microorganisms; Organic solvents; Transesterification, Chlorella vulgaris; Fatty acid esters; Long chain fatty acid; Methanol concentration; Micro-algae; Short-chain fatty acids; Situ transesterification; Transesterification reaction, Fatty acids note: cited By 45 abstract: In the present study, the effect of co-solvent and different reaction parameters on fatty acid ester yield composition produced from in-situ transesterification of wet Chlorella vulgaris was investigated. The result showed that under wet microalgae condition (75 wt of moisture content), increasing of methanol concentration resulted in more significant improvement of fatty acid ester yield as compared to H2SO4 concentration. This was due to the equilibrium shifting to the FAME product direction under high methanol concentration condition. The highest fatty acid ester yield attained under wet microalgae condition was 96.0 wt of esterifiable lipid with 650 mol/mol and 10000 mol/mol of H2SO4 and methanol concentration, respectively. Besides, by introducing small amount of n-butanol or tetrahydrofuran (THF) (0.1 mol/mol of methanol) as co-solvent resulted to remarkable enhancement in fatty acid ester yield (100 wt and 98.7 wt of esterifiable lipid corresponding to n-butanol and THF, respectively) and 33 reduction of methanol usage. This was due to the synergetic effect of co-solvent in the lipid extraction process and enhancement of solubility between lipid and methanol phase to accelerate the transesterification reaction. Moreover, n-butanol or THF also lead to different selectivity of fatty acid esters, whereby high concentration of long-chain fatty acid esters (e.g. C18) were attained with n-butanol while short-chain fatty acid esters (e.g. C10 and C16) were obtained by adding THF. Overall, the results from the present study revealed the possibility to obtain high fatty acid ester yield from wet microalgae paste that could be useful for scale-up study. © 2020 Elsevier Ltd date: 2020 publisher: Elsevier Ltd official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082664559&doi=10.1016%2fj.fuel.2020.117718&partnerID=40&md5=b9506eb47678a6699b38f42cea95a471 id_number: 10.1016/j.fuel.2020.117718 full_text_status: none publication: Fuel volume: 272 refereed: TRUE issn: 00162361 citation: Nguyen, T.T. and Lam, M.K. and Uemura, Y. and Mansor, N. and Lim, J.W. and Show, P.L. and Tan, I.S. and Lim, S. (2020) High biodiesel yield from wet microalgae paste via in-situ transesterification: Effect of reaction parameters towards the selectivity of fatty acid esters. Fuel, 272. ISSN 00162361