New microwave based transesterification techniques for biodiesel production from cultivated microalgae

Microalgae biodiesel production has its share of problems such as the high cost in microalgae producti vity, harvesting, dewatering, lipid extraction and transesterification. Thus research in this field focuses on address ing these issues from the cultivation perspective and also the processing aspe...

Full description

Saved in:

Bibliographic Details
Main Author:	Teo, Chee Loong
Format:	Thesis
Language:	English
Published:	2015
Subjects:	TP Chemical technology
Online Access:	http://eprints.utm.my/id/eprint/54695/1/TeoCheeLoongPFChE2015-KIVV.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-utm-ep.54695
record_format	uketd_dc
spelling	my-utm-ep.546952020-11-03T08:31:58Z New microwave based transesterification techniques for biodiesel production from cultivated microalgae 2015-04 Teo, Chee Loong TP Chemical technology Microalgae biodiesel production has its share of problems such as the high cost in microalgae producti vity, harvesting, dewatering, lipid extraction and transesterification. Thus research in this field focuses on address ing these issues from the cultivation perspective and also the processing aspect. In this dissertat ion both approaches were used to address the problems where marine microalgae (Tetraselmis sp. and Nannochloropsis sp.) were cultivated indoor using light emitting diodes (LED) and processed using direct transesterification (DT). During cultivation, factors influencing microalgae growth rate and lipid content such as the type of LED wavelength and light intensities were investigated in detail. Microalgae were cultivated for 14 days as under blue, red, red-blue LED and white fluorescent light. The intensity of the red, blue and mixed red-blue LED was varied at 100, 150 and 200 umol photons m·2s·l . Findings revealed both species prefer to grow under blue wavelength which showed highest growth rate (reflected by the high cell count and absorbance readings) and lipid content (indicated by the fluorescence intensity). Suitable combination of LED wavelengths and intensity; (red LED: 150, blue: 100 and mixed redblue: 200 umol photons m·2s·l ) produced maximum biomass growth and lipid content. Then, several techniques were used to improve the DT method; i) introducing the use of microwave heating (MWH) to the various extraction methods, ii) varying the type of catalyst under MWH and iii) the use of simultaneous cooling and microwave heating (SCMH). Furthermore, four different methods were used to extract the lipids: Hara and Radin, Folch, Chen and Bligh and Dyer. They were performed under MWH and conventional heating using water bath heating. Lipid yield for Tetraselmis sp. and Nannochloropsis sp. was highest when Hara and Radin (8.19%), and Folch (8.47%) methods were used respectively under MWH. Nannochloropsis sp. wet biomass was transesterified under MWH in the presence of methanol and various alkali and acid catalyst using two different types of DT; one step and two step transesterification. The biodiesel yield obtained from the microwave direct transesterification (MWDT) was compared with that obtained using conventional method (lipid extraction followed by transesterification) and water bath heating DT method. Findings revealed that MWDT efficiency was higher compared to water bath heating DT by at least 14.34% and can achieve a maximum of 43.37% with proper selection of catalysts. The use of combined catalyst (NaOH and H2S04) increased the yield obtained by 2.3 folds (water bath heating DT) and 2.87 folds (MWDT) compared with the one step single alkaline catalyst. Maximum yield was obtained using SCMH when the microwave was set at 50 °C, 800 W, 16 h of reaction with simultaneous cooling at 15°C. When the one step transester ification was performed in SCMH at optimum setting, the biodiesel yield was more than 3.75 folds than conventional method. Gas chromatography analysis depicted that the biodiesel produced from SCMW had shorter carbon chain fatty acid methyl esters « 19 C) and good cetane number and iodine value indicating good ignition and lubricating properties. Thus it was proven that the use of LED, MWH and SCMW can improve microalgae biodiesel yields. 2015-04 Thesis http://eprints.utm.my/id/eprint/54695/ http://eprints.utm.my/id/eprint/54695/1/TeoCheeLoongPFChE2015-KIVV.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:94641 phd doctoral Universiti Teknologi Malaysia, Faculty of Chemical Engineering Faculty of Chemical Engineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TP Chemical technology
spellingShingle	TP Chemical technology Teo, Chee Loong New microwave based transesterification techniques for biodiesel production from cultivated microalgae
description	Microalgae biodiesel production has its share of problems such as the high cost in microalgae producti vity, harvesting, dewatering, lipid extraction and transesterification. Thus research in this field focuses on address ing these issues from the cultivation perspective and also the processing aspect. In this dissertat ion both approaches were used to address the problems where marine microalgae (Tetraselmis sp. and Nannochloropsis sp.) were cultivated indoor using light emitting diodes (LED) and processed using direct transesterification (DT). During cultivation, factors influencing microalgae growth rate and lipid content such as the type of LED wavelength and light intensities were investigated in detail. Microalgae were cultivated for 14 days as under blue, red, red-blue LED and white fluorescent light. The intensity of the red, blue and mixed red-blue LED was varied at 100, 150 and 200 umol photons m·2s·l . Findings revealed both species prefer to grow under blue wavelength which showed highest growth rate (reflected by the high cell count and absorbance readings) and lipid content (indicated by the fluorescence intensity). Suitable combination of LED wavelengths and intensity; (red LED: 150, blue: 100 and mixed redblue: 200 umol photons m·2s·l ) produced maximum biomass growth and lipid content. Then, several techniques were used to improve the DT method; i) introducing the use of microwave heating (MWH) to the various extraction methods, ii) varying the type of catalyst under MWH and iii) the use of simultaneous cooling and microwave heating (SCMH). Furthermore, four different methods were used to extract the lipids: Hara and Radin, Folch, Chen and Bligh and Dyer. They were performed under MWH and conventional heating using water bath heating. Lipid yield for Tetraselmis sp. and Nannochloropsis sp. was highest when Hara and Radin (8.19%), and Folch (8.47%) methods were used respectively under MWH. Nannochloropsis sp. wet biomass was transesterified under MWH in the presence of methanol and various alkali and acid catalyst using two different types of DT; one step and two step transesterification. The biodiesel yield obtained from the microwave direct transesterification (MWDT) was compared with that obtained using conventional method (lipid extraction followed by transesterification) and water bath heating DT method. Findings revealed that MWDT efficiency was higher compared to water bath heating DT by at least 14.34% and can achieve a maximum of 43.37% with proper selection of catalysts. The use of combined catalyst (NaOH and H2S04) increased the yield obtained by 2.3 folds (water bath heating DT) and 2.87 folds (MWDT) compared with the one step single alkaline catalyst. Maximum yield was obtained using SCMH when the microwave was set at 50 °C, 800 W, 16 h of reaction with simultaneous cooling at 15°C. When the one step transester ification was performed in SCMH at optimum setting, the biodiesel yield was more than 3.75 folds than conventional method. Gas chromatography analysis depicted that the biodiesel produced from SCMW had shorter carbon chain fatty acid methyl esters « 19 C) and good cetane number and iodine value indicating good ignition and lubricating properties. Thus it was proven that the use of LED, MWH and SCMW can improve microalgae biodiesel yields.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Teo, Chee Loong
author_facet	Teo, Chee Loong
author_sort	Teo, Chee Loong
title	New microwave based transesterification techniques for biodiesel production from cultivated microalgae
title_short	New microwave based transesterification techniques for biodiesel production from cultivated microalgae
title_full	New microwave based transesterification techniques for biodiesel production from cultivated microalgae
title_fullStr	New microwave based transesterification techniques for biodiesel production from cultivated microalgae
title_full_unstemmed	New microwave based transesterification techniques for biodiesel production from cultivated microalgae
title_sort	new microwave based transesterification techniques for biodiesel production from cultivated microalgae
granting_institution	Universiti Teknologi Malaysia, Faculty of Chemical Engineering
granting_department	Faculty of Chemical Engineering
publishDate	2015
url	http://eprints.utm.my/id/eprint/54695/1/TeoCheeLoongPFChE2015-KIVV.pdf
_version_	1747817704844165120

New microwave based transesterification techniques for biodiesel production from cultivated microalgae

Similar Items