Stimulation of Lipid Extraction Efficiency from Sewage Sludge for Biodiesel Production through Hydrothermal Pretreatment

Jongkeun Lee, Oh Kyung Choi, Dooyoung Oh, Kawnyong Lee, Ki Young Park and Daegi Kim
Additional contact information
Jongkeun Lee: Department of Civil and Environmental Engineering, College of Engineering, Konkuk University, Seoul 05029, Korea
Oh Kyung Choi: Department of Environmental Engineering, College of Science and Technology, Korea University, Sejong-si 30019, Korea
Dooyoung Oh: Department of Civil and Environmental Engineering, College of Engineering, Konkuk University, Seoul 05029, Korea
Kawnyong Lee: Department of Environment & Health, Jangan University, Gyeonggi-do 18331, Korea
Ki Young Park: Department of Civil and Environmental Engineering, College of Engineering, Konkuk University, Seoul 05029, Korea
Daegi Kim: Department of Environmental Engineering, College of Engineering, Daegu University, Gyeongsangbuk-do 38453, Korea

Energies, 2020, vol. 13, issue 23, 1-10

Abstract: In this study, two types of sewage sludge (primary sludge and waste activated sludge) were hydrothermally treated at 125–250 °C to enhance the lipid extraction efficiency and obtain a higher biodiesel yield. The enhanced efficiency of the lipid extraction method was compared with the efficiency of the organic solvent extraction method. The results confirmed that a hydrothermal reaction could be an appropriate option for disrupting sludge cell walls and increasing the lipid extraction from sewage sludge. The highest lipid recovery efficiency was observed at 200 °C, and the lipid recovery efficiency of primary sludge and waste activated sludge increased from 7.56% and 5.35% to 14.01% and 11.55% by weight, respectively. Furthermore, transesterified lipids, such as biodiesel from sewage sludge, mostly consist of C16 and C18 methyl esters, and have features similar to those of jatropha oil-based biodiesel. During the hydrothermal treatment, the carbon content in the sludge decreased as the carbon transformed into lipids and the lipids were extracted. The volatile matter and fixed carbon content in the solid residue decreased and increased, respectively, through chemical dehydration and decarboxylation reactions under hydrothermal reaction conditions.

Keywords: hydrothermal reaction; lipid recovery; sewage sludge; biodiesel; renewable energy (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/1996-1073/13/23/6392/pdf (application/pdf)
https://www.mdpi.com/1996-1073/13/23/6392/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:13:y:2020:i:23:p:6392-:d:455750

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().