The considerable compounds content, abundance, and low costs involved has led to the proposal to use sewage sludge as raw material for biodiesel production. The transesterification reaction is catalyzed using an acid catalyst instead of base catalysts because of the high free fatty acid concentration. However, the use of a base catalyst, particularly a solid base catalyst, has certain advantages, including faster reaction speed and easier separation. In this study, we utilize in situ transesterification by base catalyst (KOH, KOH/activated carbon (AC) and KOH/CaO) with sewage sludge as raw material. Many conditions have been tested to increase biodiesel yield through single-factor tests, including mass fraction and catalyst dosage. Preliminary experiments have optimized reaction time and temperature. However, the three catalysts did not work better than H2SO4, which had a maximum yield of 4.6% (dry sewage sludge base) considering the purity by KOH, KOH/CaO, and KOH/AC. The features of the catalyst were analyzed using XRD, BETand SEM. As to BETof KOH/AC and the good spiculate formation of KOH crystal appears to be essential to its function. As for KOH/CaO, the formation of K2O and absorption points is likely essential.
Biodiesel Sewage sludge Base catalyst In situ transesterification
This is a preview of subscription content, log in to check access.
Notes
Acknowledgments
The present study is supported by the Major Science and Technology Program for Water Pollution Control and Treatment (No. 2013ZX07314-001-006-01); Fundamental Research Funds for the Central Universities (No. 51308538); and the Research Funds of Renmin University of China (No. 15XNLD04).
References
1.
Yan S, Kim M, Salley S O, Ng K Y S. Oil transesterification over calcium oxides modified with lanthanum. Applied Catalysis A, General, 2009, 360(2): 163–170CrossRefGoogle Scholar
Vyas A P, Verma J L, Subrahmanyam N. A review on FAME production processes. Fuel, 2010, 89(1): 1–9CrossRefGoogle Scholar
4.
Siddiquee M N, Rohani N J. Lipid extraction and biodiesel production from municipal sewage sludges: a review. Renewable & Sustainable Energy Reviews, 2011, 15(2): 1067–1072CrossRefGoogle Scholar
5.
Xue F, Zhang X, Luo H, Tan T. A new method for preparing raw material for biodiesel production. Process Biochemistry, 2006, 41(7): 1699–1702CrossRefGoogle Scholar
6.
Haas M J, Scott K M, Foglia T A, Marmer W N. The general applicability of in situ transesterification for the production of fatty acid esters from a variety of feedstocks. Journal of the American Oil Chemists’ Society, 2007, 84(10): 963–970CrossRefGoogle Scholar
7.
Revellame E, Hernandez R, French W, Holmes W A E, Alley E. Biodiesel from activated sludge through in situ transesterification. Journal of Chemical Technology and Biotechnology (Oxford, Oxfordshire), 2010, 85(5): 614–620CrossRefGoogle Scholar
8.
Liu B, Zhao Z. Biodiesel production by direct methanolysis of oleaginous microbial biomass. Journal of Chemical Technology and Biotechnology (Oxford, Oxfordshire), 2007, 82(8): 775–780CrossRefGoogle Scholar
9.
Jardé E, Mansuy L, Faure P. Organic markers in the lipidic fraction of sewage sludges. Water Research, 2005, 39(7): 1215–1232CrossRefGoogle Scholar
10.
Wright D A. Activated Sludge MOP OM-9. 2nd ed. Alexandria, Virginia: Water Environment Federation, 2002Google Scholar
11.
Xu G, Zhang B, Liu S, Yue J. Study on immobilized lipase catalyzed transesterification reaction of tung oil. Agricultural Sciences in China, 2006, 5(11): 859–864CrossRefGoogle Scholar
12.
Haas M J, Foglia T A. Biodiesel production. In: Biodiesel Handbook. Champaign, IL: AOCS Press, 2005, 42–61Google Scholar
13.
Mondala A, Liang K, Toghiani H, Hernandez R, French T. Biodiesel production by in situ transesterification of municipal primary and secondary sludges. Bioresource Technology, 2009, 100(3): 1203–1210CrossRefGoogle Scholar
14.
Charoenchaitrakool M, Thienmethangkoon J. Statistical optimization for biodiesel production from waste frying oil through two-step catalyzed process. Fuel Processing Technology, 2011, 92(1): 112–118CrossRefGoogle Scholar
15.
Jena P C, Raheman H, Prasanna Kumar G V, Machavaram R. Biodiesel production from mixture of mahua and simarouba oils with high free fatty acids. Biomass and Bioenergy, 2010, 34(8): 1108–1116CrossRefGoogle Scholar
16.
Nakpong P, Wootthikanokkhan S. High free fatty acid coconut oil as a potential feedstock for biodiesel production in Thailand. Renewable Energy, 2010, 35(8): 1682–1687CrossRefGoogle Scholar
17.
Yang Y N, Li H. Recovering humic substances from the dewatering effluent of thermally treated sludge and its performance as an organic fertilizer. Frontiers of Environmental Science & Engineering, 2016, 10(3): 578–584CrossRefGoogle Scholar
18.
Dufreche S, Hernandez R, French T, Sparks D, Zappi M, Alley E. Extraction of lipids from municipal wastewater plant microorganisms for production of biodiesel. Journal of the American Oil Chemists’ Society, 2007, 84(2): 181–187CrossRefGoogle Scholar
19.
Boocock D G B, Konar S K, Leung A, Ly L D. Fuels and chemicals from sewage sludge: 1.The solvent extraction and composition of a lipid from raw sewage sludge. Fuel, 1992, 71(11): 1283–1289CrossRefGoogle Scholar
20.
Qi J, Zhu F, Wei X, Zhao L, Xiong Y, Wu X. In situ transesterification of sewage sludge from A2/O and MBR processes for biodiesel production. Waste Management, 2016, 49(4): 212–220CrossRefGoogle Scholar
21.
Pastore C, Lopez A, Lotito V, Mascolo G. Biodiesel from dewatered wastewater sludge: a two-step process for a more advantageous production. Chemosphere, 2013, 92(6): 667–673CrossRefGoogle Scholar
22.
Nuithitikul K, Prasitturattanachai W. Activity of sulfated aluminium- tin mixed oxides for the esterification of free fatty acids in crude palm oil. International Journal of Green Energy, 2014, 11(10): 1097–1106CrossRefGoogle Scholar
23.
Islam A, Taufiq-Yap Y H, Chu C M, Chan E S, Ravindra P. Studies on design of heterogeneous catalysts for biodiesel production. Process Safety and Environmental Protection, 2013, 91(1–2): 131–144CrossRefGoogle Scholar
24.
Juan J C, Kartika D A, Wu T Y, Hin T Y. Biodiesel production from Jatropha oil by catalytic and non-catalytic approaches: an overview. Bioresource Technology, 2011, 102(2): 452–460CrossRefGoogle Scholar
25.
El-Mashad H M, Zhang R, Avena-Bustillos R J. A two-step process for biodiesel production from salmon oil. Biosystems Engineering, 2008, 99(2): 220–227CrossRefGoogle Scholar
26.
Hincapié G, Mondragón F, López D. Conventional and in situ transesterification of castor seed oil for biodiesel production. Fuel, 2011, 90(4): 1618–1623CrossRefGoogle Scholar
27.
Kargbo D M. Biodiesel production from municipal sewage sludges: a review. Energy & Fuels, 2010, 24(5): 2791–2794CrossRefGoogle Scholar
28.
Wang Y, Feng S, Bai X, Zhao J, Xia S. Scum sludge as a potential feedstock for biodiesel production from wastewater treatment plants. Waste Management (New York, N.Y.), 2016, 47(Pt A): 91–97CrossRefGoogle Scholar
29.
Haas M J, Scott K M, Marmer W N, Foglia T A. In situ alkaline transesterification: an effective method for the production of fatty acid esters from vegetable oils. Journal of the American Oil Chemists’ Society, 2004, 81(1): 83–89CrossRefGoogle Scholar
30.
Yang L, Lv P, Yuan Z, Luo W, Li H. Different catalysts loaded with KOH for catalytic and synthesis of biodiesel. Chemical Industry and Engineering Progress, 2012, 31(91): 90–94Google Scholar
31.
Babu N S, Sree R, Prasad P S, Lingaiah N. Room-temperature transesterification of edible and nonedible oils using a heterogeneous strong basic Mg/La catalyst. Energy & Fuels, 2008, 22(3): 1965–1971CrossRefGoogle Scholar