Acid-catalyzed esterification of Zanthoxylum bungeanum seed oil with high free fatty acids for biodiesel production

• Published in: Bioresource technology Vol. 99; no. 18; pp. 8995 - 8998
• Main Authors: Zhang, Junhua, Jiang, Lifeng
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2008; [New York, NY]: Elsevier Ltd; Elsevier
• Subjects: Acid esterification; acid treatment; acid value; alkali treatment; analysis; Biodiesel; Bioelectric Energy Sources; Biofuel production; Biological and medical sciences; Biotechnology; Catalysis; catalysts; chemistry; Energy; Esterification; fatty acid esters; Fatty Acids, Nonesterified; Fatty Acids, Nonesterified - analysis; Fatty Acids, Nonesterified - metabolism; Free fatty acids; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Magnetic Resonance Spectroscopy; metabolism; Methanol; nuclear magnetic resonance spectroscopy; Plant Oils; Plant Oils - chemistry; Plant Oils - metabolism; pretreatment; seed oils; Seeds; Seeds - chemistry; Sulfuric Acids; Sulfuric Acids - metabolism; Temperature; Time Factors; transesterification; yields; Zanthoxylum; Zanthoxylum - metabolism; Zanthoxylum bungeanum; Zanthoxylum bungeanum seed oil; Biodiesel; Zanthoxylum bungeanum seed oil; Acid esterification; Free fatty acids; Dicotyledones; Angiospermae; Rutaceae; Spermatophyta; Vegetable oil; Free fatty acid; Acid catalysis; Esterification
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2008.05.004

A technique to produce biodiesel from crude Zanthoxylum bungeanum seed oil (ZSO) with high free fatty acids (FFA) was developed. The acid value of ZSO was reduced to 1.16 mg KOH/g from 45.51 mg KOH/g by only one-step acid-catalyzed esterification with methanol-to-oil molar ratio 24:1, H 2SO 4 2%, temperature 60 °C and reaction time 80 min, which was selected as optimum for the acid-catalyzed esterification. During the acid-catalyzed esterification, FFA was converted into fatty acid methyl esters, which was confirmed by 1H NMR spectrum. Compared with the other two-step pretreatment procedure, this one-step pretreatment can reduce the production cost of ZSO biodiesel. Alkaline-catalyzed transesterification converted the pretreated ZSO into ZSO biodiesel. The yield of ZSO biodiesel was above 98% determined by 1H NMR spectrum. This study supports the use of crude ZSO as a viable and valuable raw feedstock for biodiesel production.