由於石化燃料逐漸枯竭且溫室效應造成的地球暖化日益嚴重，因此尋求適當的可再生能源取代石化燃料並減緩大氣中溫氣體的累積速率將是刻不容緩的課題。生質柴油（Biodiesel）具有可經由再生原料來製備、無毒性、生物可分解且不會增加二氧化碳的淨排放量等優點，因此近幾年來備受各界關注。傳統上，生質柴油透過轉酯化反應將動植物油脂與低碳數醇類經鹼性觸媒催化生成，但此製程必須在無水且低脂肪酸含量的條件下進行。如反應物含有過量的脂肪酸，酸性觸媒可以有效地催化生成生質柴油。在酸催化系統中，硫酸、鹽酸與硝酸常被用來當作催化酯化反應的催化劑，但只有鹽酸可重複催化酯化反應。
在本研究中，以酵素法將大豆油水解反應獲得大量的脂肪酸，在鹽酸催化下，水解獲得之脂肪酸與甲醇進行酯化反應生成脂肪酸甲酯（生質柴油），並藉由實驗設計法完整地探討醇酸莫耳比、反應溫度與觸媒濃度對於酯化反應之影響並以一均相動力學模型來描述此反應之行為。此動力學模型進一步預測反應速率常數之奇異點、脂肪酸轉化率為0.99下之最適化操作條件以及鹽酸重複使用對於脂肪酸轉化率之影響，其預測結果皆與實際實驗結果相當一致。

Biodiesel has been received much attention, because it is a renewable, non-toxic and alternative energy.
Traditionally, biodiesel is formed via the transesterification of oil with low molecular weight alcohols by using alkaline catalysts.
The alkali process of biodiesel production requires anhydrous condition and the oil with a very low amount of free fatty acids (FFAs).
Once the crude oils contain high levels of FFAs, acidic catalysts are used efficiently for biodiesel production.
For acid-catalyzed systems, sulfuric acid, hydrochloric acid and nitric acid are commonly used as the catalyst, but only hydrochloric acid can be reused in the esterification process.
In this study, fatty acids, obtained from enzymatic hydrolysis of soybean oil, are esterificated with methanol to produce biodiesel by using the acidic catalyst of hydrochloric acid.
The kinetic study of the esterification was carried out with different levels of molar ratio of methanol to free fatty acids, reaction temperature and acidic catalyst concentration by using the method of experimental design.
The experimental data were well-correlated by a second order kinetic equation.
The kinetic model was employed to predict experimental conditions, including the singular point of reaction rate constant, the optimal operating conditions at a fatty acids conversion of 99% and the influence of hydrochloric acid concentration to a fatty acids conversion.
Since the kinetic model approach the reaction system well, the experiment conformation agree with the model prediction.

Azcan N. and Danisman A., Alkali catalyzed transesterification of cottonseed oil by microwave irradiation, Fuels, 86, 2639-2644, 2007.

Bart HJ., Reidestschlager J., Schatka K., Lehmann A., Kinetics of esterification of levulinic acid with n-butanol by homogeneous catalyst, Industrial and Engineering Chemistry Research, 33, 21-25, 1994.

Berrious M., Siles J., Martin MA., A kinetic study of esterification of free fatty acid (FFA) in sunflower oil, Fuel, 86, 2383-2388, 2007.

Canoira L., Alcantara R., Torcal S., Tsiouvaras N., Lois E., Korres DM., Nitration of Biodiesel of waste oil: Nitrated biodiesel as a cetane number enhancer, Fuel, 86, 965-971, 2007.

Chiu CW., Goff MJ., Suppes GJ., Distribution of Methanol and Catalysts between Biodiesel and Glycerol Phases., American Institute of Chemical Engineers (AIChE), 51, 1274-1278, 2005.

Connemann J. and Fisher J., Biodiesel quality Y2K and market experiences with FAME, CEN/TC 19 Automotive Fuels Millennium Symposion, Amsterdam, The Netherlands, 25-26 Nov, 1999.

Demirbas A., Biodiesel production from vegetable oils via catalytic and non-catalytic supercritical methanol transesterification methods, Progress in Energy and Combustion Science, 31, 466-487, 2005.

Demirbas A., Importance of biodiesel as transportation fuel, Energy Policy, 35, 4661-4670, 2007.

Freedman B., Pryde EH., Mounts TL., Variables affecting the yields of fatty esters from transesterified vegetable oils, Journal of the American Chemists’ Society, 61, 1638-1643, 1984.

Freedman B., Butterfield RO., Pryde EH., Transesterification Kinetics of Soybean Oil, Journal of the American Chemists’ Society, 63, 1375-1380, 1986.

Georgogianni KG., Kontominas MG., Tegou E., Avlonitis D. and Gergis V., Biodiesel Production: Reaction and Process Parameters of Alkali-Catalyzed Transesterification of Waste Frying Oils, Energy and Fuels, 21, 3023-3027, 2007.

Goto S., Tagawa T., Yusoff A., Kinetics of esterification of palmitic acid with isobutyl alcohol, International Journal of Chemical Kinetics, 23, 17-26, 1991.

Guerreiro L., Castanheiro JE., Fonseca IM., Martin-Aranda RM., Ramos AM., Vital J., Transesterification of soybean oil over sulfonic acid functionalized polymer membranes, Catalysis Today, 118, 166-171, 2006.

Harwood HJ., Oleochemicals as a fuel: Mechanical and economic feasibility, Journal of the American Oil Chemists’ Society, 61, 325-324, 1984.

Haas MJ., Michalski PJ., Runyon S., Nunez A. and Scott KM., Production of FAME from Acid Oil, a By-product from Vegetable Oil Refining, Journal of the American Chemists’ Society, 80, 97-102, 2003.

Holcapek M., Jandera P., Fisher J., Prokes B., Analytical monitoring of the production of biodiesel by high-performance liquid chromatography with various detection methods, Journal of Chromatography A, 858, 13-31, 1999.

Kardash E. and Tur’yan YI., Acid Value Determination in Vegetable Oils by Indirect Titration in Aqueous-alcohol Media, CROATICA CHEMICA ACTA CCACAA, 78 (1), 99-103, 2005.

Khan AK., Research into biodiesel kinetics & catalyst development, University of Queensland, Brisbane, Queensland, 2002.

Knothe G., Dunn RO., Bagby MO., Technical Aspect of Biodiesel Standards, International News on Fats, Oils and Related Materials, 7, 827-829, 1996.

Kocsisova T., Cvengros J., Lutisan J., High-temperature esterification of fatty acids with methanol at ambient pressure, European Journal of Lipid Science and Technology, 107, 87-92, 2005.

Lachowska M., Grzesik M., Skrzypek J., Kinetics of the esterification of levulinic acid with n-hexanol and n-decanol in the presence of sulfuric acid, INZYNIERIA CHEMICZNA I PROCESOWA, 24, 441-448, 2003.

Li SF., Chen JP., Wu WT., Electrospun polyacrylonitrile nanofibrous membranes for lipase immobilization, Journal of Molecular Catalysis B: Enzymatic, 47, 117-127, 2007.

Liu KS., Preparation of Fatty Acid Methyl Esters for Gas-Chromatographic Analysis of Lipids in Biological Materials, Journal of the American Oil Chemists’ Society, 71, 1179-1187, 1994.

Lotero E., Liu Y., Lopez DE., Suwannakarn K., Bruce DA., and Goodwin JG., Synthesis of Biodiesel via Acidic Catalysis, Industrial and Engineering Chemistry Research, 44, 5353-5363, 2005.

Ma F. and Hanna MA., Biodiesel production: a review, Bioresource Technology, 70, 1-15, 1999.

Niehaus RA., Goering CE., Savage LD., Jr. Sorenson SC., Cracked soybean oil as a fuel for a diesel engine, Transactions of the ASAE, 29, 683-689, 1986.

Pasias S., Barakos N., Alexopoulos C., Papayannakos N., Heterogeneously catalyzed esterification of FFAs in vegetable oils, Chemical Engineering and Technology, 29, 1365-1371, 2006.

Roomana A., Monhamed AR., Subhash B., Kinetics of esterification of palmitic acid with isopropanol using p-toluene sulfonic acid and zinc ethanoate supported over silica gel as catalysts, Journal of Chemical Technology and Biotechnology, 79, 1127-1134, 2004.

Sanz MT., Murga R., Beltran S., Cabezas JL., Coca J., Autocatalyzed and ion-exchange-resin-catalyzed esterification kinetics of lactic acid with methanol, Industrial and Engineering Chemistry Research, 41, 512-517, 2002.

Schwab AW., Bagby MO., Freedamn B., Preparation and properties of diesel fuels from vegetable oils, Fuel, 66, 1372-1378, 1987.

Schwab AW., Dykstra GJ., Selke E., Sorenson SC., Pryde EH., Diesel fuel from thermal decomposition of soybean oil, Journal of the American Oil Chemists’ Society, 65, 1781-1786, 1988.

Sendzikiene E., Makareviciene V., Janulis P., Kitrys S., Kinetics of free fatty acids esterification with methanol in the production of biodiesel fuel, European Journal of Lipid Science and Technology, 106, 831-836, 2004.

Soumanou MM., Bornscheuer UT., Improvement in lipase-catalyzed synthesis of fatty acid methyl esters from sunflower oil, Enzyme Microbial Technology, 33, 97-103, 2003.

Su CH., Fu CC., Gomes J., Chu IM., Wu WT., A Heterogeneous Acid-Catalyzed Process for Biodiesel Production from Enzyme Hydrolyzed Fatty Acids, American Institute of Chemical Engineers (AIChE), 54, 327-336, 2008.

Tesser R., Di Serio M., Guida M., Nastasi M., Santacesaria E., Kinetics of oleic acid esterification with methanol in the presence of triglycerides, Industrial and Engineering Chemistry Research, 44, 7978-7982, 2005.

The Official of National Biodiesel Board (NBB), Spectification for Biodiesel (B100)-ASTM D6751-07b, 2007.
http://www.biodiesel.org/pdf_files/fuelfactsheets/BDSpec.PDF

Tiwari AK., Kumar A., Raheman H., Biodiesel production from jatropha oil (Jatropha curcas) with high free fatty acids: An optimized process, Biomass and Bioenergy, 31, 569-575, 2007.

University of Idaho (Department of Biological and Agricultural Engineering), Biodegradability of Biodiesel in the Aquatic Environment. Development of Rapeseed Biodiesel for Use in High-speed Diesel Engine, Progress report, 96-116, 1996.

University of Idaho (Department of Biological and Agricultural Engineering), Acute Toxicity of Biodiesel to Freshwater and Marine Organisms. Development of Rapeseed Biodiesel for Use in High-speed Diesel Engine, Progress report, 117-131, 1996.

Vicente G., Martinez M., Aracil J., Integrated biodiesel production: a comparsion of different homogeneous catalysts system, Bioresource Technology, 92, 297-305, 2004.

Watanabe Y., Shimada Y., Sugihara A., Noda H., Fukuda H., Tominaga Y., Continuous production of biodiesel fuel from vegetable oil using immobilized Candida antaractica lipase, Journal of the American Oil Chemists’ Society, 77, 355-360, 2000.

Watanabe Y., Shimada Y., Sugihara A., Tominaga Y., Enzymatic conversion of waste ediable oil to biodiesel fuel in a fixed-bed bioreactor, Journal of the American Oil Chemists’ Society, 78, 703-707, 2001.

Watanabe Y., Nagao T., Nishida Y., Takagi Y., Shimada Y., Enzymatic Production of Fatty Acid Methyl Esters by Hydrolysis of Acid Oil Followed by Esterification, Journal of the American Oil Chemists’ Society, 84, 1015-1021, 2007.

邱少華，幾丁聚醣在固定化技術上之應用，博士論文，國立清華大學化學工程研究所，臺灣新竹，2003年。

洪佃玠，利用幾丁聚醣固定脂肪分解酵素之研究，碩士論文，國立清華大學化學工程研究所，臺灣新竹，2002年。

陳介武，拯救地球環保系列報導-生質柴油發展與趨勢，美國黃豆出口協會台灣辦事處，2000年。http://www.asaim.org.tw/tech6-3.htm

陳志威，油脂轉酯化反應之製程開發及其應用，博士論文，國立清華大學化學工程研究所，臺灣新竹，2003年。

陳恭府，超低硫柴油掺配生質柴油之油品特性及污染排放分析，碩士論文，國立中山大學環境工程研究所，臺灣高雄，2005年。

謝志強，歐洲生質柴油發展勢態，ITIS智網，2007年。

謝志強，面對全球生質燃料產業快速發展-台灣準備好了嗎？，ITIS智網，2007年。

蘇家弘，油質性微藻類之培養與固體觸媒在生質柴油製程之應用，博士論文，國立清華大學化學工程研究所，臺灣新竹，2007年。