Transesterification process design for biodiesel...

6/26/2009 1

Transesterification process design for biodiesel

production

Biodiesel

Growth Conditions

Biochemical Analysis

pH

Reactor Design & Culture

Trans- esterification

2nd Semester

3rd Semester

Marine Algae

Biodiesel Production

Algal Ingredient

Biomass (Algae growth)

Results Heterotrophic growth

Literature

17/04/2009

2

CSTR , Plug flow High rate Pond

Mixed culture

Pure culture

Water Chemistry

pH, DO

COD, TN, TP

TSS, FSS,VSS Fresh water algae

Algae Sp.

1st Semester

Lipid

Oil

4th Semester

5th Semester

Chlorophyll

Carbohydrate 6th Semester

Protein

Enzyme

Acid

Alkali

TODAY

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Transesterification process design for biodiesel production

Speaker : Ramaraj Rameshprabu

Course 9116 : 3rd Year Seminar

Instructor : Dr. Paris Honglay Chen, PhD MPH PE

Sustainable Resources & Sustainable Engineering Research group 6/26/2009 3

CONTENTS 1. INTRODUCTION

2. LITERATURE REVIEW 2.1 GENERAL TRANSESTERIfiCATION REACTION 2.2 TRIGLYCERIDE SOURCES 2.3 ALCOHOLS 2.4 CATALYST AND TYPES 2.5 FACTORS AFFECTING TRANSESTERIfiCATION

3. SUMMARY

1. INTRODUCTION Transesterification is the reaction of a fat or

oil with an alcohol to form esters(Biodiesel)

and glycerol.

Key Reaction

In plant oil (Palm tree, mahua, etc..) ,

vegetable oil( sunflower oil, soya bean oil,

etc..) have many studies.

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Algae biodiesel have few research literature.

In algae : all process in acid / base / enzyme

catalysts methods not yet study well .

Research Purpose :

Find out the suitable transesterification

process / catalyst method for Algae

Biodiesel.

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1. INTRODUCTION

2. LITERATURE REVIEW

2.1 GENERAL TRANSESTERIfiCATION REACTION

2.2 TRIGLYCERIDE SOURCES

2.3 ALCOHOLS

2.4 CATALYST AND TYPES

2.5 FACTORS AFFECTING TRANSESTERIfiCATION

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Transesterification is the process of

exchanging the alcohol group of an ester

compound with another alcohol.

These reactions are often catalyzed by the

addition of an acid or base.

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2. LITERATURE REVIEW 2.1 GENERAL TRANSESTERIfiCATION REACTION

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Fatty Acid methyl Ester

Catalyst: Acid/base/Enzyme

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Triglyceride/Oil

Alcohol

FAME/Biodiesel Glycerin

Catalyst

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2.1 GENERAL TRANSESTERIfiCATION REACTION


Step 1

Step 2

Step 3

Kinetics

Rendered animal fats

Vegetable oils

Microbes

Chicken fat

Rendered greases

Recovered materials

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2.2 GENERAL TRIGLYCERIDE SOURCES 2. LITERATURE REVIEW

beef tallow, lard soybean, canola,

palm, etc. Algae

yellow grease brown grease, soapstock, etc.

Alcohols is important reactant in

transesterification process

Type: Methanol, Ethanol, Propanol,

Butanol and Amyl alcohol.

Methanol and ethanol are used most

frequently. 6/26/2009 13

2.3 ALCOHOLS


Methanol is considerably easier to recover than the ethanol. Causes:

1. Ethanol forms an azeotrope with water. so it is expensive to purify the ethanol during recovery.

2. If the water is not removed it will interfere with the reactions.

3. Methanol recycles easier because it doesn’t form an azeotrope.

Methanol has a flash point of 10 °C, while the flash point of ethanol is 8° C 6/26/2009 14

2.3 ALCOHOLS 2. LITERATURE REVIEW

Especially methanol because of its low cost and its physical and chemical advantages (polar and shortest chain alcohol, Sivaprakasam & Saravanan 2007). It can quickly react with triglycerides and NaOH is easily dissolved in it. To complete a transesterification stoichiometrically, a 3:1 molar ratio of alcohol to triglycerides is needed.

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2.3 ALCOHOLS 2. LITERATURE REVIEW

In practice, the ratio needs to be higher to drive the equilibrium to a maximum ester

yield. A molar ratio of 6 : 1 (alcohol : oil) is

recommended for optimum transesterification

(Freedman et al., 1984)

The reason for using extra alcohol is that it

“drives” the reaction closer to the 99.7% yield

we need to meet the total glycerol standard for

fuel grade biodiesel.

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2.3 ALCOHOLS


(Ref: National Renewable Energy Laboratory Report August 2002–January 2004)

A catalyst is usually used to improve

the reaction rate and yield.

Because the reaction is reversible,

excess alcohol is used to shift the

equilibrium to the products side.

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2.4 CATALYST AND TYPES 2. LITERATURE REVIEW

Most processes for making biodiesel use a catalyst to initiate the esterification reaction. The catalyst is required because the alcohol is sparingly soluble in the oil phase. The catalyst promotes an increase in solubility to allow the reaction to proceed at a reasonable rate. 6/26/2009 18


Transesterification

Catalyst Non-catalyst

1. Base (alkali)

2. Acid

3. Enzyme

1. BIOX Process

2. Supercritical alcohol(methanol)

process

2. LITERATURE REVIEW 2.4 CATALYST AND TYPES

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2.4.1 ALKALI (BASE) CATALYST

Sodium hydroxide (NaOH)

Potassium hydroxide (KOH)

Sodium methoxide (NaMeO)

Potassium methoxide (KMeO)

Its dominate current commercial production.

Base catalysts are sensitive to : water, FFA Ref :G. Vicente et al. / Bioresource Technology 92 (2004) 297–305

Current commercial biodiesel producers use: base catalyzed reactions. Base catalyzed reactions are relatively fast, with residence times from about 5 min to about 1 h, depending on temperature, concentration, mixing and alcohol:triglyceride ratio. Most use NaOH or KOH as catalysts, although glycerol refiners prefer NaOH.

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Base-catalyzed transesterification of TAGs is the most common route to manufacture

biodiesel, and proceeds at a relatively high rate at low temperatures.

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No Materials Catalyst & alcohol

Alcohol: oil ratio

Molar ratio

Temp- erature

Reaction time yield Evaluation Reference

1 Rice bran oil 0.75% (w/w

oil) NaOH

9:1 55 °C 1h 90.18% Process optimization

S. Sinha et al. / Energy Conversion and Management 49 (2008) 1248–1257

2 Used Cooking Oil

NaOH, 1% (by the weight of

the oil) 6:1 55 °C 1h 100% Process

optimization

Merve C ü etinkaya and Filiz Karaosmanog ˇlu ( 2004) Energy & Fuels, Vol. 18, No. 6,

3 Mahua oil (0.7% w/v KOH) 6:1 60 °C 30 min 98% Process

optimization

S.V. Ghadge, H. Raheman / Bioresource Technology 97 (2006) 379–384

4 Soybean oil 0.5 wt % KOH 6:1 35 ±1 °C 30 min >90%

High-frequency ultrasound

Process optimization

Mahamuni and Adewuyi (2009), Energy & Fuels, 23, 2757–2766

5 Peanut oil KOH, 1% 6:1 65 °C 1h 96.15% Process optimization

A. A. Refaat, et al. (2008) Int. J. Environ. Sci. Tech., 5 (1), 75-82, Winter

6.1 Spiroyra (macro algae)

0.25g NaOH

24 mL Methanol, oil1.8 (g)

- 3h 1-2(g) 90-95(%) Not well

studied

Sharif Hossain, Aishah Salleh, (2008)Am. J. Biochem. & Biotech., 4 (3):250-254, 6.2

Oedigonium Sp. (microalgae)

24 mL Methanol, oil

3.0 (g) - 3h

2-3(g)

95-100(%)


Sulfuric acid

Sulfonic acids and hydrochloric acid

Sulfuric acid used most frequently.

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2.4.2 ACID CATALYST 2.4 CATALYST AND TYPES


Its significantly slower than alkaline catalysis, there is no side reaction converting fatty acids to soaps.

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No Materials Catalyst & alcohol

Alcohol: oil ratio

Temperture

Reaction time

yield Evaluation Reference

1 Waste cooking oil

H2SO4

3.8:1

(methanol) 245:1

70 °C 4 h 99±1% -

S. Zheng et al. / Biomass and Bioenergy 30 (2006) 267–272 80 °C

2 trap grease 1.5-3.5 mol% of H2SO4

(Methanol) 35ml 95 °C 4.59 h 89.67% Crude biodiesl

Korean J. Chem. Eng., 25(4), 670-674 (2008)

3 Refined & crude vege.oils

sulfonic acid-6 wt %

(Methanol) 10:1

180 °C - Close to

100%

sulfonic acid-modified mesostructured catalyst

Wahlen et al2009, Energy & Fuels 2, 23, 539–547

4 Soyabean oil H2SO4 3%

(Methanol) 6:1 60 °C 96h Below

90% Very slow

M.Canakci & J.Van Gerpen, 1999, Teansations of ASAE Vol 42(5):1203-1210

6 Microalgae H2SO4

1% (Methanol)

56:1 30°C 4 h Below 70%

specific gravity from an initial value of 0.912 to a final value of 0.8637

X. Miao, Q. Wu / Bioresource Technology 97 (2006) 841–846

2.4.2 ACID CATALYST

2.4.2 Acid Catalyst

Oil/alcohol molar ratio = 1:6 ; Time= 60 min

6/26/2009 25 Energy & Fuels, Vol. 18, No. 6, 2004

Used cooking oil

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Fig. (B) The influence of catalyst quantity and temperature on the yield and the specific gravity of biodiesel product. Reaction conditions: 30:1 molar ratio of methanol to oil, 160 rpm, 5 h of reaction time. Temperature: 30 °C, 50 °C and 90 °C. The catalyst quantity based on oil weight: 25%, 50%, 60% and 100%.

2.4.2 Acid Catalyst: Algae biodiesel 2.5.6.1Catalyst type , concentration

&Temperature

30°C have low Specific

gravity

2.4.2 Acid Catalyst Algae biodiesel 2.5.6.1Effect of molar ratio of methanol to oil

Good quality of biodiesel could be obtained in the presence of 100% acid catalyst (on oil basis) at high temperature. The best combination of factors was 100% catalyst quantity (based on oil weight) with 56:1 molar ratio of methanol to oil at temperature of 30 °C, which reduced product specific gravity from an initial value of 0.912 to a final value of 0.8637 in about 4 h of reaction time.

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Biodiesel Yield <70%

Lipases also can be used as biocatalysts

Enzyme-catalyzed transesterification

processes are not yet commercially

developed. (A. Demirbas,2009)

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2.4.3 ENZYME CATALYST 2.4 CATALYST AND TYPES


Enzyme catalyzed reactions have the

advantage reacting a lower temperature

without producing spent catalysts.

The enzymes can be recycled for use again

or immobilized onto a substrate.

The enzyme reactions are highly specific. 6/26/2009 29



Alcohol can be inhibitory to some enzymes, a typical strategy is to feed the alcohol into the reactor in three steps of 1:1 mole ratio each.

The reactions are very slow, with a three step sequence requiring from 4 to 40 hours, or more.

The reaction conditions are modest, from 35 to 45 °C.

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No Materials Lipase Alcohol: oil ratio

Temp- erature

Reaction time yield Evaluvati

on Reference

1 soybean oil

R. oryzae lipase, C. rugosa

3:1 45 °C 4h 98% Optimized process

Lee et al(2008)

2 soybean oil

Lipozyme IM-77 3.4:1 36.5°C 6.3 h 92.2% Optimize

d process C.-J. Shieh et al.(2003)

3 salad oil Candida sp. 99–125 3:1 40 ◦C. 20 days 96% Optimize

d process K. Nie et al. (2006)

4 rapeseed oil

Novozym 435 4:1 35 ◦C 12h 95%

tert-Butano& methanol

L. Li et al. (2006)

5 Micro-algae Candida sp 3:1 38 ◦C 12 h 98 %

Not Well study

Li et al. (2007)

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2.4.3 ENZYME CATALYST

This process uses a cosolvent, tetrahydrofuran, to solubilize the methanol. Cosolvent options are designed to overcome slow reaction times caused by the extremely low solubility of the alcohol in the triglyceride phase. The result is a fast reaction, on the order of 5–10 min, and no catalyst residues in either the ester or the glycerol phase.

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2.4.4 BIOX C0-SOLVENT PROCESS 2.4 CATALYST AND TYPES


The BIOX process is a new Canadian process.

Developed originally by Professor David Boocock of the ; University of

Toronto. (www.bioxtech.com/bioxprocess.html)

Its performed in a stainless steel cylindrical reactor (autoclave) at 520 K (Demirbas, 2002). Water also causes soap formation and frothing (Demirbas, 2003). Variables affecting the reaction were investigated followed by a proposal that the optimum conditions were 623 K, 20 MPa, and 9 min.

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2.4.5 SUPERCRITICAL ALCOHOL(METHANOL) PROCESS


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Compared with the alkali-catalyzed method, the supercritical methanol method has advantages in terms of reaction time and purification step. In contrast to catalytic processes under barometric pressure. It has a lower reaction time, is more environmentally friendly. (Demirbas, 2003)

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2.5.1 Methods: 5 2.5.2 Materials: 2.5.3 Catalyst: w & w/o , type,

reaction time, concentration and Temperature

2.5.4. Alcohols: type, molar ratio of alcohol to oil

2.5.5. optimization 6/26/2009 36

2.5 FACTORS AFFECTING TRANSESTERIfiCATION


SUMMARY Algae biodiesel production studied by Acid and Base catalyst method.

Acid Catalyst method Biodiesel yield = <70% Base Catalyst method Biodiesel yield = >90%

Acid method studied with different parameters Base method didn’t study with all parameters. New methods: Enzyme, Biox and Supercritical alcohol method

Research: Need to study all factors of algae transesterification.

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SRSE – Lab : Algae biodiesel production flow chart Algae

sample Algae oil

extraction

Alcohol/ Catalyst Mix

Transesterification & Separation

Crude biodiesel

Crude Glycerin

Catalyst Alcohol

Algae oil

Drying washing

Biodiesel 6/26/2009 38

REFERENCE Acaroglu, M., Demirbas, A.1999. Relationships between viscosity and

density measurements of biodiesel fuels. Energy Sour Part A 29:705−712.

Bala, B.K.2005. Studies on biodiesels from transformation of vegetable oils for diesel engines. Energy Edu Sci Technol 15:1−43.

Balat, M. 2005. Biodiesel from vegetable oils via transesterification in supercritical ethanol. Energy Edu Sci Technol 16:45−52

Christie, W.W. 1989. Gas Chromatography and Lipids: a Practical Guide. The Oily Press, Dundee.

Demirbas, A. 1999. Fatty and resin acids recovered from spruce wood by supercritical acetone extraction. Holzforschung 45:337−339.

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Demirbas, A. 2002. Biodiesel from vegetable oils via transesterification in supercritical methanol. Energy Convers Mgmt 43:2349–56.

Demirbas, A. 2003. Biodiesel fuels from vegetable oils via catalytic and non-catalytic supercritical alcohol transesterifications and other methods: a survey. Energy Convers Mgmt 44:2093−2109.

Demirbas, A. 2007. Biodiesel from sunflower oil in supercritical methanol with calcium oxide. Energy Convers Mgmt 48:2271−2282.

Du, W., Xu, Y., Liu, D., Zeng, J. 2004. Comparative study on lipase-catalyzed transformation of soybean oil for biodiesel production with different acyl acceptors. J Mol Catal B Enzymat 30:125–129.

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REFERENCE

Eckey, E.W. 1956. Esterification and interesterification. JAOCS 33:575–

579.

Freedman, B., Butterfield, R.O., Pryde, E.H. 1986. Transesterification kinetics of soybean oil. JAOCS 63:1375–1380.

Furuta, S., Matsuhashi, H., Arata, K. 2004. Biodiesel fuel production with solid superacid catalysis in fixed bed reactor under atmospheric pressure. Catal Commun 5:721–723.

Gryglewicz, S. 1999. Rapeseed oil methyl esters preparation using heterogeneous catalysts. Bioresour Technol 70:249−253.

Hama, S., Yamaji, H., Kaieda, M., Oda, M., Kondo, A., Fukuda, H. 2004. Effect of fatty acid membrane composition on whole-cell biocatalysts for biodiesel-fuel production. Biochem Eng J 21:155–160.

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REFERENCE

Komers, K., Machek, J., Stloukal, R. 2001. Biodiesel from rapeseed oil and KOH 2. Compo-sition of solution of KOH in methanol as reaction partner of oil. Eur J Lipid Sci Technol 103:359–362.

Kusdiana, D., Saka, S. 2001. Kinetics of transesterification in rapeseed oil to biodiesel fuels as treated in supercritical methanol. Fuel 80:693–698.

Kusdiana, D., Saka, S. 2004. Effects of water on biodiesel fuel production by supercritical methanol treatment. Bioresour Technol 91:289−295.

Ma, F., Hana, M.A. 1999. Biodiesel production: a review. Bioresour Technol 70:1–15. Marchetti, J.M., Miguel, V.U., Errazu, A.F. 2007. Possible methods for biodiesel production.

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REFERENCE

Thank you for your attention

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Transesterification process design for biodiesel...

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