PREPARATION OF METHYL ESTERS OF FATTY ACIDS
BYGURUPRASAD VENKATAKRISHNA RAO
REVISING THE BASICS
• ESTERS OF SMALL ALCOHOLS & BIG ACIDS ( FAME ).
• USES OF THESE ESTERS
1.GREEN TAGGED PRODUCTS
2.RAW MATERIALS FOR ALCOHOLS
3.LUBRICANTS
4.USED IN IDENTIFICATION OF MICROBES (SOUNDS INTERESTING !!)
FAME
ACID OIL
FATTY ACIDS
TRIGLYCERIDES
SINGLE CELL OILS
FAME BY TRIGLYCERIDES
• OLDEST & COMMERCIAL METHODS
• REQUIREMENT OF RAW MATERIALS
1.REFINED OIL ( POSSIBLY 100 % TG )
2.CHEAPER ONE $$$
3.NARROWER RANGE OF FA CHAINS.
4.CONTINOUS SUPPLY
CHEMISTRY
CHEMICAL ENGINEERING
TG
Alcohol
Catalyst
Batch Reactor
Ester
Crude Glycerol
Alcohol
Alcohol
Wat
er
Water
Neutralized Glycerol
Wash Water
Dryer
Biodiesel
Water
Acid
Methanol+
KOH
Vegetable OilStorage
Tank1500 Kg
Methanol +
H2SO4
Motor
Storage Tank
500 Ltrs.
Motor
BiodieselStorage
Tank1000 Ltrs.
P2
SV2
Rea
cto
r 6
00 L
trs.
SV2
AirSVO
P1
SV3
P3
Set
tling
T
ank
100
0 L
trs. Vaccum
Drier
Separating Column500 Ltrs./ Charge
Washing Column500 Ltrs./ Charge
Vaccum
Drier
Glycerol Storage Tank 500 Ltrs.
Transesterification Reactor, 500Lts./Charge
P4
P5
P6P7P8
Biodiesel Unit1tpd Capacity
Design byDCE
ABOUT THE PROCESS……
• FEED STOCK IS KEPT FREE FROM MOISTURE.
• SUFFICIENT ALCOHOL IS ADDED TO MAKE UP THREE FULL EQUIVALENTS OF THE TRIGLYCERIDE, AND AN EXCESS OF USUALLY SIX PARTS ALCOHOL TO ONE PART TRIGLYCERIDE IS ADDED TO DRIVE THE REACTION TO COMPLETION
POINTS TO BE REMEMBERED
• MONITOR THE LEVEL OF FFA & WATER IN INCOMING OIL.
• CATALYST IS PREMIXED WITH ALCOHOL.
• REACTION MIX IS KEPT AT ABOVE BP OF ALCOHOL.
• FLASH EVAPOURATION IS DONE TO REMOVE ANY ALCOHOL.
CHALLENGE AHEAD…….
HIGH FFA FEED STOCK• PUT EXCESS CATALYST TO FORM SOAP
AND SOAPS ARE STRIPPED USING CENTRIFUGES (“CAUSTIC STRIPPING”).
• ACID-CATALYSIS FOLLOWED BY BASE-CATALYSIS PROCESS.
• ACID CATALYZED TRANSESTERIFICATION.•
FAME BY FATTY ACIDS
• INVOLVES ACID CATALYSED ESTERIFICATION.
• KINETICALLY SLOW .
• ADDITIONAL STAGE IN HIGH FFA FEEDSTOCK.
• MOC BECOMES EXPENSIVE.
• FAME COST INCREASES BUT WITH HIGH QUALITY.
FAME BY ACID OILS
• ACIDIFIED SOAPSTOCK CAN BE USED AS FEED STOCK.
• THERE ARE TWO STRATEGIES INVOLVED HERE.
1.FREE OIL CAN BE CAN BE SUBJECTED TO COMPLETE HYDROLYSIS AND THEN ACID ESTERIFICATION.
2.ACID & THEN BASE CATALYSED RXN STRATEGY ALSO USED
FAME BY SCO
• FUTURE LIES HERE.
• MICROBES ARE ALLOWED TO FEAST ON ORGANIC MATTER OF NATURE TO PRODUCE OIL FORCEFULLY BY RDT.
• OIL IS EXTRACTED BY SUITABLE SOLVENT & THEN BASE CATALYSED INTERESTERIFICATION IS DONE.
MICROWAVE ASSISTED PROCESS
• Microwave irradiation helps the synthesis of methyl esters (BioDiesel)and the high conversion of triglycerides in few minutes.
• The stirring process doesn’t appear to be so notable under MW irradiation as it is with conventional heating.
• The energy needed for the trans-esterification under microwave irradiation is very low (ca. 0,0156 kW/kg of biodiesel)
• A setting up of new catalysts such Ba(OH)2 H2O, which can prevent soap formation and be easily separated and recycled at the end of the trans esterification reaction has been investigated.
ENZYMATIC ROUTE
• USE ENZYMES TO PRODUCE ESTERS FROM TRIGLYCERIDES.
• RELATIVELY LONGER PERIOD OF REACTION.
• EXPENSIVE TO PRODUCE BECAUSE OF THE COST OF ENZYMES.
• NO COMMERCIAL PLANT USING ENZYMES TO PRODUCE BIODIESEL.
• CATALYST SEPARATION ISSUE CAN BE SOLVED EASILY.
! SUPERCRITICAL !
• INVOLVES USE OF SUPERCRITICAL METHANOL.
• SUPERCRITICAL METHANOL & OIL ARE IN SINGLE PHASE.
• NO CATALYST REQUIRED
• HIGH PRESSURE IS THE DISADVANTAGE.
REFERENCES
• FATTY ACIDS & OLEOCHEMICALS BY FRANK D GUNSTONE.
• OILS & FAT TECHNOLOGY BY BRECK AND BHATIA
• WWW.BAYERS.COM
• WWW.GOOGLE.COM
• SPECIAL THANKS TO Dr SUDHA RAMAN
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