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