Mam,

Try using:

(i) any bleaching agents like filler earths (acid activated), activated carbons or chemically synthesized amorphous silica compounds for decolorization.

(ii) passing steam through oil or steam distillation technique to deodourize the oil by removing volatile impurities which causes odour.

all the best and good luck mam

before lipid extraction, remove the pigment from the biomass

What is the reason behind the decolourization. If you have a biodiesel sample which has all the properties within the limits of specific standards and it has more than 95% converted ester, you need not proceed for something else like decolourization.

FOLLOWING

Dear Gokul Raghavendra Srinivasan

Thanks for your answer. I have tried bleaching earth (activated), fuller's earth, activated charcoal, acid/alkali activated bentonite clay for decoloration. Also I have tried all procedures on starting acid oil from which biodiesel is to be made. All methods impart very little bleaching effect.

ACtually the starting acid oil is very dark in color. Can you tell me more about chemically synthesized amorphous silica compounds and their efficiency?