Introduction to biodiesel
History Rudolf diesel was the inverter of
biodiesel, estimated nearly 100 years ago. It was developed in the year 1890s.
What is Biodiesel?• Alternative fuel for diesel engines• Made from vegetable oil, animal fat, microbes • Lower emissions, High flash point (>300°F), Safer• Biodegradable, Essentially non-toxic.
Fatty AcidAlcoholGlycerin
Vegetable Oil
BiodieselFA
FAFA
FA
Characteristics Of Biodiesel
Liquid varying in colorImmiscible in waterHigh boiling point of 360–640°F
(182–338°C)Low vapor pressure: < 2 mmHgSpecific gravity between 0.86 &
0.90Vapor density > 1Less hazardous in terms of
flammability
Biodiesel As Lubricant And Solvent
Biodiesel can be used straight as a
machinery lubricant.
Biodiesel’s solvent properties may be
used to clean dirty or greasy engine or other
machine parts.
Advantages of Biodiesel
Renewable energy source
Less polluting
Utilizes excess production of soybeans for manufacture
Can distribute through existing
diesel fuel pumps
Can use in existing oil
heating systems and diesel engines Can be mixed
with petroleum diesel at any concentration
and time
Disadvantages Of Biodiesel
More expensive
Could harm rubber hoses in engines
Requires energy to:
Produce biodiesel from soy crops & sow, fertilize and
harvestRequires frequent filter
changingRequires improvement in distribution infrastructure
Relative Greenhouse Gas Emissions
0 20 40 60 80 100 120 140 160
Gasoline
CNG
LPG
Diesel
Ethanol 85%
B20
Diesel Hybrid
Electric
B100B100 = 100% BiodieselB20 = 20% BD + 80% PD
Relative emissions: Diesel and Biodiesel
0 20 40 60 80 100 120
Total Unburned HCs
CO
Particulate Matter
**NOx
Sulfates
PAHs
n-PAHs
Mutagenicity
CO2
Percent
B100 **B20Diesel
Trans esterification
CH2OOR1 catalyst CH2OH| |CHOOR2 + 3CH3OH 3CH3OORx + CHOH| |CH2OOR3 CH2OHTriglyceride 3 Methanols Biodiesel Glycerin
R1, R2, and R3 are fatty acid alkyl groups.
Biodiesel Reaction
Vegetable Oil or
Animal Fat (100 lbs.)
+Methanol or
Ethanol(10 lbs.)
Biodiesel
(100 lbs.)+
Glycerin(10 lbs.)
In the presence of a catalyst
Combining
Yields
NRRaje Feb 06
Conventional feed stocks
Rapeseed, the major source (>80%)
Sunflower oil (10%, Italy and Southern France)
Soybean oil (USA)
Palm oil (Malaysia)
Linseed, olive oils (Spain)
Cottonseed oil (Greece)
Beef tallow (Ireland), lard, Jatropha (Nicaragua),)
Microorganisms available for biodiesel production
Microalgae Bacteria Fungi Yeast
Biodiesel production using microbial lipids, which is named as single cell oils (SCO), has attracted great attention in the whole world.
Lipids from all cannot be converted into biodiesel mainly due to less yield
Oleaginous microorganisms are able to accumulate lipids above the 20% of their biomass, on dry basis.
Stages of Lipid accumulation
...
Cells reach limit of obesity → stop accumulating.
Lipid accumulation → cells expand
Cells convert C → storage lipid (intracellular)
Exhaustion of N, cells stop divide
Microorganisms grow and multiply until a certain time
Prepare medium: high Carbon, low Nitrogen
• Can grow rapidly • Live in harsh conditions due to their unicellular or simple multicellular structure. Of the 33,000 known species of algae at least forty
are considered oleaginous
Good candidates for biodiesel production,
higher photosynthetic efficiency higher biomass production and faster growth compared to other energy crops
MICROALGAE
continue.. • Can be induced to accumulate substantial quantities of lipids thus contributing to a high oil yield.
• Some of the common algae
chlorella, crypthecodinium, cylindrotheca, dunaliella, isochrysis, nannochloris, nannochloropsis, neochloris, nitzschia, phaeodactylum, porphyridium, schizochytrium, tetraselmis, etc,….
average lipid content- (1-70%) maximum- 90%
How to obtain biodiesel from algae?
Picking up the best algaeGrowing the algaeExtractionTrans esterificationBiodiesel
Choosing an Algae
Important characteristics of AlgaeHigh % of total
biomass is oilMaintains a high %
of oil even under stress
Compatible with our regional climate
Where To Grow It
Extensions onto our water treatment plantsClean up our waste and generate fuel
Agriculture runoffWater ponds
Algae could well grow on salty water as well as soft water
DIFFERENCE B/W BIODIESEL FROM ALGAE AND OTHER
PLANT/VEGETABLE OILS • The yield• According to some estimation, the yield (per acre) of oil from algae
is over 200 times the yield from the best-performing plant/vegetable oils.
ADVANTAGES OF MICROALGAE AS A SOURCE OF BIODIESEL
• High Yield -low cost of production
• Algae can grow –In places away from farm land (No destruction to food chain) –Sewages –Near to power plants (takes CO2from smokestacks and yields oil)
• Oil Productivity –Greater than best producing oil crops
• Higher grade protein→Animal Feed
• Balanced N : P ratio→Organic Fertilizers
Biodiesel from FungusOleaginous fungi has also been considered as
potential oil sources for biodiesel production because they accumulate large amounts of lipidsAmong these microorganisms, particular attention has been dedicated to various oleaginous zygomycetes species, such as Mortierella isabelina and Cunninghamella echinulata, which may accumulate up to 86% and 57% of lipids in the dry biomass, respectively
Biodiesel from Fungus
Fungal Bio Mass Mucor circinelloides
Three Different Solvent Systems: Chloroform:Methanol (C:M), Chloroform:Methanol:Water (C:M:W)
n-hexaneAcid Catalyst ( BF3, H2SO4 and HCl )
Materials
Biodiesel from Fungal Bio MassExtraction of lipids Solvent +Dried
biomass Mixture
Ultrasonication
Centrifugation
Rotary Evaporation
Lipids
Rhodosporidium sp., Rhodotorula sp. and Lipomyces sspecies can accumulate intracellular lipids as high as 70% of their biomass dry weight.
• Cryptococcus curvatus oleaginous yeast Accumulate storage lipid up to >60% on a dry weight basis)
Biodiesel from yeasts
MediaPre-culture
YM medium was used as pre-culture to cultivate oleaginous yeast cellso glucose as a carbon sourceo Peptoneo yeast extract
Sterlisation - 120 ºC temperature for 20 minutes
Semi-synthetic medium was used as main culture to grow oleaginous yeastso Glucose, xylose or a mixture of both were used as carbon sourceso nitrogen sources (NH4Cl)o phosphate buffer (KH2PO4)o Mineral-element solution (CaCl2×2H2O ,FeSO4×7H2O ,citric acid×H2O)
Medium pH - 5.8
Main culture
Freeze drying
o Collected samples were centrifuged at 10 min and washed with sterile water once, then centrifuged again
o The pellets were transferred into pre-weighed vials and kept at -50 °C until freeze drying
Lipid extractionChloroform- Methanol Method
Adding Choroform: Methanol mixture
Centrifugation
Freeze dried pellets + HCL and incbated at 55° C
Solvent Evaporation
Extracted lipids
Biodiesel from BacteriaBacteria can accumulate oil of about 20-
40% of dry biomass Arthrobacter sp. - 40% Acinetobacter calcoaceticus - 38%
Have a superiority in the production of biodiesel due to Highest growth rate (reach huge biomass only need 12–24 h) Easy culture method. Actinomycete group high amount of fatty acids (up to 70% of the cellular dry weight) using glucose under growth-restricted condition
Downside
• Very few are oil producer
• Only a few bacteria accumulate complicated lipoid.
• It is difficult to extract because these lipoid are generated in the outer membrane
• So there is no industrial significance in the actual production of biodiesel by using oleaginous bacteria as raw material
Quality of biodiesel from microbes • Biodiesel fuel, in the form of FAME, is now manufactured in many countries.
• Relevant standard to assess biodiesel are;
ASTM D6751 ( In USA) EN 14214 (In EU, intended for vehicle use) EN 14213 (In EU, for use as heating oil)
Conclusion • At present plant oil is the main feedstock for biodiesel production. • However, at present biodiesel is not competitive with conventional fuels in the whole world due to high cost of production.
• Production of microbial based diesel can be an economical beneficial.
• However, it still needs lots of improvement which could be done using the various biotechnological techniques and methods.
• Developing high lipid content microorganisms for biodiesel production from microbes are promising option in future and opens a possibility for academic research