2. What is Biodiesel?
Alternative fuel for diesel engines
Made from vegetable oil or animal fat
Meets health effect testing
Lower emissions, High flash point (>300F), Safer
Biodegradable, Essentially non-toxic.
Chemically, biodiesel molecules are mono-alkyl
esters produced usually from triglyceride esters
Fatty Acid
Alcohol
Glycerin
Vegetable Oil
Biodiesel
FA
FA
FA
FA
3. Biodiesel can be used in existing
Diesel Engines
Pure Biodiesel (B100) or blended with
petroleum diesel (B20, BXX).
Rudolf Diesel: peanut oil.
Little or no engine modifications
Use existing fuel distribution network.
Available now
4. Environmental Issues
Burning fossil fuels increases atmospheric levels of carbon
dioxide
Fossil fuels are a
finite resource
Graph taken from USF Oceanography webpage
Biodiesel’s Closed
Carbon Cycle
30% Increase
5. Relative Greenhouse Gas Emissions
0 20 40 60 80 100 120 140 160
Gasoline
CNG
LPG
Diesel
Ethanol 85%
B20
Diesel Hybrid
Electric
B100
Data from “A Fresh Look at CNG: A Comparison of Alternative
Fuels”, Alternative Fuel Vehicle Program, 8/13/2001
B100 = 100% Biodiesel
B20 = 20% BD + 80% PD
6. ** B100 (100% biodiesel) with NOx adsorbing catalyst on vehicle
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 **
B20
Diesel
9. Penyusun Lemak
Gliserida/Asam lemak
minyak makanan, bahan baku industri sabun,
bahan campuran minyak pelumas, dan bahan
baku biodiesel
Terpena dan terpenoid(Minyak Atsiri)
-Bahan dasar wangi-wangian (parfum) dan minyak
gosok. -Golongan ini berasal dari tumbuhan dan
dianggap memiliki khasiat penyembuhan
(“aromaterapi”).
-Kelompok minyak ini memiliki aroma yang kuat
karena sifatnya yang mudah menguap pada suhu
ruang (sehingga disebut juga minyak “aromatik”).
10. Minyak Nabati
Edible oils
minyak kelapa, minyak kelapa sawit,
minyak zaitun, minyak kedelai, minyak
kanola
Non Edible oils
minyak kayu putih, dan minyak jarak
11. TEKNOLOGI LEMAK DAN MINYAK
(FAT AND OIL TECHNOLOGY)
KEPENTINGAN LEMAK DAN MINYAK BAGI KEHIDUPAN:
1. NUTRITIONAL FUNCTION
* SUMBER ENERGI /KALORI
* NONKALORI (KOMPONEN MEMBRAN SEL,
PELARUT VITAMIN, SUMBER ASAM LEMAK
ESENSIAL)
2. NON-NUTRITIONAL FUNCTION
*SENSORY CHARACTERISTIC) FLAVOUR,
TEXTURE
* HEAT TRANSFER MEDIUM
12. LEMAK DAN MINYAK DUNIA
* > 70% DARI LEMAK PANGAN DARI NABATI
* PRODUKSI MENINGKAT DENGAN TAJAM
SEBAGAI RESPON DARI
- PENAMBAHAN JUMLAH PENDUDUK
- PENINGKATAN KUALITAS HIDUP
- PENINGKATAN DAYA GUNA LEMAK DAN
MINYAK
13. SUMBER LEMAK DAN MINYAK
1. TANAMAN (NABATI)
A. KELOMPOK TANAMAN PALAWIJA
(JAGUNG, KEDELAI, KACANG TANAH, BIJI
MATAHARI DLL)
B. KELOMPOK. TANAMAN TAHUNANAN
( KELAPA SAWIT, KELAPA, OLIVE)
C. KEL. BIJI2AN TANAMAN TAHUNANAN
(CACAO, INTI SAWIT, KAPAS, KEMIRI DLL)
14.
15. 2. HEWANI
A. HEWAN PELIHARAAN
( LEMAK SUSU SAPI, SAPI,
LEMAK DAGING SAPI, DOMBA DLL)
B. HASIL LAUT
( MINYAK IKAN PAUS, IKAN SARDINE
DLL)
16. PENGGUNAAN LEMAK DAN MINYAK
1. KELOMPOK PANGAN
* SHORTENING INDUSTRY
* MARGARINE INDUSTRY
* LIQUID OIL INDUSTRY
* BUTTER INDUSTRY
* FOOD INDUSTRY
2. KELOMPOK NON-PANGAN
* INDUSTRI SABUN
* INDUSTRI OBAT2AN
* INDUSTRI CAT
* INDUSTRI LAINNYA
(RUBBER, PLASTICK POLIMER
* INDUSTRI KOSMETIK
* INDUSTRI BIODISEL
17. KLASIFIKASI LEMAK DAN MINYAK
BERDASARKAN KEGUNAAN PADA INSDUSTRI PEMAKAI
LEMAK DAN MINYAK
1. KELOMPOK LEMAK SUSU (MILK FAT GRUP)
* DARI HEWAN PELIHARAAN DAN MEMPUNYAI KOMPOSISI YG HAMPIR
SAMA UTK SETIAP SUMBER
(EX :BUTTER MILK OF COW, GOAT, )
KOMPOSISI
- ASAM LEMAK DENGAN BM RENDAH DALAM
JMLAH YG BESAR CTH: ASAM BUTIRAT (3,5%)
- AS LEMAK JENUH CTH: MIRISTAT, PALMITAT, STEARAT (45 – 50%)
- ASAM LEMAK TIDAK JENUH (OLEAT) (30-40%)
- IODINE NUMBER (BILANGAN IODINE) 32 - 37
18. 2. KEL. ASAM LAURAT (LAURIC ACID ROUP)
HASIL DARI PENGOLAHAN TANAMAN PALMA
(EX; KELAPA, PALM KERNEL)
KOMPOSISI :
- KANDUNGAN AS. LAURAT YANG TINGGI (40 - 50%)
- AS.LEMAK JENUH LAINNYA C 8,10,14,16.18 (KECIL)
- AS. LEMAK TIDAK JENUH OLEAT DAN LINOLEAT (SEDIKIT)
- BM. RENDAH ----- > TITIK CAIR RENDAH
- PENGGUNAAN ( MEDIA PENGGORENGAN, INDUSTRI SABUN,
KOSMETIK DLL)
- PRODUKSI TINGGI ----> RELATIF LEBIH MURAH DARI KEL. MILK
FAT
IN 7,5 - 10
19. 3. KEL. LEMAK SAYURAN (VEGETABLE BUTTER
GROUP) ----> CTH: COCOA BUTTER
KOMPOSISI:
* AS.LEMAK BM. RENDAH ( .>50% ) C14,16,18
* TRIGLISERIDA DARI ASAM LEMAK JENUH ( OLEO
PALMITO STEARIN, OLEODISTEARIN)
* AS.LEMAK OELAT DAN LINOLEAT (SEDIKIT)
- IN 33 – 44
* INDUSTRI FARMASI DAN MAKANAN
* RELATIF LEBIH MAHAL DARI KEL. ASAM LAURAT
4. KEL. LEMAK HEWAN (ANIMAL FAT GROUP)
(EX: LARD DR LEMAK BABI , TALLOW DR SAPI)
KOMPOSISI:
* AS. LEMAK JENUH C16 DAN 18 DG BM. TINGGI DOMINAN (40-50%)
* TRIGLISERIDA TIDAK JENUH OLEAT DAN LINOLEAT (SEDIKIT)
* BERBENTUK PADAT PADAT PADA SUHU KAMAR
24. Food
Percentages of
Trans-Fatty Acids
Butter 3.6
Soft Margarine, High in PUFA 5.2
Soft Margarine, Low in PUFA 9.1
Hard Margarine 12.4
Vegetable Oils, Including Safflower,
Sunflower, and Soy
0.0
Beefburger, Fried or Grilled 0.8
Chocolate Cake with Icing 7.1
25. Trans fat has both the benefits and drawbacks of a saturated
fat.
- It has a longer shelf life than regular vegetable fat and is solid at
room temperature.
-Trans fat tends to raise "bad" LDL- cholesterol and lower "good"
HDL-cholesterol, although not as much as saturated fat.
-Trans fat is found in margarine, baked goods such as doughnuts
and Danish pastry, deep-fried foods like fried chicken and French-
fried potatoes, snack chips, imitation cheese, and confectionary
fats.
26. Fatty acid
In addition to saturation, fatty acids have
different lengths, often categorized as short,
medium, or long.
Short-chain fatty acids (SCFA) are fatty acids
with aliphatic tails of fewer than six carbons.
Medium-chain fatty acids (MCFA) are fatty
acids with aliphatic tails of 6–12. carbons,
which can form medium-chain triglycerides.
Long-chain fatty acids (LCFA) are fatty acids
with aliphatic tails longer than 12 carbons.
Very-Long-chain fatty acids (VLCFA) are fatty
acids with aliphatic tails longer than
22 carbons
35. SUNFLOWER SEED
Healthy, natural sunflower oil is produced from oil type
sunflower seeds. Sunflower oil is light in taste and
appearance and supplies more Vitamin E than any other
vegetable oil. It is a combination of monounsaturated and
polyunsaturated fats with low saturated fat levels.
There are three types of sunflower oil available; mid-oleic,,
linoleic and high oleic sunflower oil. All are developed with
standard breeding techniques. They differ in oleic levels
and each one offers unique properties.
36. COTTONSEED
Like the name suggests, cottonseed oil is extracted
from cottonseed. Cottonseed is mainly an
unsaturated oil, as 70% of this oil is unsaturated
(18% monounsaturated (oleic acid), and 52%
polyunsaturated (from linoleic acid).
Cottonseed oil is often preferred over many other
oils that would have to be hydrogenated (like
soybean oil).
37. SOYBEAN
The soybean (U.S.) or soya bean (UK)
(Glycine max) is a species of legume
native to East Asia.
The oil and protein content together
account for about 60% of dry soybeans
by weight; protein at 40% and oil at 20%.
The remainder consists of 35%
carbohydrate and about 5% ash.
Soybean cultivars comprise
approximately 8% seed coat or hull, 90%
cotyledons and 2% hypocotyl axis or
germ.
39. RAPESEED
Traditionally, rapeseed is used for birdseed or industrial
purposes.
Industrial varieties of rapeseed contain about 55 percent erucic
acid and are used to make lubricants and diesel fuel
substitutes and to manufacturer plastics.These varieties have
high levels of toxic glycosinolates along with high erucic-acid
levels, which renders the processed meal unsuitable for
human or livestock consumption.
New varieties of rapeseed, developed in Canada and Europe,
are low in erucic acid and glycosinolates. These varieties are
the so-called “double low” types and sometimes are marketed
as Canola. The extracted oil is used as an edible vegetable
oil. Domestic markets are expected to increase because
previousrestrictions are being relaxed.
40. CORN GERM
Corn oil is oil extracted from the germ of corn (maize). Its main use
is in cooking, where its high smoke point makes it a valuable
frying oil. It is also a key ingredient in some margarines.
One bushel of corn contains 3% of oil. Corn agronomists have
developed high-oil varieties, however, these varieties tend to
show lower field yields, so they are not universally accepted by
growers. Refined corn oil is 99% triglyceride, with proportions of
approximately 59% polyunsaturated fatty acid, 24%
monounsaturated fatty acid, and 13% saturated fatty acid.
Corn oil is also one source of biodiesel. Other industrial uses for
corn oil include soap, paint, rustproofing for metal surfaces,
inks, textiles, and insecticides. It is sometimes used as a carrier
for drug molecules in pharmaceutical preparations.
41. HAZELNUT
Hazelnuts are rich in protein and unsaturated
fat. Moreover, they contain significant
amounts of thiamine and vitamin B6, as well
as smaller amounts of other B vitamins.
Hazelnut oil, pressed from hazelnuts, is
strongly flavoured and used as a cooking oil.
42. In the fatty acid composition of
hazelnut oil, there is around 71-91% of
oleic acid.
Hazelnut oil also contains linoleic acid
at a rate of around 2-21%.
Hazelnut oil is rich in calcium and
vitamin E.
43. OLIVES
The Olive (Olea europaea) is a species of
small tree in the family Oleaceae, native to
coastal areas of the eastern
Mediterranean region, from Syria and the
maritime parts of Asia Minor and northern
Iran at the south end of the Caspian Sea.
Its fruit, the olive, is of major agricultural
importance in the Mediterranean region as
the source of olive oil.
47. The oil and fat products used for edible purposes can be divided into two
distinct classes:
-liquid oils, such as olive oil, peanut oil, soybean oil, or
sunflower oil; and
-plastic fats, such as lard, shortening, butter, and margarine.
Crude fat and oil derived from plant and animal sources are
subjected to several commercial refining processes before the
final products reach the consumer market.
During these processes, water, carbohydrates, proteins,
pigments, as well as phospholipids, free fatty acids, sterols,
waxes and tocopherols are removed.
Oil and Fats Processing
48. In general, fat and oil undergo four processing steps:
1. Extraction
2. Refining (Neutralization or Degumming)
3. Bleaching
4. Deodorization
49. Fat and Oil Extraction
•Rendering
•Mechanical pressing
•Solvent extraction
50. Rendering
•more often employed for the extraction of fats from animal
tissues.
•oil-bearing tissues are chopped into small pieces and boiled in
water
•the oil floats to the surface of the water and skimmed
•water, carbohydrates, proteins, and phospholipids remain in
the aqueous phase and are removed from the oil
•degumming is also performed during this step to remove
excess phospholipids
•the separated proteins are often used as animal feeds or
fertilizers.
51. Mechanical Pressing
•often used to extract oil from seeds and nuts
•shells or hulls of the plant materials are removed and the kernels or meats
are grinded to rupture the cellular structures
•the coarse meal is then heated and pressed in hydraulic or screw presses to
extract the oil
•In some cases, oil is pressed without heating. Such oil is known as cold-
pressed or virgin oil. It contains the least amount of impurities and is often of
edible quality without further refining.
•For seeds or nuts containing a higher oil content than soybeans it became
customary to press the material in screw presses to remove a large proportion
of the oil before extraction. Since this prepressing also ruptures the cellular
structures of oil-bearing materials, most of the residual oil is easily removed
with solvents
52. Solvent Extraction
•For seeds or nuts containing a higher oil content, not all of the
oil is removed during pressing.
•Organic solvents such as petroleum ether and hexane can be
added to the pressed cake to recover the residual oil.
•The oil-sovent solution will then be separated from the meal.
•Finally, the solvent is evaporated from the oil.
57. Refining (Neutralization or Degumming)
Free fatty acids, phospholipids, pigments, and waxes in the
extracted oil lead to undesirable properties of the final products.
Many of these impurities can be removed by treating fats at 40º
to 85º C with caustic soda (sodium hydroxide) or soda ash
(sodium carbonate).
58.
59.
60.
61.
62. Bleaching
Bleaching The major purpose of bleaching is the removal or
undesire color materials in the oil.
Heated oil (~85 oC) may be treated with various bleaching
agents such as fuller's earth, activated carbon, or activated
clays.
Many impurities, including chlorophyll and carotenoid pigments,
are adsorbed onto such agents and removed by filtration.
However, bleaching also promotes lipid oxidation since some
natural antioxidants are removed together with the impurities.
63.
64.
65. Deodorization
Deodorization is the final step in the refining of oils.
Deodorization involves the use of steam distillation under reduced
pressure.
In Europe, a deodorization temperature of 175 - 205º C is common, but in
the United States, higher temperatures of 235 - 250º C are usually
employed.
Volatile compounds with undesirable odors and tastes can be driven off,
resulting a odorless product.
The oil produced is referred to as "refined oil" and is ready to be consumed
or for the manufacture of other products.
About 0.01 percent of citric acid is often added during this step to
inactivate pro-oxidant metals such as iron or copper.
66.
67.
68.
69.
70.
71. These processes are used to modify physical properties
of an oil or fat such as melting point and consistency.
84. Chemistry of Triglycerides
Biodiesel is made from the combination of a triglyceride
with a monohydroxy alcohol (i.e. methanol, ethanol…).
What is a triglyceride? Made from a combination of
glycerol and three fatty acids:
85. Transesterification
While actually a multi-step process, the overall
reaction looks like this:
CH2OOR1 catalyst CH2OH
| |
CHOOR2 + 3CH3OH 3CH3OORx + CHOH
| |
CH2OOR3 CH2OH
Triglyceride 3 Methanols Biodiesel Glycerin
R1, R2, and R3 are fatty acid alkyl groups (could be different, or the
same), and depend on the type of oil. The fatty acids involved
determine the final properties of the biodiesel (cetane number, cold
flow properties, etc.)
86. Individual step of Transesterification
First step, triglyceride turned into diglyceride, methoxide
(minus Na) joins freed FA to make biodiesel, Na joins
OH from water (from methoxide formation) to make
NaOH. Other H joins the diglyceride.
H O H
| | |
HCOR1 H HCO H O
| | | | |
HCOOR2 + HCONa +H2O CHOOR2 + HCOR1 + NaOH
| | | |
HCOR3 H HCOR3 H
| | | |
H O H O
Triglyceride + Methoxide + H2O Diglyceride + Biodiesel + NaOH
90. CHEMICAL CATALYSED PROCESS
BIOCATALYST PROCESS
Chemical Catalyst Process:
Ø One Step Process with a Base Catalyst like Sodium
Hydroxide or Potassium Hydroxide or their Alkoxides when
the Oils/Fats are Refined (RBD).
Ø Two-Step Process on oils Containing FREE FATTY ACIDS
(I) Esterification with Conc. H2SO4, H3PO4
(ii) Transesterification with a base catalyst NaOH,KOH,
NaOMe
or High Pressure Esterification and Alcoholysis for straight
way conversion to Biodiesel.
91. One-Step Biocatalyst Process for
Biodiesel Production
Simultaneous Esterification And
Transesterification (Alcoholysis) of
Triglyceride Oils.
Esterification:
Lipase
R.COOH + MeOH R.COOMe +
H2O
94. Chemical Process For Biodiesel
Production
A. Single Stage or Direct
Transesterification (Alcoholysis)
Process.
Refined or Neutral Oil (< 1.5% F.F.A.)
+
Alcohol (Methanol) 1.6-2 Times
95. The Theoretical Amount
Base Catalyst 500C-700C
KOH OR NaOH 4-6 Hr.
0.3-1.5% or
NaOMe 0.5% or
Less
ALKYL ESTER PRODUCT
Necessary Post-Treatment
BIODIESEL (95% yield of 97% purity)
96. B. TWO-STAGE (COMBINED ESTERIFICATION AND
TRANSESTERIFICATION) PROCESS.
1st STAGE
ESTERIFICATION Acid Catalyst + Alcohol (1.6-2 Times
PROCESS (Conc. H2SO4 the Th. Amount)
0.1-1% on F.F.A 1000-1200C/10-12 hrs.
Basis Or 600C/4-5 hrs.Or
350C/2 hrs.1-2 hrs.
Ester Phase Glycerol Phase
97. 2nd STAGE
TRANSESTERIFICATION ESTER PHASE
PROCESS Base Reflux Or at 600C
Catalyst For 0.5-6hrs.
Alkyl Ester Phase Glycerol Phase
Purification Acidified
Final Ester Biodiesel Glycerol Phase Acidic
Esters
Purification
98. AUTOCATALYTIC ESTERIFICATION PROCESS
Acidic Oils (>5% FFA) Or Acid Oils (>50% FFA)
Esterifying Agent 1800C-2200C
Like Glycerol 2-6 Torr,
(Theoretical Or 6-12 hrs
20-60% Excess
Over theoretical
Neutral Oil
Transesterfication Process
Methyl Ester Glycerol
Purification (Recycled in the
Esterification)
Biodiesel
99. DIRECT OR IN SITU
TRANSESTERIFICATION OF SEEDS:
Properly Sized Seeds
Contacted with Methanol
Containing a base catalyst
(NaOH Or KOH Or NaOMe)
Liquid Phase
(Methyl Ester)
A Typical Example: Soy Flakes
% FAME 95-100
Depending on The Moisture
Content
101. Transesterification
O O
|| ||
CH2 - O - C - R1 CH3 - O - C - R1
|
| O O CH2 - OH
| || || |
CH - O - C - R2 + 3 CH3OH => CH3 - O - C - R2 + CH - OH
| (KOH) |
| O O CH2 - OH
| || ||
CH2 - O - C - R3 CH3 - O - C - R3
Triglyceride methanol mixture of fatty esters glycerin
102. Amateurs’ Page
Batch homebrew
Thanks to “Journey to
Forever” and Mike Pelley
Melted fat
Methanol and Sulfuric acid
stage
After acid esterification
103. Second stage
MeOH and NaOH
addition
Glycerol
layer
settles
out
More
glycerol
settles out
First
wash
105. Free Fatty Acids (FFAs)
FFAs are present in oils and fats. Low in
virgin and high in low-grade or waste.
O
||
HO - C - R
Carboxylic Acid (R is a carbon chain)
O
||
HO - C - (CH2)7 CH=CH(CH2)7CH3
Oleic Acid
(i.e. hydrocarbon chain)
106. O
|| + KOH
HO - C - (CH2)7 CH=CH(CH2)7CH3
Oleic Acid Potassium Hydroxide
O
||
→ K+ -O -C - (CH2)7 CH=CH(CH2)7CH3 + H2O
Potassium oleate (soap) Water
Free Fatty Acids react with
alkali catalyst to form soap
107. Water is a problem
Water hydrolyses fats to form free fatty
acids, which then form soap. Dry
feedstocks best.
O
||
CH2 - O - C - R1 CH3 - OH
| |
| O | O O
| || | || ||
CH - O - C - R2 + H2O >>> CH3 - O - C - R2 + HO - C-R1
| |
| O | O
| || | ||
CH2 - O - C - R3 CH3 - O - C - R3
Triglyceride Water Diglyceride Fatty acid
108. Soap generation
Can can cause the the entire product
mixture to gel into a semi-solid mass,
giving headaches with separation and
washing.
Increased water use and treatment
costs
Loss of biodiesel product
109. Free Fatty Acid (FFA) levels in
Feedstocks
Biodiesel feedstocks vary from edible oils to stinking
wastes
Refined vegetable oils < 0.05%
Crude soybean oil 0.3-0.7%
Restaurant waste grease 2-7%
Animal fat 5-30%
Trap grease 75-100%
Price decreases as FFAs increase
High FFA feeds need special processing to avoid
soap.
But certain processes use FFA as the feed.
110. COMPARISON OF CERTAIN
FEEDSTOCKS WITH Aust Stnd
Grease Flux Used Aust Stnd Notes
Trap Tallow Cooking biodiesel
Waste Oil
FFA (wt%) 44 83 3.5 <2.5 (implied)
Iodine number 34 72 46 120 1
Phosphorus (ppm) 250 110 5 10
Sulfur (ppm) < 500 6000 < 500 10 2
Potassium 65 22 12 5 3
Acid Value † 89 94 8.1 0.8
Total Glycerol (wt%) ? ? ? 0.25
† mg of KOH per gram 1. European stnd Aust standard is open
2. beginning 2006 3. total Na and K
111. Methods for High FFA feeds:
Acid catalysis followed by base
catalysis
1. Acid catalysis methylates FFAs to methyl
esters, until FFA < 0.5%.
◦ Alkaline esterification of FFA is relatively fast (1
hour) but acid-catalyzed transesterification is
slow
◦ Water formed by
FFA + methanol ==> methyl ester + water
can be a problem.
2. Then separate, add additional methanol and
base catalyst to transesterify the
112. Methoxide Pre-esterification
Dissolving potassium metal in methanol makes
dry potassium methoxide (with release of
hydrogen). This reacts with FFA to make
FAME and KOH but no water is released.
Used to pretreat feeds < 10% FFA
Expensive and hazardous but is in use.
113. Feedstocks
Common to all processes
“Triglygeride” or fats and oils soybean oil –
vegetable oils, animal fats, greases, waste
VO, soapstock, etc.
Primary alcohol: usu. methanol or ethanol
(typically in stoichiometric excess)
… for conventional process
Catalyst (sodium or potassium hydroxide)
Neutraliser (sulfuric or hydrochloric acid)
Washwater
114. Process Evolution
Batch mixing at < 60 deg C
Continuous < 60 deg C
Continuous pressurised homogenous
catalyst, at say 120 deg C, 6 bar (most
common)
Continuous pressurised heterogeneous
catalyst (State of the art?)
Co-solvent (commercialised as BIOX)
Supercritical (not commercial)
Supercritical co-solvent (not commercial)
115. Batch Processes
Good for smaller plants (<4 million litres/yr).
Does not require continuous operation.
Provides greater flexibility wrt feedstock
variations.
Higher labour costs.
Physically large plant cf continuous.
Heat integration awkward.
Greater risk levels:
116. Heightened Risks of Batch
Processes
Due to the inherently large inventory:
• Vapour exposure to workforce,
neighbours
• Vapour explosion and fire
• Large leaks
117. Continuous Processes
Better safety, lower risks
Lower unit labour costs
Better economies of scale as capacity goes
up
More compact plant
Heat recovery inherent
Allows better use of high-volume separation
systems (e.g. centrifuges)
High capex at small scale but ROI better at
larger scale
118. Supercritical Methanol
SC methanol is a high-density chemically-labile vapour that cannot be
compressed into the liquid state. (80 bar 240 deg C)
It is miscible with oils and fats or FFAs
It reacts without catalyst to form FAME, glycerol and water.
Fast reaction ( = 4 mins)
See Saka and Kusdiana Kyoto U
However …
Not commercial as yet.
Large xs methanol required 42:1 mole ratio.
MeOH recycle costs are significant
119. Heterogeneous Catalysis
WHY ?
1. Homogenous catalysts are used up
2. They make soap with FFAs
3. Product needs lots of washing, ergo wastewater
costs
Can we use a solid that has catalytic properties that
will stay in the reactor?
YES we can … enter the Heterogeneous Catalyst.
120.
121.
122.
123. Testing of Biodiesel
The Testing
◦ Standards of quality have
been established to
prevent engine damage
◦ Measures completeness
of the reaction and
contaminates in the fuel
◦ Ensures consumer
confidence
126. Pros and Con
Pros
Reduced emissions
◦ Burns more completely
High lubricity
Biodegradable
Renewable
Positive energy
balance
◦ 3.2 units gained per unit
expended
Cons
Lower energy
◦ 8% less
energy/gallon
Higher cold flow
point
◦ Jells faster
◦ Varies with type of
oil used
Shorter storage life
Not always less
expensive
