HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY
FALCUTY OF CHEMICAL ENGINEERING
DEPARTMENT OF PETROLEUM ENGINEERING
Subject name: Refinery Operation Principles
BIOETHANOL FUEL RISK MANAGEMENT
INSTRUCTOR: MR. ANDREW HOANG
GROUP:
NGUYEN HUYNH HUNG MY
1040
HOANG MANH HUNG 1040
PHUNG THI CAM VAN 1040
NGUYEN TRONG HAI
VO DUC MINH MINH10401077
HO CHI MINH CITY, NOVEMBER 2010

CONTENT
Page 3
I. INTRODUCTION
Page 4
Transportation fuels worldwide are almost exclusively derived from petroleum,
and 75% of the world’s petroleum reserves belong to the countries of the Middle
East. Oil-importing countries around the world are extremely vulnerable both
strategically and economically to fuel supply disruptions. In addition, there is a
growing global concern about the environmental impacts of using petroleum and
other fossil fuels. Therefore, much research has been directed toward using
renewable energy like bio-fuels, wind power, solar power, tidal power, hydro-
electricity … Especially, biofuels such as bio-ethanol and biodiesel offer great
flexibility in their usage as engine fuels because they can be used in almost any
type of current and future vehicle technology. Bioethanol, in general terms, is a
fuel-grade ethanol made by fermentation. And the form of gasohols (bioethanol-
gasoline blends) is considered as one of the current and near-term transportation

fuel options.
Ethanol fuel mixtures have "E" numbers which describe the percentage of ethanol
in the mixture by volume, for example, E85 is 85% anhydrous ethanol and
15% gasoline. Gasoline is the typical fuel mixed with ethanol but there are
other fuel additives that can be mixed, such as an ignition improver used in the
E95 Swedish blend. Low ethanol blends, from E5 to E25, are also known
as gasohol, though internationally the most common use of the term gasohol refers
to the E10 blend.
II. COMPARISON THE ADVANTAGES AND INDISADVANTAGES OF
BIOETHANOL WITH OTHER OXYGENATES (MTBE, ETBE, TAME,
ButanolOH…) WHEN BLENDING IN GASOLINE
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Table II.1: Comparison the advantages and disadvantages of oxygenates
Page 6
Ethanol MTBE ETBE TAME BuOH
Advantage Be considered a
renewable energy
resource because it is
primarily the result of
conversion of the sun's
energy into usable
energy;
Can improve
agricultural economies
by providing farmers
with a stable market
for certain crops, such
as maize and sugar
beets;
Reduce emissions and

greenhouse gases;
Benefit energy security
as it shifts the need for
some foreign-produced
oil to domestically-
produced energy
sources;
Burn more cleanly
(more complete
combustion);
It benefits air
quality by
making
gasoline burn
cleaner, thus
reducing
automobile
emissions;
MTBE can be
directly
blended into
gasoline;
Can be stored
and transported
in storages and
pipeline that is
designed
petroleum
products;
Blending

gasoline with
additive MTBE
reduce T50 (Ts
50%vol)
Reduce
emissions and
greenhouse
gases;
Unlike ethanol,
ETBE does not
induce
evaporation of
gasoline, which
is one of the
causes of smog,
and does not
absorb moisture
from the
atmosphere;
Can be stored
and transported
in storages and
pipeline that is
designed
petroleum
products.
The blending
octane of
TAME is
slightly lower

than that of
MTBE or
ETBE, but the
Reid Vapor
Pressure
blending value
is significantly
lower than
MTBE’s and
half of ETBE’s.
Thus, there is
some advantage
in using TAME
as fuel
oxygenate over
MTBE or
ETBE;
Reduce
emissions and
greenhouse
gases.
Be considered a
renewable energy
resource as
ethanol
Combustion heat
is higher than
ethanol (104.800
BTU/gallon to
82.450

BTU/gallon);
Butanol is less
corrosive and
RVP lower than
ethanol;
Because its longer
hydrocarbon
chain causes it to
be fairly non-
polar, it is more
similar to gasoline
than it is to
ethanol.
Butanol can be
blended into
gasoline with ratio
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Ethanol MTBE ETBE TAME BuOH
Reduces the amount of
high-octane additives.
Power acceleration and
cruising speed is not
compromised with an
ethanol/gasoline mix.
higher than
ethanol without
engine
modification
(butanol: 8-32%,
ethanol: 5-10%);

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Ethanol MTBE ETBE TAME BuOH
Disadvantag
e
In gasohol form is
highly corrosive;
Easily absorbs water
and dirt, both of which
will affect the engine
block;
Fuels with more than
10% bioethanol
content are not
compatible with non
E85-ready fuel system
components and may
cause corrosion of
ferrous components;
Can negatively affect
electric fuel pumps by
increasing internal
wear and undesirable
spark generation;
Is not compatible with
capacitance fuel level
gauging indicators and
may result in
erroneous fuel quantity
indications in vehicles
If gasoline

containing
MTBE leaks
from an
underground
tank at a gas
station, it can
get into
groundwater
and
contaminate
wells.
MTBE is not
biodegradable
fuel.
Although ETBE
can be produced
from bioethanol,
isobutylene is
derived from
fossil sources, so
TBE is not
biodegradable
fuel.
TAME is not
biodegradable
fuel.
As the heat of
vaporization of
butanol is less
than half of that of

ethanol, an engine
running on
butanol should be
easier to start in
cold weather than
one running on
ethanol or
methanol
While ethanol and
methanol have
lower energy
densities than
butanol, their
higher octane
number allows for
greater
compression ratio
and efficiency.
Higher
combustion
engine efficiency
allows for lesser
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Ethanol MTBE ETBE TAME BuOH
that employ that
system;
Contribute to higher
food prices due to
competition with food
crops;

Accelerating
deforestation (with
other potentially
indirect land use
effects also to be
accounted for);
Potentially have a
negative impact on
biodiversity; and
compete for scarce
water resources in
some regions;
Bioethanol has a
smaller energy density
than gasoline. It takes
about 1.5 times more
ethanol than gasoline
to travel the same
distance. However,
greenhouse gas
emissions per unit
motive energy
extracted;
The viscosity of
alcohols increase
with longer
carbon chains. For
this reason,
butanol is used as
an alternative to

shorter alcohols
when a more
viscous solvent is
desired. The
kinematic
viscosity of
butanol is several
times higher than
that of gasoline
and about as
viscous as high
quality diesel fuel.
High price
Page 10
Ethanol MTBE ETBE TAME BuOH
with new technologies
and dedicated ethanol-
engines, this is
expected to drop to
1.25 times.
Page 11
Table II.2: Comparison of typical properties of common oxygenates
ST
T
Các chỉ tiêu Xăng Metanol Etanol
Butano
l
MTB
E
1

2
3
4
5
6
7
Tỷ trọng 15,5
o
C, kg/m
3
Nhiệt độ sôi,
o
C
RVP 37,8
o
C, kPa
Nhiệt bay hơi, KJ/kg
Nhiệt cháy, MJ/kg
Trị số Octan
RON
MON
Không khí / nhiên liệu
735 -
760
30 - 190
40 - 80
289
42,69
97 - 99
87 - 91

14,4
796
64,7
32
1110
9,94
106
87
6,4
794
78,3
16
854
26,80
106
87
8,94
792
82,8
12
510
11,1
113
100
11,1
746
55,3
54
337
35,20

117
100
11,7
Page 12
Figure II.1: Blending octane values of common oxygenatesThe fuel oxygenate
ethanol has been used both as a fuel and fuel additive for nearly 100 years -
including its early use as the fuel for the original Ford Model-T motorcar.
Other oxygenates, such as MTBE (methyl tertiary butyl ether), ETBE (ethyl
tertiary butyl ether) and TAME (tertiary amyl methyl ether), have been used
as effective octane enhancers in gasoline since the mid- to late 1970s.
OXYGENATES HAVE LED TO LESS POLLUTION AND CLEANER AIR
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Expanded use of oxygenates began in the late 1980s in states seeking to reduce
harmful wintertime carbon monoxide (CO) emissions. Since their introduction, the
use of these oxygenated gasolines has been tremendously effective—helping
reduce wintertime carbon monoxide emissions so much that the majority of these
states no longer have a problem with CO pollution.
The factual data showed that oxygenates provided a number of important
environmental benefits:
• Increased the oxygen content in gasoline—allowing for more complete fuel
combustion;
• Reduced carbon monoxide emissions during the winter months;
• Reduced smog-forming volatile organic compounds (VOCs) in the
summertime;
• Reduced air toxic emissions year round.
OXYGENATES HELP REDUCE LEVELS OF CARCINOGENS IN
GASOLINE
Since the late 1970s, as lead was removed from gasoline, use of aromatics such as
benzene were increased to replace the lost octane. The scientific, medical and
environmental communities had long advocated the removal or reduction of

aromatics in gasoline. Oxygenates were seen by Congress as a way to effectively
reduce aromatic content in gasoline, while maintaining octane levels.
II.1 Advantages
II.1.1 Bioethanol
Bioethanol has many positive features as an alternative liquid fuel.
• Bioethanol is considered a renewable energy resource because it is primarily
the result of conversion of the sun's energy into usable energy. Creation of
bioethanol starts with photosynthesis, which causes feedstocks, such as
sugar cane, to grow. These particular feedstocks are processed into
bioethanol. Therefore, it can reduce the rate of depletion of fossil fuels
reliant on carbon-based compounds, which have a limited reserve;
• It can improve agricultural economies by providing farmers with a stable
market for certain crops, such as maize and sugar beets;
Page 14
• It reduces emissions and greenhouse gases (carbon neutral fuel): using
bioethanol might decrease emissions of certain emissions. Toxic, ozone-
forming compounds are emitted during the combustion of gasoline, such as
aromatics, olefins, and hydrocarbons, would be eliminated with the use of
bioethanol (the emissions produced by burning ethanol are less reactive with
sunlight than those produced by burning gasoline, which results in a lower
potential for forming the damaging ozone). The concentration of
particulates, produced in especially large amounts by diesel engines, would
also decrease. However, emissions of carbon monoxide and nitrogen
oxides are expected to be similar to those associated with newer,
reformulated gasolines. Carbon dioxide emissions might be improved (-
100%) or worsened (+100%), depending the choice of material for the
ethanol production and the energy source used in its production. For
example, bioethanol-blended fuel as E10 (10% ethanol and 90% gasoline)
reduces greenhouse gases by up to 3.9%;
• It benefits energy security as it shifts the need for some foreign-produced oil

to domestically-produced energy sources;
• It burns more cleanly (more complete combustion);
• It reduces the amount of high-octane additives. Power acceleration and
cruising speed is not compromised with an ethanol/gasoline mix;
• The fuel spills are more easily biodegraded or diluted to non toxic
concentrations.
II.2 Disadvantages
II.2.1 Bioethanol
• Bioethanol in gasohol form is highly corrosive. The entire train from fuel
tank through to engine block will have to be made more corrosion and
damage resistant. It is likely that fuel tanks might have to be constructed of
stainless steel and all hoses of an alternate material, as bioethanol rapidly
corrodes rubber;
• Bioethanol easily absorbs water and dirt, both of which will affect the engine
block;
Page 15
• Fuels with more than 10% bioethanol content are not compatible with non
E85-ready fuel system components and may cause corrosion of ferrous
components;
• It can negatively affect electric fuel pumps by increasing internal wear and
undesirable spark generation;
• It is not compatible with capacitance fuel level gauging indicators and may
result in erroneous fuel quantity indications in vehicles that employ that
system.
• It contribute to higher food prices due to competition with food crops;
• An expensive option for energy security taking into account total production
costs excluding government grants and subsidies;
• Provide only limited GHG reduction benefits;
• Accelerating deforestation (with other potentially indirect land use effects
also to be accounted for);

• Potentially have a negative impact on biodiversity; and
compete for scarce water resources in some regions.
• Bioethanol has a smaller energy density than gasoline. It takes about 1.5
times more ethanol than gasoline to travel the same distance. However, with
new technologies and dedicated ethanol-engines, this is expected to drop to
1.25 times.
ETBE
A colorless, flammable, oxygenated hydrocarbon ((CH3)3COC2H5) blend stock
formed by the catalytic etherification of isobutylene with ethanol. ETBE has
characteristics superior to other ethers: low volatility, low water solubility, high
octane value, and a large reduction in carbon monoxide and hydrocarbon
emissions.

III. THE STATUS OF USING GASOHOL IN THE WORLD
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Gasohol has been widely used in Brazil, which uses 12 billion liters of bioethanol
each year for blending with gasoline. The United States has been using 4.7 billion
liters of bioethanol each year while France has been using 120 million liters of
ethanol each year. The world use of gasohol grows continuously.
The use of bioethanol as car fuel started since the first age of car invention.
Bioethanol has been in use in the United States as car fuel since 1880. The use of
bioethanol became less popular following the discovery of oil wells, distillation
technology which led to cheaper oil production.
When an oil crisis happened in 1970, the use of fuel made from agricultural
produce received attention again in the United States and Brazil.
The US government has promoted the use of gasohol through the enactment of
laws and tax privileges since 1975. Currently, gasohol has been widely used in the
United States, such as in the states of Minnesota and Illinois, especially in big
cities like Chicago. Gasohol used in the US is a blend of 10% ethanol and 90%
gasoline. The use of gasohol is expected to be adopted by other states when there is

enough ethanol production.
Table III.34: Low bioethanol blends used around the world
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Country / Region
(1)
Ethanol blend Legal use
Australia E10 Optional
Austria E10 Optional
Brazil E20 – E25 Mandated
Canada E5 Mandated
(1)
China E10 Nine provinces
Colombia E10 Mandated
(2)
Costa Rica E7 Mandated
(3)
Denmark E5 Optional
Finland E5 Optional
France E10 Optional
India E5 Mandated
Ireland E4 Mandated
Jamaica E10 Mandated
(4)
New Zealand E10 Optional
Pakistan E10 Optional
Paraguay E12 Mandated
Sweden E5 Mandated
Thailand E10/E20 Mandated
United States - states where
mandatory only

(5)
: Florida, Hawaii,
Iowa, Kansas, Louisiana, Minnesota,
Missouri, Montana, Oregon
(6)
,
Washington
E10
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(1) Starting on December 15, 2010
(2) In Colombia mandatory blend was enforced only in cities with more than 500.000 inhabitants
(3) Mandatory blend for the entire country scheduled for 2009 was postponed. Sales of E7 continue
for 3 years now in the two original trial regions
(4) Since November 1, 2008 became available in some cities and will become mandatory in May
2009
(5) Though mandated only in 10 states, ethanol blends in the US are available in other states as
optional or added without any labeling, making E blends present in two-thirds of the US gas
supply Florida effective in 2010
(6) The State of Oregon exempted premium unleaded gasoline (91 octane or higher) from the 10%
ethanol mandate for road use, effective January 2010
Brazil is a gasohol leader. This country has been seriously promoting the use of
gasohol as an alternative fuel since the government resolved to reduce the import
of oil, which made up 80 percent of oil used in the country. The Brazilian
government set up the National Alcohol Program in 1975 when the crude-oil price
skyrocketed. The program aims to promote the production of ethanol for blending
with gasoline at the ratio of 20-25:80-75. Since then, ethanol has been used in high
amount in Brazil.
All vehicles in Brazil, both imported and locally made, must have their engines
modified to be able to use gasohol with ethanol ratio being higher than 20 percent.
Some vehicles have been developed to use pure ethanol without having to blend

with gasoline first. However, the pure-bioethanol vehicle engines are not popular
because shortage of ethanol had erupted in the past.
To promote the use of bioethanol as an alternative energy, auto manufacturers have
developed engines that can use various levels of ethanol blends. This kind of
engines is called Flexi Fuel engine, which can use different ratios of ethanol blend
including 100 percent bioethanol. It is expected that Flexi Fuel engines will
become popular in the near future because their prices are not much different from
ordinary engines.
European Union countries have been using gasohol for over 20 years because they
need to find markets for agricultural produce, which are grown in the areas
prohibited for growing foods. Currently, EU countries are promoting the use of
gasohol to reduce greenhouse gas emissions in line with what measured under the
Kyoto Protocol to the United Nations Framework Convention on Climate Change.
Australia is another country where gasohol has been used widely because of
government’s promotion. Gasohol in Australia uses 5 to 10 percent of ethanol
blending.
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Asian countries, such as China and India, are now giving much consideration to the
use of alternative energy, especially ethanol. The Indian government has issued a
regulation to require all types of gasoline to be mixed with ethanol at the rate of 5
percent. The Indian government has also promoted and developed technology to
produce 99.5 percent-pure ethanol for domestic consumption. India has also
exported the ethanol production technology to several countries, including
Thailand.
Although Japan uses a lot of gasoline, its government has a policy to promote the
use of gasohol with 3 percent bioethanol, which is lower than what used in other
countries. This is because Japan has to import ethanol. It is expected that Japan
will begin seriously using ethanol for blending with gasoline in 2008.
Source: IFQC, present at SAE Fuels & Lubes meeting – May 13th, 2005
Figure III.2III.3: Gasohol mapping in the world

IV. BIOETHANOL PRODUCTION
Bioethanol production based on vegetable feedstock can be made through different
technology routes - similarly to alcoholic beverages.
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Through biological routes, bioethanol may be produced based on any biomass
containing significant amounts of starch or sugars. Nowadays, there is a slight
predominance of production based on starchy materials (53% out of the total), such
as corn, wheat and other cereals and grains. In such cases, conversion technology
typically starts by separating, cleaning and milling the grains. Milling may be wet,
where grains are steeped and fractionated before the starch conversion into sugar
(wet milling process), or dry, when this is done during the conversion process (dry
milling process). In both cases starch is typically converted into sugars by means
of an enzymatic process, applying high temperatures. Sugars released are then
yeast-fermented and the wine produced is distillate to purify bioethanol. In
addition to bioethanol, these processes typically involve several co-products, which
differ according to the biomass used.
Source: Elaborated by Luiz Augusto Horta Nogueira
Figure IV.4IV.5: Technological routes for ethanol production
V. THE KEY FEATURES OF GASOHOL
V.1 Phase separation
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Unlike petrol, ethanol is highly soluble in water. When the water content of the
bioethanol – gasoline blend reaches a critical level the bioethanol component and
associated water will separate from the blend and form an ethanol/water phase.
This will accumulate at the bottom of a tank leaving petrol (without the bioethanol
component) in the upper layer and is known as phase separation. If phase
separation occurs the process is essentially irreversible, there is no straightforward
means of re-blending the ethanol back into the petrol at a filling station. In most
cases, both phases will need to be taken off site for appropriate handling as a
hazardous waste.

With the introduction of oxygenated gasoline came the concern of water phase
separation. Water in gasoline can have different effects on an engine, depending
on whether it is in solution or a separate phase, and depending on the type of
engine being used. While separate water phases in a fuel can be damaging to an
engine, small amounts of water in solution with gasoline should have no adverse
effects on engine components. If precautions to prevent water from entering the
fuel system are taken, water phase separation will likely not occur.
The amount of water tolerated by a gasoline/ethanol blend is dependent upon the
content of ethanol and product temperature. The lower the temperature, the lower
ethanol content, the lower the water tolerance.
Source: RFA 2005
Figure V.6: Water tolerance of Gasoline/Fuel ethanol blends
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Figure V.7: Effect of water content on quality of Gasohol
According to figure 3, higher moisture content will contribute lower octane
number especially for low octane number of gasohol.
Water separation will occur with higher moisture / water content in gasohol when
water content exceed water tolerance. If phase separation occur when water and
ethanol combined and drop to the bottom of the tank, the effected product must be
taken out of service untill the problem is corrected.
However, various substances such as benzene (benzol), acetone, and butyl alcohol
can be added to the blend to increase water tolerance. Closed fuel systems, now in
use, prevent moisture from forming inside the gas tank. Oil companies, given the
proper incentive, could dry out their storage facilities and pipelines. Also,
extensive use of alcohol blends over the past 50 years is ample evidence that the
problem can be solved.
V.2 Microbial growth
Bacteria, yeasts and moulds can enter a filling station storage system through the
distribution chain, via tanks, pipelines, filters, water and air. It is in the water phase
that microbes survive, drawing nutrients from the fuel phase.

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Microbial growth in the water phase can exacerbate localized corrosion, which
may result in the blocking of dispenser filters and fuel lines.
V.3 Solvent properties
The solvent properties of E5 can have a cleaning effect on existing storage
systems. This can cause a softening and loosening of any organic residues, dirt or
scale present in the tank system. This loosening can bring this material into a
suspended state, and can therefore increase the risk of filter blockage.
In other hand, certain materials commonly used with gasoline are totally
incompatible with alcohols. When these materials (such as aluminum) come in
contact with ethanol, they may dissolve in the fuel, which may damage engine
parts and may result in poor vehicle driveability. Even if parts do not fail, running
an ethanol-fueled vehicle with contaminated fuel may cause deposits that could
eventually harm the engine.
Some materials become degraded by contact with fuel ethanol blends having high
alcohol concentrations. Zinc, brass, lead, and aluminum are sensitive metals. Terne
(lead-tin-alloy)-plated steel, which is commonly used for gasoline fuel tanks, and
lead-based solder are also incompatible with gasohols. Avoid using these metals
because of the possibility of fuel contamination and potential difficulties with
vehicle driveability. Unplated steel, stainless steel, black iron, and bronze have
shown acceptable resistance to ethanol corrosion.
Nonmetallic materials that degrade when in contact with fuel ethanol include
natural rubber, polyurethane, cork gasket material, leather, polyvinyl chloride
(PVC), polyamides, methyl-methacrylate plastics, and certain thermo and
thermoset plastics. Nonmetallic materials that have been successfully used for
transferring and storing fuel ethanol include nonmetallic thermoset reinforced
fiberglass, thermo plastic piping, buna-N, Neoprene rubber, polypropylene, nitrile,
Viton, and Teflon materials.
V.4 Electrical conductivity and corrosion
Because of the strong association with water of bioethanol, gasohols have a greater

electrical conductivity than standard gasoline. The bio-component present in the
blend can increase the risk of corrosion in existing filling station systems from
galvanic and electrolytic reactions where particular material combinations may be
present. This can in turn increase the risk of filter blockage.
V.5 Combustion properties
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Ethanol is composed of 35% mass of oxygen, which results to a more complete
combustion.
V.6 Volatility
Another important quality in a motor fuel is "volatility", or the ability to be
vaporized. As previously noted, methyl alcohol contains less than half the heat
value of gasoline and ethyl alcohol contains only about 60%. The next higher
alcohol, propyl alcohol with three carbon atoms, contains only 26.6% oxygen and
thus about 74% of the heat value of gasoline. It is apparent that the more complex
the alcohol, the closer its heat value comes to that of gasoline. Cetyl alcohol
(Figure 2-1), for example, contains only about 6.6% oxygen and thus has about
90% of the heat value of gasoline. However, this alcohol is a solid wax! It can't be
conveniently vaporized and mixed with air in an engine and so is useless as a
motor fuel. Consequently, in considering alcohol fuels, a compromise must be
made between heat value and volatility.
Closely related to volatility is a quality called "latent heat of vaporization". When a
liquid is at its boiling point, a certain amount of additional heat is needed to change
the liquid to a gas. This additional heat is the latent heat of vaporization, expressed
in Btu/lb in Figure 2-2. This effect is one of the principles behind refrigeration and
the reason that water evaporating from your skin feels cool.
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