Alternative fuels

SRI KRISHNA COLLEGE OF ENGINEERING AND TECHNOLOGY
DEPARTMENT OF MECHATRONICS ENGINEERING
Session: Alternative Fuels
11/24/2020 16MT407 - Theory of Automobile Engineering 1
MODULE 1

SESSION OBJECTIVES
 On the completion of this session, the students might
be able to understand,
 Need of Alternative Fuels in Vehicles

Topics
 Fossil Fuels
 Need of Alternative resources
 Alternative Fuels
 Combustion and Emission Characteristics of
Alternative fuels in CI & SI Engine.

FOSSIL FUELS
FOSSIL FUELS:
 Group of energy sources that were
formed from ancient plants and
organisms during the carboniferous
period.
 Approximately 360 to 286 million
years ago, prior to the age of
dinosaurs.
 Dead plants & Organisms are sank
at the bottom of swamps and
oceans.
 To formed a spongy material called
peat.

FOSSIL FUELS
FOSSIL FUELS:
 Over millions of years, the peat
was covered by sand, clay and
other minerals.
 Which converted the peat into
sedimentary rock.
 Over time different types of fossil
fuels formed, depending on the
combination of organic matter
present, Buried duration,
temperature & pressure conditions
existed when they were
decomposing.

FOSSIL FUELS
FOSSIL FUELS: Types
 Coal
 Oil
 Natural Gas

FOSSIL FUELS
High Pressure

FOSSIL FUELS
FOSSIL FUELS: High Density Energy
Carrier
 Natural Gas – 56.3 Megajoules per
Kilogram
 Crude Oil – 46.3 Megajoules per Kilogram
 Coal Energy density – 24 Megajoules per
kilogram
 6.7 Kilowatt-hours per Kg
 325 Kg coal can glow 100 W bulb for
one year.

Need of Alternative resources
Population Energy and Transportation: Trends of world population &
vehicle sold per year
World Population in billion
Passenger car sold per year
Data’s from Hybrid Electrical vehicles –
Principle & Application with practical
perspective

Population Energy and Transportation: Crude oil consumption and
Demand per day by country in 2008

Population Energy and Transportation: The history & projections of oil
demand & production
World oil Demand & Depletion History and Projection

Environmental Factors: Pollution
Global Fossil carbon emission from 1800 – 2004 . On the right tip points, from top
to bottom: Total Co2 emission by Oil,Coal,Cement Production and other
GHG

Environmental Factors: Atmospheric Temperature
Global Annual Mean Surface Air Temperature

ALTERNATIVE FUELS
 Non Conventional Fuels
 Any material or substance that can be used as a
fuel, Other than fossil fuel fuels or conventional
fuels.
 Refers “Renewable Energy Resources”

ALTERNATIVE FUELS
Types:
 Alcohol Fuels,
 Methanol
 Ethanol
 Compressed Natural Gas,
 LPG – Gas
 Biodiesel
 Hydrogen Fuel
 Electric Cars
 Fuel cell vehicle

ALTERNATIVE FUELS
Methanol:
 It is an Alcohol fuel.
 Primary alternative methanol fuel being used is M85.
 It is 85% Methanol & 15% gasoline.
 Near future M100 may possible.
 Created from synthesis gas (Hydrogen & CO), which is
reacted in the presence of catalyst.
 CO2 + 3H2 CH3OH + H2O
 Also produced from non-petroleum feed stocks such as coal
& Biomass.
 Emissions from M85 are slightly lower than gasoline
powered vehicle.
 Nox & Hydrocarbons – lower than gasoline
 But CO higher than gasoline vehicle.

ALTERNATIVE FUELS
Methanol: Production
Feed
Preparation
Steam
Reforming
Methanol
Synthesis
Methanol
Distillation
Natural Gas
Desulphurised
Natural Gas
Synthesis Gas
CO2
Air/O2
Steam
Crude
Methanol
Refined 99% Methanol

ALTERNATIVE FUELS
Stage 1 : Feed preparation
 Natural gas feedstock is desulphurised in order to
reduce the Sulphur content.
Stage 2 : Steam Reforming
 The reforming process transforms methane(CH4) &
Steam into Hydrogen, Carbon Monoxide, and carbon
dioxide called synthesis gas (Syngas).
 The partial oxidation of natural gas with air produce
carbon dioxide and water.
 The oxidation process is very slow compare to
reforming process.
 Produce small amount of hydrogen.

ALTERNATIVE FUELS
Stage 2 : Steam Reforming
 For efficiently produce methanol, CO2 is also added
with feed gas stream to produce a mixture of
components in an ideal manner (Syngas)
Stage 3 : Methanol Synthesis
 Now synthesis gas are sent to methanol synthesis
reactor to produce Crude ethanol fuel.
 CO + 2H2 CH3OH
 CO + H2O CO2 + H2
 CO2 + 3H2 CH3OH + H2O

ALTERNATIVE FUELS
Stage 4 : Methanol Distillation
 Crude methanol has the purity level 68%
 Then its sends to distillation column for refining
process.
 The refining methanol has purity level 99%
 It is classified as Grade AA refined methanol.

ALTERNATIVE FUELS
Methanol: Advantage
 High octane number & Good performance
characteristics (power of Ability to resist engine
Knocking).
 Methanol – 109
 Gasoline – 91 to 94 (Premium)
 Lower emission
 Lower risk of flammability
 Can be used in flexible fuel vehicles.
 Used in spark – ignition engines, can offer increase
thermal efficiency & increase output power than
conventional gasoline vehicle.
 High heat of vaporization

ALTERNATIVE FUELS
Methanol: Modification in fuel line system

ALTERNATIVE FUELS
Ethanol:
 It is an Alcohol fuel.
 It is a renewable energy resources.
 Made by fermenting from a variety of starch based
feedstock such as sugar cane, potatoes, sweet potatoes,
molasses, corn, cassava, etc..
 Also called ethanol or ethyl alcohol can be used as a fuel
when blended with gasoline.
 Blending ratio – E10, E15, E85.
 30-50% smog forming is reduced than a gasoline
vehicle.
 Air toxics are also reduced by about 50% when
compared to gasoline.

ALTERNATIVE FUELS
Ethanol:
 Vehicle using ethanol emit minor amounts of aldehydes.
 A catalytic converter on the vehicles ensure this.
 Aldehydes initiate cancer & affects respiratory system.

ALTERNATIVE FUELS
Ethanol: Production
 Ethanol is produced from biomass mostly via fermentation process using
Glucose.
 Glucose is a simple sugar with molecular formula C6H12O6
 Derived from sugars, starch, cellulose.

ALTERNATIVE FUELS
Ethanol: Production
 Ethanol is manufactured via a process where glucose is transformed by yeast
into ethanol called fermentation.

ALTERNATIVE FUELS
Ethanol: Production process

ALTERNATIVE FUELS
Step 1 :Pretreatment process
 Process starts by grinding up the feedstock/Biomass.
 Water, Steam or chemical (Acid) to convert the bio mass into cellulose,
hemicellulose, Lignin – Organic polymer
 The PH level is balanced by adding Base.
 Now the mixture is cooled before enzymes added.
 It is called as Macromolecular Biological Catalysts
 This accelerate the chemical reaction
 Enzymes perform a chemical reaction called “Enzymatic Hydrolysis”
 This will break the cellulose chain into glucose & Hemicellulose chain into
xylose.
 This sugars readily fermented into ethanol or other bio fuels.

ALTERNATIVE FUELS
Ethanol: Production
Step 2 : fermentation process
 The mixture is inoculated with microbes such as yeast or bacteria that digest
sugars.
 The secrete compounds that can be used as biofuels.
 This conversion process takes 3 to five days.

ALTERNATIVE FUELS
Step 3 : Distillation process
 Based on difference in boiling point, this method separate the ethanol from
secrete compounds.
 The resulting ethanol is collected & purified for use in blending with gasoline
fuel.

ALTERNATIVE FUELS
Step 4 : Dehydration
 With the addition of hydrogen these molecules are processed into renewable
gasoline & Diesel.

ALTERNATIVE FUELS
Step 5 : Stillage processing
 The solids and liquids remaining after distillation known as stillage.
 Then undergoes series of steps to remove water from the mixture.
 Converts into
 DDGS – Dried distillers grains & soluble
 Fertilizer
 WDGS – Wet distillers grains & soluble
 Liquid Fertilize

ALTERNATIVE FUELS
Ethanol: Properties
 Molecular Formula – CH3CH2OH.
 Clear & Colorless liquid.
 Ethyl alcohol, grain alcohol.
 High Auto Ignition temperature : 326oc (Petrol 240 - 280oc, Diesel 210oc
 Will ignite and explode without any external ignition source.
 Ensure more safer fuel
 Ethanol energy content 30 % less than gasoline
 Ethanol 21.1 MJ/L < Gasoline 34.8 MJ/L
 E10 – 33.7 MJ/L (also called Gasohol)
 Higher Octane than gasoline
 Octane value – 108
 Provides premium blending properties.
 Prevents engine Knocking & gives drivability.

ALTERNATIVE FUELS
Ethanol: Modification in gasoline flexible engine
Basic Engine Terminologies:
Compression Ratio: CR
 Assume total volume of cylinder
is 1000 cc
 Swept volume is 900cc
 Clearance volume – 100 cc
 Left inside the cylinder when
the piston reached TDC.
 NOW CR = 1000 : 100 / 10 : 1
 Higher CR able to extract more
mechanical energy from a given
mass of Air-Fuel mixture due to
its higher thermal efficiency
Petrol Engine : 10:1 to 14:1
Diesel Engine : 18:1 to 23:1

ALTERNATIVE FUELS
Basic Engine Terminologies:
Thermal Efficiency:
 Dimensional performance
measure of a device.
 States how well the thermal
energy is utilized to produce
mechanical output power from
engine.

ALTERNATIVE FUELS
Main jet Changes :
 Allows entry of air fuel in cylinder.
 Greater Octane number than petrol.
 Requires greater compression ratio.
 Increase in orifice diameter of the main jet
 Need increase of 20 to 40%

ALTERNATIVE FUELS
Idle Orifice changes :
 Allows entry of fuel in idle mode.
 Idle orifice needed for supply of air fuel mixture in slow speeds or idle status.
 Diameter to be increased for proper supply of mixture.

ALTERNATIVE FUELS
Power Valve changes :
 Operated by vacuum controlled valve, spring loaded & shuts off valve units to
conserve fuel.
 Allows extra fuel to blend with the air fuel mixture, when accelerator pedal is
depressed.
 Requires 25% greater flow capacity sufficient to increased power.

ALTERNATIVE FUELS
Accelerator pump changes :
 Supplies extra fuel on sudden accelerator pressing.
 Increase the size approx. by 25%
 Larger size may create difficulty in reverting back to gasoline.

ALTERNATIVE FUELS
Compression Ratio Changes:
 Ethanol has Good Octane Rating.
 Compression Ratios up to 15:1 may be suitable.
 Difficulty in reversing back to gasoline.
 Remedy: Installation of water injection system for cooling to revert back to
gasoline.

ALTERNATIVE FUELS
Ethanol: Modification in gasoline
flexible engine
Compression piston changes:
 High compression pistons is used.
 So connecting rod & Bearing replaced
for withstand heavy loads.
 Installing a turbocharger
 No excessive compression during
engine startup
High compression pistons
Turbocharger

ALTERNATIVE FUELS
Cold Weather Starting:
 Alcohol does not vaporize as easily as gasoline.
 Therefore, starting the engine in cold condition is problem.
 Remedies :
 Use of extra Fuel tank for petrol
 Use of fuel preheater.
 Use of air preheater

ALTERNATIVE FUELS
Ethanol: Modification in gasoline flexible
engine
Fuel Preheating:
 Necessary to preheat fuel in cold
condition.
 Can be done by making fuel flow over the
hot engine parts through tubes.
Drawbacks:
 Time consuming
 Not very effective

ALTERNATIVE FUELS
engine
Air Preheating: Air cleaner – “snorkel”
 Clean the air before prepare the mixture.
 Heat up the air during engine warm up.
 Types
 Ram Snorkel
 Vortex snorkel Ram Snorkel
Vortex snorkel

ALTERNATIVE FUELS
engine
Air Preheating: Air cleaner – “snorkel”
 A flap within the air cleaner “Snorkel”
shuts off this supply when engine warms
up and allows ambient air enter.
 Flap is usually either thermostatically or
vacuum controlled.

ALTERNATIVE FUELS
engine
Air Preheating: External heater
 External type resistance air heater may
also be used

ALTERNATIVE FUELS
engine
Thermostat Change:
 Used to hold the coolant in the cylinder
head until it reaches the certain
temperature.
 Thermostat decides the temperature at
which the coolant will enter the cylinder
head.
 Ethanol engine works at less temperature
than the petrol engine of same
horsepower.

ALTERNATIVE FUELS
Ethanol: Advantage
 Has complete combustion.
 Little CO2 is formed.
 Does not contain Sulphur.
 Emission & Pollution is reduced.
 Cheaper than gasoline and diesel.
 Keeps engine clean.
 Can produced from grains & sugarcanes

ALTERNATIVE FUELS
Ethanol: Drawbacks
 Alcohol will act as a cleansing agent and will clean out fuel tank, fuel lines,
and filters, remove engines internal parts of built up carbon, gum, and
varnish deposits.
 What happens?
 A lot of filth will be floating around in fuel.
 It may clog fuel filter to the point of not allowing any fuel to pass.
 Loosened internal engine deposits can foul the spark plugs badly
 Firing Tip coated with Fuel,Oil,carbon

ALTERNATIVE FUELS
Alcohol fuel vehicle: Example
- 1996Ford Taurus first
flexible fuel vehicle.
- Capable of running
with either E85 or M85
blended with gasoline
- 2003 VW Golf 1.6 Total
flex was the first
commercial flexible
fuel vehicle
- Capable of running
E20 – E25 & E100

ALTERNATIVE FUELS
Natural Gas:
 It is a mixture of hydrocarbon mainly Methane (CH4).
 It was formed by dead marine organism under earth at
high pressure & Temperature for the millions of years to
transform into gas
 Extracted from gas wells or in conjunction with crude oil
production or it can be produced as a by product of
landfill operations.
 It can be stored on a vehicle either in a compressed
gaseous state (CNG) or in a liquefied state (LNG)
 LNG is help for transporting purpose, under the
temperature of -162oc, its volume shrinkage about 600
times.

ALTERNATIVE FUELS
Natural Gas:
 Comparing conventional fuel vehicle it takes less
operating cost.
 44.30Rs/Kg & 18 Km/kg mileage
 CNG is made by compressing natural gas to less than 1%
of the volume it occupies at standard atmospheric
pressure.
 Stored in a cylindrical/Spherical container at a pressure
of 200 – 248 bar (2900 – 3600 PSI).

ALTERNATIVE FUELS
Natural Gas: Advantage
 CNG is cheapest, cleanest and least environmentally
impacting alternative fuel.
 Less toxic emission than Gasoline vehicle
 Such as carbon monoxide and hydrocarbon
 Auto ignition temperature is 550oc – More safer (Not
easily explosive)
 But CNG requires more air for ignition.

ALTERNATIVE FUELS
Natural Gas: Usage by India
 Cheapest fuel in India
 Delhi & Gujarat state government make mandating for
public transport.
 Because it has low CO emission & Particulate matter
emission

ALTERNATIVE FUELS
Natural Gas: Engine Modification
 Taken From International journal of engineering &
Technological innovation.
 Title is as Modification Design of Petrol Engine for
Alternative fueling using compressed natural gas.
Specification of petrol Engine :
Manufacturer Honda Siel Cars India Ltd
Engine Type 4 – Cylinder in line petrol engine
Bore Diameter 86.00 mm
Stroke length 86.00 mm
Compression Ratio 9.8
Maximum Power 103 Kw at 6500 Rpm
Maximum Torque 184.4 Nm at 4000 Rpm
Valve 4 Valves per Cylinder, DOHC
Ignition and Fuel system Electronic PGM FI

ALTERNATIVE FUELS
 Make Sealing plate thickness smaller than Petrol Engine
 Leads to CNG Combustion chamber smaller than that of petrol Engine.
 CNG Engine runs high compression ratio than the petrol engine.
Sealing Plate Before Modification Sealing Plate after Modification

ALTERNATIVE FUELS
 Compression height of the CNG’s piston is longer than that of the petrol
Engine
 This Yields High compression ratio
Piston Before Modification Piston after Modification

ALTERNATIVE FUELS
Comparative Analysis :
Parameter Petrol Engine CNG Engine % Increase
Engine Type 4 – Cylinder Inline
petrol Engine
4 – Cylinder Inline
CNG Engine
No change
Bore * Stroke 86.00 * 86.00 86.00 * 86.00 No Change
Compression Ratio 9.8 11.79 20.3
Air standard
Efficiency
59.9 62.7 4.67
Max Power at 6500
Rpm (KW)
103 83.6 -18.8
Air Standard Efficiency :
 Measure of the Thermal efficiency of the Internal Combustion Engine.
Ƞth =
𝑁𝑒𝑡 𝑊𝑜𝑟𝑘𝑑𝑜𝑛𝑒
𝑁𝑒𝑡 𝐻𝑒𝑎𝑡 𝐴𝑑𝑑𝑒𝑑

ALTERNATIVE FUELS
Diesel to natural Gas Conversion:
Changes in compression ratio:
 Typical diesel engine has compression ratio between 16 and 18.
 While CNG works b/n 10 and 12.
 It requires newly modified pistons & appropriate shaped combustion
chamber for proper Air/Fuel mixing.
Requirement of Spark Plug :
 Diesel’s don’t have spark plug, Instead they have fuel injector.
 A Diesel conversion replaces the injector with a spark plug.
 High compression ratio & Use of gaseous fuel requires higher spark
voltage than a petrol car.

ALTERNATIVE FUELS
Changes in Valves:
 Natural gas is a dry fuel.
 Valve seat in a converted engine need to be hardened to prevent abnormal
wear.

ALTERNATIVE FUELS
Changes due to thermal issues:
 Spark Ignited engines run hotter than diesels.
 Upgraded Thermal management is required.
 Larger Oil coolers
 Larger Radiators
 Heat shield around the exhaust components

ALTERNATIVE FUELS
No need of Catalytic Converter:
 A Catalyst will generally required to meet the
emission regulation.
 If the injection, Ignition, timing are properly
controlled means, can able to meet emission
regulation without catalytic converter.

ALTERNATIVE FUELS
Natural Gas: Usage vehicles
The Brazilian Fiat Siena – First
multi fuel car (Tetrafuel 1.4) –
Runs on Pure Gasoline, E25 or
E100, Natural Gas
A Bus powered by CNG are
common in the united states.

ALTERNATIVE FUELS
LPG: Liquefied Petroleum Gas
 Also called Propane
 Molecular Formula C3 H8
 Produced during Natural Gas processing & Crude oil
refining process.
 It involves Separation & collection of gas from its
petroleum base.
 It is Nontoxic, Colorless, and odorless gas
 Ethyl Mercaptan (C2H6S) Odorant is typically
added for detection
 At atmospheric pressure and ambient temperatures
Propane exists in a vapours form.
 Heavier than air (1.5 to 2.0 Times)
 Propane is a NFPA Class I - A Flammable Liquid

ALTERNATIVE FUELS
LPG: Liquefied Petroleum Gas
 The LPG run vehicles have lower emission of
reactive hydrocarbons.
 NOX – 20% less than Gasoline vehicle.
 CO – 60% less than Gasoline Vehicle.

ALTERNATIVE FUELS
LPG: Liquefied Petroleum Gas Vs Petrol
Regular Petrol LPG
Less fuel consumption Higher fuel consumption
Petrol has odour LPG is Odourless
Octane rating - 81 Octane Rating – 110
Knocking Occurs
Higher Octane Rating – Eliminated
Knocking
Not free from lead Lead free gas
The air fuel mixture may passes
through piston rings & Wash it away
from cylinder wall. Results in Black
carbon deposition & Create wear in
engine moving parts
No oil is wash out from cylinder wall &
No Black carbon deposition
Less engine life More Engine Life
Life of spark plug is less, due to carbon
deposition
No carbon Deposition on spark plug &
life of spark plug is increased.
Carburetor/Fuel injector supply Air-
Fuel mixture to Engine
A pressure controlling device called
vaporizer regulate the flow of gas.

ALTERNATIVE FUELS
LPG: Advantage
 It contains hydrocarbons, so it burns clearly.
 Has higher calorific value than other fuel, ensure pure
combustion. (7 times>Coal gas, 3>Natural Gas)
 It has High Thermal Efficiency and Heating Rate.
 Less health hazard, Even in case of Leakage.
 Needs little care for maintenance.
 Free from CO & Nox – Less air pollutants

ALTERNATIVE FUELS
LPG: Disadvantage
 The vaporizer allows fixed volume mixture to the Engine. Produce 10% less
horse power than engine at full throttle.
 Higher ignition temperature (410 – 580oc). High voltage spark is required &
Reduce the valve life.
 A good cooling system is required For converting liquid LPG to gas, vaporizer
uses the coolant temperature.
 More weight because of heavy pressure LPG Cylinders.
 A special fuel feed system is required for LPG Gas supplies.

ALTERNATIVE FUELS
LPG: Engine Modification
 Taken From ARPN Journal of Engineering & Applied
Science.
 Title is as Conversion of a Gasoline Engine Into an LPG-
Fuelled Engine .
Manufacturer
Proton Gen 2 (1600 cc) – Malaysian
Manufactured
Engine Model S4PH – 1.6
Number of cylinders 4
Orientation East-West
Valve Train DOHC – 16V
Combustion Chamber Pentroof Type
Bore*Stroke 76.0mm * 88.00mm
Compression Ratio 10.0:1
Fuel Injection Indirect Injection

ALTERNATIVE FUELS
 Taken From ARPN Journal of Engineering & Applied
Science.
 Title is as Conversion of a Gasoline Engine Into an LPG-
Fuelled Engine .
Cooling System Water Cooled
Maximum Torque 148 Nm (4000 rpm)
Maximum Power 110hp (6000 rpm)

ALTERNATIVE FUELS
 The conversion is mainly depends on Fuel
delivery system.
 Either by Carburetor or Injection system.
 Conversion methodology subjected to space
constraint and availability.
 LPG Installation done by very little
modification on Vehicle.
 After installation, the vehicle is able to switch
between two fuel system operation.
LPG – Selector Switch

ALTERNATIVE FUELS
 This conversion were very
crucial & must comply all safety
specifications.
 The fuel tank met the
requirement of MS 642 : 1982.
 So maximum capacity is 34
liter & Maximum pressure
of 33 bar is chosen.
 The fuel line must met the
standard of MS ISO 8789:2005
with the 25 bar maximum
pressure and able to operate in
the temp range -40 to 100oc

ALTERNATIVE FUELS
 ECU & Solenoid valve controlled
the LPG Injection into the
intake manifold.
 Injector size depends on
Engine & Cylinder size.
 The solenoid valve is a shut off
valve, enables the LPG Flow to
the injector.
 The LPG Fuel pump is a
Diaphragm pump that
circulates the LPG in the fuel
line system. shut off valve

ALTERNATIVE FUELS
 Maximum pressure provide by
the pump is 6 Bar.
 A pressure sensor is helps to
regulate the pressure in the
LPG Line.
 LPG system is operated by a
custom ECU, That integrated
with the petrol ECU.
 This ECU receives signals from
Lambda sensor, Pressure
sensor, Temperature sensor,
Ignition coil and petrol
injectors, then calculates the right injection quantity and timing of the LPG.

ALTERNATIVE FUELS
LPG Vehicle: Example
Dutch Bus – LPG Fuel
LPG Fuel Tank

ALTERNATIVE FUELS
Biodiesel:
 Biodiesel is a fuel made from vegetable oil, Animal fats, Used Restaurant
grease.
 It is a straight replacement of diesel or blend with diesel in the ratio of 20%
Biodiesel & 80% Diesel.
 Biodiesel can be produced through a transesterfication process, Forming fatty
ester
“Ester is Chemical
Compound derived from
Alcohol”

ALTERNATIVE FUELS
Biodiesel:
 20% blending with diesel provides reduced CO2 emission by 15%.
 100% Biodiesel can lower CO2 emission by 75%
 It can produce Fewer particulate matter, Carbon Monoxide, and Sulphur
dioxide emission.
 One of the byproducts of biodiesel production is Glycerol,
 It is widely used in a food industry as a sweetener.
 Commonly seen in several cosmetic products like moisturizer cream,
Shave cream, Eye Drops.
 More safe to store, handle, and transport, because it has higher flash point of
150oc
 Gasoline = - 43oc, Diesel >52oc, Ethanol 70% = 16.6oc

ALTERNATIVE FUELS
Biodiesel: Transesterfication
 Most economical process to produce
Bio-Diesel.
 Low temperature & Pressure is
required.
 98% Conversion yield is achieved.
 Triglycerides is a main constituents of
body fat from animals & Vegetable
 Triglycerides are formed by combining
glycerol with three fatty acids
molecules.
 Process of a Triglyceride (Fat/oil) with
an alcohol to forms esters & Glycerol.

ALTERNATIVE FUELS
Biodiesel: Transesterfication
 The alcohol reacts with the fatty acids
to form mono-alkyl ester and crude
glycerol.
 In most production Methanol or Ethanol
alcohol is used
 Common base Catalyst will be NAOH or
KOH
 Methanol forms methyl ester & Ethanol
forms ethyl ester.

ALTERNATIVE FUELS
Biodiesel: Advantages
 Most environmental friendly fuel – Less
emission.
 Helps to lubricate the engine itself, decreasing
engine wear
 It can be used in any diesel engine – No
conversion is required.
 Safe to transport easily & Safer to store – have
high flash point (Not to ignite easily)
Bio Diesel Powered
Bus in Nebraska

ALTERNATIVE FUELS
Hydrogen fuel :
 Most abundant element in the universe.
 But does no exist by itself in nature.
 But it is available by bonded to other elements.
 Such as water, Natural gas, Coal, Gasoline, Methanol.

ALTERNATIVE FUELS
Hydrogen fuel :
 Hydrogen can produce from a number of different
sources, including natural gas, Coal, or biological
material.
 Generally two methods followed for hydrogen production.
 Electrolysis
 Synthesis gas production from steam reforming or
partial oxidation.
 Hydrogen can be used by fuel cells to produce electricity
to power an electric automobile.
 When burned in an internal combustion engine, small
amounts of nitrogen oxides and small amount of
unburned hydrocarbons and carbon monoxide are
produced.

ALTERNATIVE FUELS
Hydrogen : Why hydrogen fuel
 Most abundant element in the
universe
 Excellent energy carrier
 H – 142MJ/Kg
 Petrol – 46.4MJ/Kg
 Ultra low/Zero emissions
 Economically competitive
 H – Cost per gallon: $1 – 1.80
 Petrol – Cost per gallon: 2.32$
 Safe and secure
 Can be used safely as gasoline
 Domestically produced from a variety
of sources
Weight of energy system to
travel 100 miles
Batteries Petrol Hydrogen
0
300
Typical Engine Efficiency
Fuel Cell IC Engine

ALTERNATIVE FUELS
Hydrogen fuel production
:Electrolysis
 It is a promising option for hydrogen
production from renewable resources.
 It is the process of using electricity to
split water into hydrogen and oxygen.
 This reaction takes place in a unit
called electrolyzer.

ALTERNATIVE FUELS
:Electrolysis - Working
 Like fuel cells, electrolyzers consists of
an anode and a cathode separated by
an electrolyte.
 Electrodes are separate by Polymer
electrolyte membrane (PEM)
 Water reacts at the anode to form
hydrogen and positively charged
hydrogen ion’s (Protons)
Anode : 2H2O O2 + 4H+ + 4e-

ALTERNATIVE FUELS
:Electrolysis - Working
 The electrons flow through an
external circuit and the hydrogen ions
selectively move across the PEM to
the cathode.
 At cathode, Hydrogen ion’s combine
with electrons from the external
circuit to form hydrogen gas.
Anode : 4H+ + 4e- 2H2

ALTERNATIVE FUELS
Hydrogen fuel production :Steam Reforming
 Most of the hydrogen produced through the
CO2 intensive process called steam Methane
reforming.
 High temperature steam (700oc – 1000oc) is
used to produce hydrogen from a methane
source, such as Natural gas.
 Methane reacts with steam under 3-25 Bar
pressure in a presence of catalyst to produce
hydrogen, Carbon Monoxide, and small
amount of Carbon Dioxide.
 It is a endothermic, heat must supplied to the
process for the reaction to proceed

ALTERNATIVE FUELS
 Subsequently : Water – Gas shift reaction
will happen
 Now Carbon Monoxide & Steam are
reacted using a catalyst to produce
Carbon Dioxide and more hydrogen.
 Pressure swing adsorption:
 Carbon dioxide & Other impurities are
removed from the gas stream,
 And leaves essentially pure hydrogen.
 Steam reforming can also be used to produce
hydrogen from other fuels, such as ethanol,
Propane or even gasoline.
HTS – High temperature shift
Iron Oxide – Chromium Oxide
LTS – Low temperature shift
Copper Based catalyst

ALTERNATIVE FUELS
Steam Methane Reforming reaction:
 CH4 + H2O + Heat CO +3H2
Water Gas shift Reaction :
 CO + H2O CO2+H2+Small amount of heat

ALTERNATIVE FUELS
Hydrogen fuel production :Partial Oxidation
 Also called gasification
 Chemical reaction – a Mixture of a hydrocarbon
feedstock and a sub-stoichiometric amount of pure
oxygen are reacted together.
 This will produce a syngas stream with typical
H2/CO ratio range of 1.6 to 1.8
Steam Methane Reforming Reaction:
CH4 + H2O+Heat CO+3H2
Water gas shift reaction
Co + H2O CO2+H2+Small amount of heat

ALTERNATIVE FUELS
 POX Reactor is for hydrogen extraction from coal
 Carbon feedstock is reacted with oxygen is called
Exothermic reaction.
 This forms Carbon Monoxide (CO).
 Now the CO flow through water shift reactor, where
CO reacts with steam, forming a mixture CO and H2

ALTERNATIVE FUELS
 Typically Two POX systems are available:
1. TPOX – Thermal Pox
 Temp range > 2200oF
 Used with high sulfur feedstock
2. CPOX – Catalytic POX
 Uses with low Sulfur feed stock & Sulfur
sensitive catalyst
 Temperature range – 1475 – 1650oF
 Which reduces energy consumption

ALTERNATIVE FUELS
Hydrogen fuel : Advantage
 Burns more efficiently in an internal combustion
engine, creates energy more efficiently than
gasoline.
 Perfect fuel for fuel cells
 Cause pure hydrogen reacts with oxygen to
release water thus no emission.

ALTERNATIVE FUELS
Hydrogen fuel : Engine Modification
 Hardened valves & Valve seats are required to
compensate for reduced lubricating properties
 Gasoline fuel has some oil like properties
that typically keep the engine components
properly lubricated
 But hydrogen does not
 Iridium Spark Plug must be used to with
stand high temperature
Hardened valves & Valve seats
Iridium Spark Plug

ALTERNATIVE FUELS
 Ignition coil must be different due to the
properties of hydrogen as fuel.
 Fuel injector must be designed for gas not a
liquid.
 A heftier crank shaft required to with stand
bigger kick provide by hydrogen fuel.
 Pistons, Connecting rods and piston rings
must able to withstand the higher forces &
pressures produced.
 Head gasket must be able to withstand the
higher combustion pressure

ALTERNATIVE FUELS
 Intake manifold modified to accommodate a
supercharger.
 Twin screw supercharger and water-to-air
intercooler to increase power.
 Engine oil must be able to withstand higher
Temperature & Pressure.
 Migration of Hydrogen in oil requires a
separator in engine oil system.
 By product of combustion is Water – Exhaust
system must withstand it.

ALTERNATIVE FUELS
Hydrogen fuel Vehicle : Example’s
Mazada RX - 8BMW Hydrogen - 7

COMBUSTION & EMISSION CHARACTERISTICS
Combustion & Emission Characteristics For Alcohol Fuel:
Testing Procedure :
 Non Road Gasoline Engine used for
Testing Purpose
 Single Cylinder
 Carbureted
 Four Stroke – Stroke Engine
 Spark Ignition Engine
 56 mm Bore Diameter
 58 mm Stroke Length
 Rated Power 2.2 K.W

Testing Procedure :
 A Series of experiments carried out
with Gasoline – Ethanol/Methanol
different Blend Proportion.
 Engine was started & warm up for a
period of 20 – 30 Min.
 Before Run engine with new fuel
blend, it allowed to run for a sufficient
time to consume the remaining fuel
from the previous experiment.
 All the blends were tested under
varying speed conditions.

Testing Procedure :
 Test conducts at Maximum to idling
rpm engine speed.
 Dynamometer control the load of the
engine.
 The engine speed, Fuel Consumption,
Load were measured.
 The brake Power, Brake Torque &
Brake specific fuel consumption were
Computed.
 For Each experiment – 3 Runs were
performed to obtain an average value
of Experimental Data

Testing Procedure :
 After a engine reached a stable
working condition
 Emission parameters such as CO,CO2
HC & NOX From an Online exhaust gas
analyzer were Recorded.
 CO, CO2 HC & NOX emissions reached
average value of acquired data within
20s for each stable operating
condition.

Basic Engine Characteristics : Brake Power
 The power of engine is divided two types:
The net power available at the crank shaft is measured by applying the brake
and is called brake power.
 Indicated Brake Power
 Brake power

Basic Engine Characteristics : Brake Power
Indicated Brake Power :
 The total power available from the expanding of the gases in cylinder.
 This will transmitted through the piston connecting rod & Crank.
 The power will be lost some amount due to the friction of moving part of
Engine.
Brake Power :
 Net Brake power = Indicated power – Power loss due to friction
 Brake Power =
2𝜋𝑁𝑇
60
N – RPM of the Engine
T – Torque produced by engine in NM

Basic Engine Characteristics : Brake Torque
 Essentially power of the Braking system.
 Effective Radius : Brake caliper acts on the disc at a certain distance from
the hub center.
 The force exerted by the caliper, multiplied by the effective radius of the
system – Called as brake torque.
 Brake pad exert a frictional force on the wheels, which creates a torque on
the main axle.
 This force impedes the axle’s current direction of rotation, thus stopping the
car’s forward movement.

Basic Engine Characteristics : Brake Torque
 𝑇 = 2𝜇𝐹𝑟
Where,
T – Braking Torque.
μ – Coefficient of Friction.
F – Force on each pad.
r – Mean Radius (From Center wheel to
center pad)

Basic Engine Characteristics : Brake Specific Fuel Consumption
 Parameter that reflects the efficiency
of a combustion engine.
 Which burn fuel and produces
Rotational power.
 The literal meaning of BSFC is how
much fuel is consume in one hour to
produce one Kilowatt Brake power.
 “Power available at engine shaft”

 BSFC =
𝑚 𝑓
𝑃𝑒
. 3600
 BSFC =
𝑚 𝑓
𝜔 𝑒 𝑇𝑒
 𝑚 𝑓 − 𝐹𝑢𝑒𝑙 𝑀𝑎𝑠𝑠 𝑓𝑙𝑜𝑤 𝑅𝑎𝑡𝑒.
 𝑃𝑒 − 𝐸𝑛𝑔𝑖𝑛𝑒 𝐵𝑟𝑎𝑘𝑒 𝑝𝑜𝑤𝑒𝑟
 BSFC – Brake Specific Fuel
Consumption
 The lower the Brake specific fuel
consumption represent engine is more
efficient.

 𝑇𝑒 =
𝑛 𝑐 𝑉 𝑑 𝑃 𝑚𝑒
2𝜋𝑛 𝑟
 𝑛 𝑐 − 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝐶𝑦𝑙𝑖𝑛𝑑𝑒𝑟
 𝑉𝑑 − 𝐶𝑦𝑙𝑖𝑛𝑑𝑒𝑟 𝑉𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑖𝑐 𝐷𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑚𝑒𝑛𝑡
 𝑃𝑚𝑒 𝑝𝑎 − 𝑀𝑒𝑎𝑛 𝐸𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒 𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒
 𝑛 𝑟 − Number of crankshaft rotation for a
Complete Engine Cycle

Blended Ethanol : Brake Power
 Increased Ethanol content in the blended fuel, Increased the engine brake
power all engine speed.
 With increase in ethanol blend, The Density & Engine Volumetric Efficiency is
Increased.
 This cause increase in power.

Blended Ethanol: Brake Torque
 Increased Ethanol content in the blended fuel, Increased the engine brake
Torque.
 Additional of Ethanol the Octane Numbered is Raised.
 Improves the Antiknock Behavior.
 It allowed more spark advance timing
 Result in Higher Combustion pressure & Higher Torque.

Blended Ethanol : BSFC
 BSFC Decreased as the Ethanol percentage increased.
 As the engine speed increases reaching 600 RPM, The BSFC decreases
reaching its minimum value.

Blended Methanol : Brake Power
 With an increasing fraction of methanol engine power slightly decreased for
all engine speeds.
 The brake power of Gasoline was higher than those of M10 – M30 at High
engine speeds.

Blended Methanol : Brake Torque
 The increase of methanol content decreased the slightly the torque of the
engine.
 The Brake torque of gasoline was higher than higher than those of M10 –
M30.

Blended Methanol : BSFC
 BSFC Increased as the Methanol percentage increased.
 As the engine speed increased reaching 1600 R.P.M. In all proportion the
BSFC decreased reaching its minimum value.

Ethanol add with unleaded Gasoline : Brake Power, Brake Torque
 The Brake Power & Brake Torque is slightly decreased as the percentage of
ethanol increased for all engine speed.

Ethanol add with unleaded Gasoline : BSFC
 The BSFC decrease continued until the percentage of ethanol reached 40%.
 Above this point BSFC Increased.

Methanol add with unleaded Gasoline : Brake Power, Brake Torque & BSFC
 The brake power, Brake Torque,BSFC – Characteristics have opposite line
tendency between Lower & Higher Engine speed.
 These characteristics increased as the percentage of methanol increased for
lower engine speeds (700 – 1400 Rpm).
 While the Characteristics slightly decreased for higher engine speeds (1700 –
2300 Rpm).

Comparison of brake power characteristics under different ethanol and
methanol blended fuels & engine speeds
 Ethanol/Gasoline blends have significant high brake power values than
methanol gasoline blends until the percentage of this blends reaches 40% for
lower engine speeds (700-1400 rpm).
 Beyond that Both the brake power characteristics starts to converge.

 Ethanol/Gasoline blends have significant high brake power values than
methanol gasoline blends until the percentage of this blends reaches 40% for
lower engine speeds (700-1400 rpm).
 Beyond that Both the brake power characteristics starts to converge.

 For Higher engine speeds (1700-2300 rpm) brake power characteristics are
converging until the percentage of the blends reaches 60%.
 Afterwards it’s starts to diverge.

Comparison of BSFC characteristics under different ethanol and methanol
blended fuels & engine speeds
 One can see that ethanol /gasoline blends having significant lower BSFC
values than Methanol/gasoline blends.
 For lower engine speeds, BSFC Characteristics values are converging.

 For lower engine speeds, BSFC Characteristics values are converging.

 While BSFC Characteristics values are diverging for higher engine speed.

Methanol/Ethanol Gasoline : Engine Emission Characteristics
 The engine were run at 2000 rpm with full throttle valve opening.
 For testing the emission characteristics of Toxic gases CO, CO2, HC, NOx

Methanol/Ethanol Gasoline : Engine Emission Characteristics for CO
 CO – Results due to
incomplete
combustion.
 Blended fuel results
in better combustion
of Engine & therefore
CO emission is
reduced.
E5 (M5) 3.654% (3.637%)
E10 (M10) 3.161% (3.145%)
E20 (M20) 2.842% (2.825%)
E40 (M40) 2.337% (2.306%)
E60 (M60) 1.851% (1.824%)
E80 (M80) 1.275% (1.248%)

Methanol/Ethanol Gasoline : Engine Emission Characteristics for CO2
 CO2 – Non toxic, but
contributes to the
greenhouse effect
 Blended fuel results
in reduced CO2
concentration than
gasoline
 Because of Ethanol &
Methanol contains
less C – Atoms than
gasoline.
 This gives low CO2.
E5 (M5) 13.12% (12.96%)
E10 (M10) 12.95% (12.78%)
E20 (M20) 12.25% (12.12%)
E40 (M40) 11.73% (11.68%)
E60 (M60) 10.42% (10.39%)
E80 (M80) 9.78% (9.57%)

Methanol/Ethanol Gasoline : Engine Emission Characteristics - PPM
 One PPM is equivalent to the absolute fractional amount
multiplied by one million.
 To visualize putting four drops of ink in a 55 – gallon
barrel of water mixing it thoroughly.
 Mathematically – One part of solute per million parts of
solution.
𝑃𝑃𝑀 =
1
106
= 10−6

Methanol/Ethanol Gasoline : Engine Emission Characteristics for HC
 Partially Oxidized hydrocarbon when they are
added to the blended fuel.
 Therefore, HC emission decrease to some extent
as ethanol/Methanol added to gasoline increases
 Has high heat of vaporization compared to
gasoline, causes to reduce the cylinder
temperature at high Ethanol/Methanol and Low
Ethanol/Methanol content.
 Causes Misfire & Partial burn in the regions near
to the cylinder wall.
 HC emission increases and the engine power can
slightly decreases.
HOV :
Methanol – 1162.64
Ethanol – 918.42
Diesel – 243
Gasoline - 349

Methanol/Ethanol Gasoline : Engine Emission Characteristics for HC
E5 (M5) 341 (304)
E10 (M10) 301 (297)
E20 (M20) 282 (223)
E40 (M40) 265 (234)
E60 (M60) 273 (261)
E80 (M80) 380 (372)
E5 (M5) 8.98% (11.88%)
E10 (M10) 12.75% (13.91%)
E20 (M20) 18.26% (35.36%)
E40 (M40) 23.19% (32.17%)
E60 (M60) 20.86% (24.35%)
E80 (M80) +10.14% (+7.83%)
Concentration in terms PPM
Gasoline – 345 ppm

Methanol/Ethanol Gasoline : Engine Emission Characteristics for NOx
 Ethanol/Methanol has higher heat of vaporization.
 It cause blends temperature at end intake stroke
to decrease.
 Leads to Engine - out Nox Emission is Decreased.
HOV :
Methanol – 1162.64
Ethanol – 918.42
Diesel – 243
Gasoline - 349

Methanol/Ethanol Gasoline : Engine Emission Characteristics for NOx
E5 (M5) 1957 (1945)
E10 (M10) 1841 (1828)
E20 (M20) 1724 (1574)
E40 (M40) 1498 (1379)
E60 (M60) 1366 (1338)
E80 (M80) 1223 (1207)
E5 (M5) 12.91% (13.44%)
E10 (M10) 18.07% (18.65%)
E20 (M20) 23.27% (29.95%)
E40 (M40) 33.33% (38.63%)
E60 (M60) 39.21% (40.45%)
E80 (M80) 45.57% (53.72%)
Concentration in terms PPM
Gasoline – 2247 ppm

Methanol/Ethanol Gasoline : Engine Emission Characteristics results
 From results E40 & M20 – Most suitable in terms of HC
 By comparing CO,CO2 and NOX - E80 & M80 Were more suitable blend fuel.

END

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