DIMETHYL ETHERAN ALTERNATIVE
FUEL
INTRODUCTION
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World present oil resources may be wiped out
in 42 years
Need for clean and pollution free environment.
Diesel engine operated on DME fuel has low
combustion noise and low emission.
Fuel is economical and has many utilities.
Variety of choices for raw material sources
MANUFACTURING PROCESS
OF DME
Manufactured presently in two methods
1.Catalytic dehydration of methanol to DME
2CH3OH
CH3OCH3+H2O
2.Direct synthesis of DME
3CO +3H2
CH3OCH3+CO2
PROCESS FLOW OF LARGE
SCALE BENCH PLANT
CHARACTERISTICS OF DME
AS A FUEL
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Gas at ambient temperature and atmospheric pressure.
Colourless clear liquid under six atmospheres.
Can be transported and stored as a liquid at low
temperatures.
No sulphur or nitrogen compounds and low toxicity.
No corrosive effect on metals.
Oxygenated fuel.
Combustion is not accompanied by black smoke or
soot.
PHYSICAL AND CHEMICAL
PROPERTIES OF DME AND DIESEL
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COMPARISION CHART
PROPERTY
Chemical Formula
Boiling Point(0c)
Liquid Density(gram/Cm3)
Liquid Viscosity (Cp)
Ignition Temperature(0c)
Cetane Number
Latent Heat Of Evaporation (KJ/Kg)
Low Heating Value (MJ/Kg)
DME
CH3-O-CH3
-24.9
0.668
0.15
235
55-60
460
28.43
DIESEL
C3H7
180-360
0.84
4.4-5.5
250
40-55
290
42.5
•Combustion characteristics were compared with those of diesel engine.
•A DME powered van was developed and its trial operation was carried out on
highway.
Diagram of fuel supply system of DME engine.
PERFORMANCE AND COMBUSTION
CHARACTERSTICS OF DME POWERED
VEHICLE
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1.
2.
3.
Study was conducted on diesel engine using
DME as fuel.
Following parameters were optimised.
Plunger diameter.
Fuel delivery advance angle.
Distance of nozzle tip into cylinder.
OPTIMIZATION OF
PARAMETERS OF COMBUSTION
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Fuel delivery advanced angle: optimal
timing is 190 CA BTDC at rated
operation conditions and 150 CA BTDC
at low speed
Thermal efficiency maximum at an
injection pressure of 15MPa
INJECTION PRESSURE: OPTIMUM
PRESSURE IS 15 MPA FOR DME
COMBUSTION
CHARACTERISTICS
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Figure below shows indicator diagram and rate of
pressure rise of DME and diesel engine.
THE COMBUSTION CHARACTERISTICS
OF DME AND DIESEL FUEL ARE SHOWN
IN FIG BELOW
OPERATIONAL RESULTS OF
DME POWER VEHICLE
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Noise is equivalent to gasoline vehicle below
90 km and smoke free combustion is realized.
Maximum speed and accelerating performance
are equivalent to that of diesel operation.
No apparent wear was observed by adding
some lubricant.
Larger amount of mechanical work and
smaller amount of wasted internal energy.
DME UTILISATION
TECHNOLOGY
The combustion of DME with municipal gas
13A was done and good combustion was
observed.
2.Used as a diesel fuel alternative
1. Ideal for use in diesel engines due to same
or higher cetane value.
2. Modifications to fuel supply system only is
needed.
3. Low soot emissions and greatly reduced
NOx emission
4. Thermal efficiency is similar to that of diesel.
5. Reduced noise levels.
APPLICATIONS
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Used as an aerosol propellant.
Propellant for cosmetic and coating
material.
Can be used as fuel for power generation.
Raw material for chemical processes.
DISADVANTAGES OF DME
FUEL
1.
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3.
4.
5.
Poor Lubrication And Viscosity
Low Heating Value
No Infrastructure Of Fueling System Of
DME
High Vapour Pressure
Low Boiling Point
CONCLUSION
1. Excellent And Environmental Friendly Alternative Fuel
For Diesel Engine
2. Cost of the fuel is much lower than diesel fuel on an
equal basis.
3. Relative high cetane number and low soot emissions
offset the disadvantages of the fuel for the use in CI
engines.
4. It is hoped that the use of DME vehicles will become
widespread in the near future.