DIMETHYL ETHER- DIMETHYL ETHER- AN ALTERNATIVE AN ALTERNATIVE

FUELFUEL

INTRODUCTIONINTRODUCTION World present oil resources may be wiped out World present oil resources may be wiped out

in 42 yearsin 42 years Need for clean and pollution free environment.Need for clean and pollution free environment. Diesel engine operated on DME fuel has low Diesel engine operated on DME fuel has low

combustion noise and low emission.combustion noise and low emission. Fuel is economical and has many utilities.Fuel is economical and has many utilities. Variety of choices for raw material sourcesVariety of choices for raw material sources

MANUFACTURING PROCESS OF DME

Manufactured presently in two methods

2.Direct synthesis of DME

3CO +3H2 CH3OCH3+CO2

1.Catalytic dehydration of methanol to DME

2CH3OH CH3OCH3+H2O

PROCESS FLOW OF LARGE PROCESS FLOW OF LARGE SCALE BENCH PLANTSCALE BENCH PLANT

CHARACTERISTICS OF DME CHARACTERISTICS OF DME AS A FUELAS A FUEL

Gas at ambient temperature and atmospheric Gas at ambient temperature and atmospheric pressure.pressure.

Colourless clear liquid under six atmospheres.Colourless clear liquid under six atmospheres. Can be transported and stored as a liquid at low Can be transported and stored as a liquid at low

temperatures.temperatures. No sulphur or nitrogen compounds and low toxicity.No sulphur or nitrogen compounds and low toxicity. No corrosive effect on metals.No corrosive effect on metals. Oxygenated fuel.Oxygenated fuel. Combustion is not accompanied by black smoke or Combustion is not accompanied by black smoke or

soot.soot.

PHYSICAL AND CHEMICAL PHYSICAL AND CHEMICAL PROPERTIES OF DME AND DIESELPROPERTIES OF DME AND DIESEL

COMPARISION CHARTCOMPARISION CHARTPROPERTYPROPERTY DMEDME DIESELDIESEL

Chemical FormulaChemical Formula

Boiling Point(Boiling Point(00c)c)

Liquid Density(gram/CmLiquid Density(gram/Cm33))

Liquid Viscosity (Cp)Liquid Viscosity (Cp)

Ignition TemperatureIgnition Temperature(0(0c)c)

Cetane NumberCetane Number

Latent Heat Of Evaporation (KJ/Kg)Latent Heat Of Evaporation (KJ/Kg)

Low Heating Value (MJ/Kg)Low Heating Value (MJ/Kg)

% Wt Of Oxygen% Wt Of Oxygen

CH3-O-CH3CH3-O-CH3

-24.9-24.9

0.6680.668

0.150.15

235235

55-6055-60

460460

28.4328.43

34.834.8

C3H7C3H7

180-360180-360

0.840.84

4.4-5.54.4-5.5

250250

40-5540-55

290290

42.542.5

00

•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 PERFORMANCE AND COMBUSTION CHARACTERSTICS OF DME POWERED CHARACTERSTICS OF DME POWERED

VEHICLEVEHICLE

Study was conducted on diesel engine using Study was conducted on diesel engine using DME as fuel.DME as fuel.

Following parameters were optimised.Following parameters were optimised.1.1. Plunger diameter.Plunger diameter.

2.2. Fuel delivery advance angle.Fuel delivery advance angle.

3.3. Distance of nozzle tip into cylinder.Distance of nozzle tip into cylinder.

OPTIMIZATION OF OPTIMIZATION OF PARAMETERS OF COMBUSTIONPARAMETERS OF COMBUSTION Fuel delivery advanced angle: optimal Fuel delivery advanced angle: optimal

timing is 19timing is 1900 CA BTDC at rated CA BTDC at rated operation conditions and 15operation conditions and 1500 CA BTDC CA BTDC at low speed at low speed

Thermal efficiency maximum at an Thermal efficiency maximum at an injection pressure of 15MPainjection pressure of 15MPa

INJECTION PRESSURE: OPTIMUM INJECTION PRESSURE: OPTIMUM PRESSURE IS 15 MPA FOR DMEPRESSURE IS 15 MPA FOR DME

COMBUSTION COMBUSTION CHARACTERISTICSCHARACTERISTICS

Figure below shows indicator diagram and rate of Figure below shows indicator diagram and rate of pressure rise of DME and diesel engine.pressure rise of DME and diesel engine.

THE COMBUSTION CHARACTERISTICS OF DME AND DIESEL FUEL ARE SHOWN

IN FIG BELOW

OPERATIONAL RESULTS OF OPERATIONAL RESULTS OF DME POWER VEHICLEDME POWER VEHICLE

Noise is equivalent to gasoline vehicle below Noise is equivalent to gasoline vehicle below 90 km and smoke free combustion is realized.90 km and smoke free combustion is realized.

Maximum speed and accelerating performance Maximum speed and accelerating performance are equivalent to that of diesel operation.are equivalent to that of diesel operation.

No apparent wear was observed by adding No apparent wear was observed by adding some lubricant.some lubricant.

Larger amount of mechanical work and Larger amount of mechanical work and smaller amount of wasted internal energy.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.

APPLICATIONSAPPLICATIONS Used as an aerosol propellant.Used as an aerosol propellant. Propellant for cosmetic and coating Propellant for cosmetic and coating

material.material. Can be used as fuel for power generation.Can be used as fuel for power generation. Raw material for chemical processes.Raw material for chemical processes.

1.1. Poor Lubrication And Viscosity Poor Lubrication And Viscosity

2.2. Low Heating Value Low Heating Value

3.3. No Infrastructure Of Fueling System Of No Infrastructure Of Fueling System Of DMEDME

4.4. High Vapour PressureHigh Vapour Pressure

5.5. Low Boiling PointLow Boiling Point

DISADVANTAGES OF DME DISADVANTAGES OF DME FUELFUEL

CONCLUSION1. 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.