DME as Diesel Fuel

In 1992, Topsoe discovered that DME has attractive properties as a diesel fuel. These attractive properties include a high cetane number, smooth auto-compression ignition, low engine noise and ultra low soot emission.

Property

DME

Diesel

Cetane number

> 55

38-53

Autoignition temperature, ° C

235

250

Oxygen content, % wt

35

0

Due to the absence of sulfur and metals in the fuel, the emission from a DME powered diesel engine does not contain such compounds. Furthermore, due to the absence of carbon-carbon bonds at the molecular level, DME does not form any soot or other particulate. NOx and a number of other pollutants are substantially reduced as well.

DME as a diesel fuel was field tested in a demonstration project featuring a DME fueled city bus. This field test was performed in a Volvo B10BLE bus with a Volvo DH10A engine, and it demonstrated:

  • Low emission
  • Thermal efficiency potential equivalent to conventional diesel
  • Low noise
  • Safe and feasible handling in fuel storage, vehicle maintenance and drivability

The demonstrated emissions are listed in the following table together with current and future emission requirements for heavy diesel vehicles. Emissions are in g/kWh.

 

Project
results

ECE R49

Project
goals

ECE R49

Euro 2

ECE R49

Euro 3

ECE R49

Euro 4

ESC

NOx

2.99

3.0

7.0

5.0

3.5

HC

0.12

0.3

1.1

0.66

0.46

CO

0.25

0.5

4.0

2.1

1.5

PM

<0.02

0.05

0.15

0.10

0.02