**4. DME handling, storage and distribution**

**Table 4** shows the boiling points of propane, butane and DME.

**Table 4** illustrates that the boiling point of DME is in between that of propane and butane and all three are gas at room temperature of 15°C. The storage and handling facilities for LPG can therefore be repurposed for DME at a low cost. LPG storage and handling infrastructure is widespread in many countries including India. In addition to the use of existing LPG facilities new installations need to be created for DME. In the existing LPG installations changes will be needed for seals, valves, pressure regulators, gaskets, pumps to handle DME.

#### **4.1 Suitability of materials and storage and handling equipment**

Storage, handling and transport of DME is as a liquid under pressure similar to LPG. DME is compressed to 5 bar pressure for liquefaction at room temperature. Material compatibility of DME with the seals and gaskets in stationary and moving parts has to be established. ASTM specification D7901 gives directions on safety and handling of DME, which includes elastomer selection for gaskets and seals (to avoid their failure). Also, all equipment for DME storage and handling have necessarily to be overground. **Table 5** provides compatibility of different elastomers with DME as per ASTM D7901. Rubber and plastics swell and deteriorate easily on contact with DME as


#### **Table 4.**

*Boiling points of propane, DME and butane [15].*


3 = Moderate to severe effect, 10 to 20% volume swell, 4 = Not recommended for DME use

#### **Table 5.**

*Compatibility of DME with elastomers as per ASTM D7901 [12].*

#### *Replacement of Diesel Fuel by DME in Compression Ignition Engines: Case for India DOI: http://dx.doi.org/10.5772/intechopen.104969*

compared to LPG. Nitrile rubber seals (NBR) and fluoro rubber seals (FKM) are used with LPG but swell in contact with DME and therefore cannot be used with DME.

Cylinder tanks for DME fuel will be similar to LPG, will be fabricated structure consisting of cylindrical shell and panel with filling valve, outlet valve, return valve, safety valve, overfill prevention device, quick coupling and fluid level gauge.
