Storage Stability of Plastic-derived Diesel Fuel

6 STORAGE STABILITY OF PLASTIC-DERIVED DIESEL FUEL 

As diesel ages a fine sediment and gum forms in the fuel brought about by the reaction of diesel components with oxygen from the air. The fine sediment and gum will block fuel filters, leading to fuel starvation and engine failure. Frequent filter changes are then 

Diesel fuel made from the thermal cracking of plastics is more susceptible to oxidation and polymerization than refinery-made diesel fuels. This is because plastic-derived diesel fuels generally have terminal unsaturation (i.e. double bonds) at the ends of the diesel chains as a result of the P-scission chain cleavage. Over time free radicals that form in the plastic-derived diesel fuels during storage cause the diesel chains with double bonds (a-olefins) to polymerize resulting in a sludgy sediment also known as gum . 

Factors which decrease storage life of diesel  

The expected life of a diesel fuel is indicated by the oxidation stability test (ASTM D-2276). The test measures how much gum and sediment will be deposited after conditioning the fuel at 120°C in the presence of oxygen for 16 h. It roughly corresponds to a years storage at 25°C. A result of less than 20 mg/L of sediment and gum after the test is considered acceptable for normal diesel. 

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