Distilled Waste Plastic Oil as Fuel for a Diesel Engine: Fuel Production, Combustion Characteristics, and Exhaust Gas Emissions

Waste plastic oil (WPO) derived from pyrolysis of plastic debris and municipal waste is one of the promising alternative fuels because of its similar carbon chain characteristics and physical properties to diesel fuel. WPO also contains naphtha which is gasoline-like and may not be well-suited to a diesel engine. Technically, naphtha should be eliminated from WPO by distillation, and the resulting product is called distilled waste plastic oil (WPOD). This work experimentally investigates the influences of these fuels burned in a diesel engine on combustion characteristics and exhaust gas emissions. Both WPO and WPOD fuels contribute to the larger amount of nitrogen oxides than diesel fuel. Carbon-based emissions increase when the engine operates with these pyrolysis fuels by retarding the ignition onset of their combustion occurrences. Meanwhile, their shorter-carbon-chain links provide a lower smoke index. However, brake thermal efficiency and brake specific fuel consumption are beneficial because of their high calorific value and cetane index.

Automated summary

This study investigates the combustion characteristics and exhaust gas emissions of waste plastic oil (WPO) and distilled waste plastic oil (WPOD) fuels in a diesel engine. It is found that both WPO and WPOD fuels increase nitrogen oxide emissions compared to diesel fuel. However, they have lower smoke index due to their shorter carbon chains. Furthermore, their high calorific value and cetane index contribute to improved brake thermal efficiency and lower brake specific fuel consumption.