Investigation of the effects of palm biodiesel dissolved oxygen and conductivity on metal corrosion and elastomer degradation under novel immersion method

•Copper and NBR compatibility with biodiesel under modified immersion was studied.•Modified immersion simulated CRDE operation through fuel renewal.•Biodiesel dissolved oxygen and conductivity promoted materials degradation.•Good compatibility exists between biodiesel and fuel delivery materials.•Dissolved oxygen and conductivity reductions lessen materials degradation. The aim of this work was to investigate the compatibility of fuel delivery materials with palm biodiesel fuel under novel immersion method which simulated diesel engine operation. For this, a two-stage investigation was conducted. In the first stage, the effects of biodiesel dissolved oxygen concentration and conductivity value on fuel delivery materials degradation under standard immersion were determined as a baseline study. In the second stage, modified immersion investigations which simulated the deterioration of biodiesel under common rail diesel engine operation (CRDE) were carried out to ascertain the compatibility present between fuel delivery materials and palm biodiesel. Palm biodiesel dissolved oxygen and conductivity were found to adversely affect both copper corrosion and nitrile rubber (NBR) degradation. The copper corrosion rate and NBR volume change increased by 9% and 13%, respectively due to 22.5% increase in the conductivity. In contrast, the copper corrosion rate and NBR volume swelling reduced by 91% and 27%, respectively due to 96% reduction in the dissolved oxygen concentration. Copper corrosion and NBR degradation were found to be lowered by up to 93% and 85%, respectively under modified immersion as compared to standard immersion. This study has inferred that good compatibility is present between fuel delivery materials and biodiesel under CRDE operation.