Combustion of preheated raw animal fats-diesel fuel blends at diesel engine

摘要

Because of pollution problems, after the Mayors Summit 2016 takes place, certain European capital cities want to be free from diesel engines automotive equipped with diesel engine by the year 2020. Also, the International Energy Agency affirms that the per cent of bio energy must increase till the year of 2025 and estimates that biofuels can grow to as much as 30% of the world's road transport fuel mix by 2050. The global share of biofuel in total transport fuel would grow from 2% today to 27% in 2050. According to a European Commission report on the Future Transport Fuels, the 2020 Red target could be supported by vehicles fuelled by fuels based also on animal fats. The objective of the paper is directly related with these worldwide aspects. The paper presents combustion aspects at a diesel engine fuelled by raw animal fats blended in per cent's of 5% and 10% with diesel fuel. For the same engine adjustments, the preheated raw animal fats use leads to the decrease of in-cylinder pressure with 5% and 12%, depending on animal fats content. Even if the animal fat use provides the increase in the combustion duration with 20 CAD and later achieving per cycle of the mass fraction burned, the heat release rate decreases with 16% (at 5% animal fats) and 20% (at 10% animal fats) assuring the decreasing of the NOx emission level with 22% versus diesel fuel. The smoke opacity decreases with 22% (at 5% of animal fats in blends with diesel fuel) and with 52% at the rise of animal fats content to 10%. The novelty of the paper is assured by aspects like: an efficiently recover of raw animal fats from the leather industry assuring an important decrease of waste stocks and of financial costs, an optimal correlation between animal fats per cent and diesel engine combustion performance. The raw animal fats can be considered a very good alternative biofuel for the diesel engines and can be used for fuelling without major constructive modifications of the engine.