The Esso Energy Award Lecture, 1988 - Improvements in the combustion of heavy fuel oils

The changing pattern of demand for oil products has required that refining practices be adjusted to maximize yields of premium products from crudes. There has been a concomitant deterioration in the quality of the ‘residual’ or ‘heavy’ fuel oil used in power generation. A major constraint on the burning of such heavy fuel is a restriction on particulate emissions. These emissions largely comprise carbon particles (coke), which form from the individual oil spray droplets and remain unburnt. Poorer quality oils have an increased propensity to form coke, and can give rise to unacceptable emissions. One way of countering these increases is to make the fuel spray finer and hence improve burn-out. Research has been aimed firstly at quantifying the effects of those oil properties that directly influence coke formation and combustion and then at developing improved atomizers and water-in-oil emulsions to reduce droplet sizes.