Low and high volatile bituminous coals are widely used in PCI blends, but petroleum coke has also been used, often as a cheaper substitute for low volatile coal. The paper aims to study the effect of blending petroleum-cokes with bituminous coals on the combustion characteristics under laboratory conditions. Both physical and chemical properties of coals and pet-cokes were characterized using a range of analytical techniques. The carbon structure of coal and char samples was characterized using X-ray diffraction. Coal and pet-coke blends were injected in an experimental drop-tube furnace (DTF) to characterize char characteristics and burnout under controlled combustion conditions. Char reaction rates were measured in an experimental fixed-bed reactor. The burnout of high volatile coal was higher compared to low volatile coal as expected, however the burnout and reaction rates could not be related to total volatile matter of coal blends. In general, burnout of pet-coke blends was lower than the burnout of coals. The carbon structure of pet-cokes is shown to have a strong influence on the burnout such that up to 10% blending of pet-coke did not show any appreciable effect on the burnout of coals.
