Petroleum coke is a common solid fuel of petrochemical industry and is usually used in the form of co-combustion with coal. Because of its high sulphur content

limestone is often employed to capture SO_2.Meanwhile

limestone and various solid materials generated during the combustion process may influence the emission of NO_x. To investigate this influence rules

the effects of limestone

coal ash

petroleum coke ash

fly ash

slag and solid materials on NO formation during co-combustion of coal and petroleum coke are studied on a horizontal tube furnace. The results show that the burn out time of char is shortened and the formation of SO_2 is suppressed by CaO. Besides

the formation of NO is significantly promoted by limestone on account of limestone or the decomposition of limestone. Coal ash and petroleum coke ash with abundant Fe

V and Ni can also promote the formation of NO. While the effects of fly ash

slag and furnace ash are not obvious. This result is conducive to understand the effects of solid materials on NO formation during co-combustion of coal and petroleum coke

and is of positive significance for taking reasonable measures to reduce NO_x emission.