PETROLEUM COKE

Petroleum coke (often abbreviated pet coke or pet coke) is a carbonaceous solid delivered from oil refinery coker units or other cracking processes.[1] Coking processes employed for making pet coke include coking, fluid coking, flexicoking, and delayed coking. Other coke has traditionally been delivered from coal.

This coke can either be fuel grade (high in sulr and metals) or anode grade (low in sulr and metals). The raw coke directly out of the coker is often referred to as green coke.[1] In this context, "green" means unprocessed. The further processing of green coke by calcining in a rotary kiln removes volatile residual hydrocarbons from the coke. The calcined petroleum coke can be further processed in an anode baking oven in order to produce anode coke of the desired shape and sical properties. The anodes are mainly used in the aluminum and steel industries.

Petcoke is over 90 percent carbon and emits 5 to 10 percent more carbon dioxide (CO2) than coal on a per-unit-of-energy basis when burned. As pet coke has a higher energy content, pet coke emits between 30 and 80 percent more CO2 than coal per unit of weight.[2] The difference between coal and coke in CO2 production per unit energy produced depends upon the moisture in the coal (increases the CO2 per unit energy -- Heat of combustion) and volatile hydrocarbon in coal and coke (decreases the CO2 per unit energy).