Petcoke

Petroleum coke
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Petroleum coke
Petroleum coke (often abbreviated Pet coke or petcoke) is a carbonaceous solid derived from oilrefinery coker units or other cracking processes.[1] Other coke has traditionally been derived from coal.
Marketable coke is coke that is relatively pure carbon and can be sold for use as fuel (i.e.fuel grade coke), or for the manufacture of dry cells, electrodes, etc. (i.e., anode grade coke). Needle coke, also called acicular coke, is a highly crystalline petroleum coke used in the productionof electrodes for the steel and aluminium industries and is particularly valuable because the electrodes must be replaced regularly. Needle coke is produced exclusively from either FCC decant oil orcoal tar pitch. Catalyst coke is coke that has deposited on the catalysts used in oil refining, such as those in a fluid catalytic cracker. This coke is impure and is only used for fuel.
Fuel GradeCoke is classified as either sponge coke or shot coke morphology. While oil refiners have been producing coke for well over 100 years, the mechanisms that cause sponge coke or shot coke to form are notwell understood and cannot be accurately predicted. In general, lower temperatures and higher pressures promote sponge coke formation. Additionally, the amount of heptane insolubles present, andfraction of light components in the coker feed contribute.
Its high heat and low ash content make it a good fuel for power generation in coal fired boilers, but petroleum coke is high in sulfur and low involatile content which pose some environmental and technical problems with its combustion. In order to meet current North American emissions standards some form of sulfur capture is required, acommon choice of sulfur recovering unit for burning petroleum coke is the SNOX Flue gas desulphurisation technology[2][3], which is based on the well-known WSA Process. Fluidized bed combustion is...