The Use of Petroleum Coke in Coal-Fired Plant
AUTHOR: Rohan Fernando
DATE: November 2001
This report considers the use of petroleum coke particularly in utilities and the cement industry. It describes the production of petroleum coke worldwide. It discusses how the different types of petcokes are produced and their physical and chemical properties. It considers the markets for utilising petcokes worldwide and the economics of firing petcokes. It describes issues regarding the transport, storage and handling of the fuel. The factors affecting the combustion of petcokes and the features required in burners and boilers firing petcokes are discussed. The mechanisms of corrosion and fouling in boilers firing fuels containing high concentrations of heavy metals are considered and the reasons for differences between residual fuel oil and petcokes are described. The high sulphur and heavy metal content of petcokes raises considerable environmental concerns both regarding emissions to air and land which are considered in the report as are the factors affecting the operation of emission control technologies when firing petcokes in CFB and IGCC plant.
There is considerable worldwide experience in firing petcokes in CFB plant including the NISCO cogeneration facility which is in the USA. This and other CFB plant are described and the operational issues that have arisen are discussed. The AES Deepwater cogeneration plant is one of the few pulverised fuel units designed to fire 100% petroleum coke and the design and operation of the plant are discussed. The experience gained at the St. Johns River Power Park in Florida, USA when cofiring coal and petroleum coke and data available for a petcoke trial at Drax power plant in the UK are described. Examples chosen for experience of petcoke firing in IGCC plant include the Wabash River and the Motiva Enterprises repowering projects in the United States and the Puertollano plant in Spain. A brief description is given of the design and operation of cement kilns and the issues that arise when firing petroleum coke in them.
The author wishes to thank Dr. J S. Smart for his help and advice.