Improvements in Production Technique for Pitch-Coke

Abstract

Nittetsu Chemical considered the use of coal tar soft pitch as raw material for coke production because of relatively abundant supply, relatively low cost, and the need for coke in Japan. Although pitch coke has been produced commercially coking at high temperature in coke ovens, Nittetsu was looking for a quicker and economical process to produce pitch coke. The expansion of alminum industry greatly increases the demand for coke especially coke with low sulfur, ash, and metal contents.Thus the world's first coking plant using coal tar sofe pitch was built in Tobata, Kita-Kyushu city, Japan. Delayed coking plant was designed to produce 75000 metric tons per year of green coke and calcining plant was designed to produce 60000 metric tons per year of calcined pitch coke.The basic design and engineering of Delayed Coking Plant was prepared by The Lummus Company in United States. The detailed engineering and construction of the plant were carried out by Toyo Engineering Corporation. The basic design and engine-ering of Calcining Plant was prepared by Petrocarb Incorporated in the United States.The detailed engineering and construction of the plant were carried out by Nissho-Iwai Co., Ltd.(Iwai & Co., Ltd. before merger) and Ishikawajima-Harima Heavy Industries Co., Ldt.Nittetsu Plant has been in continuous good operation from start up (August 26. 1968) except for the scheduled shut-down.The quality ofpitch coke by a new process is higher than petroleum coke and is now used for electrodes and anodes in the aluminum industry in Japan.