Demonstration of Using Bio-coke from Mixed Feedstock at General Waste Incineration Facilities and Cupola Furnaces

Abstract

Bio-coke is carbon-neutral fuel, and expected for CO₂ reduction method in some industries using coal coke and foundry coke. Municipal waste incineration facilities in Japan often use gasification melting furnaces due to their high environmental performance and ash volume reduction. Cupola furnaces are also widespread in foundry industry manufacturing ductile iron pipes, gas pipe, etc. This study aims to achieve two objectives: (1) development of effective and economic technology to produce bio-coke from mixed feedstock generated in Yokote City, Akita Prefecture (mainly rice husks, bark and mushroom bed) and (2) demonstration of reduction of CO₂ emissions from gasification melting furnace and cupola furnace by using bio-coke as a substitute for coal coke and foundry coke. In the demonstration of using bio-coke at the gasification melting furnace, the coal coke consumption is reduced up to 51%. In the cupola furnace test, the foundry coke consumption is reduced about 5% by using bio-coke. However, some challenges of using bio-coke at the cupola (change of stack gas components, storage condition and mechanical strength, etc.) are identified.