Exergy Analysis of Charcoal Charging Operation of Blast Furnace

Effective use of biomass resource is expected to be one of the solutions to the environmental problems, since a sort of biomass absorbs carbon dioxide through photosynthesis reaction. One of the possibilities to utilize such biomass resources is the replacement of coal and/or coke with charcoal. With nature of charcoal it is known that the hot metal quality can be improved as well as abatement of environmental impact through less slag generation and virtually no CO 2 and SO 2 emissions. This paper performed an exergy analysis on charcoal charged blast furnace. As a result, it is revealed that the charcoal system needs more enthalpy and exergy inputs than conventional ironmaking system while it produces more energy available in the other processes. This keeps exergy loss in charcoal system in the comparable level with the conventional system. The analysis shows that each process included in the system still has a possibility to be improved. Thus the performance of the charcoal system is expected to be equivalent to or even better than the conventional system. Therefore ironmaking system with charcoal charged blast furnace is expected to be a key technology to contribute environmental issues.