Abstract
In the South-Tyrol region (Italy), 46 gasifiers are currently operating and €200,000 are annually paid to
dispose of as a waste 1300 tons of char. Therefore, there is a considerable interest in finding alternatives
for the valorization of this solid by-product. The aim of this work is to assess the potential of char as
energy source and to compare two scenarios. The first scenario considers the possibility of exploiting char
in a dedicated burner integrated in the gasification plant. The second scenario assumes that all the char is
collected from South-Tyrol and co-fired with biomass in an existing combustion-ORC plant. An economic
analysis was performed evaluating the discounted payback time and both scenarios were modeled using
Aspen Plus. The results reveal that substantial savings in the operating costs of the plants can be
achieved. In the first scenario the owners of the gasification plants could save from 50% to 94% of the char
disposal costs with a payback time ranging between 3 and 7 years. In the second scenario, the owner of
the plant could save approximately €235 k per year with a payback time of approximately 7 years. The
present study provides a basis for further techno-economic studies on char combustion. The results can
be helpful for the owners of the gasification plants in determining the most cost-effective way to dispose
char and to avoid disposing it of as a waste. Furthermore, it is demonstrated how char could be used as a
renewable fuel, with better performance than raw biomass.