Analysis of the economic feasibility of industrial production of charcoal from malt bagasse

Abstract

Activated carbon is of paramount importance in adsorption processes in effluent treatment plants. In this context, the academic community directs efforts toward the production of alternative and lower cost adsorbents using agro-industrial residues. In particular, malt bagasse, a residue from the brewing industry, can be used to obtain charcoal, which has been applied on bench scale in the removal of drugs in aqueous systems. Due to the potential for their removal, the present study contributes with an analysis regarding the economic viability of the industrial production of this coal. An analysis focusing on Net Present Value and Internal Rate of Return was used, based on literature, in order to determine the minimum selling price/kg of coal, with pre-established hypotheses. An analysis of the implementation of a charcoal production unit inside the breweries (on site), as well as a company directed to the purchase of bagasse and production of charcoal (off site) was carried out, obtaining a sale price on site of US$ 1.78/kg, and of US$ 1.84/kg for off site, both confirming the economic viability of the project. Furthermore, with a production of 108 tons of charcoal per year with a minimum selling price of US$ 1.78, it is possible to pay the costs, generating a return of 9%. Finally, off-site production becomes more economically interesting, as it is not necessary to reach an agreement with a brewery, whose production takes place within its premises.