Energy recovery from industrial waste of a confectionery plant by means of BIGFC plant

The search of environment friendly solutions for waste management, along with increasing costs and recent regulations on waste disposal, leads toward the recovery of energy and requires research activities related to plant definition and thermo-economic comparison. On the other hand, energy recovery from waste has never been an easy task. The high pollutant level in waste combustion gases requires low maximum temperatures in thermodynamic cycles thus affecting the efficiency of the "heat to electricity" conversion process. The recent progress of high temperature fuel cells seems to bring a significant change in this scenario, thanks to the feasible combination with advanced gasification systems. A thermo-economic comparison of different solutions for energy recovery from industrial waste is reported, considering an advanced dual bed gasification-MCFC integrated plant. The solution has been applied to a confectionery plant. Even if this system seems to promise high thermodynamic efficiency, a lot of effort in research is necessary for technical analysis of the advanced plant open issues and for the thermo-economic evaluation of potential advantage over consolidated systems. The thermodynamic analysis has been conducted interfacing Aspen(+) flowsheets developed with the integration of a proprietary numerical code. The definition of a complex plan of costs would have been presumptuous at this stage of the development; therefore, a reverse economic approach has been used and is suggested by the authors; a specific solver has been implemented for this purpose. An extensive survey of the confectionary plant has been conducted considering the present energy system, the current supplies, and the trends of the required energy needs. The results show that the proposed advanced energy system can represent a valid solution for both industrial waste management and for integration in energy supply. (C) 2004 Elsevier Ltd. All rights reserved.