Exergy-Based Efficiency Analysis of Pyrometallurgical Processes

Abstract

Exergy based efficiency analysis provides a powerful tool for optimizing industrial processes. In this paper, the use of this technique for pyrometallurgical applications is explored in four steps.First, the exergy concept is introduced, the outline of exergy calculations is presented and the role of a reference state is discussed. Second, it is shown that an unambiguous exergy calculation for pyrometallurgical streams with a complex, unknown phase composition is not straightforward.Hence, a practical methodology is proposed in which a suitable phase-based stream description is estimated prior to the actual exergy calculation. For this, the equilibrium phase composition is calculated while all known stream properties are incorporated as boundary conditions. Thirdly, the proposed methodology is validated by recalculating literature results. This reveals significant deviations for exergy values of the same pyrometallurgical streams. Our results are probably more accurate due to the incorporation of additional phase related information. And fourthly, a full analysis of a zinc recycling process is presented. In a base case scenario, the total exergetic efficiency turns out to be only 1.2%. Based on this result, different process modifications are suggested and quantitatively evaluated. We find that significant efficiency gains are possible.

Exergy based efficiency indicators for the silicon furnace

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Minería a microescala para el desarrollo regional sostenible: Análisis exergético de un caso en Guerrero, México

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Exergy in Copper Converting and Its Relation to SO2 Emissions

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