Investigation of a Fixed-Bed Reactor for the Calcination of CaCO3 by the Simultaneous Reduction of CuO with a Fuel Gas
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- 作者：José R. Fernández ; Juana M. Alarcón ; J. Carlos Abanades
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2016
- 出版时间：May 11, 2016
- 年：2016
- 卷：55
- 期：18
- 页码：5128-5132
- 全文大小：254K
- 年卷期：0
- ISSN：1520-5045
文摘
The exothermic reduction of CuO to Cu using a fuel gas as a source of heat to carry out the simultaneous calcination of CaCO3 in a fixed bed has been evaluated. A dynamic pseudohomogeneous model has been developed to describe in detail the transient behavior of this operation. The experimental tests have been performed in a lab scale packed-bed reactor (i.d. × L = 38 mm × 920 mm) containing a mixture of CaO- and CuO-based particles (with 12 and 60 wt % of active phase, respectively). Preliminary heat-transfer studies have been carried out using inert gases at different temperatures to estimate the overall heat transfer coefficient of the system. An overall heat transfer coefficient of around 5 W/m2 K has been obtained, which is a sufficiently low value to claim an operation close to adiabatic conditions. Hydrogen has been chosen as reducing gas. A Cu/Ca molar ratio of 1.8 in the bed allows both the reduction and calcination fronts to advance together, with moderate maximum temperatures of around 870 °C, leaving behind totally converted solids. The effect of the solids temperature on the operation has also been evaluated. A rapid and complete reduction of CuO with H2 has been achieved, even with starting temperatures slightly higher than 400 °C. However, the calcination of CaCO3 was complete only in those zones of the bed where the temperature profile reached 870 °C.