Alkali removal with mineral sorbents-Part II: Fixed-bed experiments and model validation

In this work, alkali capture experiments with three sorbents, kaolin, bauxite and bentonite, are performed in a fixed-bed reactor under industry-oriented conditions. The influence of temperature and sorption duration on the loading curve and the sorption efficiency as well as the influence of the sample preparation and the operating conditions on structural properties of the sorbents are investigated. Regarding the alkali reduction in the gas phase, bauxite and bentonite show higher efficiencies compared to kaolin, although sintering leads to a significant decline of the porous structure of both sorbents. In addition to the experimental studies, a 1-D simulation model of the fixed-bed reactor including kinetic data of the sorbents is developed. The simulated loading curves show a good agreement with the experimental results. This validation confirms the suitability of the kinetic model and the model parameters for the mathematical description of the alkali sorption in industrial processes. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, alkali capture experiments were conducted using three sorbents in a fixed-bed reactor under industry-oriented conditions. The efficiency of alkali reduction in the gas phase, as well as the structural properties of the sorbents, were investigated with the influence of temperature, sorption duration, sample preparation, and operating conditions. A 1-D simulation model of the fixed-bed reactor was developed and showed good agreement with experimental results, confirming the suitability of the kinetic model for describing alkali sorption in industrial processes.