Fluid particle group reaction model and experimental verification

Based on a shrinking core model (SCM) that takes into account the particle size distribution (PSD) and product characteristics, a model is established to simulate the reaction process of the fluid particle group. In this model, a total reaction rate coefficient km is defined to describe the reaction behavior. Simulation results show that the particle group conversion is determined by km, the PSD pattern, and reaction condition. The dissolution characteristics of five kinds of limestone from different places in China are studied by using the pH-stat method in a stirred tank at different temperatures (30–60 °C), pH values (4.6–6.2) and PSD. By choosing proper km, the model can well describe the limestone dissolution process in acid with different reaction conditions. For different reaction conditions, the average total reaction coefficient can be obtained via iteration. Moreover, km can be deduced numerically at a given reaction time, which we propose a new way of obtaining the reaction parameter from experiment.

In our model, a parameter named total reaction rate coefficient km is defined to describe the reaction property. The constants of five samples are in a narrow range, which shows that the coefficient km is independent of characteristics of sample. This parameter can be deduced with numerical technique by coupling mathematical model with experimental data, which proposes a new way of obtaining the reaction parameter from experiment.Figure optionsDownload as PowerPoint slideHighlights
► A fluid particle group reaction model is established incorporated particle size distribution.
► A microscope parameter km controlling the reaction is defined in the model.
► The work proposes an algorithm to deduce microscope parameter km from experiment data.
► The calculation results show that km of samples with different particle size distribution are close.
► The apparent activation energy of limestone dissolution reaction is 18.79 kJ mol−1.