Effect of water losses by evaporation and chemical reaction in an industrial slaker reactor

Abstract

A dynamic model of the slaker reactor was developed and validated for Klabin

Modeling, simulation, and analysis of a reactor system for the generation of white liquor of a pulp and paper industry

“…The causticizing reactors C1 to C9 were analyzed in this work in the same experiment in which the slaker reactor was previously modeled and simulated by Andreola et al (2007). The causticizing reactor mathematical model was obtained by component mass balances, according to Equations 1 to 7, and energy balance, Equation 9, based on causticizing reactor i.…”

“…Next, C2 was simulated by admitting that it was initially in the same conditions as those of C1 at steady state, and so forth until the last reactor (C9). It would be worth pointing out that the initial conditions of simulation of C1 were obtained from steady state values reported by Andreola et al (2007) for the operation of the slaker reactor of the system depicted in Figure 1 operating in steady state.…”

“…The kinetic parameters used were those employed by Swanda (1994), while the global heat transfer coefficients of causticizing reactors C1 to C4 were estimated with Equation 15 (Lydersen, 1979), as described by Andreola (2007). The values of U were considered null for causticizing reactors C5-C9, as they were thermally isolated.…”

“…In this model, the causticizing reaction speed was obtained by adding a Ca(OH) 2 concentration term to the empirical kinetics equation of Holman et al (1991) to account for the influence of the added amount of lime, while the slaking reaction rate was approximated by a firstorder reaction rate expression. Andreola et al (2007) analyzed the effect of water loss by evaporation and chemical reaction in an industrial slaker reactor operating in steady state. They developed a dynamic model using an approach similar to that used by Swanda et al (1997).…”

“…1). Mathematical models were developed for nine causticizing reactors using the same approach adopted by Andreola et al (2007). The models were numerically resolved with the concepts of apparent and actual concentrations, and the simulation results were compared to each other and with the plant measurements of temperature, AA and TTA.…”