Design of solids processes: production of potash

Abstract

The adsorption of water from toluene was studied using the following desiccants: activated alumina, 3A molecular sieves, and 4A molecular sieves. Water isotherms were measured, mass-transfer rates were studied by means of batch-type kinetics experiments, and breakthrough data were determined by means of flow experiments using fixed beds of the desiccants. A linear driving force mass-transfer model was found to fit the breakthrough results, with equilibrium and mass-transfer parameters determined from the isotherm and kinetics experiments. The results showed that intraparticle diffusion offers the controlling resistance to the transport of water.

Synthesis of processing system around a crystallizer

“…Then the filter cake is washed with water to get rid of reaction solvent (Rule 6). In a potash plant (Rajagopal et al, 1988), the evaporative crystallizer effluent is recycled back to the dissolver to replenish dissolved potash (Rule 15). Seed crystals are recycled from the solid-liquid separation system to the crystallizer in an alumina plant (Rule 16) (Hill and Ng, 1997).…”

“…They found that the crystal size can be constrained by the mother liquor entrainment limit of the crystallizer, and that the crystal size affects the residual moisture content in the centrifuge and, thus, the drying cost. Similarly, for a potash plant, Rajagopal et al (1988) found an optimal dominant crystal size which depends on a tradeoff between the crystallizer cost and the filter cost.…”

Screening procedure for synthesizing isothermal multiphase reactors

“…The finite difference method is conceptually the simplest. It calculates the sensitivity to a small change in a via difference approximations; see Rajagopal et al (1988) for an example. Our sensitivity analysis is based on the direct differential method, which involves the solution of the sensitivity equations derived from Eq.…”

Simulation of solids processes accounting for particle‐size distribution

“…The input parameters used for this case study are summarized in Table 3. Rajagopal et al (1988) studied the same process using the dominant crystal size. To show the possible error caused by ignoring the PSD, simulations are performed with the mean particle size ( D ) and with the PSD.…”