An Integrated Framework for Model-Based Solids Process Engineering

Solids processes are estimated to rarely reach more than 60% of design capacity and require 10 times longer to start-up than those involving only liquid-gas streams.  The business costs associated with these staggering statistics are exacerbated by the capital and energy-intensive nature of solids processes.

This contribution therefore focuses on the development of a model-based engineering tool that can help address these problems through a better understanding of the process and associated risks.

The first part of this contribution describes a new modelling framework for solids process aimed at providing a step change in the facilities available to engineers responsible for the design and operation of industrial solids processes.  This framework has the following characteristics:

Use of fully discretised population balances (particle size distributions and composition distributions).

Ability to address true dynamics.

Robust handling of large numbers of recycles.

Support for model validation (parameter estimation and experiment design).

Optimisation capability for design and operation of processes.

Interfacing to standard CFD packages.

Phenomenological approach to model development that facilitates rapid and consistent development of models.

An intuitive user interface.

The second part of this paper covers a number of typical case studies investigated with this new framework:

1. Model discrimination and parameter estimation using experimental data from a fed-batch agglomeration process.
2. Analysing the impact of uncertainty in model and design parameters on process performance in order to quantify risk associated with capital expenditure decisions.
3. Determining the optimal trade-off between on the one hand low capital cost and reduced start-up times of the process and on the other hand the robustness of the process with respect to downstream disturbances (e.g. blockages).
4. How does the operation of upstream units, in this case a crystalliser, impact the capacity of downstream solids handling?
5. How can information from lab-scale studies coupled with CFD simulations of plant-scale equipment be coupled to aid plant scale equipment design and optimisation?