an entire process. It would be impossible to acquire the same
knowledge level using ndustrial trials alone.
Q:Can partial processes within a larger process be opti- mized (i.e., deodorization or tocopherol recovery)?
Any of the process units within the refining process can be
optimized through process simulation; one of the key applications of process modeling and simulation in vegetable refining
is deodorization optimization.
Deodorization is a steam stripping process in which
different and complex phenomena occur (mass transfer,
liquid-vapor phase equilibrium, side reactions and hydraulic
effects, as well as the chemistry of a complex mix of lipids). A
process simulation model can take all these phenomena into
consideration, making it possible to predict changes in the
composition of outlet streams (deodorized oil and distillates)
under different process conditions, or with composition
changes in bleached oil, with a high degree of certainty.
For instance, the procedure typically used to study the
possibility of reducing the stripping steam consumed in the
deodorizer is to reduce the total stripping steam flowrate
injected into the column. However, in some cases it is better
to understand the effect of closing the injection of stripping
steam in the last stage (last tray). For this analysis, you must
know the free fatty acid (FFA) concentration in the oil at each
stage. Although this thought process is not feasible in a real
deodorizer, a simulation model can do these studies quickly
due to its stage-to-stage column design.
The process simulation of tocopherol concentration is
another clear application of processing optimization. For example, in a process performed in a double scrubber, the tocopherol
concentration and drawn mass are sensitive to the condensing
temperature of the so-called “hot scrubber.” However, due to the
nature of phase equilibrium of the compounds present in the
distillate, there is a peak in the tocopherol concentration curve
related to this temperature. This peak is not easy to find during
industrial tests, but it is easily detected with process simulation.
Locating this peak and matching it with the amount of drawn distillate, allows us to find the process point that maximizes concentration and therefore the revenue of tocopherol distillate.
Q:How has process simulation been implemented in the Mercosur region?
Within Mercosur, and in fact in all of South America, soft
oils (soybean, canola, sunflower), tallow, and tropical oils (palm
oil and its fractions) are used for specific final applications. This
makes it necessary to obtain the same final product from variable stock, sometimes with changes in processing conditions.
Processors in Mercosur using process simulation now have
a great tool to anticipate processing scenarios using variable
Q:Can process simulation increase safety at the plant The application of process simulation to process optimization is more straightforward than it is for industrial safety.
Also, there is software in the market that is more specific for
industrial safety analysis, for instance for relief systems, thermal stress analysis, and so on.
Q:On a practical level, how do simulation models for veg- etable oil refining work?
Using a rigorous and complex simulation platform
embedded in MS Excel, but at the same time a simple to use
tool, you can run any kind of processing scenario to asses a
new scenario or to diagnose a current one. The key is to build
the model and to validate it against plant conditions and lab
data, so you will have a high degree of certainty of results.
These are the steps we follow when we build a given process
simulation model. The process engineer can then apply it to
any kind of processing scenario and select which one should
be tested at the industrial scale.