Rigorous Process Simulation Services for the Vegetable

oils & Fats refining industry (Degumming - Neutralising

– Bleaching – Deodorising/Physical Refining)

PROCESS SIMULATION TECHNICS

ProSimTechs MODELLING & SIMULATION

The Deodorising process

2

Deodorising is by far the most energy

consuming stage along the overall vegetable

oil refining process.

On the other hand, the last overall refining

stage along the vegetable oil refining

process.

Also, it is a critical process in terms of the key

quality parameters of final oil.

What we want to get from a Deodoriser ?

Quality

To remove FFAs ?

To remove peroxides, aldehydes and ketones ?

What about the quality of the outlet streams ?

Do we have a given target of tocopherol

concentration in final oil ?

Do we have the same for the distillates ?

Process conditions

But also to use steam as less as possible

To minimize the energy involved

To reduce the waste water

Are a given set of deodorising conditions the same

from a deodoriser and another ?

What if the quality at the oil inlet changes, how

impacts on oil outlet and distillates ?

Do I have to change the deodorising conditions

(temp, sparge steam) ?

Which one first and what would be the new value

for each ?

FATTY ACID

α-TOCOFEROL

Process

Type of Process

Vegetable oil

Equipment

Process condition

s

Lab results

Neutralising

Bleaching

Deodorising

Acid Degummin

g

Deodorising and Physical Refining Process

ProSimTechs MODELLING & SIMULATION

Do all deodorisers have the same performance ?

3

The Deodorising/Physical Refining Process Unit is one the

economic heart of today’s refinery. Small increases in yield can

bring significant gains in productivity and revenues.

Rigoruos process simulation studies have diagnosed operating

problems and helped improve the performance of all major

components of Deodorisers.

Each project is customized to provide the information needed

to optimize or troubleshoot your specific process. All testing is

performed while the unit is online and will not interfere with

normal unit operations or production scheduling.

Data collected can be used to identify operating parameter

changes to improve unit productivity, or gauge the accuracy of

process modeling and simulation.

A typical study employs a rigorous, accurate

and customized model of the process taking

into account the characteristics of the oil, the

flowsheet and the equipment (Deodoriser).

The starting information for the complete

study is the actual information managed by

the plant, for example:

Capacity of processing

Vegetable oil inlet-outlet composition –

Distillate composition

Flowsheet (P&IDs or PFDs) and

equipment characteristics.

Current process conditions

ProSimTechs MODELLING & SIMULATION

4

Modelling and Process Simulation

Process modelling is the activity of building a

mathematical model of the process by describing its

fundamental physical and chemical relationships, by

means of equations.

Process simulation is one of the activities that one

can perform with that process model, using an

appropriate mathematical method to solve it.

Process modeling and simulation are

used to describe a physico-chemical

process as a set of physic-chemical

equations in order to perform all the

calculations involved in it, in a

powerful, accurate, reliable, quick way.

A point during the process of building the model of the vegetable refining process, is to

select the appropriate models for each main parts of simulation model:

Thermodynamic models: the fatty compounds requires a very specific

thermodynamic model, more over considering Unit Operations with liquid-vapor

equilibrium (LVE) processes.

Unit operations models rigorous: most of the key process equipments are quite

particular and non std designs (deodorising trays, packed columns, scrubbers).

Compounds (basic data and temperature dependent properties): quite complex

molecules, a few info available, predictive approach is required.

Flowsheet Streams 94

No of Components 15

Stream IDs 1 2 3 4 5 6 7 8 9 10 11

Labels ED oil RD oil880A RB

outl

881B RD

outlet1 FDA

881A RD

outl

Temperature C 100,0 226,2 155,8 229,6 40,0 0,0 243,6 155,8 30,0 36,0 109,0

Pressure bar 0,0025 0,002129 0,0022 0,002129 3 0 0,0015 0,0022 3 3 3

Enthalpy kcal/h -19936204 -16380971 -14630424 -16310434 -20447798 0 -1756602 -14630424 -879883840 -8,78E+08 -19054854

Vapor Mole Fraction 0,017944 0 0 0 0 0 1 0 0 0 0

Total Mole FlowRate kmol/h 51,61 47,04 77,94 47,13 47,04 0,00 26,55 77,94 12911,57 12911,57 47,04

Total Mass FlowRate kg/h 42562,0 41511,3 29370,4 41539,2 41511,3 0,0 1440,1 29370,4 232602,0 232602,0 41511,3

Total Std. Liq. Vol. FlowRate m3/h 47,59 46,42 32,88 46,45 46,42 0,00 1,56 32,88 232,60 232,60 46,42

Total Std. Vap. Vol. FlowRate m3/h 1156,72 1054,25 1746,95 1056,42 1054,25 0,00 595,15 1746,95 289395,31 289395,31 1054,25

Flowrates kg/h

Soybean oil 8001 41441,9 41436,0 8357,8 41436,4 41436,0 0,0 5,9 8357,8 0,0 0,0 41436,0

Water 62 16,6 0,0 0,1 0,0 0,0 0,0 413,3 0,1 232602,0 232602,0 0,0

Sodium Hydroxide 429 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0

Phosphoric Acid 474 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0

Oleic Acid 549 1049,6 35,8 16525,5 62,7 35,8 0,0 1013,8 16525,5 0,0 0,0 35,8

PhosphatidilColi 8002 0,3 0,3 0,0 0,3 0,3 0,0 0,0 0,0 0,0 0,0 0,3

TriNa Phosphate 985 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0

Na oleate 8003 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0

PA Ca salt 8004 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0

Phosphatidic aci 8005 1,5 1,5 0,0 1,5 1,5 0,0 0,0 0,0 0,0 0,0 1,5

Air 475 0,8 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0

TriCalcium Phos 8006 0 0 0 0 0 0 0 0 0 0 0

a-Tocopherol 8007 29,38913 17,14102 3115,846 17,62821 17,14111 0 5,782386 3115,846 0 0 17,14111

Sitosterol 8008 21,91007 20,55648 1371,233 20,69374 20,55651 0 1,353522 1371,233 0 0 20,55651

1,000

2,000

3,000

4,000

5,000

6,000

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8,000

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10,000

11,000

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138 140 142 144 146 148 150 152 154 156 158 160 162 164 166 168 170 172 174 176 178 180 182

To

co

ph

ero

l co

nc (%

w/w

)

Hot Scrubber condensing Temperature (ºC)

Tocopherol conc (% w/w) in 1FDA

6,0

8,0

10,0

12,0

Spargingsteam (Kg/Tn)

SCREEN SHOT OF

PROCESS SIMULATION

OF A DEODORISING

ProSimTechs MODELLING & SIMULATION

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Study case: Soybean oil in Physical Refining /Deodorising + Double Scrubber

Relevant information for the Modelling

Process conditions

Oil inlet temperature (ºC)

Final heating temperature (ºC)

Temperatures in heat recovery stages

Oil outlet temperature (design)

Vacuum at suction (mbar)

Final heating temperature (ºC)

Sparge steam distribution (Kg/h, or Kg/Tn)

Motive steam (Kg/h each stage)

Condensing temperature

Equipment

Type and general dimensions of

the main equipments

Heat exchange areas

Distillate/s composition

FFA (%)

Tocopherol (%)

DAG (%)

MAG (%)

Sterols (%)

Vegetable oil inlet composition

FFA (%)

Tocopherol (ppm)

DAG (%)

MAG (%)

Water (%)

Sterols (%)

Vegetable oil outlet composition

FFA (%)

Tocopherol (ppm)

DAG (%)

MAG (%)

Water (%)

Sterols (%)

Relevant information for validation of first simulation run

ProSimTechs MODELLING & SIMULATION

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Objectives

Modelling of the process

Simulation of a given scenario in terms of process conditions and oil inlet quality

Validation of the modelling against plant

Sensitivity studies and optimisation

To analyse sensitivity variables of Tocopherol scrubber

To compare tocopherol concentration vs distillate amount

Piping and instrumentation diagram (P&ID)

Study case: Soybean oil in Physical Refining /Deodorising + Double Scrubber

High

pressure

boiler

Sparging

steam

Inlet oil pump

Degummed

bleached oil Deareator

tank

Stripping

Outlet oil

pump

Vacuum

system

Deodoriser

Hot

Scrubbing

TOD

circulating

pump

CWS

TOD

CoolerCooling

water pump

CWR

TOD

collecting

tank

TOD

(Toco enriched

distillate)

Final

heating

CWS

CWR

Economiser

Final

cooler

Refined

palm oil

Superheater

Natural

gas

Combustion

gas

Degummed

oil

Degummed

oil

Cold

Scrubbing

FAD

circulating

pump

CWS

FAD

CoolerCooling

water pump

CWR

FAD

collecting

tank

FAD

(FFA enriched

distillate)

From the real P&Id of the plant

A flowsheet of the process with the

main streams is then built, in order to

be considered during the construction

of the simulation model of the

process

ProSimTechs MODELLING & SIMULATION

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Simplified Process Diagram + Relevant process information

Sensitivity analysis

- To choose those critical process variables as independent variables

- To set up the working value range of each variable

- To plot results and to analyse the figures

Objective

- We want to find an optimum point for both tocopherol concentration in

TOD distillate and drawn TOD distillate.

Introduction

- Base case (current situation) was modelled and simulated. Tocopherol

concentration in tocopherol enriched distillate (TOD), under current

conditions, is around 12 % in weight.

ProSimTechs MODELLING & SIMULATION

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Sensitivity analysis – Tocopherol

concentration in TOD

In these 2 graphs, it is shown the

influence of stripping steam and

condensing temperature on the

tocopherol concentration of the distillate

drawn from first scrubbing stage (Hot

Scrubber). The rest of the process

conditions are kept constant.

What is taking place is on one hand, as

the sparging steam increases, the

amount distilled of tocopherols and other

volatile compounds also increase. On the

other hand, increasing the condensing

temperature in hot scrubber, the

tocopherol concentration begins to rise

up to a given value ( a max optimum

value), then from this point the

tocopherol concentration falls down, as

the temperature continues increasing.

Basically, what is happening is that along the first

part of the curve, most of the lower vapor pressure

compounds are condensed with also a given

fraction of fatty acids (higher vapor pressure

compounds), as the temperature increase is fesible

to achieve a max tocopherol concentration, since

lesser amount of fatty acids are condensed.

ProSimTechs MODELLING & SIMULATION

9

Sensitivity analysis – Tocopherol concentration in TOD

Now, normally to increase tocopherol

concentration in tocopherol enriched

distillate has a compromise: amount of

drawn distillate.

The effect of increasing the condensing

temperature in Hot Scrubber aiming to

maximise the tocopherol concentration in

this distillate, has the collateral effect of

reducing the amount of distillate, this is

due to, as was said, now a fraction of

fatty acids is not condensed in this stage,

achieving the objective of increasing the

tocopherol concentration. What also, a

given fraction of tocopherol is not

condensed in this stage as well. Which is

going to be finally condensed in the final

scrubbing section (cold scrubber)

together with the rest of fatty acids. So, here the objective is to optimise both

tocopherol concentration jointly with the

amount of distillate, with the final target

of getting the maximum market price of

this by-product.

ProSimTechs MODELLING & SIMULATION

10

Remarkable Facts/Summary

Physical refining / Deodorising is a very complex process from the point of view

of the distillation

Vegetable oil is a multicompound mixture

Quality of the outlet streams are very sensitive to the process conditions

Also configuration and type of the equipment plays a role towards a given product

quality

Each plant is very particular in terms of equipment configuration, oil quality and

process conditions and target

Modelling and Simulation is an optimum and very valuable tool to predict and

analyse different scenarios and see “what if”

The information from a simulation run, sensitivity analysis and global optimisation

allows to have an in-depth knowledge on our process, then to make the appropriate

decision-making.

There is a new point of view to analyze your processes. Let us exchange ideas.

info@prosimtechs.com www.prosimtechs.com

ProSimTechs MODELLING & SIMULATION