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OLI Systems, Inc. Determining the Ionic Dew Point Amine Surveys in Refinery Overhead Chemistry using OLI Studio Rasika Nimkar May 5, 2017
OLI Systems, Inc.
Determining the Ionic Dew Point Amine Surveys in Refinery Overhead Chemistry using OLI Studio
Rasika Nimkar May 5, 2017
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Copyright© 2017
OLI Systems, Inc.
All rights reserved.
The enclosed materials are provided to the lessees, selected individuals and agents of OLI
Systems, Inc. The material may not be duplicated or otherwise provided to any entity without
the expressed permission of OLI Systems, Inc.
240 Cedar Knolls Road
STE 301
973‐539‐4996
(Fax) 973‐539‐5922 [email protected]
www.olisystems.com
Disclaimer:
This document was produced using the OLI Studio version 9.5.2. As time progresses, new data and refinements to
existing data sets can result in values that you obtain being slightly different than what is presented in this manual.
This is a natural progress and cannot be avoided. When large systematic changes to the software occur, this
document will be updated.
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Amines survey in Refinery Overhead Chemistry
OLI Added MSE parameters for the pure, binary and multicomponent systems of the targeted species.
A list of amines and amine hydrochlorides in the existing OLI V9.5.2 database
Descriptive
name Chemical formula OLI Formula
OLI Tag Cation name Amine Hydrochloride name
OLI Tag Name for hydrochloride
Alkyl amines
Methylamine CH3NH2 CH3NH2 MEAMINE MEAMINEHION Methylamine hydrochloride
MEAHCL
Dimethylamine (CH3)2NH C2H7N DMEA DMEAHION Dimethylamine hydrochloride
DMEAHCL
Trimethylamine (CH3)3N C3H9N TRIMEAMINE TRIMEAMHION Trimethylamine hydrochloride
TMEAHCL
Ethylamine CH3CH2NH2 C2H7N ETAMINE ETAMINEHION Ethylamine hydrochloride
EAHCL
Diethylamine CH3CH2NHCH2CH3 C4H11N DIETHYLAMN DIETHYLAHION Diethylamine hydrochloride
DEAHCL
Propylamine CH3(CH2)2NH2 C3H9N PROPYLAMN PROPAMHION n‐Propylamine hydrochloride
PROPAMHCL
Butylamine CH3(CH2)3NH2 C4H11N BUTYLAMINE BUTYLAMHION Butylamine hydrochloride
BUTAMHCL
2‐Butanamine CH3CH2CH(CH3)NH2 C4H11N SECBUTYAMN SECBUAHION 2‐Butylamine hydrochloride
SECBAHCL
Cyclohexylamine c‐(CH2)5CHNH2 C6H13N CYCLHEXAMN CHEXAMNHION Cyclohexylamine hydrochloride
CHEXAHCL
Ethylenediamine H2N(CH2)2NH2 C2H8N2 ENAMN2 ENAMN2HION Ethylenediamine dihydrochloride
ENAMN2HCL
Table 1
Alkanolamines
Ethanolamine HO(CH2)2NH2 NH2C2H4OH MEXH MEXH2ION Ethanolamine hydrochloride
MEXHCL
Diethanolamine HO(CH2)2NH(CH2)2OH
HN(C2H4OH)2
DEXH DEXH2ION Diethanolamine hydrochloride
DEXHCL
Dimethylethanolamine
(CH3)2N(CH2)2OH C4H11NO DMEXH DMEXH2ION
Diglycolamine HO(CH2)2O(CH2)2NH2
NH2C2H4OC2H4OH
DGXH DGXH2ION
Dimethylisopropanolamine
HOCH(CH3)CH2N(CH3)2
C5H13NO DMIPA DMIPAHION Dimethylisopropanolamine hydrochloride
DMIPAHCL
Methyldiethanolamine
CH3N(C2H4OH)2 C5H13NO2 MDEXH MDEXH2ION
Table 2
Oxygenated amines
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3‐Methoxypropylamine
H2N(CH2)3OCH3 C4H11NO MOPA MOPAHION 3‐Methoxypropylamine hydrochloride
MOPAHCL
Morpholine c‐(CH2)2O(CH2)2NH C4H9NO MORPHOLN MORPHHION Morpholine hydrochloride
MORPHHCL
N‐Methylmorpholine c‐(CH2)2O(CH2)2NCH3
C5H11NO NMM NMMHION N‐methylmorpholine hydrochloride
NMMHCL
N‐Ethylmorpholine c‐(CH2)2O(CH2)2NC2H5
C6H13NO NEM NEMHION N‐Ethylmorpholine hydrochloride
NEMHCL
Table 3
Amines and amine hydrochlorides: In refinery overhead type of application, traditionally the chemistry of interest has been CO2, H2S, H2O,
HCl, NH4Cl, hydrocarbons and amines. Our goal in demonstrating the following parametric survey in OLI
Studio is to demonstrate OLI’s capability in predicting the overhead chemistry behavior at various
temperature ranges.
Process: In the following example, we will mix two different streams together in a Mixer and export the output of
the mixer as a molecular stream. We will then perform a survey on it.
Step1: Adding an Assay stream:
Figure 1
Add a stream
Rename is to “Crude Assay”
Change the Stream amount and Inflows units to lb/hr
Change the Temperature unit to °F.
Add an Assay with the shortcut Shift +Enter
Change the Assay Data type to TBP Curve
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Leave all other items with their default values.
Step 2: Adding the Distillation Data: Add the following data set for the TBP curve:
Figure 2
Assay Parameters: Select the Average Bulk Density Type as Specific Gravity and use 0.855 as the value. Input 10 as the number
of Distillation Curve Cuts. The Thermo Method is API‐8.
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Step 3: Additional Components stream: Add a second stream and rename it as Additional Components.
The conditions:
T (°C) 230
P (atm) 3.05 Table 4
Inflows in lb/hr
H2O 48501.6
HCL 6.99
NH3 1.90E‐05
C2H6 9.93E‐03
C2H4 1.00E‐03
C3H8 0.02755
C3H6 5.63E‐04
H2 1.80E‐04
C6H14 0.012691
C4H10 0.015563
TBUTEN 3.76E‐05
BUTENE1 5.51E‐05
CBUTEN 1.75E‐05
ISOBUTANE 0.031126
ISOBUTENE 5.51E‐05
C5H12 9.66E‐03
IPENTAN 0.012879
N2 0
MEXH 0.011 Table 5
The stream will look like the following:
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Figure 3
Step 4: Add a Mixer:
Add both the streams in this Mixer.
Figure 4
Perform a Single Point Mix calculation at 121 °C and 1 atm.
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Figure 5
Click on Add as Stream button circled above.
Rename the exported stream as a Mixed Stream.
Figure 6
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Step 5: Add a survey:
Figure 7
Click on Specs and select the survey by Temperature. Put the range in from 65.5 °C to 148.8 °C with an
increment of 1.1.
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Figure 8
Click OK.
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Step 6: Formatting an OLI plot to see Ionic Dew Point: In the above example, we have Ethanolamine which has the OLI tag name MEXH 1.This particular amine
at the given conditions does not form a solid salt but forms a highly concentrated ionic liquid instead. OLI’s
parameters for the temperature survey are unit flow rates of all the phases. To see the ionic dew point
effect more clearly, it is advised to add the MEXH2ION and CLION as parameters on the Y‐axis.
Figure 9
Convert the Y‐Axis to Logarithmic Scale to see the following plot:
1 OLI has internal OLI tag names for chemical components. The amine tag names are outlined in Table 2.
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Figure 10
Analysis of the Plot: These plots are conventionally read from high temperature to low temperature because in the refinery
overhead process this type of behavior has highest probability of occurring at the top trays of a distillation
column. The formation of the Ionic phase starts at 105°C.
Below 94°C, we observe high concentrations of MEXHION and CLION. The above phenomenon indicates
the initial formation of the aqueous phase corresponding with a high ion concentration in that phase. In
this specific example, the formation of a concentration solution of ions should be identified as the
separation of a liquid salt. It should also be noted that the liquid salt will practically never be pure because
the ionic amine hydrochloride liquids are freely miscible with water. Thus, we term this behavior as
identification of ionic dew point.
Solid forming Amine: Now that we observed the ionic dew point phenomena, we will plot an amine which does have a
distinctive salt point. For this calculation, we will modify the Additional Components Stream and add 0.5
lb/hr of Ethylenediamine which has OLI tag name ENAMN2.
Repeat Step 4 to Step 6, which involves adding a mixer and adding the Crude stream along with the
modified Additional Components stream and exporting the output at a new stream. Once a survey is
added to the above stream which we can name as Salt Point, we can see the following plot. Remember to
change the Y‐axis to Logarithmic Scale by right clicking on the Y‐Axis.
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Figure 11
The salt point plot can be seen below:
Figure 12
Analysis of the Plot:
Because we have both the ion forming amine as well as the solid forming amine, we can identify both the
ionic dew point and the salt point in the above plot. The water dew point (WDP) in such cases is the
temperature where a large amount of H2O is condensing from the vapor stream. The mole fraction of
H2O in this phase is largest concentration as a rule.
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