Solving reactor models via alternate specs Jeff Bull Software user conference 2018, USA

1. © 2018 Valero. All rights reserved.
Solving Reactor Models
via Alternate Specs
Jeff Bull
The opinions and views expressed in this presentation are those of the author(s)
and do not necessarily reflect the views of Valero Energy Corporation.

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Agenda
1 What – Reactor Model Targets
2 Why – Limited Standard Targets
3 When – Alternate Target Required
4 Where – Hydrocracker/Reformer Models
How – Adjust Blocks5
6 Examples

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What – Reactor Model Targets
Reactor Model Target Types
– Operational Based (Reactor T)
– Severity Based (Conversion, C5+ RONC)
Reactor Model Targets Represent Independent Variables

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Why – Limited Standard Targets
Reactor Model Targets
– Historical Limitations
– Process Technology Changes
– Situation Dependent
One Size Does Not Fit All

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When – Alternate Target Required
Alternate Target Scenarios
– Standard Targets Not Representative of Plant Data
– Standard Targets Calculated in a Different Manner
– Standard Targets Do Not Capture Secondary Effects
Can Be Used In Either Calibration Or Predict Modes

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Where – Hydrocracker and Reformer Models
Hydrocracker
– Calibration Mode – H2 Consumption (Solubility and Leakage)
– Predict Mode – Alternate Conversion Calculation
Reformer
– Predict Mode – C5+ RONC (Debutanizer Bottoms)

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How – Adjust Blocks
Adjust Blocks
– Very Simple Operation
– Allows Any Independent Variable to be Adjusted to Target a
Second Variable

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Hydrocracker Calibration Mode
Problem
– Calibration Mode – H2 Consumption (Solubility and Leakage)
– Applied in a Unit Monitoring Application
– Two Reactor Once Through Operation
– R2 Hydrogen Consumption Estimate Required
– HCR Model Solves over Wide Range of Hydrogen
Consumptions
– Hydrogen Estimate Distorts Yield Profile

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Hydrocracker Calibration Mode
Solution
– Set Adjust to Change the Estimated Hydrogen Consumption of R2

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Hydrocracker Calibration Mode
Solution
– Until the Hydrogen Solubility and Leakage Reaches the Value
of 35 SCF/BBL

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Hydrocracker Predict Mode
Problem
– Predict Mode – Alternate Conversion Calculation
– Applied in a Flowsheet Predict Mode
– Single Reactor Once Through Operation
– Mild LCO Hydrocracker
– Low As Produced Conversion
– Design Case Based around 380 F Cut Point (Actual ~290 F)

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Hydrocracker Predict Mode
Solution
– Set Adjust to Change the As Produced Conversion Target

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Hydrocracker Predict Mode
Solution
– Until the 380 F Cut Point Conversion Target is Met

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Reformer Predict Mode
Problem
– Predict Mode – C5+ RONC (Debutanizer Bottoms)
– Applied in Flowsheet Predict Mode
– RON of the Debutanizer Bottoms is Typically Control Target for
Reformer Operations
– C5+ RONC and C6+ RONC Targets Do Not Represent
Debutanizer Bottoms Stream

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Reformer Predict Mode
Solution
– Set Adjust to Change the Specified C5+ RONC

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Reformer Predict Mode
Solution
– Until the RON Target of the Debutanizer Bottoms is Met

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Questions and Answers