2.1 refsys reactor models

8/19/2019 2.1 RefSYS Reactor Models

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As en Petroleum Refinin Reactors(RefSYS Reactors)


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Layered Products for Upstream and DownstreamAspen HYSYS is the Foundation for Process Modeling

Aspen

FCC

Reformer

PIPESIM

Prosper/GAP

Upstream Oil & Gas Upgrading & Refining

©2006 Aspen Technology, Inc. All rights reserved 2

Aspen HYSYS

RefSYS

HYSYSUpstream

Hydrocracker

Spiral(CrudeManager)

PVTSim, PVTProMultiflash

OLGA

Black Oils Equation Oriented Capabilities


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Layered Products for DownstreamAspen HYSYS is the Foundation for Process Modeling

FCC

Reformer

Hydrotreater

Hydrocracker

SpiralCrudeManager

Aspen RefSYS

E uation Oriented Ca abilities

Shortcut Models


Aspen HYSYS

Rigorous HeatExchangers

Cost Estimation

Heat NetworkDesign

Column Design

Custom Models

Aspen SimulationWorkbook


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RefSYS Refinery Reactors

• Three broad types are available− Rigorous models are discussed in this presentation

− RefSYS rigorous reactors• FCC (RefSYS CatCracker)• Na htha reformer RefSYS Reformer


• Hydrocracker (RefSYS Hydrocracker and bed model)• C5 Isomerization

− RefSYS Petroleum Shift Reactor• Simple linear shift model. Not rigorous. Short cut model.

− HYSYS reactor options in general flowsheet• Plug flow reactor, etc.


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RefSYS Rigorous Reactors

Overview

• Best in class refinery reactors− Only Exxon Mobil has comparable technology

• Reactors are flow sheet based− Build up reactors from unit operations toolkit− One core bed model is used to build simple hydrotreaters up to

multiple bed hydrocrackers and resid treaters


• Reactors are EO (Equation Oriented)− First EO technology in HYSYS was refinery reactors migrated from

Aspen Plus

• Reactors use software components from broader Aspen

− Aspen Properties, Aspen Open Solvers, etc.

• Reactors are up to date with modern trends for multiple“lumps” in feed characterization and reactor kinetics


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Refinery Reactor Products

Type of Process HYSYS based

Offline application

focus (RefSYS)

Aspen Plus based

Online application

focusFCC Aspen HYSYS

CatCrackerAspen Plus CatCracker

Na htha Reformer As en HYSYS Reformer As en Plus Reformer


Hydroprocessing Aspen HYSYSHydrocracker &

HBED option(single bed)

Aspen PlusHydrocracker

C5 Isomerization ISOM model option

Delayed Coking

Visbreaking

Future


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Nature of Models

• Operational vs. Design Models

• RefSYS reactors are operational models− Not very sensitive to mechanical or catalyst design− Run with “feedback”, calibration or “base case”− Model theor is biased to fit actual data


• Work process for running models− Calibrate to one or more base cases (test runs or

snapshots of unit operation)− Predict moves from base

• Feed rate and feed property chnages• Reactor temperatures• Other operational variables


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Rigorous Reactor Design

• Common model framework

− Components common to all reactors

• Specific reaction systems

−


• FCC

• Reformer

• Hydroprocessing


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Common Model Framework

• Components common to all models

− All are objects in a HYSYS flowsheet− Use HYSYS interface

− Use Aspen Simulation Workbook interface (Excel)

−


• Use Aspen Properties package• Heat balances based on heats of formation

− Easy to use flowsheet connections

− Standardized user environments• Simulation

• Calibration

• Configuration wizards


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Specific Reactor System Features

• Multiple reaction lumps

• Networks of first order reaction pathways• Coke deactivation models

•


• Global connections tie numerous kinetic constantsto limited number of plant measurements

• Other unit operations added as needed• Core reactor model is EO based


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Reactors integrated with flowsheet

RefSYS

Reactor Model

L um

D e-l u

Reactor

Rigorous model including all reactorsegments (fractionation, recycles)components in EO environment


Feed streamsReactorEffluent

p

er p er

Section

Feed stream from the RefSYSbasis is converted to the kinetic

lumps used in the kinetics model

The kinetic lumps are converted backto the RefSYS basis and Petroleum

Properties are populated


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Reactor User Environments

• Environments

− HYSYS word for sets of screens. How model screensare organized for easy user navigation.

•


− Drill down through these environments

• Main simulation environment

− Model simulation environment

• Calibration environment• Configuration wizard


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EO Models

• EO = Equation Oriented

• EO uses a matrix of equations along with theanalytical derivatives to drive the whole modelsimultaneously to solution


• Solves complex problems efficiently− Good for recycles (beds with quenches)

− Data reconciliation (minimize error in calibration)

− Optimization


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Reactor Model EO Cores

• Reactor models have EO cores to solve robustly

• FCC EO core− Reactor + regenerator− Converge catalyst recycle between reactor + regenerator


− Reactors + Product separator flash + recycle gas− Converge kinetics and reactor temp drops with recycle gas

conditions

• Hydrocracker EO core− Reactor beds + High pressure separator + Multiple recycle

quench gas stream to beds− Converge kinetics and bed temp profiles with many bed

quenches


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Reactor Lumps

• Lumps are equivalent of pseudo-components

− Pseudo-components

• Based on boiling range, ie, 300-325 DegC

•


− Lumps• Based on reaction classes, ie, paraffins

• Used in reactor models


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Lump Measurement

• How to measure reactor lumps?

• Lab cannot measure them.

• Develop standard base compositions


− - , , .

• Shift base to current using routine lab data− Leverages routine refinery lab data

− For example, shift base composition to match current streamdistillation

− Models contain code to perform these shifts to build feed compositions

• So today’s feed = base + shift from lab data


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Reactor Lumps

• FCC− 21 lumps

− By boiling range and simple composition (PNA)

• Naphtha Reformer


− umps

− Almost pure components with some lumping of isomers

• Hydrocracker− 125 lumps

− Complex classes of reactions


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FCC Design

• Simplest

• 21 lumps• Dominated by two effects

− Reactor vs. regen heat balance effects


− Uncrackable aromatics in the feed

• Core model is reactor + regen

• Calibration can be configured to be “square”, equal

numbers of measurements vs. fitting parameters.


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Naphtha Reformer Design

• Medium complexity

• 68 lumps• Feed GC can produce almost all lumps

•


gas loop

• Calibration is complex balance− Competing reactions

− Reactor endotherms− Need EO based error minimization for calibration


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Hydrocracker Model Design

• Most complex

• 125 lumps• Lumps span many types of reaction classes

• Core model are reactor beds + high pressure flash +


recyc e quenc es to e s• Model good for any hydroprocessing process

• Calibration is complex balance

− Competing reactions− Reactor exotherms with quenches− Need EO based error minimization for calibration

2.1 refsys reactor models

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