aspen plus innovations (fluid/solid) classifying ... – based on drying kinetics ... –aspen plus...

© 2013 Aspen Technology, Inc. All rights reserved |

1 © 2013 Aspen Technology, Inc. All rights reserved

Modeling Solids Dryers and Granulators with Aspen Plus V8

Ajay Lakshmanan and Claus Reimers

Product Management, AspenTech

Solids Process Modeling Webinar

April 16, 2013 Hosted by:

Julie Levine and Ron Beck,

Product Marketing, AspenTech


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Ongoing Series of Technical Webinars Engineering webinars for education and best practices

RECENT WEBINARS:

Model Solids Processes Easily with Aspen Plus (Technical)

Case Study: Maximizing Energy Efficiency with Maturus Optimi

UPCOMING WEBINARS OF INTEREST:

Compressor Modeling using Aspen HYSYS Dynamics (Technical) – April 23rd

Utilizing Property Data with Aspen Properties in Aspen Plus (Technical) – May 15th

ALSO UPCOMING:

OPTIMIZE 2013 Global Conference – May 6th-8th


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Common Models & Data

aspenONE Integration

Support Manufacturing & Supply Chain

Conceptual Engineering

Basic Engineering

Detailed Engineering

aspenONE Engineering Best-in-class engineering solutions in an integrated workflow

Aspen Simulation Workbook & Aspen Online Deployment

Aspen Petroleum Downstream & HYSYS Upstream

Aspen Equipment Design & Rating

Aspen Basic Engineering Aspen Capital

Cost Estimator (ACCE)

Aspen Plus Dynamics, ACM & Flare System & Energy Analyzer

Aspen Plus

Aspen HYSYS

Aspen Process Economic Analyzer (APEA)

Detailed Engineering

Aspen Plus

Aspen HYSYS


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Agenda

Introduction

Convective Drying

Demonstration 1

Belt and Fluidized Bed Drying

Granulation

Demonstration 2

Granulation and Agglomeration

Questions & Discussion


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Why is Solids Modeling Important?

Mineral Raw Material

Fluid Products

Extractive Industry Process Coal, Oil Sands, Cement, Phosphates, Alumina

Solids + Fluids Solids + Fluids

Grinding (solids)

Separation (solids/liquid

/gas)

Reactions (fluid/solid)

Classifying (fluid/solid)

Specialty & Agricultural Chemical Process Fertilizers, ChlorAlkali, pTA, Silicones

Solids + Fluids Fluids

Reactions (liquid/gas)

Drying (solids/gas)

Crystallization (liquid/solid)

Fluid Raw Material

Solid Product

Separation (liquid/gas)


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Modeling Processes with Solids Traditional Approach

Manual Data Transfer

Inconsistent Properties

Aspen Plus Urea Synthesis Model

SolidSim Urea Granulation Model

Local Optimization

Two Models


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AspenTech and SolidSim Bringing Our Strengths Together

Physical Properties

Reactions & Electrolytes

Fluid Unit Operations

Integrated Workflows

Worldwide Support

University Program

Solids Process Modeling

Solids Characterization

Solids Unit Operations

Deep Expertise

Relationship with universities researching solids technology


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Aspen Plus V8.0 Optimizing Processes with Solids – Made Easy

Sample Templates

Online Training

Visualize PSD

10 Unit Operations

Optimize Entire Process


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Agenda

Introduction

Convective Drying

Demonstration 1


Granulation

Demonstration 2




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Why is Convective Drying Important?

Problem: High Energy Consumption

Benefit: Optimizing design and operation reduces energy use by 25-30%


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Drying periods

Initial period

Heat the wet solids

Constant rate period 1st Drying period

– Dry moisture on surface

– Moisture content above critical moisture content

Falling rate period 2nd Drying period

– Dry moisture inside particles

– Moisture content below critical moisture content and above equilibrium moisture content

– Ends at equilibrium moisture content

Convective Drying – Drying Curves 11


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Convective Drying – Model Description

Flow patterns

– Co-current

– Counter-current

– Cross-current

Solids in plug flow in axial, ideally mixed in lateral direction, gas in plug flow

Solids ideally mixed, gas in plug flow

Drying model

– Based on drying kinetics

– Normalized drying curve describes falling rate drying

– Mass transfer coefficient between particles and gas:

Sherwood number

Mass transfer coefficient

Product of mass transfer coefficient and surface area

Number of Transfer Units

– Heat Transfer Coefficient user defined or calculated


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Normalized drying curve describes the falling rate period

Normalized drying rate Normalized moisture content

eqcr

eq

XX

XX

Normalized Drying Curve

period drying 1 rate drying

rate dryingcurrent )(

stv

X: Current moisture content Xcr: Critical moisture content Xeq: Equilibrium moisture content

Normalization


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How is the Normalized Drying Curve Determined from Measured Data?

The normalized drying curve is typically derived from experiment data


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Step 1: Determine critical moisture content, equilibrium moisture content

– Current case Critical moisture content: Xcrit = 0.1 kg/kg

Equilibrium moisture content: Xequi = 0.005 kg/kg


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Step 2: Calculate the drying rate and determine the drying rate at the 1st drying period

– Current case Constant drying rate: MI = 1.65 g/(kg*s)


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Step 3: Calculate normalized drying rate and normalized moisture content

Critical moisture content: Xcrit = 0.1 kg/kg

Equilibrium moisture content: Xequi = 0.005 kg/kg

period drying 1 rate drying

rate dryingcurrent )(

stv

eqcr

eq

XX

XX


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Convective Dryer Forms 18

Drying Curve Tab

Normalized moisture content

Normalized drying rate

Define critical and equilibrium moisture content

Define normalized drying curve via tabular data or use of a function


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Agenda

Introduction

Convective Drying

Demonstration 1


Granulation

Demonstration 2




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Convective Drying – Fluidized Bed Dryer

The following example will demonstrate how a multi-chamber fluidized bed dryer could be modeled with Aspen Plus

Live Demo


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Convective Drying – Fluidized Bed Dryer – Summary

– Aspen Plus can be used to model fluidized bed dryers with multiple drying chambers

– Beside the drying of the material also entrainment and gas-solid separation can be considered in an Aspen Plus model

– Model shows the behavior of the overall drying process

Temperatures

Moistures

Flow rates

Particle size distributions

– Model gives information's about the internal streams in the dryer that normally could not be measured


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Convective Drying – Belt Dryer

The following example will demonstrate how a Belt Dryer could be modeled and optimized with Aspen Plus

– Modeling of a complex apparatus

Several drying zones with profiles of air recirculation and temperature along the dryer

Cooling zone with heat recovery

Humid exhaust air

zone 1 zone 2

ambient air

cooling zonezonezone zone

preheated make-up air


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Convective Drying – Belt Dryer

Drying of Solids – Solids are dried from ~261 g/kgdry to less than 11 g/kgdry by use of a 4

chamber belt dryer with internal air recirculation

In the current setup the dryer has an energy consumption of 561 KW-Hr/ton product

approx. 93% of that heating energy is provided by the primary heater

Objective: – Reduce the energy demand of the dryer by at least 10%

Constraints: – Throughput should be unchanged (~ 2 t/h)

– Solids Temperature profile along the dryer should be mostly unchanged

– Product moisture should be less than 11 g/kgdry


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Belt Dryer Demonstration

Live Demo


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Convective Drying – Belt Dryer – Summary

– Aspen Plus can be used to model Belt Dryers with multiple drying and cooling chambers

– Temperature and moisture profiles along the dryer can be calculated

– Model can be used to optimize the energy demand of an industrial Belt Dryer by

Investigate the impact of cooling stages

Determining optimal flow rates and temperature


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Agenda

Introduction

Convective Drying

Demonstration 1


Granulation

Demonstration 2




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Why is Granulation Important?

Problem: Product quality and process stability variability

Benefit:

– Improve coating and product purity

– Increase throughput


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Granulation

Growth of particles due to deposition of solid material on primary particles (seeds)

– Granulation: Seed and deposited solids are the same material

– Coating: Seed and deposited solids are different materials


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Agglomeration

Agglomeration: Aggregation of two or more primary particles

– Agglomeration by use of a binder

Binder could be water, a suspension, solution or melt

Particles are ‘glued together’

– Agglomeration by use of mechanical forces

No binder is added

Particles are ‘pressed together’


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Modeling Agglomeration and Granulation

The Aspen Plus Granulator can be used for: – Granulation and Coating

– Agglomeration using binder

using mechanical forces

Drum Fluidized Bed Plate

Drum Fluidized bed Plate

Compacting Press Roller Agglomerator


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Granulation – Model

Particle Growth – Population balance

– Mixed Ideal mixing in radial and axial direction

Growth rate proportional to

– Surface, Volume or Diameter

– Plug flow Ideal mixing in radial direction

No mixing in axial direction

Drying of particles Define solids moisture content at the outlet

Entrainment in Fluidized Beds Upstream gas velocity

Terminal velocity of the particles


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Agglomeration – Model

Particle Growth

– Population balance

– Growth rate described by kernels

– Time-dependent part b0(t)

– Parameterize using experimental data

– Flux number approach used for fluidized bed

– Size-dependent part b(u,v)

– Several models implemented

– Ideal mixing for radial and axial direction

– Pure binary agglomeration is assumed

Drying of particles Define solids moisture content at outlet

Entrainment in Fluidized Beds Upstream gas velocity

Terminal velocity of the particles


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Agenda

Introduction

Convective Drying

Demonstration 1


Granulation

Demonstration 2




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Agglomeration Example

The following example will demonstrate how a fluidized bed agglomerator could be modeled with Aspen Plus

– Flux number approach is used to obtain the time part of the agglomeration kernel

Live Demo


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Agglomeration Summary

Aspen Plus can be used to model fluidized bed agglomerators

The use of the Flux number approach allows calculating the time-dependent part of the agglomeration kernel based on operating conditions

– Binder flow rate and superficial gas velocity have a direct influence on the product particle size distribution


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Granulation Example

The following example will demonstrate how a industrial granulation process can be simulated and optimized with Aspen Plus

– Simulation of a granulation process with external classification/grinding circuit and product cooling

– Optimization study to increase throughput

Live Demo


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Granulation Summary

Aspen Plus can be used to model industrial granulation processes with external classification and grinding circuit

Multi-chamber granulators can be described by use of a hierarchy block

– Information about internal streams can be obtained

Model can be used to optimize the process with regard to

– Throughput

– Product quality

– …


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Agenda

Introduction

Convective Drying

Demonstration 1


Granulation

Demonstration 2




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Registration Discount for Webinar Attendees!

$1,700 – a savings of 15% off the standard conference fee! For more information, visit www.optimize2013.com and use the promotional code APWEB2013 to receive the discount. Offer Expires April 22!

OPTIMIZE 2013 6 – 8 May 2013 The Westin Waterfront Hotel Boston, MA USA

http://www.optimize2013.com/


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Optimize 2013 Global Conference

Hitachi Zosen Ethanol distillation membrane separation model with Aspen Custom Modeler and Aspen Plus

Evonik Industries Dynamic simulation for safety analysis of columns

Renmatix

Scale-up of biochemical cellulosic conversion processes

May 6-8, 2013

See these and over 50 additional presentations and training sessions

Cansolv (Shell) Modeling of CO2 Capture with unique amine solvents


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What Next?

Get more information now

– Call your AspenTech account manager or

– Call Aspen Telesales Direct:

USA: +1-855-882-7736

EUROPE & MIDDLE EAST: +44-1189-226400

ASIA/PACIFIC and INDIA: +65-6395-3900

– Or email us at [email protected]

– Presentations, videos, and getting started resources available at: www.aspentech.com/products/solids-aspen-plus.aspx

– Videos also available at: www.youtube.com/user/aspentechnologyinc

Contact info for today’s presenter and hosts – Ajay Lakshmanan [email protected]

– Claus Reimers [email protected]

– Ron Beck [email protected]

– Julie Levine [email protected]

mailto:[email protected]

http://www.aspentech.com/products/solids-aspen-plus.aspx





http://www.youtube.com/user/aspentechnologyinc






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aspen plus innovations (fluid/solid) classifying ... – based on drying kinetics ... –aspen plus...

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