TIER 3 STEADY STATE SIMULATION PIECE PAPRICAN ECOLE POLYTECHNIQUE UNIVERSIDAD DE GUANAJUATO 1 How to Apply Simulation in the Real World 3 Tier

TIER 3 STEADY STATE SIMULATION PIECE

PAPRICAN ECOLE POLYTECHNIQUE UNIVERSIDAD DE GUANAJUATO

1

How to Apply Simulation in the

Real World

3

Tier



2

Statement of Intent

In this section an open – ended problem will be presented. Since this kind of problem can be solved from different points of view, some of them will be discussed in the following sections.

Statement of intent



3

Structure of tier 3

Approach to Open – ended problem

Case of Study.

Contents



4

Open – Ended Problems

An open – ended problem is one which does not have a single right answer.

Usefulness of open – ended problems: Similar to most important real – world problems. Develop creative divergent thinking skills.

General concepts



5

How to approach open – ended problems

State the problem clearly, including goals, constraints, and data requirements.

Define the trade – offs intrinsic to the problem. Define the criteria for a good solution. Develop a set of cases to simulate which

explore interesting options. Perform the simulation and evaluate results

against solution criteria. Evaluate solutions against environmental and

safety criteria.

General concepts



6

Thermo – Mechanical Pulping Plant Study (TMP)



7

Case studyConstruction of a

Thermo – Mechanical Pulping Plant (TMP)

installed and operating cost. Production and product quality. Performance, energy, and efficiency. Environmental impact. Maintenance requirements. Safety.

Case study



8

Justification

The price of kraft and sulfite pulp has increased significantly in recent years.

Environmental impact of many older kraft and sulfite mill is now unacceptable.

Thermo – mechanical pulping (TMP) produces a good quality pulp at much less cost and environmental impact.

Case study



9

ObjectiveTo study the economic feasibility of construction

of a TMP unit in a mill already in existence.

Production (bleached pulp) 665 ton/d.

Freeness 60 ml.

brightness higher to 70 % ISO.

Return of investment (ROI) 5 years (20% each year).

Compliance with environmental and safety requirements.

Case study



10

Case studyThermo – mechanical pulping process



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Description of the TMP process

Chips are heated with steam (before and during refining) to soften them and preserve long fibre.

Chips are refined to obtain pulp at 50% consistency.

The pulp is screened to obtain the desired fibre length distribution.

Rejects are refined again in the reject refining unit, with the accepts returned to the primary screen feed.

The screened pulp is then bleached.

Case study



12

Using Simulation in a Plant Design

A plant design requires of many combined equipments to obtain a desire product. Simulation is used to determine this target.

Select equipment. Analyze “what if” scenarios. Compositions, product production, and

characteristics. Improve performance.

Case study



13

Choosing parameter for working scenario

Feasible operating rangesAre the ranges in which the plant can operate

(Temperature, Flow, Pressure, Size, etc.)

Impact and sensitivity variablesDefines a range of parameter variation for which

the identified solution remains optimal.

Areas of maximum economic benefitCost sensitivity analysis provide a useful tool to

determine the most economic operation range.

Case study



14

Multi-criteria optimizationDesigning a plant may have more than 1

alternative. It is hard to decide which option is best.

Taking a decision, may involve several aspect: Operability. Controllability. Economic.

Some of the goals are usually conflicting each other, so that an optimal solution does not exist.

Safety.Production.Others.

Case study



15

Units proposed to be studied

HeatRecovery

BleachingEffluent

Treatment

Case study



16

Reception and Storage Chips humidity 45% Chips between 10 and 30 mm will be accepted.

Store, Refining and Reject



17

Drum WasherWashing Systems are an essential prerequisite for obtaining first-class final products.


Refiner



18

Thickener

DIL-001

Screens

Screens

Screensreject

Papermachine

Bleaching

BleachingP-15

RES-002EPA-001

White Water REB-002

White Water REB-001

P-16

P-32

E-21

P-34 P-35

E-23

E-22

POM-010

POM-006

POM-007

POM-008

POM-009

P-36

E-24



19

ThickenerDrum Thickener is a simple and reliable filter for dewatering papermaking stock and broke as well as for virgin and recycled fibers in a consistency range from 0.5% to 5%.

Disc Filter is a vacuum filter. The vacuum is generated by drop legs. The stock is pumped to the inlet box through the feed section.




20

Mass Balance

TMP plant



21

Mass balanceMass balance



22

Mass balanceMass balance



23

Mass balance

Mass balance



24

HEAT RECOVERY



25

Heat recovery system components

Reboiler Vent condenser Feed water / condensate exchanger White water / condensate exchanger Feed water deaerator. Atmospheric scrubber.

Heat recovery



26

Feed (demineralized) water inlet conditions Flow 1484 ton/day.

Pressure 101.3 KPa. Temperature 90°C.

Clean steam outlet conditions Flow 1484 ton/day.

Pressure 250 KPa. Temperature 127.4°C.

Condensate outlet conditions Flow 1744 ton/day.

Pressure 300 KPa. Temperature 133.5°C.

Heat recovery



27

Heat recovery system TMP Steam

Silencer

ATMScrubber

PressurizedScrubber

ReboilerVent

Condenser

SystemVent

Feed Water

Dirty Condensate

Heater

Clean Steam

Scrubbed Steam

The reboiler will treat the dirty steam coming from the refining lines to produce clean steam for the paper machines.

Heat recovery



28

Vapor PTMHeat recovery



29

heat exchangerHeat recovery



30

BLEACHING



31

Bleaching

It is necessary to add an bleaching process to satisfy the require brightness quality 70 %ISO.

Bleaching



32

NaOH

H2O2

SO2Bleaching

Tower

SodiumSilicate

Pulp

From PaperMachine

PaperMachine

Pulp 675 t/dConsistency 5%

Mixer

13.3 t/dConcentration 50%

6 t/dConcentration 28.6%

26.5 t/dConcentration 50%

1Dilution

2Dilution

3Dilution

Whitewater

screw


Pulp 6 t/dConsistency 0.1%

Storage



SO2 2.8 t/d

10%

Water&

Peroxide

First press Second press



33

Effluent Treatment



34

Effluent treatment

Biologic Sequential Reactor. It consist of 4 basins operating in automatic sequence. Replenishment, Reaction, Sedimentation and racking.

DBO 20 t/d MES 11 t/d Total flow 26000 m3/d. Mud production .06 kg/kg DBO removed.

Second Treatment RBS 22 t DBO/d

Main Treatment MES clarifier volume: 1562 m3 and height of 6.7m.

The retention time is 8.3 hrs. for 4500 m3/d. Mud production 28 t/d

Effluent treatment



35

BiologicalReactor

Clarifier

Bleaching Rejects

Treated water

Screw PressSolidsPurge

Press

Effluent Treatment

Effluent treatment



36

Process Analysis Cost

Process analysis cost



37

Product Characteristics and cost

Product



38

Operation cost

Product



39

New equipment and Installation Cost

The company 1 offers a cheaper project cost, therefore, it is chosen as the company which

provide the equipment.The detail description in each stage is describe

below.

Process analysis cost



40

SAFETY



41

Safety

The new plant must follow the rules of health and safety. The equipment acquired uses new technology so the risk of accident is low.

The possible danger sources must be identified and a manual written to describe the procedure to follow if an accident occurs.

Safety



42

ConclusionThis Tier is not finished, things to point out in the

project:

What were the best solutions found. Why were they preferable to others. How would simulation help to find these solutions. What are the advantages of using simulation in a

project like this, versus other approaches such as using a standard design, adapting a plant design from elsewhere, or building a pilot scale process.



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END OF TIER

3

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TIER 3 STEADY STATE SIMULATION PIECE PAPRICAN ECOLE POLYTECHNIQUE UNIVERSIDAD DE GUANAJUATO 1 How to Apply Simulation in the Real World 3 Tier