How to Apply Simulation in the Real World

1. Tier 3 How to Apply Simulation in the Real World

2. Statement of intent 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.

3. Contents Structure of tier 3 • Approach to Open – ended problem • Case of Study.

4. General concepts 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.

5. General concepts 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.

6. Thermo – Mechanical Pulping Plant Study (TMP)

7. Case study Case study Construction of a Thermo – Mechanical Pulping Plant (TMP) • installed and operating cost. • Production and product quality. • Performance, energy, and efficiency. • Environmental impact. • Maintenance requirements. • Safety.

8. Case study 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.

9. Case study Objective To 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.

10. Case study Thermo – mechanical pulping process

11. Case study 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.

12. Case study 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.

13. Case study Choosing parameter for working scenario • Feasible operating ranges Are the ranges in which the plant can operate (Temperature, Flow, Pressure, Size, etc.) • Impact and sensitivity variables Defines a range of parameter variation for which the identified solution remains optimal. • Areas of maximum economic benefit Cost sensitivity analysis provide a useful tool to determine the most economic operation range.

14. Case study Multi-criteria optimization Designing 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.

15. Case study Units proposed to be studied Heat Recovery Bleaching Effluent Treatment

16. Store, Refining and Reject Reception and Storage • Chips humidity 45% • Chips between 10 and 30 mm will be accepted.

17. Store, Refining and Reject Drum Washer Washing Systems are an essential prerequisite for obtaining first-class final products. Refiner

18. Thickener P-15 Bleaching Screens E-24 POM-006 P-16 Screens P-34 P-35 RES-002 DIL-001 EPA-001 POM-007 POM-010 P-32 Screens reject P-36 E-23 Bleaching POM-008 E-22 E-21 Paper machine White Water REB-002 POM-009 White Water REB-001

19. Store, Refining and Reject Thickener Drum 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 balance Mass balance

22. Mass balance Mass balance

23. Mass balance Mass balance

24. HEAT RECOVERY

25. Heat recovery Heat recovery system components • Reboiler • Vent condenser • Feed water / condensate exchanger • White water / condensate exchanger • Feed water deaerator. • Atmospheric scrubber.

26. Heat recovery 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.

27. Silencer Scrubbed Steam Clean Steam ATM Scrubber Vent Condenser Reboiler System Vent TMP Steam Pressurized Scrubber Feed Water Heater Dirty Condensate Heat recovery Heat recovery system The reboiler will treat the dirty steam coming from the refining lines to produce clean steam for the paper machines.

28. Heat recovery Vapor PTM

29. Heat recovery heat exchanger

30. BLEACHING

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

32. Water & Peroxide SO2 Bleaching Tower 1 Dilution White water NaOH Pulp Sodium Silicate 2 Dilution Storage 3 Dilution H2O2 Second press First press Pulp 675 t/d Consistency 5% Mixer screw 13.3 t/d Concentration 50% SO2 2.8 t/d Pulp 647 t/d Consistency 10% 10% 6 t/d Concentration 28.6% 26.5 t/d Concentration 50% Pulp 643 t/d Consistency 31% Pulp 6 t/d Consistency 0.1% Pulp 663 t/d Consistency 3% Paper Machine From Paper Machine

33. Effluent Treatment

34. Effluent treatment Effluent treatment 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 Second Treatment RBS 22 t DBO/d • 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.

35. Clarifier Biological Reactor Effluent treatment Effluent Treatment Bleaching Rejects Press Treated water Screw Press Purge Solids

36. Process analysis cost Process Analysis Cost

37. Product Product Characteristics and cost

38. Product Operation cost

39. Process analysis cost 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.

40. SAFETY

41. Safety 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.

42. Conclusion This 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.

43. END OF TIER 3