Aracruz Uses a Dynamic Simulator for Control System ... - Andritz

INTRODUCTION
With capital expenditures of US$ 850 million (US$ 575 million for the pulp mill), Mill “C” will add 700.000
air dry tons per year of market pulp capacity to the existing two-line Aracruz mill. The new line began
operations on May 23, 2002, significantly ahead of schedule.
The implementation plan for the Mill “C” project included an innovative partnering concept with the EPC
(Engineer, Procure and Construct) process “island” suppliers and their various sub-contractors, in order to
achieve common quality, schedule and budgetary goals. One noteworthy innovation within this concept was
the development and use of a dynamic process Simulator.
In mid-March 2001, the company which is now called IDEAS Simulation, Inc. of Atlanta, USA, was asked to
proceed with process model development for the Simulator project. The Simulator project involved the
development of dynamic process models in seven Mill “C” operating areas: Digester and Pressure Diffusers;
Oxygen-Delignification and Screening; Bleaching; Chlorine Dioxide Plant; Pulp Drying; Evaporation; and
Recausticizing and Lime Re-burning.
The Simulator was aimed at assisting the project team in achieving an exceptional mill start-up and rapid
ramp-up to full production. To do this, the Simulator was applied to the role of Distributed Control System
(DCS) staging and operator training.
Besides the project objectives, the Simulator can be used, after the start-up, to support operations by testing
the effect of changes in the process, including process configuration, operating conditions, or equipment
changes, and predict unforeseen process complications. In addition, the process control systems in each area
can be analyzed, tested and improved, all before attempting changes in the field.
WHAT IS THE SIMULATOR?
The Simulator is a combination of mostly standard computer hardware and some highly specialized software.
In short, the structure adopted by Aracruz consists of three essential parts:
• The operator’s workstation, using exactly the same operator-interface graphics as in the real plant.
• Specialized emulation software and hardware to run the DCS configuration, again exactly as it will be
run in the field.
• Specialized process modeling software to simulate the processes in the real mill, and standard
computers upon which to run the models.
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