PRO-PLAN Pulp Mill & Recovery Scheduling System

PRO-PLAN - Pulp Production The Pro-Plan Pulp Mill & Recovery Scheduling System is a short to medium term scheduling and simulation system to determine the maximum Pulp Mill production rate consistent with constraints on: pulp demand and storages, weak black liquor storage and evaporator throughput, and white liquor supply.

Applicability It is especially useful when two or more pulp lines are vying for a limited supply of white liquor, or limited black liquor processing capacity. Rules are employed to determine priorities and allocate available capacity logically.

Recovery Throughput It will also calculate the appropriate production rates for evaporators, recovery boilers, recausticizers and lime kilns to achieve and maintain the optimal levels in WBL, SBL, Green Liquor and White Liquor storages. Evaporators Recovery Boilers GL Clarifier

It is intended as an aid to mill coordinators, and Pulp Mill, Recovery and Recaust. operators to determine the most appropriate production rates for maximising production and minimising rate changes. Causticizers WL Clarifier GL Clarifier Lime Kiln Mill Coordination

With no constraints, the model will calculate production rates to achieve and maintain the levels in the pulp silos and liquor storages that will best cope with unplanned shuts upstream or downstream of each storage. This is based on the probability of plant downtime upstream and downstream of each storage. Optimal Production Rates

Pro-Plan Demands Constraints Demands Constraints Maximise Available Capacity Minimise Rate Changes Better Storage Management Reduced Inventory Increased Production Uniform Quality Less Shuts Lower Costs Results

If there is a mismatch in pulp demand and minimum or maximum production, best use will be made of the available capacity in the storages to maintain production. Constraints include white liquor supply, black liquor processing, or plant throughput. The plant bottleneck may change from day to day. If pulp mill production is limited by white liquor supply or evaporator throughput, the maximum production rate is calculated according to the current priorities and available capacity in the white liquor or WBL systems. Constraints

The system also determines whether: washer Dilution Factors need to be changed to reduce WBL volumes, evaporator performance has degraded and the WBL system has capacity for an evaporator wash. recycling of strong black liquor back to the weak black liquor system is required. Other Functions

PRO-PLAN I/O The Inputs are: Paper machine making plans Planned Shuts Current stocks Restrictions Plant reliabilities The Outputs are: Optimal levels Optimal production rates Predicted levels Predicted stocks

The Business Case How often does the digester need to shut or slowdown due to a breakdown or restriction in another area? How is the new rate determined? What is the lost opportunity? How are tank level and stock level targets set now?

Financial Benefits The financial benefits from using the PRO-PLAN Pulp Mill Scheduling System will vary from mill to mill, and are dependent on the types of constraints and the method of operation of the mill prior to using the system. Typical improvements might be: Better utilisation of capacity Increased production of 1% of 500 tonnes/day for 350 $200 margin = $ 350,000 p.a. Better storage management If there are 10 unscheduled upsets per year, and the storages are 5% closer to optimal levels: 10 x 5% x 500t x $200 = $ 50,000 p.a.

Pro-Plan has been developed using Gensym’s G2 platform. G2 is a graphical, object-oriented “expert system” for building intelligent operations management applications. These applications reason about operational data in real time to provide advice and take corrective actions. G2 enables organisations to dramatically improve operational availability, safety and optimisation. G2

To discover more about Pro-Plan and its potential payback for your situation, contact Norm Lasslett at Procex on: Tel/fax: (613) Mobile: Procex Pty Ltd ACN Balmoral Avenue Brunswick East, Australia 3057 Contact Procex

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