Global Processing

Emerson helps Alcan increase production capacity by 12 percent

August 4, 2003
Emerson Process Management was recently selected by Alcan to help improve processing operations within their Alumina and Specialty Chemicals facility at the Jonquiere Complex in Quebec. The plant produces Specialty Hydrates, which have to be manufactured with very stringent quality requirements - a process that leads
to challenging dynamic process control applications. Previous loop-tuning work had been undertaken with little business impact. Emerson''s team then applied their dynamic analysis process to reduce variability and Alcan experienced significant production increases.

In February 2003, Alcan engaged the services of Laurentide Controls and Emerson''s Process Solutions division with the objective of improving the washing and drying operations within the plant. Using Emerson''s EnTech™ Diagnostic ToolKit, the team quickly realized that process optimization would more likely be achieved by a revision of the process control strategy and design than by loop tuning.

Following the implementation of the initial modifications in the mill''s PROVO® system, Alcan recorded a 60% reduction in the dryer temperature variations, as well as a 12 percent production increase. In financial terms this production increase will be worth over 1 million dollars a year.

The control loops were re-tuned in a very conservative manner by utilizing the systematic Lambda method. The reduction of variability at its source (before it reaches the PID controller) allowed for a much more robust tuning and reduced resonance to a minimum.

The next phase of work will have a different aim. The overall objective is a 15 percent reduction of natural gas usage per ton produced. In the interim, it is likely that Alcan will install advanced control tools such as Model Predictive Control (MPC) to further enhance their operations.

Alcan is a multinational, market-driven company and a global leader in aluminum, packaging, and recycling with 2002 revenues of US$12.5 billion.