ABB Ability™ Expert Optimizer Facilitates APC in Pulp & Paper

SCA is a leading global forest products company based in Sundsvall, Sweden. They boast one of the largest production lines for bleached softwood sulfate pulp in the world at Östrand and have recently built a new fiberline to increase production as well as leverage ABB Industrial Software to increase operating efficiency.

Process control is critical for efficient fiberline production. It plays a major role in determining the quality of product delivered and at what cost. Manufacturing in pulp and paper, and more specifically the fiberline process is a highly dynamic, multivariable interacting system, difficult to control as a human operator with only the traditional distributed control system (DCS) or programmable logic controller (PLC).

Due to changes in feed sources, coupled with complex pulping processes, manual operators with PID control tend to remain at “safe distances” from process constraints. ABB’s Advanced Process Control (APC) solution, ABB Ability™ Expert Optimizer tackles the complexity of fiberline control, minimizes the effect of variability in feed and drives the process in the direction that increases operating efficiency and production.

The installation topology allows it to be deployed both inside ABB’s 800xA control system and on top of third-party control systems, making it applicable to any type of control system setup. The benefit of integration inside ABB’s 800xA is that there is easier navigation to the APC applications, PID loops, model predictive control trends and function blocks, with a similar look and feel as the rest of the operator user interface. One of the SCA plants located in Sweden, worked with ABB to increase operating efficiency by leveraging Expert Optimizer to reduce "off-spec" or "reject" pulp by keep all quality parameters on target even during disturbances. The primary focus being the bleaching and oxygen delignification processes.

Gain more through better control

Expert Optimizer enhances control of the process using distinguished advanced process control techniques: such as fuzzy logic and model predictive control (MPC).

Expert Optimizer Bleach stabilizes and then optimizes bleaching operations in real time. The Advanced Process Control solution tightly controls pH to preserve chemical reactions, while also minimizing chemical usage and reducing formation of chloro-lignin compounds. The result ensures more consistency in achieving brightness targets.

Expert Optimizer Oxygen removes maximum lignin in the oxygen stage, while safeguarding optimum pulp strength levels. By optimizing oxygen/alkali charge ratios and H-factor, even during inlet Kappa variations or grade changes, this Advanced Process Control solution makes it easier to produce higher quality pulp at lower chemical consumption. The result is maximum delignification ratio and reduced bleach loads at the lowest possible cost.