Mill optimisation project - A South American Case Study

摘要

A coastal bleached kraft pulp mill in Brazil had been operating for more than 10 years and its production had plateaued. Did the mill reach its maximum capacity? Did the mill need capital investment to lift its output? Senior managers on site were convinced the mill was losing production opportunities. Beca AMEC was engaged to undertake a 6-week mill optimisation project (MOP) to answer these questions. The MOP process is designed to assist pulp mills, paper mills and other industrial plants improve the returns from their existing physical assets. It is a structured approach that focuses on the actual issues that are preventing stable production. The aim of the exercise is to deliver a capacity increase, improve cost performance and enhance quality. An MOP has five key steps: 1. Baseline analysis 2. Benchmarking 3. Project definition 4. Implementation 5. Monitoring & feedback The MOP process begins with a review of the existing operations and equipment. A baseline analysis assesses the current performance, variation of the key production and process elements, and it provides the data for cause and effect analysis. An internal and external benchmarking exercise is then completed to highlight the production limitations. Particular emphasis is placed on the internal benchmarking to accommodate the unique character of the site, minimising day-to-day production variations and eliminating production bottlenecks were two areas focussed on. After the benchmarking has been completed, site projects are developed and implemented to improve the site's performance. The implemented projects often involve systematic operational changes to optimise the site rather than relying on capital expenditure. The MOP process concludes with a detailed monitoring and feedback of each on the implemented changes and a reassessment of the performance of the site. This Brazilian mill's best production to date had been an average 1,380 adt/d over a 12 month period. Using experienced engineers, a well proven methodology and with the full cooperation of the mill team, Beca AMEC undertook the in-depth assessment to determine how the mill could improve its output. Based on the initial review, it was believed that a Mill Optimisation Project (MOP) focussing on the pulp production and paper machine performance could achieve: 1. Increased revenue per tonne output through improved quality. 2. Decreased cost per tonne output through better chemical and raw material utilisation. 3. Incremental increases in tonnes output through stabilising production. Twelve months after the MOP was completed the mill was averaging 1,800 adt/d. To illustrate the MOP technique, this paper will discuss the methodology used to allow the Brazilian mill to achieve the significant increase in production increase.