Tereos France is a leading company in the French sugar industry with nine sugar factories, five distilleries and four packaging facilities, producing an annual total of 1.5 million tonnes of sugar and 500,000 cubic metres of alcohol and bioethanol from beet.
Each year the Tereos Boiry Sainte Rictrude sugar factory, located near Arras (in the region of Pas de Calais), produces 250,000 tonnes of white sugar for manufacturers in the agro-industrial sector (drinks, chocolate, jam, biscuit and dairy product manufacturers). This sugar is produced over a very short period, known as the "sugar campaign", which runs from mid-September to December each year, during which time the sugar beet is harvested and transported to the sugar factory for processing.
Every day during the campaign, Boiry processes 20,000 tonnes of beet, produces 2,800 tonnes of sugar and consumes 15MW of electricity! The sugar factory produces this energy itself, by means of two boilers that supply a turbo-generator with steam. The factory is connected to the national electricity grid (EDF) only at start-up and outside the campaign period.
These boilers are the very lifeblood of the sugar factory, and can produce up to 140 and 120 tonnes of steam per hour respectively. 85% of this steam is used to produce electricity; the remaining 15% is used for the various processes in the manufacture of sugar. In 2009, Tereos decided to replace the now obsolete distributed control system which governed the two boilers.
Tereos' objective: to modernise and optimise control of these boilers and integrate these within a single control and command system for the whole factory. The company contacted a number of suppliers and, after examining the proposals, chose to migrate command of the boilers to the Rockwell Automation PlantPAx system.
The decision was taken in March 2009… with the sugar campaign due to start in September. This presented quite a challenge for Rockwell Automation, since the factory cannot operate without a boiler. Furthermore, boiler control requires very specific expertise: highly complex regulation algorithms, fine tuning of the burners and extremely sophisticated calculations to anticipate load demand.