VAUDREUIL REFINERY’S ELECTRIC BOILER JOURNEY

The Vaudreuil alumina refinery is located in Saguenay, Canada, a region blessed with substantial hydroelectric power production facilities. The refinery commissioned immersed electrode boilers in 1959 and operated them sporadically until July 2018. Since then, they have operated three (3) of such electric boilers almost continuously at over 80% uptime, supplying on up to 35% of the total steam demand of the plant. The usage of these boilers has contributed to reduce Vaudreuil’s carbon emission by 21% per ton of calcined alumina from 2017 to 2022. The operation of electric boilers in conjunction with natural gas boilers was not new for Vaudreuil, but the continuous operation of electrode boilers not only has redefined maintenance practices and process control strategies while also provides a potential pathway for total steam decarbonization. This paper will first provide an overview of electrode boiler technology and the specific challenges of providing steam to a large industrial complex in a nordic climate, followed by a description of the new maintenance practices aimed at maximising uptime and the control strategy for the dual operation of electric and gas boilers to minimize GHG emissions. This article also provides practical suggestions and guidance for the very much sought after decarbonization of alumina refineries’ steam production.