Investigation of the influence of heavy metals on corrosion ensures reliable power plant operation

Project title and number: Intermediate temperature corrosion in used-wood fired boilers – the influence of lead, zinc and their chlorides, KME-717.

The most important project results
Combustion of used (recycled) wood is of economic interest as a non-fossil fuel for combined heat and power, CHP plants. Used wood frequently contains heavy metals such as lead and zinc. These elements are a concern regarding corrosion of the boiler. This project has investigated the corrosion risks involved at intermediate temperatures of about 200-400 °C of which little were known. Fuel additives are used to prevent corrosion at boiler parts operating at higher temperatures. The chemical nature of these additives may result in increased corrosion at other boiler parts. Preliminary results indicate that the corrosion is manageable at intermediate temperatures if proper precautions are taken. This will be further investigated during the continuation of the project.

Is there something, some results, that has emerged during the project that you did not expect?
There was great concern regarding the corrosion risk at intermediate temperatures. It is very promising that the preliminary results indicate that it is manageable if proper precautions are taken.

Name of PhD students, project participants and project leader of project
PhD student: Annika Talus (Swerea KIMAB)

Project participants
Annika Stålenheim (Vattenfall), Annika Talus (Swerea KIMAB), Christoph Gruber (Andritz), Dorota Bankiewicz (Åbo Akademi University), Eva-Katrin Lindman (Fortum), Pamela Henderson (Vattenfall), Patrik Yrjas (Åbo Akademi University), Rikard Norling (Swerea KIMAB)

Project leader
Rikard Norling

List the companies that participate in the project
Andritz, Fortum, Vattenfall