Removal of NOx from flue gases in pelletising plants – evaluation of two possible alternatives

Purpose and goal
The project objective was to evaluate two technologies (LoTOx and SCR) for reduction of NOx emissions from flue gases, with the aim to identify the most suitable purification technology for possible future installations at pelletising plants. Relevant properties of the flue gases have been compiled, plants visits have been performed and well defined process concepts have been developed in cooperation with experts and suppliers. Due to lack of knowledge concerning the LoTOx technology, it is currently only possible to recommend considering SCR installations at selected plants.

Structure and implementation
The project has been performed in cooperation with LKAB staff and suppliers and experts within SCR and LoTOx. Process concepts, economic assessments and benefit analyses have been made. Strengths, weaknesses, risks and possibilities of each technology have been discussed and these have been analysed based on technical, energy and environmental (both external and working environment) aspects. This work will facilitate the judgement of which of the technologies is overall more suitable for installation at the pelletising plants of LKAB.

Results
The LoTOx technology is currently not assessed to be ready for full scale installation according to the suggested process concepts. Hopefully the results of this project will help in the planning of future work concerning LoTOx, so that the uncertainties regarding the technology can be sorted out. Process concepts for SCR have been developed within the project. SCR installations are currently judged to be interesting for further evaluation at primarily two of the plants, and this project is anticipated to facilitate future work due to the identification of critical aspects.