This Master’s Thesis discusses about the pulp mill’s main fossil emissions source, lime kiln, fossil free fuel options and the effects of new fuels to lime kiln and to whole pulp mill. The main goal is to create a plan for Stora Enso Imatra Mill’s about the replacement of natural gas usage in lime kilns and to give good basis for continuing project onto next phase.

In theory part the focus is in white liquor plant, where lime kiln plays a major role. Within the fuel options, solid fuels get the main focus as the need for processing and equipment investments are relatively high compared to typical liquid and gaseous ones.

For Imatra Mill’s the only option for the main fuel is bark, which would be gasified to product gas. With the old kilns both needs own gasifier but drying would be done with one dryer. In new kiln option there is possibility to integrate the kiln in old recausticizing plant or alternatively to build a completely new white liquor plant.