Carbon dioxide emissions from lime kilns in Sweden have been reduced by more than 36 000 tonnes per year. This has been achieved through a research collaboration between the Centre for Sustainable Cement and Quicklime Production at Umeå University, Nordkalk AB and the Swedish Energy Agency.
The five-year research project “Renewable Energy Carriers in Quicklime Production” which started in February 2019, aims to investigate and demonstrate how biofuels can be introduced as an alternative to fossil fuels in lime kilns.
The project focuses on implementing biofuels as an alternative to fossil fuels in lime kilns, which has been very successful, said Matias Eriksson, Director of the Centre for Sustainable Cement and Quicklime Production and Adjunct Associate Professor at the Department of Applied Physics and Electronics at Umeå University.
The aim is to reduce fossil carbon dioxide (CO2) emissions in the production of quicklime by promoting the use of renewable energy carriers, such as forestry or agricultural residues, or refined biofuels.
The project goal is to reduce carbon dioxide emissions from non-renewable energy carriers in Nordkalk AB’s quicklime production by 46 percent, which corresponds to 71 000 tonnes of carbon dioxide per year, Matias Eriksson said.
To achieve this, the project has set two sub-goals, to implement 100 percent renewable energy carriers at Kalkproduktion Storugns AB’s (KPAB) lime kiln in Lärbro, and to integrate 30 percent renewable energy carriers at Nordkalk AB’s lime kiln in Köping.
Nordkalk has achieved remarkable success in replacing coal with biofuels at the lime kiln in Köping. The kiln in Köping, which produces high-quality lime for steel and pulp customers, has exceeded the target of 30 percent of the fuel being biomass and is now working to reach 50 percent. Trial runs with 100 percent liquid biofuel are also being conducted at KPAB on Gotland, a company in which Nordkalk is the majority shareholder. These tests aim to evaluate the suitability of the biofuel for continuous operation, said Matias Eriksson.
In addition to providing practical implementation support to Nordkalk and KPAB, researchers and PhD students at the Centre for Sustainable Cement and Quicklime Production have conducted laboratory studies investigating selected biofuels in a simulated industrial environment.
These studies evaluate the impact of biofuels on limestone, quicklime, and refractory materials under controlled conditions, providing a detailed understanding of the possibilities and limitations of fuel switching, said Markus Broström, Professor at the Department of Applied Physics and Electronics at Umeå University.
The project has also resulted in the publication of several research papers.