Use of Biomass as Alternative Fuel in Magnesia Sector

Abstract

The European Union has started a progressive decarbonization pathway with the aim to become carbon neutral by 2050. Energy-intensive industries (EEIs) are expected to play an important role in this transition as they represent 24% of the final energy consumption. To stay competitive as EEI, a clear and consistent long-term strategy is required. In the magnesia sector, an essential portion of CO2 emissions result from solid fossil fuels (MgCO3, pet coke) during the production process. This study concerns the partial substitution of fossil fuels with biomass to reduce carbon emissions. An experimental campaign is conducted by implementing a new low-NOx burner at the magnesia plant of Grecian Magnesite (GM). Life cycle assessment (LCA) is performed to quantify the carbon reduction potential of various biomass mixtures. The experimental analysis revealed that even with a 100% pet coke feed of the new NOx burner, NOx emissions are decreased by 41%, while the emissions of CO and SOx increase slightly. By applying a biomass/pet coke mixture as fuel input, where 50% of the required energy input results from biomass, a further 21% of NOx emission reduction is achieved. In this case, SOx and CO emissions are additionally reduced by 50% and 13%, respectively. LCA results confirmed the sustainable impact of applying biomass. Carbon emissions could be significantly decreased by 32.5% for CCM products to 1.51 ton of CO2eq and by 38.2% for DBM products to 1.64 ton of CO2eq per ton of MgO in a best case scenario. Since the calcination of MgCO3 releases an essential and unavoidable amount of CO2 naturally bound in the mineral, biomass usage as a fuel is a promising way to become sustainable and resilient against future increased CO2 prices.