Fossil-free coating drying : Replacing natural gas in process heat production

Abstract

Natural gas is used in industrial processes for process heat production, amongst other things. Despite natural gas having lower emissions than other fossil fuels, its combustion contributes to climate change and the problems arising from global warming. In the European Union (EU), approximately 30 % of used natural gas is consumed in the industry sector. Decarbonizing industry presents a big emission reduction potential, but industry is a heterogeneous sector, and different industries will require different solutions. Multiple options for decarbonization are possible, but based on a literature study electrification, alternative fuels, solar thermal technologies, and carbon capture and storage (CCS) were further explored in this thesis. All these technologies have their own advantages and disadvantages that were evaluated against the criteria of a pressure sensitive label manufacturing process. Pressure sensitive label is manufactured in a process where different layers are stacked on top of a release liner. These layers need to be dried in drying ovens that are currently heated up to 200 °C with gas burners that mainly utilize natural gas. Once the drying process is complete the release liner is laminated together with a face material to produce a complete product. The decarbonization of two coating machines in Country 1 (C1) and Country 2 (C2) was examined in this study. The technologies discovered in the literature study were ranked by nine criteria specific to this manufacturing process. The top two highest ranked decarbonization solutions (electrification with an electric boiler and biomethane) for both C1 and C2 were then evaluated more thoroughly in an economic and environmental study. Using the net present value (NPV) method investment calculations were done for both case studies. The NPV in both cases went into the negatives and there was no payback time for the electrification investment with a 7 % interest rate. To have a payback time of three years electricity price had to be 7.55 €/MWh in C1 and 10.08 €/MWh in C2. This is a very low electricity price considering the countries’ usual price level. The environmental benefits of electrification or using biomethane are significant. Switching fuels to biomethane or electrifying the drying process with electricity from renewable sources can lead to 100 % emission reductions. However, using electricity from renewable sources for electrification is essential as emissions can increase if the emission factor for electricity generation is very high. In the cases where emissions were reduced a levelized cost for carbon abatement (LCCA) was calculated. In C1 the lowest value for LCCA was achieved in the case of electrification with electricity from renewable sources. The LCCA was 118.06 €/tCO2e. Similar results were obtained for C2 where LCCA for electrification through renewables was 221.11 €/tCO2e. Even the lowest values for LCCA were quite high considering the price for carbon in emissions trading has stayed under or close to 100 €/tCO2e. Switching to biomethane resulted in an LCCA of 197.12 €/MWh and 245.29 €/MWh for C1 and C2, respectively. This study shows that there is a plethora of options that can be considered when decarbonizing an industrial process, but options need to be individually evaluated for different processes. The results of this thesis suggest that decarbonizing can be economically non-feasible while environmentally beneficial. Technological development and development in energy prices will have a significant impact on the economic feasibility of decarbonization and therefore the rate of deployment these solutions will have.