Vi utgår från observationer av universum och vår planet för att utveckla modeller och verktyg som möter globala utmaningar kring resurser, energiförsörjning och klimatpåverkan.
Vart är vi på väg? Var kommer vi ifrån? På vår institution söker vi svaren på de riktigt stora frågorna. I ett långt tidsperspektiv ger stjärnor och galaxers livscykler en inblick i universums, jordens och livets uppkomst – och framtid. Vi observerar också vår planet och samspelet mellan samhälle, teknik och natur för att kunna utveckla teknik, modeller och verktyg som kan möta globala utmaningar inom naturresurser, klimatpåverkan och energiförsörjning.
Observes the universe and our planet, to develop models and tools that meet global challenges regarding resources, energy supply and climate impact.
Where do we come from and where are we going? At our department we search for answers to the really big questions. In a long time perspective, the lifecycles of stars and galaxies provide an insight into the origin and future of the universe, earth and life. We also observe our planet and the interaction between society, technology and nature in order to develop technologies, models and tools that can meet global challenges regarding natural resources, climate impact and energy supply.
(2022) Dahiya, Abhishek; Chalmers tekniska högskola / Institutionen för rymd-, geo- och miljövetenskap; Andersson, Klas; Gunnarsson, Adrian; Järvinen, Mika
Industrial emissions constitute approximately 30% of total greenhouse gas emissions in 2019. Several industrial sectors have taken steps to replace their energy sources with renewables such are solar and wind power. However, many industrial processes require high temperatures which have traditionally been achieved by combustion of fossil fuels. It has proved challenging to develop alternative processes to reduce carbon dioxide emissions from these processes. One such process is secondary aluminium smelting, and as much as one-third of all aluminium produced globally comes from scrap products. An important part of the recycling process is melting and alloying with current state of the art furnaces being equipped with oxy-fuel burners. Partial or complete electrification of this process could cut emissions and reduce dependence on fossil supply and prices. Though, the high temperature and melt rates, fundamental to the process, are not achievable through Direct Electric Heating.
A potential alternative for high temperature processes is to switch fossil fuel burners with electrically generated thermal plasma using plasma torches. This study presents a comparison of oxy-propane and CO2-based plasma burners in the aluminium smelting process. Real process data as delivered by an industrial partner is used to establish a reference case. With process parameters kept constant, the radiative heat load from a plasma torch is modelled in a first step. Process conditions, energy costs and emissions from using a plasma torch in the process is evaluated and compared to the reference case with oxy-fired technology. It was found that the energy costs are 39.1% higher and an increase in melting time by 14%. Although, along with reduced dependence on gas, process modification leads to 94.7% cut in carbon emissions from primary energy. Additionally, this master thesis also includes a brief study of the expected effects from exchanging the burners for plasma torches in a steam cracker.