Energy Consumption and Carbon Footprint of Secondary Aluminum Cast House
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Primary aluminum production brings about severe environmental burden due to its energy intensive process. Secondary aluminum production contributes to cutting off high energy demand around 90-95% and greenhouse gas emission by remelting scraps. However, previous research indicates melting furnace’s energy efficiency in secondary plant is still very low, which is around 26-29% and more than 70% heat is lost in different way. The objective of this project is to investigate energy consumption and greenhouse gas (GHG) emission in secondary aluminum cast house through process analysis. The result offers a comprehensive overview to aid decision-maker to compare energy consumption and environmental impacts caused by different product or process.
This project has been done in collaboration with SAPA Heat Transfer. This project consists of two tasks. First task is aimed to give an overview of annual energy distribution and carbon footprint of per ton aluminum slab in SAPA cast house. In order to analyze energy distribution, mass and energy conservation has been applied for calculation. Meanwhile, International standard method, life cycle assessment, has been used to evaluate greenhouse gas contribution of the whole production process. The second task intends to investigate two effects (melting furnace type, raw material type) on products’ energy consumption and carbon footprint. Melting furnace’s effect is compared by selecting electric induction furnace and oxy-fuel furnace. On the other hand, raw material’s effect is studied by comparison of four different cast house products which have different raw material recipe.
Calculation and analysis results indicates that per ton Sapa cast house aluminum slab consumes energy 3826MJ and contributes to 306kgCO2eq. green house gas. Meanwhile, comparison results show that oxy-fuel melting furnace has higher energy efficiency than electric induction furnace, however, it contributes much more GHG due to consumption of propane fuel. In addition, primary ingot has been concluded as distinct carbon footprint contribution than others contributors (i.e. fuel) for Sapa cast house’s slab.
Place, publisher, year, edition, pages
2012. , 50 p.
secondary aluminum cast house, energy consumption, carbon footprint, melting furnace, efficiency
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-122081OAI: oai:DiVA.org:kth-122081DiVA: diva2:620633
Subject / course
Materials Science and Engineering
Master of Science - Engineering Materials Science
, SEFSTRÖM (the old “fikaroom”) at Brinellvägen 23 (English)
Yang, Weihong, Docent
Blaziak, Wlodzimierz, Professor