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The Experts below are selected from a list of 3423 Experts worldwide ranked by ideXlab platform
Xiangzhi Li – 1st expert on this subject based on the ideXlab platform
environmental footprint of Aluminum Production in chinaJournal of Cleaner Production, 2016Co-Authors: Yanlu Zhang, Jinglan Hong, Jing He, Xiangzhi LiAbstract:
Abstract Life cycle assessment was performed using a bottom-up approach combined with national and regional statistical data to estimate the environmental footprint of Aluminum Production in China. In the footprint of Aluminum Production, the environmental effects of bauxite, Aluminum oxide, and electrolytic Aluminum accounted for approximately 1.4%, 8%, and 90.6% of the overall environmental burden, respectively. The amounts of CO 2 , particulates, NO X and SO 2 generated in the Aluminum industry accounted for approximately 3.53%, 1.99%, 3.47%, and 5.34% of the total national emission in China in 2012, respectively. More than 94% of the global warming and fossil depletion potential impacts can be saved through Aluminum recycling. Electricity and natural gas consumption, transport, and solid waste disposal were the dominant contributors to primary and secondary Aluminum Production. The use of bitumen and inorganic chemicals also influenced primary and secondary Aluminum Production, respectively. Effective approaches to reduce the environmental burdens of Aluminum Production include replacing coal with clean energy sources for electricity Production, improving the efficiency of energy and raw material consumption, and increasing the national recycling rate of Aluminum.
Gudrun Saevarsdottir – 2nd expert on this subject based on the ideXlab platform
Aluminum Production in the Times of Climate Change: The Global Challenge to Reduce the Carbon Footprint and Prevent Carbon LeakageJOM, 2019Co-Authors: Gudrun Saevarsdottir, Halvor Kvande, Barry J. WelchAbstract:
This paper addresses the global challenge of greenhouse gas emissions facing the Aluminum industry. The demand, Production and use of Aluminum are increasing and so are the emissions. From bauxite mine to Aluminum ingot, the total global average emissions vary somewhat in the literature, but most reported values are now between 12 and 17 metric tonnes of CO_2-equivalents per tonne of Aluminum, depending on the various estimates and assumptions made. Two-thirds of these gases are emitted because the electricity used for electrolysis is produced from fossil fuel sources, mainly coal but also natural gas. Reduction of these emissions is now the main environmental challenge for the Aluminum industry. Globally, the best result is obtained by maximizing Aluminum Production using green electrical energy from renewable sources. Aluminum Production is categorized as an activity at very high risk of carbon leakage, which occurs when there is an increase in carbon dioxide emissions by new Production in one country as a result of ceased Production with emissions reduction in a second country with a strict climate policy.
Waste Heat Recovery from Aluminum ProductionEnergy Technology 2018, 2018Co-Authors: Miao Yu, Maria S. Gudjonsdottir, Pall Valdimarsson, Gudrun SaevarsdottirAbstract:
Around half of the energy consumed in Aluminum Production is lost as waste heat. Approximately 30–45% of the total waste heat is carried away by the exhaust gas from the smelter and is the most easily accessible waste heat stream. Alcoa Fjarðaál in east Iceland produces 350 000 tons annually, emitting the 110 °C exhaust gas with 88.1 MW of heat, which contains 13.39 MW exergy. In this study, three scenarios, including organic Rankine cycle (ORC) system, heat supply system and combined heat and power (CHP) system, were proposed to recover waste heat from the exhaust gas. The electric power generation potential is estimated by ORC models. The maximum power output was found to be 2.57 MW for an evaporation temperature of 61.22 °C and R-123 as working fluid. 42.34 MW can be produced by the heat supply system with the same temperature drop of the exhaust gas in the ORC system. The heat requirement for local district heating can be fulfilled by the heat supply system, and there is a potential opportunity for agriculture, snow melting and other industrial applications. The CHP system is more comprehensive. 1.156 MW power and 23.55 MW heating capacity can be produced by CHP system. The highest energy efficiency is achieved by the heat supply system and the maximum power output can be obtained with the ORC system. The efficiency of energy utilization in Aluminum Production can be effectively improved by waste heat recovery as studied in this paper.
Wei-qiang Chen – 3rd expert on this subject based on the ideXlab platform
Historical evolution of greenhouse gas emissions from Aluminum Production at a country levelJournal of Cleaner Production, 2014Co-Authors: Luca Ciacci, Matthew J. Eckelman, Fabrizio Passarini, Wei-qiang Chen, Ivano Vassura, Luciano MorselliAbstract:
Abstract Standard material flow analysis (MFA) and life cycle assessment (LCA) models were combined to analyze the historical evolution of greenhouse gas emissions of Italian Aluminum over the years 1960–2009 with the aim of providing key features to Italy for prioritizing future industrial and environmental policies. Annual greenhouse gas emissions were calculated for primary and electrical energy, process-related and transportation. Cradle-to-gate emission factors were defined per ton of Aluminum produced and used to quantify the cumulative carbon footprint. Consolidation of the model was carried out at domestic and foreign levels for Aluminum Production in order to analyze the shift in emissions transfers between the location of Production and that of use. Overall, average percent contributions from the main CO2e-related process reflect the trend of the global Aluminum industry in upgrading to standardized Production processes worldwide. Cumulative carbon footprint of Italian Aluminum was estimated in about 375 MtCO2e, of which only 188 MtCO2e is from domestic Production. Because Italy is a net importer of Aluminum, greenhouse gas emissions from the final use of Aluminum have increased the impact of domestic Production by 140% in the last decade. A potential carbon emissions savings of ∼160 MtCO2e could result if the current anthropogenic Aluminum in-use stock will be quantitatively recycled. The study showed potentials for combining MFA and LCA to improve completeness when approaching environmental issues. The outcomes revealed chances for decreasing the contribution to climate change from the Aluminum industry and allowed the setting of country indicators usable in future national LCA studies.
analysis of Aluminum stocks and flows in mainland china from 1950 to 2009 exploring the dynamics driving the rapid increase in china s Aluminum ProductionResources Conservation and Recycling, 2012Co-Authors: Wei-qiang ChenAbstract:
Abstract This paper analyses the anthropogenic stocks and flows of Aluminum in mainland China from 1950 to 2009 using time-series data for mining, Production, fabrication, manufacturing, trade, and loss rates, and applies a dynamic top-down method to model scrap generation. Results show that growth rates of all flows increased from decade to decade, with 75% of most of the flows taking place in the last two decades. Of the 230 Tg Aluminum entering China’s anthroposphere, only 34% accumulates in in-use stock, and China’s per-capita in-use stock (58 kg) in 2009 is 12% of the per-capita in-use stock in 2006 in the United States (490 kg). In addition, the share of secondary Aluminum in the Production of unwrought Aluminum was less than 25% after 2000. These results imply that China’s in-use stock of Aluminum is still too “young” and small to generate high quantities of Aluminum scrap for domestic secondary Aluminum Production. Because of this, China still depends mainly upon primary Aluminum. From the 1980s to the period of 1990 to 2009, China changed from a net exporter of raw materials into a net importer and from a net importer of manufactured products into a net exporter. In 2009, China’s static depletion time of bauxite was less than 15 years. Given the potential to increase its in-use stock, a secure supply of bauxite may become a challenge for China in the near future. Three dynamics driving China’s rapid increase of primary Aluminum Production (PAP) were identified, and their impacts from 1991 to 2009 were quantified. The first, demand for Aluminum by domestic in-use stock , was the most significant factor driving China’s PAP increase. The second dynamic, China’s net export of Aluminum in the metallic form , became an important factor in stimulating PAP’s increase in the 2000s. Lastly, the impact of losses to the environment in the metallic form on PAP is substantial and stays that way throughout time. Minimizing losses represents an opportunity to offset some demand.