Reducing the environmental impacts of aluminum extrusion
Reducing the environmental impacts of aluminum extrusion
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DOI：
10.1016/j.resconrec.2021.106120
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发表时间：
2022-04-01
影响因子：
13.2
通讯作者：
Cooper, Daniel R.
中科院分区：
文献类型：
--
作者：
Oberhausen, Gregory;Zhu, Yongxian;Cooper, Daniel R.
铝挤压行业正在迅速发展;然而，在量化或减少挤压对环境的影响方面的工作很少。本文首先推导出摇篮到门的累积能源需求，温室气体排放量和直接铝挤压成本模型，使用从挤压公司收集的数据，生命周期库存测量（例如，电力需求）从我们自己的案例研究，和基于物理的推断。这些模型表明，在提高工艺能源和材料效率方面有很大的空间;然而，只有提高材料效率才能带来显著的环境效益和成本节约。随后，对2018年北美挤压行业的合金形状应用材料流进行了分析，以突出整个供应链中提高材料利用率的机会。材料流数据整理现有的学术和灰色文献，除了半结构化的采访北美挤出专家。材料流分析表明，在所有铸造成挤压坯料的铝中，约有40%在完成制造产品之前被废弃，这使制造型材的成本增加了约16%，温室气体排放量和累积能源需求增加了约40%。大多数废料是通过去除当前工艺固有的结构和表面光洁度挤出缺陷而产生的。确定并讨论了可能减少因这些缺陷而报废的材料的工艺调整。即使挤压过程中的废料减少10%，也可以为北美（美国和加拿大）挤压行业每年节省2.7 - 3.11亿美元，并每年减少0.5 - 2.3 Mt.CO2eq的排放。
The aluminum extrusion industry is growing rapidly; however, there has been little work on quantifying or reducing extrusion's environmental impacts. This article first derives cradle-to-gate cumulative energy demand, greenhouse gas emission, and cost models for direct aluminum extrusion using data collected from extrusion companies, life cycle inventory measurements (e.g., electricity demand) from our own case studies, and physics-based extrapolations. These models show there is significant scope for increasing both the process energy and material efficiency; however, only increasing the material efficiency will lead to significant environmental benefits and cost savings. Subsequently, an alloy-shape-application material flow analysis of the 2018 North American extrusion industry is conducted to highlight opportunities for improved material utilization throughout the supply chain. Material flow data were collated from existing academic and gray literature in addition to semi-structured interviews with North American extrusion experts. The material flow analysis reveals that around 40% of all aluminum cast into extrusion billets is scrapped before completion in a fabricated product, which increases the cost of the fabricated profile by approximately 16% and the greenhouse gas emissions and cumulative energy demand by approximately 40%. Most of this scrap is created by removing structural and surface finish extrusion defects that are inherent to the current process. Process adaptations that might reduce the material scrapped due to these defects are identified and discussed. Even a 10% reduction in extrusion process forming scrap could save the North American (U.S. and Canada) extrusion industry 270-311 million USD per year and prevent the release of 0.5-2.3 Mt.CO2eq annually.