我国原铝冶炼行业温室气体排放模型

我国原铝冶炼行业产业集中度较低,生产水平参差不齐,随着国内原铝产量不断增加,原铝行业碳排放及其计算方法备受关注. 针对我国原铝冶炼过程原料类型、能源结构复杂的特点,对国内外已有碳排放核算框架进行细化,从物料、工序、工艺3个层面构建了复杂的原铝冶炼系统温室气体排放计算模型. 在广泛文献调研的基础上,选取典型原铝冶炼企业开展现场调研及专家咨询,进而形成模型的基础数据库. 利用上述模型对我国2011年原铝冶炼过程碳排放进行核算. 结果表明:综合考虑氧化铝生产工艺结构、电解铝行业分布区域的电网能源结构,我国原铝冶炼系统CO₂排放因子(以铝锭计)为14.70t/t. 电解铝生产过程电耗相关排放占70%,南方电网区域电解铝生产电耗相关CO₂排放分别比华中、华北地区低13%、30%. 原铝冶炼行业可通过优先选用碳排放因子较低的物料、淘汰落后氧化铝工艺、开发引进低温低电压工艺技术等手段,进一步实现物料、工序及工艺的多层次温室气体减排. 

Calculation Model for Greenhouse Gas Emission of Primary Aluminum Industry in China

Different technological levels and low industrial concentrations presents in the primary aluminum production industry of China. With domestic primary aluminum outputs increases, the greenhouse gass(GHG) emission and associated calculation methods are widely applied. In order to study the complexity of feedstock types and energy mix in China's primary aluminum industry, decomposition based on the existing carbon emission accounting framework was carried out to establish an appropriated GHG calculation model for the complex system. All levels of raw materials, processes and technologies were involved in the model of this study. Moreover, an associated fundamental database was formed through detailed field researches and expert consultations on the typical aluminum enterprises. GHG emission from primary aluminum production was quantified based on database and calculation model mentioned above. The result showed that considering alumina refining technology mix and distinguished grids distribution of smelting production capability. The specific CO_2emission for primary aluminum production of China in 2011was estimated for 14.7t/t. CO_2emission associated with the electricity consumption of smelting process accounts for 70% of the overall emission. Emissions from those smelters located in South grid were 13% and 30% lower than that from Central and North China grid, respectively. It also demonstrated that a further mitigation of GHG emission could be carried out from multi-respects of material, process and technologies. The corresponding methods involve preferring to low carbon materials, eliminating backward refining technologies, introducing advanced smelting technology with low temperature and voltage.