生命周期评价方法在钢铁企业低碳发展规划中的应用

在当前“碳达峰”“碳中和”的背景下,很多钢铁企业在制订低碳发展规划的过程中,对于减碳措施的减碳潜力没有数字化的概念,缺乏量化的评价手段和科学的数据支撑。为此,提出应用生命周期评价(LCA)进行钢铁企业低碳发展规划的方法,建立产品碳足迹与组织层级碳核算的关联。在此基础上,通过建立覆盖全公司的产品生命周期评价模型,以量化评估新技术新工艺应用、产品结构变化、能源结构变化、废钢利用率提升、节能减排改进、供应链优化等因素对于企业组织层面的碳减排绩效,可实现数字化碳减排路线图的描绘。给出了钢铁企业主要措施与策略碳减排潜力的评价方法与案例,可为钢铁企业的低碳发展规划提供参考。     

全氧燃烧在120 t钢包烘烤器上的应用

随着钢铁行业能源环保压力日益加重,节能减排是钢铁企业高质量发展的必然选择。主要阐述了全氧燃烧技术节能减排原理以及在某厂钢包烘烤上的应用实践。采用工业试验对比的方式,对全氧燃烧在该厂120 t钢包烘烤器上的应用效果进行分析,结果表明,全氧燃烧技术的应用可以有效提高钢包烘烤效果,减少烘烤过程中烟气和NO_x排放,降低煤气消耗约43.79%,提高钢包烘烤终点内衬温度约223 ℃,降低转炉出钢过程钢水温降约9.10 ℃,降低吨钢精炼成本约4.77元。     

Control of greenhouse gas emissions from electric arc furnace steelmaking: evaluation methodology with case studies

Abstract

The energy intensive nature of electric arc furnace (EAF) steelmaking necessitates that efforts to reduce greenhouse gas (GHG) emissions will affect steelmakers directly and/or through electric power producers. A model of GHG emissions from an EAF meltshop has been developed using the life cycle assessment approach. Direct and indirect sources of GHG gas emissions are estimated and ranked. Furnace combustion optimisation was evaluated in case studies conducted on a Canadian conventional EAF and a British scrap preheating `shaft' furnace. The analysis assumed 32 and 68% fossil fuel electricity generation, respectively. These case studies show that indirect GHG emission sources, in particular electricity generation, are more significant than direct emissions from the EAF. For the conventional EAF, offgas analysis and improved combustion control reduced electricity consumption by 40 kWh t^-1, costs by US$1·05/t, and GHG emissions by 20 kg CO₂-eq./t. For the shaft EAF, real time offgas monitoring and closed loop burner control reduced electricity consumption by 25 kWh t^-1, costs by US$3·6/t, and GHG emissions by 15 kg CO₂-eq./t. The case studies show that combustion optimisation using an EAF offgas analysis and combustion control system provides greater electricity, cost, and GHG reductions than previously reported in the literature.     

The Contribution of Niobium Bearing Steels and Enhanced Sustainability

With the growing concern for the environmental impact of greenhouse gases and the rapid depletion of important resources,the use of Nb-bearing steels for advanced high strength steel applications can reduce raw material usage and the carbon footprint.The conservation and more efficient use of ironmaking and steelmaking raw materials is an urgent issue for steel producers globally.Recently-developed Nb-microalloyed steel applications provide a more effective product design and reduce CO 2 emissions and energy consumption per tonne of steel.A sustainability structural steelstudy presents the positive cost and reduced environmental impact of Nb-microalloyed steels.This analysis compares the CO 2 emission reduction and energy savings in the steelmaking process melted in both the Basic Oxygen Furnace (BOF) and the Electric Arc Furnace (EAF).Nb-microalloyed structural steels offer the opportunity to reduce the total weight of a given structure compared to a non-microalloyed steel construction.Generally,one considers the savings associated with less material and lower construction costs.In addition,there is an environmental benefit in the reduction in emissions (kilograms of CO 2) and less energy consumption (GJ) due to the fact that less steel is melted.Plus,there are lighter sections and less material weight in the final end user design which reduces transportation and fabrication costs.A forecasted trend is presented which introduces an increased usage of microalloyed steel grades to replace traditional commodity-type non-alloyed higher carbon-manganese grades for environmental benefits and significant cost reduction.     

中美能源消费对比与产业节能减排效应测算

在自然灾害频发、全球气候变暖的挑战面前,中美两国在清洁能源等领域已开展合作。中国科学院预测科学研究中心从产业的角度研究了中、美两国各类能源的消费结构,将中国经济系统分为工业、商业、交通和民用四大产业,42个部门,对其能源消耗、二氧化碳排放和其他经济数据进行了测算,从中观层面分析得出中国目前的节能减排潜力主要在工业。对我国制定进一步的可再生能源发展规划和节能减排政策提出了建议。     

Change in Carbon Dioxide (CO2) Emissions From Energy Use in China's Iron and Steel Industry

As the largest energy consuming manufacturing sector and one of the most important sources of carbon dioxide (CO2) emissions, the China's iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMDI) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emissions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.     

Steel’s CO2 balance—a contribution to climate protection

Steel making is energy and material intensive.That is why steel is always demonized and confronted with incriminations and requirements for reduction of its environmental impact.Those pure demands-like for emission trading are short-sighted as they do not base on an integrated approach.Instead they merely consider CO₂ emissions during the production process.A forward-looking,global climate and environmental policy needs a sustainable life cycle approach.Therefore it must for example also take into account the contribution of steel towards cutting emissions in its application-in the energy.automotive and household sectors.Steel will play a key role in climate protection. One-third of the remaining CO₂ reduction target planned in Germany by 2020 can only be achieved with the help of innovative steel products and their applications.This is the conclusion of an independent study by The Boston Consulting Group（BCG） on behalf of Steel Institute VDEh,and German Steel Federation.The study compares CO₂ savings from important innovative steel applications（such as more efficient power stations,wind turbines,or lighter vehicles） with CO₂ emissions caused by steel production. By adopting this comprehensive perspective,the study for the first time provides a CO₂ balance for the material steel by comparing the CO₂ reductions made possible through innovative steel applications with the CO₂ emissions resulting from steel production.The balance was calculated on the basis of eight selected innovative steel applications in Germany for the period 2007 to 2020,whereby the CO₂ emissions caused by steel production were considered throughout the entire life cycle of the particular steel use.For the selected examples,the use of innovative steels resulted in a total savings potential of 74 Mt of CO₂ in 2020.The calculations are based on conservative assumptions;for example without counting of potentials by exported steel or by comparison with competitive materials. The production of steel in Germany,including the extraction of raw materials,transports and further processing, causes annual emissions of approx.67 Mt CO₂ This can be more than compensated by the above mentioned CO₂ savings.The balance is even more positive if one only considers the emissions of about 12 Mt/a CO₂ caused by the selected eight steel applications.Innovative steel use thus saves six times as much CO₂ as is generated by its production. Steel is part of the story and helps to achieve CO₂ reduction targets.On this basis the steel industry should start up with a new global approach to be accepted as a CO₂ killer,too,instead of being the devil.This needs a political discussion on an integrated approach taking into account the whole life cycle,which finally can lead away from stringent emission caps or incompatible emissions trading systems for the different regions.     

Change in Carbon Dioxide （CO2） Emissions From Energy Use in China＇s Iron and Steel Industry

 As the largest energy consuming manufacturing sector and one of the most important sources of carbon dioxide (CO2) emissions, the China′s iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMDI) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emissions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.     

Life-Cycle Analysis of Energy and Greenhouse Gas Emissions from Anaerobic Biodegradation of Municipal Solid Waste

Energy requirements and greenhouse gas (GHG) emissions for current landfilling of municipal solid waste (MSW) was compared to potential biodegradation of MSW in anaerobic digesters (AD) throughout the United States. A hybrid life-cycle analysis was completed to assess the potential for anaerobic biodegradation of MSW to methane, a valuable energy source. Conversion of MSW to methane in AD would generate a form of renewable energy, reduce GHG emissions, and save landfill space for nonbiodegradable materials. Based on laboratory- and pilot-scale studies conducted in the United States, full-scale data from facilities in Europe, and economic input-output life-cycle analysis, the annual 127 million t of MSW landfilled in the United States could be biologically converted to 5.9?billion?m3 of methane. Net methane production would have an estimated value of $1.5 billion/year when converted to an equivalent amount of electricity at an assumed value of $0.1/kWh. The 15 billion kWh/year of renewable energy released through the biodegradation process is estimated to satisfy the annual consumption of 1.3 million United States households. The analysis also suggests that diversion of MSW from landfills to AD systems would result in GHG emissions reductions of 146 million t CO2e per year, due to decreased landfill activity and use of biogenic methane instead of fossil fuel for electricity production. This represents a reduction in total emissions of 1.9% compared to U.S. GHG emissions in 2006. Nationwide AD systems are projected to reduce cumulative energy consumption by nearly 15 million TJ and reduce GHG emissions by 7.2 billion t CO2e, over a 50-year period. Logistics and capital costs of developing a nationwide reactor-based system for MSW management are considerable. Development of appropriate national policy and incentives would be needed to stimulate such a transition from the current landfill-based system that currently exists. It is estimated that a carbon emissions credit on the order of $30 to $60/t CO2e would facilitate break-even economics for nationwide implementation of AD systems. Alternatively, renewable energy credits would enhance the value of electricity produced from AD biogas. Carbon emissions taxes on landfills would further improve the economics of AD systems.     

电硅热法生产300系不锈钢工艺的可行性

 提出一种电硅热法生产300系列不锈钢母液新工艺,该工艺针对低品位红土镍矿二氧化硅含量高的特点,用矿热炉生产出高硅镍铁,然后利用高硅镍铁的硅还原铬粉矿中的铬、铁,得到镍铬不锈钢母液,再经成分、温度调整后转入AOD或VOD精炼工艺,生产出300系列不锈钢。因此,该工艺不仅有助于解决红土矿生产低硅镍铁的技术问题,而且可以直接使用铬精矿粉。物料与能量平衡计算结果表明,对比传统的“二步法”工艺,新工艺可降低原料成本6.3%～7.2%,降低综合能耗7.1%左右,降低CO2排放6.1%左右。台架试验结果表明,采用还原脱磷方法可将硅质量分数为20%左右的高硅镍铁中的磷质量分数降至0.03%以下,能满足新工艺的设计要求;脱磷后的高硅镍铁进行脱硅增铬,最终可得到磷 、硅 、碳质量分数符合不锈钢初炼钢水要求的镍铬不锈钢基料。     

石灰石代替石灰造渣炼钢减排CO2 的研究

为了分析石灰石代替石灰造渣炼钢这项技术在节能环保方面产生的效果,本文将石灰石直接进转炉造渣 炼钢模式和原有的“煅烧石灰-造渣炼钢”模式的CO 2 排放进行详细的对比计算,结果得到用石灰石替代1 kg石 灰,在冷料为废钢和生铁块的情况下,分别能够减排1.29 kg和1.12 kg CO 2 。该技术为钢铁行业节能减排带来的 效益巨大。     

钢铁工业二氧化碳排放计算方法实例研究

实现钢铁生产中CO₂排放的准确量化和计算是分析评估其环境影响及各种减排技术的基础和保障.基于Y钢厂2015年的实际生产数据，分别利用国内推荐的投入产出法和国际钢铁协会推荐的生命周期法计算了Y钢厂的吨钢CO₂排放量.计算结果表明:生命周期法计算的Y钢厂的吨钢CO₂排放量为2.183 t CO₂，明显高于国内推荐的投入产出法计算的Y钢厂的吨钢CO₂排放量1.940 t CO₂，这主要是由于钢铁协会提出的计算方法统计项目更为丰富并且考虑了物料和能源的上游产生的二氧化碳排放.结合《温室气体排放核算与报告要求》计算方法和国际钢铁协会所提出的计算方法，从计算边界、排放因子、物料和能源分类以及评价基准线层面提出了一套基于全生命周期方法的符合中国钢铁企业国情的温室气体排放计算方法.      

电弧炉电能需求的生产实践与评价

电耗是电弧炉的重要技术指标之一,在当前发电行业背景下,降低电弧炉电耗具有显著的经济和环境效益。根据典型电弧炉企业生产数据,系统分析各项工艺参数与电耗之间的关系,并进一步评价了各种方法降低电耗的环境效益。结果表明,优化供电制度和强化供氧是具有良好环境效益的节电手段。对于连续加料电弧炉,天然气喷吹对降低电耗的作用被极大减弱,天然气消耗与电耗的相关系数为-1.13 kW·h/m³,其应用不利于CO₂减排。尽管兑加铁水可以显著降低电耗,但是兑加40%(质量分数)铁水的连续加料电弧炉能耗和碳排放量分别是全废钢连续加料电弧炉的2.25和2.50倍,不利于推动钢铁工业节能减排工作。因此,降低电弧炉电耗需要通过增加电弧炉中化学能和物理热的供应及减少能量损失的手段来实现。     

Current status and future trends for material flow analysis applications at CSC

Material Flow Analysis（MFA） is a crucial instrument for sustainable development and creating industrial ecology system.MFA studies could balance and analyze the sources,flows,and consumes of specific materials or substances.The results of MFA studies could support the strategies or decisions making for energy, resource,and waste management,especially achieving sustainable resource management.At CSC,the dynamic simulating software,STELLA,is used to develop a MFA model for scenario analysis.CSC also uses the freeware STAN 2.0 as a tool for visualizing and simulating material flows and stocks.Case studies of greenhouse gases MFA for integrated steel works are conducted.The results showed that the carbon content of hot-metal is an important hidden flow for balance analysis,and the different GHG emission scenarios and mitigation action scenarios are assessed.In addition,the Iron-making GHG I/O MFA Model,based on worldsteel Global Steel Sector Approach（GSSA）,is developed for calculating the CO₂ and energy intensity of coke making,sintering,and BF processes.This MFA model was used to analyze the CO₂ reduction potential for iron-making process.The cases conducted for MFA applications at CSC were such as greenhouse gas,zinc,etc.In the future,CSC is going to develop a "CSC Environment Management and Decision Supporting System" which combine MFA,LCA（life cycle assessment）,and environment risk assessment.This supporting system expects to promoting energy efficiency and best resource use,supporting environment policymaking,creating environmental information value,etc.     

炼铁新技术及基础理论研究进展

从炼铁新技术及基础理论研究方面介绍了烧结球团提质降耗新技术、焦炭在高炉内行为解析研究、高炉喷吹清洁燃料技术、高炉长寿技术、高炉炼铁数据建模技术以及冶金尘泥再处理技术。从基础研究出发,提出了目前最具有潜力的炼铁新技术;然后在国家碳中和战略的大背景下,综述了目前国际上的非高炉炼铁技术研究进展,为我国低碳炼铁发展提供依据;最后从最新微观研究手段出发,介绍了目前炼铁研究领域在微观尺度的研究进展,多尺度综合调控研究高炉炼铁过程机理,为未来低碳炼铁发展方向提供思路。      

钢铁企业热电厂碳排放的评价研究

热电厂是钢铁企业重要的能源生产部门,热电联产的碳排放量关系到整个企业碳减排成效。采用单位能源产品碳排放量指标结合火用分析来评价热电厂的碳排放量,将单位能源产品碳排放量分解成最小排放量和附加排放量进行研究。结果表明:热电联产通过能源梯级利用,提高能源转换效率,减少化石能源使用,有利于实现钢铁企业减少碳排放。     

钢包全程加盖设备与工艺研究现状

通过大量文献调研,介绍了炼钢生产中钢包全程加盖设备与工艺研究现状,为重钢环保搬迁改造,落实国家节能减排政策,建设低成本洁净钢平台,实现绿色、环保、高效生产提供有益借鉴.     

基于LMDI?STIRPAT模型的中国钢铁行业碳达峰路径研究

基于排放因子法核算中国钢铁行业2000—2019年碳排放,运用两阶段对数平均迪式分解法（LMDI）和STIRPAT模型分析碳排放增长的影响因素和2030年碳排放。结果表明,碳排放持续增长,2014年达到阶段峰值18.48亿吨。规模因素是碳排放增加的主要原因,能源强度是最大的抑制因素。情景分析表明,基准情景下将在2025年达峰,碳排放量为19.04亿吨;低碳情景下碳达峰时间为2021年,碳排放量为18.67亿吨;强低碳情景已于2020年达到碳排放峰值,碳排放量为18.52亿吨;快速发展情景则无法在2030年前实现碳达峰。      

联合钢厂采用无碳排放的ENERGIRON直接还原方案减少温室气体的排放

在基于高炉冶炼的联合企业中,始终有一些过剩的焦炉煤气、转炉煤气和高炉炉顶煤气,通常这些煤气用于电厂发电。另一种替代方法是使用这些现有的能源气体生产直接还原铁(DRI),将其作为金属化炉料加入高炉,提高粗钢产量,以减少化石燃料单耗。优化利用主要的化石燃料可以显著降低吨钢CO2排放量。采用传统的BF-BOF流程,即使在优化工艺流程的基础上,吨钢CO2排放量也有1.7～1.8t左右。而用产自天然气、焦炉煤气和高炉炉顶煤气的DRI作为金属化炉料加入高炉或电炉,却可显著降低CO2排放量。     

钢铁厂节能温室气体减排现状及对策

钢铁行业是温室气体排放的主要行业之一,温室气体减排技术包括节能和温室气体利用两方面.介绍国外温室气体的减排现状、中国的能源现状及日本和美国目前主要的节能减排技术;着重介绍宝钢开展的减排工作,包括节能技术的推广应用、新的节能减排技术的研发应用,如蓄热燃烧技术、多孔介质燃烧技术等;提出了应对后京都时代的措施.