CO2在炼钢工艺的应用及发展

钢铁生产过程CO2排放占工业CO2排放量的16%左右。如何降低CO2排放并使CO2进行资源化利用是钢铁工作者关心的重要问题。以CO2在炼钢过程中的资源化利用为出发点,分析了国内外CO2作为炼钢过程的搅拌气源、反应介质及保护气源的应用情况,并介绍了笔者在炼钢应用CO2方面所做的前期研究工作的进展。     

以钢铁联合企业副产煤气为燃料的热电厂CO_2捕集

采用高炉—转炉联合流程的钢铁企业应优先考虑减少CO2排放,以缓解对环境的影响。其中,选择之一就是在能效方面进行持续不断的重要改进,这虽然可以实现排放量和原材料消耗的大幅度降低,但采用该方法达到进一步提高减排效果却变得越来越困难;另一种选择是对炼铁过程进行基础的重新设计,例如ULCOS项目。现提供第三种选择,即对钢铁企业中产生的CO2进行捕集。典型的高炉—转炉厂主要产生三种煤气:焦炉煤气、高炉煤气以及转炉煤气。按所带能量来说,高炉煤气带走的能量最多。很大一部分高炉煤气在热电厂燃烧后转化为冷风和电能,而在热电厂排放的烟气中,CO2量在整个钢铁厂的CO2排放量中占有很大的比例。低热值烟气燃烧产生的单位能量排放的CO2量要远高于火力发电厂烧煤或燃烧天然气所排放的CO2量,甚至高于其他烟气排放的CO2量。因此,将所有CO2捕集过程中的能耗降至最低显得尤为重要。以能耗为基准,对采用高炉煤气与空气或氧气燃烧发电的火力热电厂的CO2捕集方式,即标准的胺类溶液吸收、变压吸附和冷凝分离等燃烧后捕集方式进行评价。     

高炉炼铁降低CO2排放的潜力

在多方努力减少温室气体排放以及欧盟加紧实施CO2排放贸易的大背景下,高炉工艺也开始重新考虑减少CO2排放的可能性。由蒂森克虏伯钢公司开发的高炉平衡模型可提供减少还原剂加入量,即减少CO2排放量的方法。与实际生产高炉作对比,对"理想"高炉进行了计算。"理想"高炉中浮氏体还原动力学的"理想操作点",直接取决于贝-波反应平衡曲线,可在远离平衡位置的低温下实现。统计分析发现,"理想高炉"的燃料比只比德国高炉目前的平均燃料比低5%。高炉中加入预还原炉料,如热压铁块(HBI),对降低还原剂消耗和高炉过程的CO2排放都起有利作用。为了评估减少还原剂消耗和CO2排放的潜力,应用平衡模型对与传统高炉不同的两种新的高炉工艺进行了评价。这两种新流程是无氮高炉和等离子加热高炉,其共同特点是都配有从炉顶煤气中脱除CO2的装置,这两种新工艺虽然降低了还原剂消耗量,但都需要消耗更多的电能,特别是等离子加热高炉工艺。     

低碳炼铁 节能减排 实现清洁生产

高炉炼铁工序是钢铁生产中CO2的主要排放工序,因此降低炼铁工序CO2排放量,即低碳炼铁是钢铁工业减少CO2排放量的重中之重。以＂低碳炼铁、节能减排、实现清洁生产＂为主题的2010年全国炼铁生产技术会议暨炼铁学术年会,为如何实现炼铁系统的低碳生产、     

Current Situation of CO2 Emission and Point Sources Distribution in China＇s Iron and Steel Industry

在对中国钢铁企业的产能、产量数据进行调研的基础上,计算了单个钢铁企业及整个行业CO2排放量,分析了中国钢铁行业的CO2排放现状及2000-2009年间的变化情况。在此基础上绘制了中国钢铁行业2000、2004和2009年的排放点源空间分布图,分析了排放点源随时间的变化趋势及空间分布特征。结果表明,近年来,中国钢铁行业CO2排放量呈现快速增长,2009年达到969．49Mt,是2000年的2．4倍。2009年,中国钢铁行业CO2排放点源数量312个,主要集中于河北、江苏、山东、辽宁、山西、上海、广东、湖北等省市,且大规模排放源逐年增多,CO2减排压力巨大。     

钢铁生产CO2过程排放分析

钢铁生产成为大气中温室气体CO2的一大来源,准确测算钢铁生产CO2过程排放量是评估企业或行业减排的保障。建立基于CO2排放模块的CO2排放模型,选定国内典型钢铁生产企业进行分析,发现炼铁工序的CO2排放占总流程的60%左右,同时进一步分析了整体CO2排放强度与吨钢能耗的关系及工序CO2排放强度的分布。     

中国钢铁行业CO2排放现状及点源分布特征

 在对中国钢铁企业的产能、产量数据进行调研的基础上,计算了单个钢铁企业及整个行业CO2排放量,分析了中国钢铁行业的CO2排放现状及2000~2009年间的变化情况。在此基础上绘制了中国钢铁行业2000、2004和2009年的排放点源空间分布图,分析了排放点源随时间的变化趋势及空间分布特征。结果表明,近年来,中国钢铁行业CO2排放量呈现快速增长,2009年达到96949Mt,是2000年的24倍。2009年,中国钢铁行业CO2排放点源数量312个,主要集中于河北、江苏、山东、辽宁、山西、上海、广东、湖北等省市,且大规模排放源逐年增多,CO2减排压力巨大。     

炼铁流程用氢减碳潜力分析

本文对氢气高炉喷吹、氢气还原铁等炼铁领域的几种工艺用氢降低CO2排放潜力效果进行了分析.结果表明:氢气喷入高炉可以降低CO2排放,减排最大潜力为21.4％,但吨铁氢气耗量超过700 m3;焦炉煤气喷入高炉,可以降低煤粉喷吹量,有一定的节能效果,50 m3的焦炉煤气可直接减排59.4 kg的CO2,综合减排20 kg的C...     

基于系统动力学的我国钢铁工业碳足迹研究

我国钢铁工业正在快速发展,目前已经成为世界钢铁大国,但还不是钢铁强国,在当前建设资源节约型、环境友好型社会的要求下,钢铁工业需要加强CO2减排工作。笔者在对中国钢铁工业节能减排现状研究的基础上,利用系统动力学,建立了中国钢铁工业钢铁需求量、能耗水平和CO2排放模型,并进行了相应计算,根据计算结果提出了中国钢铁工业CO2减排的对策。结论表明从内部需求和外部驱动两方面看,中国钢铁工业需要走低碳发展道路,钢铁工业可以在2020-2025年后将CO2排放量基本稳定下来。     

钢铁流程结构及对CO_2排放的影响

温室气体排放引起的气候变暖已经成为全球性的重要命题。介绍了国内钢铁工业温室气体(主要是CO2)的排放情况,指出能源消耗是造成钢铁工业CO2排放的主要原因。在对比两类典型钢铁生产流程的CO2排放情况的基础上,深入分析了钢铁工业的能源结构及不同流程中原燃料来源结构对CO2排放的影响;最后对新一代钢铁制造流程的CO2排放进行了估算。     

A Brief Overview of Low CO2 Emission Technologies for Iron & Steel Making

 The global steel production has been growing for the last 50 years, from 200 million metric tons in 1950s to 1,240 million metric tons in 2006. Iron and steelmaking industry is one of the most energy-intensive industries, with an annual energy consumption of about 24 EJ, 5% of the world's total energy consumption. The steel industry accounts for 3-4% of total world greenhouse gas emissions. While enhancing energy efficiency could be a short-term approach for the steel industry to reduce greenhouse gas emission, the long-term approaches to achieve a significant reduction in CO2 emissions from the steel industry would be through (1) developing and applying CO2 breakthrough technologies for iron and steelmaking, and (2) increasing use of renewable energy (in particular, bio-energy) for iron and steelmaking. This paper presents an overview of new CO2 breakthrough technologies for iron and steelmaking, and the current research and development for the use of biomass and bio-fuels as substitutes for coke, coal and natural gas in various iron and steelmaking processes including iron-ore sintering, blast furnace operations, and new iron and steelmaking processes. The key challenges for utilization of bio-energy on a large scale for iron and steelmaking are also discussed in this paper.     

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.     

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.     

钢铁联合企业CO2排放研究综述

摘 要：回顾了近年来国内外研究钢铁联合企业CO₂排放的文献,建立了钢铁生产过程碳素流模型;总结和分析了钢铁联合工业影响CO₂排放因素;介绍了国外利用reMIND和CLPEX建立的过程集成优化分析生产成本和CO₂排放量的模型;总结了钢铁联合企业CO₂排放量的估算方法和注意事项;提出我国钢铁联合企业目前应该加快建立适合本国钢铁联合企业温室气体排放计算标准和方法;展望了钢铁联合企业研究CO₂排放的研究方向。     

Carbon dioxide emissions reduction technology and its application prospects in the steel industry

Fossil-fuel burning greenhouse gas induced global warming has been recognized as global environmental problems,reduce and ultimately control the energy production in the use of CO₂ emissions, global energy production will be a major challenge.As a highly intensive materials and energy,iron and steel enterprises,need to be invested to produce one ton of steel about two tons of material and 0.7 t of standard coal energy,and while producing two tons of CO₂.Therefore,reducing CO₂ emissions from iron and steel industry has become the focus of the global steel industry.This paper describes an integrated domestic and international measures to control carbon dioxide emissions research progress and future technology trends, with emphasis on the domestic steel industry emissions of carbon dioxide status of technology development and industrialization of implementation of the proposed on this basis,including dry quenching technology, gas,power generation,coal moisture control technology,blast furnace injection plastics technology,the use of coking process for treating municipal waste plastics technology,sintering heat generation,low pressure saturated steam for power generation,metallurgical slag heat recovery technology,coke oven gas hydrogen technology and the other key technologies energy saving technologies,including the development,promotion and popularization of the steel industry in China will be the CO₂ emission reduction technology direction and focus.At this stage,the Chinese steel industry can be improved the energy efficiency and recycling of waste heat and energy,reduce unit GDP,CO₂ emissions;but in the long run,should increase CO₂ capture and storage on the input of technology can possible effective control of the adverse effects of CO₂ emissions.     

氢冶金基础研究及新工艺探索

氢冶金是钢铁工业减少CO₂排放的有效方法之一。但当前大规模制氢仍然依靠化石燃料,因此,即使采用氢冶金总量减排不明显。利用钢铁企业的含能气体制氢或“可燃冰”制氢可以为氢冶金提供氢源并能减少CO₂排放。探讨了低温氢冶金的关键技术。同时还研究了碳-氢熔融还原工艺。为氢冶金技术的发展奠定了一定的理论基础。     

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。     

中国钢铁行业低碳模式及其相关政策分析

基于全过程分析和情景分析建立耦合模型,从中国钢铁工业的发展模式和政策角度,结合中国当前成熟的节能减碳技术,分析中国钢铁工业CO2的低碳发展模式和相关政策,并探讨未来中国钢铁工业CO2的最优减排量和优化技术路线。分析结果表明：若控制好经济发展和钢产量速度,实施提出的减碳技术路线,与2010年相比到2020年中国钢铁工业在焦化、烧结、炼铁、转炉、电炉和轧钢工序单位产品可减少CO2排放量分别为77.33、4.4、7.13、54.36、116.2和42kg/t;若同时保证相关末端处理技术的实施,到2020年吨钢CO2排放量为1.49t。可见,建立中国钢铁工业的低碳发展模式,主要在于促进相关成熟技术利用的政策调整,该发展模式可为中国钢铁行业的持续发展提供一定的理论依据。     

Flexible Operation of Coal Fired Power Plants with Postcombustion Capture of Carbon Dioxide

Carbon capture and storage is one family of technologies that could be used to significantly reduce global carbon dioxide (CO2) emissions. This paper reviews the likely flexibility of power plants with postcombustion capture, with a focus on an improved characterization of the dynamic performance of power plants with CO2 capture. The literature has focused on design and optimization for steady state operation of power plants with capture, often at a single design point. When dynamic behavior is considered, it is possible that designs should be altered for best overall plant performance. Economic trade-offs between improving transport and storage scheme flexibility and constraining power plant operations should also be carefully analyzed, particularly if the captured CO2 is to be used in another process such as enhanced oil recovery. Another important aspect of real plant operation will be adhering to legislative requirements. Further work is required to identify mechanisms that allow flexible operation without undermining any targets set for storing CO2 and/or restricting global CO2 emissions.