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.     

Preferential Oxidation of Carbon Monoxide in Excess Hydrogen over Au/Co3O4-CeO2 Catalysts

Fuel cells are considered to be the propulsionsystem of the near future,since they can produceelectricity without pollutingthe environment,and pos-sess the necessary specific power,power density anddurability to replace conventional internal combustioneng…     

CuO／CeO2 Catalysts for Selective Oxidation of Carbon Monoxide in Excess Hydrogen

CuO/CeO2 catalysts were prepared by a coprecipitation method and tested for CO removal from reformed fuels via selective oxidation. The influence of the calcination temperature on the chemical compositions and catalytic performance of CuO/CeO2 catalysts were studied. It was found that CuO/CeO2 catalysts exhibit excellent CO oxidation activity and selectivity, and the complete removal of CO is attained when the catalysts are calcined at appropriate temperatures. XRD, TPR and XPS results indicate that CuO/CeO2 catalysts exhibit higher catalytic performance in CO selective oxidation due to the strong interaction between copper oxide and cerium dioxide, which promotes the dispersion and hydrogen reduction activity of copper.     

Plasma Reduction of Iron Oxide by Methane Gas and its Process Up‐scaling

This paper investigates the characteristics of the methane plasma reduction of iron ore in comparison to that of the hydrogen plasma reduction process. Although hydrogen plasma smelting reduction (HPSR) has potential advantages as a steelmaking alternative in terms of simplicity (less operation units) and less harmful detrimental environmental implications, its high cost has a negative influence on its usage. In this regard, natural gas (> 96 % methane) could be adopted in the field of plasma smelting reduction. A brief comparison between hydrogen and methane options has been carried out experimentally. Heat and mass balance models were conducted to explore the features of up‐scaled processes with respect to consumption figures and CO₂ emissions. It was found that the methane plasma is a good alternative iron oxide smelting process.     

Experimental Investigation on Optimal Carbon/Hydrogen Ratio for Developing Iron Bath Reactor with H2–C Mixture Reduction

The basic idea of H₂–C mixture reduction reflects advantages of hydrogen for fast reaction and low heat absorption in smelting reduction reactor, where hydrogen is used as main reducing agent and carbon as main heat generator on purpose to cut down total energy consumption and CO₂ emission. This article aimed at the experimental investigation of optimal carbon/hydrogen ratio, a key parameter of iron oxide reduction with mixture reductive agents of carbon and hydrogen. Experiments were carried out using a pure Al₂O₃ crucible which was placed in a tubular furnace for high temperature. Two investigation methods were adopted, one was injecting acetylene/hydrogen mixture reducing gas into molten iron oxides and another was blowing hydrogen into iron bath during continuous feeding fine ore mixing solid carbon dust. Parameters such as apparent de‐oxidation rate and utilization ratio of reductive agents were calculated from content analysis of exhaust gas after dust removing and drying. In experiments highest total de‐oxidation rate and satisfied apparent utilization ratio of hydrogen were obtained under conditions with temperatures of 1823 K and carbon/hydrogen ratio in region from 0.5:1 to 2:1.     

煤中氢对含碳球团还原的影响

针对含碳球团还原过程中的煤种选择问题,研究了烟煤和无烟煤挥发分中氢对含碳球团还原的作用以及温度、加热速度对氢还原过程的影响。结果表明,含碳球团中煤热解产生的氢对铁氧化物有还原作用。由于煤中挥发分的热解析出温度与氢还原铁氧化物的还原温度不一致,氢在还原初期迅速放出,导致氢的还原作用率低;提高温度和加热速度可提高煤中氢的还原作用率和挥发分的利用率。综合考虑,含碳球团实际生产选择煤种时,应选择反应性好的无烟煤。     

Reduction of Fine Ores in Argon‐Hydrogen Plasma

The steel industry is a major source of global CO₂ emission. Larger reductions of greenhouse gases are the challenge to develop new processes, like Hydrogen Plasma Smelting Reduction (HPSR). The present paper shows physical and chemical fundamentals for the reduction of iron oxides with hydrogen plasma. The behaviour of different hematite iron ores during melting and reduction with hydrogen plasma were investigated with thermogravimetry and a laboratory plasma furnace. The path of iron oxides during smelting and reduction in the Fe‐O phase diagram are described. Reduction tests in the laboratory furnace show the possibility to reduce hematite iron ores with hydrogen plasma in a short time with high utilization degrees without direct CO₂ emissions.     

氢气还原铁氧化物反应表观活化能的评估

搜集并评估了氢气还原铁氧化物反应的表观活化能。分析了反应动力学条件与反应机理和表观活化能的关系。得出：气体内扩散控速和铁离子固态扩散控速时,还原过程的表观活化能分别为８．０～２８．０ ｋＪ／ｍ ｏｌ和＞ ９０ ｋＪ／ｍ ｏｌ;界面化学反应控速时,将Ｆｅ２Ｏ３,Ｆｅ３Ｏ４ 和‘ＦｅＯ’还原为Ｆｅ的表观活化能分别为４０．０～７０．０ ｋＪ／ｍ ｏｌ,５５．０～６５．０ ｋＪ／ｍ ｏｌ和４２．０～５２．０ ｋＪ／ｍ ｏｌ;两个环节混合控速时,表观活化能介于每个环节单独控速的表观活化能范围之间。     

富氧燃烧技术及燃烧产物利用的研究进展

综合现有文献,阐述了富氧燃烧理论,重点分析了其燃烧与热力学特性、节能减排特性。与此同时,富氧燃烧实现了劣质燃料的有效利用,且燃烧产物得到了充分利用,减少了污染物的排放。还分析了当前富氧燃烧存在的不足。     

A Brief Overview of Low CO_2 Emission Technologies forIron and Steel Making

The global steel production has been growing for the last 50 years,from 200Mt in 1950s to 1240Mt in 2006. Iron and steel making 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. Enhancing energy efficiency and employing energy saving/recovering technologies such as coke dry quechning (CDQ) and top pressure recovery turbine (TRT) can...     

日本COURSE 50技术研究现状

介绍了日本COURSE 50技术,包括高炉氢气冶炼及其支持技术以及从高炉煤气捕集、分离和回收CO2的技术(CCS)。阐述了高炉氢气冶炼及其支持技术开发现状,主要包括高炉氢气冶炼技术的实验室研究结果、瑞典小高炉工业试验及结果以及焦炉煤气改质技术和Hypercoal技术的研究现状,高炉煤气分离回收CO2的技术及其支持技术开发现状以及COURSE 50于2013~2017年的研究课题。指出其中一些支持技术对提升企业竞争力和促进钢铁企业的可持续性发展具有很大战略意义。     

炭素生产用煤气净化及废气余热利用改造工程方案

通过对碳素生产过程中生产用煤气净化及废气余热利用改造的必要性介绍,进行了具体的改造工艺及经济分析,为企业洁净生产、能源高效利用提出了一个可行的方案.     

Theoretical and Experimental on Carbon Dioxide Sequestration Degree of Steel Slag

 The limitation and experimental CO2 sequestration degree of steel slag is the focus. The theoretical and the practical CO2 sequestration degree was assessed under mild operating conditions. After calculation in theory, it can be found that the CO2 sequestration limitation degree for every kilogram steel slag is about 442 g when taking magnesium into consideration, and the experimental CO2 sequestration degree for every kilogram slag is about 77 g, under the conditions that the liquid to solid ratio is 50 L/kg, CO2 flow is 0. 5 L/min and the temperature of reaction is the ambient temperature. When solution NH4Cl and CH3COOH for experiments and other conditions keep the same, the actual potential CO2 sequestration for every kilogram slag is 69. 3 g and 31. 20 g respectively. Thus, optimization of process parameters like granularity of slag is necessary to enhance the carbon dioxide sequestration degree for steel slag.     

节能减排 低碳炼铁 实现中国高炉生产的科学发展

介绍了中国近年来高炉炼铁的概况,侧重介绍在节能降耗、高风温、装备大型化等方面的技术进展。进而深入论述炼铁技术科学发展观的内涵,主要包括：加强炼铁工业结构调整,认真转变发展方式,转变观念,以精料为基础;以低碳炼铁为目标,寻求与冶炼条件相适应的合适冶炼强度,合理富氧喷煤、提高风温、大力降低焦比;重视高炉煤气流分布及能量利用,降低风耗、电耗乃至所有能耗;重视环境保护,努力降低排放,并加强其无害化处理;从而实现高炉炼铁在低耗、高效、优质、长寿和环保诸方面新的突破;与此同时,要采取坚决措施整顿炼铁的无序生产,不能让落后产能复出或继续生产。节能减排,低碳炼铁,是实现中国高炉炼铁生产科学发展的中心环节。     

反应气氛和温度对热压含碳球团还原反应进程的影响

热压含碳球团是利用煤的热塑性而将铁矿粉和煤粉热压成型的一种新型优质炼铁原料.还原性是炉料主要冶金性能之一,而反应气氛和温度对热压含碳球团还原反应进程有重要的影响.通过还原失重试验,重点研究了反应气氛和温度对热压含碳球团还原反应进程的影响.研究表明,热压含碳球团整个还原反应进程可分为两个阶段:第一阶段还原速率明显大于第二...     

高碳锰铁冶炼生产节能减排技术改进

为达到节能减排目的,针对云南省鹤庆锰业有限责任公司冶炼厂的特点,对电炉高碳锰铁生产的节能措施进行了探讨,针对设备选型和无熔剂生产工艺进行了实践,在提高成品率、节约能耗、无固废排放上取得了初步成果,同时简述了电炉炉衬、自焙电极等关键设备对节能的影响,对锰粉尘的回收和炉渣的综合利用作了探讨.     

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.     

Two-Stage Clathrate Hydrate/Membrane Process for Precombustion Capture of Carbon Dioxide and Hydrogen

A hybrid process for the capture of CO2 and H2 from a treated fuel gas mixture is presented. It consists of two hydrate crystallization stages operating at 273.7?K and 3.8 and 3.5?MPa, respectively. The CO2-lean stream from the first stage is directed to a membrane separation unit whereas the CO2-rich one is directed to the second hydrate stage. These operating pressures at the crystallization stages are possible by adding 2.5% by mole propane. Propane enables the reduction in the hydrate formation pressure and thus reduces the cost associated with the compression of the fuel gas. The two hydrate stages would operate at 7.5 and 3.5?MPa without adding propane. This work provides the relevant kinetic data, as well as the separation efficiency and recoveries achieved.     

Cost and Life Cycle Analysis for Deep CO2 Emissions Reduction for Steel Making: Direct Reduced Iron Technologies

Among heavy industrial sectors worldwide, the steel industry ranks first in carbon dioxide (CO₂) emissions. Technologies that produce direct reduced iron (DRI) enable the industry to reduce emissions or even approach net-zero CO₂ emissions for steel production. Herein, comprehensive cradle-to-gate (CTG) life cycle analysis (LCA) and techno-economic analysis (TEA) are used to evaluate the CO₂ emissions of three DRI technologies. Compared to the baseline of blast furnace and basic oxygen furnace (BF–BOF) technology for steel making, using natural gas (NG) to produce DRI has the potential to reduce CTG CO₂ emissions by 33%. When 83% or 100% renewable H₂ is used for DRI production, DRI technologies can potentially reduce CO₂ emissions by 57% and 67%, respectively, compared to baseline BF–BOF technology. However, the renewable H₂ application for DRI increases the levelized cost of steel (LCOS). When renewable natural gas (RNG) and clean electricity are used for steel production, the CTG CO₂ emissions of all the DRI technologies can potentially be reduced by more than 90% compared to the baseline BF–BOF technology, although the LCOS depends largely on the cost of RNG and clean electricity.