Investigation of Carbon Deposition During Natural Gas and Oxygen Injection for the Direct Reduction Ironmaking Process

Author(s):  
J. Carmona ◽  
E. Chen ◽  
R. Liu ◽  
T. Okosun ◽  
Q. Syed ◽  
...  
1966 ◽  
Vol 5 (10) ◽  
pp. 844-846
Author(s):  
A. A. Sigov ◽  
V. V. Veselov ◽  
V. P. Dorokhovich

Author(s):  
Martin Hammerschmid ◽  
Stefan Müller ◽  
Josef Fuchs ◽  
Hermann Hofbauer

Abstract The present paper focuses on the production of a below zero emission reducing gas for use in raw iron production. The biomass-based concept of sorption-enhanced reforming combined with oxyfuel combustion constitutes an additional opportunity for selective separation of CO2. First experimental results from the test plant at TU Wien (100 kW) have been implemented. Based on these results, it could be demonstrated that the biomass-based product gas fulfills all requirements for the use in direct reduction plants and a concept for the commercial-scale use was developed. Additionally, the profitability of the below zero emission reducing gas concept within a techno-economic assessment is investigated. The results of the techno-economic assessment show that the production of biomass-based reducing gas can compete with the conventional natural gas route, if the required oxygen is delivered by an existing air separation unit and the utilization of the separated CO2 is possible. The production costs of the biomass-based reducing gas are in the range of natural gas-based reducing gas and twice as high as the production of fossil coke in a coke oven plant. The CO2 footprint of a direct reduction plant fed with biomass-based reducing gas is more than 80% lower compared with the conventional blast furnace route and could be even more if carbon capture and utilization is applied. Therefore, the biomass-based production of reducing gas could definitely make a reasonable contribution to a reduction of fossil CO2 emissions within the iron and steel sector in Austria.


2013 ◽  
Vol 805-806 ◽  
pp. 654-659 ◽  
Author(s):  
Xin Jiang ◽  
Lin Wang ◽  
Feng Man Shen

Coke constitutes the major portion of ironmaking cost and its production causes the severe environmental concerns. So lower energy consumption, lower CO2 emission and waste recycling are driving the iron and steel industry to develop alternative, or coke-free, ironmaking process. Midrex and HYL Energiron are the leading technologies in shaft furnace direct reduction, and they account for about 76% of worldwide production. They are the most competitive ways to obtain high quality direct reduced iron (DRI) for steelmaking. Therefore, in the present paper, some detailed information about these two processes are given. Much attention has been paid on process scheme, the feedstock, DRI product, heat recovery, reforming gas, hot discharge and transportation, and by-product emission. Its very important for direct reduction development in both natural gas-rich counties and natural gas-poor counties.


1966 ◽  
Vol 5 (10) ◽  
pp. 839-843
Author(s):  
A. Domsa ◽  
A. Palfalvi ◽  
L. Sabo ◽  
Z. Spyrkhez ◽  
L. Botka

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4835
Author(s):  
Sébastien Pissot ◽  
Henrik Thunman ◽  
Peter Samuelsson ◽  
Martin Seemann

A dual fluidized bed (DFB) gasification process is proposed to produce sustainable reducing gas for the direct reduction (DR) of iron ore. This novel steelmaking route is compared with the established process for DR, which is based on natural gas, and with the emerging DR technology using electrolysis-generated hydrogen as the reducing gas. The DFB-DR route is found to produce reducing gas that meets the requirement of the DR reactor, based on existing MIDREX plants, and which is produced with an energetic efficiency comparable with the natural gas route. The DFB-DR path is the only route considered that allows negative CO2 emissions, enabling a 145% decrease in emissions relative to the traditional blast furnace–basic oxygen furnace (BF–BOF) route. A reducing gas cost between 45–60 EUR/MWh is obtained, which makes it competitive with the hydrogen route, but not the natural gas route. The cost estimation for liquid steel production shows that, in Sweden, the DFB-DR route cannot compete with the natural gas and BF–BOF routes without a cost associated with carbon emissions and a revenue attributed to negative emissions. When the cost and revenue are set as equal, the DFB-DR route becomes the most competitive for a carbon price >60 EUR/tCO2.


Author(s):  
Abhinav Bhaskar ◽  
Mohsen Assadi ◽  
Homam Nikpey Somehsaraei

Reducing emissions from the iron and steel industry is essential to achieve the Paris climate goals. A new system to reduce the carbon footprint of steel production is proposed in this article by coupling hydrogen direct reduction of iron ore (H-DRI) and natural gas pyrolysis on liquid metal surface inside a bubble column reactor. If grid electricity from EU is used, the emissions would be 435 kg CO2/tls without considering methane leakage from the extraction, storage and transport of natural gas. Solid carbon, produced as a by-product of natural gas decomposition, finds applications in many industrial sectors, including as a replacement for coal in coke ovens. Specific energy consumption (SEC) of the proposed system is approximately 6.3 MWh per ton of liquid steel(tls). It is higher than other competing technologies, 3.48 MWh/tls for water electrolysis based DRI, and, 4.3-4.5 MWh/tls for natural gas based DRI and blast furnace-basic oxygen furnace (BF-BOF) respectively. Utilization of large quantities of natural gas, where the carbon remains unused, is the major reason for high SEC. Preliminary analysis of the system revealed that it has the potential to compete with existing technologies to produce CO2 free steel, if renewable electricity is used. Further studies on the kinetics of the bubble column reactor, H-DRI shaft furnace, design and sizing of components, along with building of industrial prototypes are required to improve the understanding of the system performance.


1999 ◽  
Author(s):  
Angela O. Nieckele ◽  
Mônica F. Naccache ◽  
Marcos S. P. Gomes ◽  
William T. Kobayashi

Abstract In the present work, a numerical simulation of the 100% oxy-firing combustion process inside an industrial Aluminum Remelting Reverb Furnace is presented. A staged combustion oxy-fuel burner is being simulated. The natural gas and oxygen were injected toward the aluminum bath, which was considered as an isotherm wall at melt temperature. Two types of burners are compared. For the first case, the oxygen and natural gas jets at the burner exit are parallel to each other, while for the second burner, a divergent oxygen jet is employed. The furnace heat loss to the ambient is neglected since it is small in relation to the heat liberated by the combustion process. The k-ε model of turbulence was selected to represent the turbulent flow field. The combustion process was determined based on the Arrhenius and Magnussen Laws, and the discrete transfer radiation model was employed to predict the radiation heat transfer. The numerical procedure was based on the Finite Volume Method. This numerical model is utilized to determine the flame pattern, species concentration distribution, and the velocity field. The temperature distribution is very useful in the evaluation of the furnace performance. Further, critical regions associated with high temperature spots at the refractory surface were discovered. The effect of the divergent jet in the heat flux distribution at the aluminum bath is also investigated.


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