Effect of the natural gas hydrogen on variation of the heat and reducing processes along the blast furnace radius

The expenses for the blast furnace coke are one of most significant part of the hot metal cost. To save the coke, various technologies are used, capable to replace the coke by cheaper additional fuel (AF), in particular by natural gas (NG). The injection of considerable volumes of NG results in an increase of hydrogen share in the blast furnace gases and in a significant variation in the blast furnace technology. Study of peculiarities of such variations is necessary to use the NG more effectively. Based on the mathematical model of the blast furnace process, estimation of the effect of natural gas hydrogen on changes in the heat and reducing processes along the blast furnace radius was accomplished. A formula was elaborated, confirmed by practice, for calculating the degree of hydrogen usage ηН2 along the radius of the furnace. It was determined, that the reducing action of hydrogen along the furnace radius takes place unevenly –decreasing from the periphery to the axial zone of the blast furnace. To estimate the quantitative relations of the reducing action of hydrogen, parameters of the PAO “MMK” and PAO “ArcelorMittal Krivoy Rog” blast furnaces for a long period of operation were analyzed. It was determined, that in the axial and intermediate zones of a blast furnace, values of criterion RН2, designating the oxygen share in the burden removed by hydrogen, are in the range of 0.11–0.16 and weakly depend on the NG consumption. In the peripheral zone near the walls, the value of R Н 2 sharply increases to 0.22–0.27. In this zone of the blast furnace the quantity the burden oxygen, removed by hydrogen, accounts for 80–85%. Therefore, hydrogen accomplished the heat and reducing processes mainly in the peripheral zone of the furnace. At the NG consumption increase, the ore load should be increased for the peripheral zone, near the walls individually accounting hydrogen action along the furnace radius. This will make possible to increase the degree of hydrogen usage and decrease the coke consumption.

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Improving the blast furnace process by raising the natural gas flow rate in the upper heat exchnage stage

Vestnik of Nosov Magnitogorsk State Technical University ◽

10.18503/1995-2732-2017-15-1-37-44 ◽

2017 ◽

Vol 15 (1) ◽

pp. 37-44 ◽

Cited By ~ 2

Author(s):

Salavat K. Sibagatullin ◽

◽

Aleksandr S. Kharchenko ◽

Vitaly A. Beginyuk ◽

Valentin N. Selivanov ◽

...

Keyword(s):

Blast Furnace ◽

Natural Gas ◽

Flow Rate ◽

Gas Flow ◽

Blast Furnace Process ◽

Gas Flow Rate ◽

Furnace Process ◽

Natural Gas Flow

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Study of transient processes in a blast furnace based on the heat exchange scheme analysis

Ferrous Metallurgy Bulletin of Scientific Technical and Economic Information ◽

10.32339/0135-5910-2020-2-132-138 ◽

2020 ◽

Vol 76 (2) ◽

pp. 132-138

Author(s):

N. A. Spirin ◽

O. P. Onorin ◽

A. S. Istomin ◽

I. A. Gurin

Keyword(s):

Heat Transfer ◽

Blast Furnace ◽

Heat Exchange ◽

Natural Gas ◽

Iron Ore ◽

Thermal Conditions ◽

Transient Processes ◽

Hot Metal ◽

Ore Load ◽

Hot Blast

A blast furnace is a complicated metallurgical facility, which is characterized by considerable delay and inertia in the flow of heat and mass exchange. Therefore, the analysis of transient processes based on modern ideas about heat transfer is an important issue in solving technological problems of blast furnace smelting managing. A two-stage heat transfer scheme along the height of a blast furnace of modern technology presented. When studying the thermal state of a blast furnace as a control object, it is advisable to divide it into two thermal zones - the upper zone and the lower zone. The border between the zones is located in the upper part of the mixed reduction region, between the start level of coke carbon gasification and the horizon below which iron oxides are directly reduced. It was shown, that the upper and lower thermal zones have fundamental differences in heat exchange conditions and are interconnected through the index of iron direct reduction degree. The transient processes of silicon variation in the hot metal studied at variation of iron ore load, natural gas flow rate, temperature and humidity of the hot blast, oxygen content in the hot blast and slag basicity. It was shown that the oscillatory transition process is observed in case, after applying the perturbation, it will have the opposite effect on the thermal conditions of the lower and the upper stages of heat exchange in the blast furnace. The iron ore load, hot blast humidity and slag basicity were found to be the most predictable input parameters affecting the concentration of silicon in hot metal. Change in oxygen concentration in hot blast and natural gas consumption have an alternating character of influence on thermal conditions of the blast-furnace hearth. At that, the characteristics of the transient processes of blast furnaces through various channels of action vary and depend significantly on the properties of the smelted raw materials, design and operational parameters of the furnaces

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COMPARATIVE ASSESSMENT OF GASEOUS FUEL EMISSION

Bulletin of the National Technical University KhPI Series Chemistry Chemical Technology and Ecology ◽

10.20998/2079-0821.2021.01.13 ◽

2021 ◽

pp. 83-91

Author(s):

Olena Hryhoriivna Levytska ◽

Yulia Vladimirovna Voytenko ◽

Anastasiia Oleksiivna Orishechok

Keyword(s):

Blast Furnace ◽

Natural Gas ◽

Carbon Content ◽

Coke Oven ◽

Combustion Products ◽

Comparative Assessment ◽

Blast Furnace Gas ◽

Furnace Gases ◽

Harmful Substances ◽

Emissions Of Harmful Substances

The work presents estimated comparative assessment of emissions release in combustion products during work of high–power steam boilers with the use of traditional fuel – natural gas and alternative fuels – blast–furnace and coke–oven gases generated in the process of technological cycle at iron and steel and coke–chemical enterprises. Calculation algorithm is shown and formulas for assessment of carbon content in exhaust gases are defined, conclusions on ecological efficiency of gaseous fuels are given. The purpose of the work was to evaluate the emissions of harmful substances generated during the combustion of natural, blast furnace and coke oven gases, justification of the calculation of carbon content of a given chemical composition and determine the optimal environmental impact of analogues of natural gas. The comparative estimation of pollutant emissions into atmospheric air during combustion of natural, coke oven and blast furnace gases revealed: – high sulfur dioxide emissions from combustion of blast furnace and coke oven gases due to the presence of sulfur compounds in the composition of these gases; – relatively high emissions of nitrogen compounds for natural and coke oven gases and relatively low emissions for blast furnace gas; – сarbon emissions are high for all types of fuels which have been considered, most carbon dioxide gets into the air when burning natural gas, least – when burning blast furnace gas; – significantly higher methane emissions are observed during the combustion of natural and coke oven gases, respectively, smaller – for blast–furnace gas combustion; – coke oven and natural gases are characterized by low mercury emissions. Comparative assessment of the calculated values of hazardous substances emissions in the combustion products in the process of combustion of natural, coke–oven and blast–furnace gases shows that even at lower working heat of combustion values the coke–oven and blast–furnace gases can compete with natural gas. For the first time, a comparative characterization of the emissions of harmful substances in the combustion of natural, coke oven and blast furnace gases is presented, and it is shown that the gases used in coke and metallurgical industries, which are used as analogues of natural, are logical to use, but require the installation of treatment systems. The paper defines a formula for calculating the carbon content in natural gas from the Urengoy–Uzhhorod gas pipeline. The provided calculations and the introduction of simplified formulas serve as an example for the calculation of emission factors and emissions in assessing the level of safety of existing equipment and can be used in the development of permit documents of enterprises that carry out emissions of harmful substances to the environment.

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