Enrichment of combustion air with oxygen
Consumption of natural gas by Ukraine’s metallurgical industry reached nearly 2.0 billion cu m in 2019, a great burden for the national economy depending on primary energy sources import. The major gas-fired unites are blast furnace air-heaters, reheating and treatment furnaces of rolling workshops as well as industrial boilers.
Reduction of such a consumption rate is possible by wide application of new downstream technologies, enhancing units’ energy efficiency, optimization energy balances of plants and total waste heat recovery at all levels of manufacturing processes.
One of the proven ways of solving the problem is the use of pure oxygen or enrichment of the combustion air on its basis. In some cases, in dependence on manufacturing conditions, it leads to improvement of energy efficiency as well as productivity by 25-50%.
However, there are also a number of featured setbacks preventing Ukraine’s industry from wide oxygen use such as: low investment capacity of stakeholders; unpredictable pricing on metallurgical products as well their demand affecting the oxygen balance within a plant; lack of stability on energy market. Thus, the oxygen for enhancing combustion process remains uncommon practice here.
According to some experts’ evaluation, up to 5-10% of generated oxygen is sent back to atmosphere.
A case study by TMEC engineers for a blast furnace air-heater of 57 000 sq m heating area shows that the increase of oxygen in combustion air by 5% result in full exclusion of the natural gas from the unit (full switch to blast furnace gas) securing the temperature under the stove dome at 1350C. The economic viability of the approach is proven only if the price of the oxygen remains less than 32$ / 1000 cu m.
Together with Industrial Partners TMEC engineers continue their work on development of technical solutions aiming at wide oxygen application in industrial processes.