The injection of ultrahigh rates of reducing gas into a modern blast furnace
The pilot plant for gas injection consists of a screw compressor unit to supply two blast furnaces with reduction gas. Almost all of the reducing gas will react in the raceway only a small part will combust inside the tuyère. Comparing different injection systems in the case with two lances, the gas will react faster than for the one lance system where the gas is more trapped inside a beam. During the project the melting rate of the furnace was increased by more than 30 %. Injecting reducing gas compensates increased RAFT by higher oxygen enrichment rates. The operation results showed that a lower RAFT and low-quality raw material result in increased consumption of reducing agents. 1 kg COG substitutes 0,81 kg oil and 1,03 kg coke. Sulfur input was reduced by 40 % in comparison with heavy fuel oil operation. The top-gas calorific value is increased up to 30 %. This reduces the consumption of natural gas used to control a constant calorific value in the gas network. A high hydrogen content up to 12 % is no problem for the gas consumers. Tests with simultaneous COG/BOF gas injection have shown that a decrease in the oil rate can be compensated. The replacement of a carbon-rich reductant such as coke and oil in the BF process with a carbon-lean reductant such as COG leads to an absolute reduction in the CO2 emissions of the BF process and the power plant of approximately 184.000 t/a for both BFs or 102 kg/tHM.
Bibliographic Reference: EUR 22405 EN (2007), 101 pp. Euro: 25
Availability: Katalogue Number: KI-NA-22405-EN-S The paper version can be ordered online at: http://bookshop.europa.eu
ISBN: ISBN: 92-79-03032-9
Record Number: 200718829 / Last updated on: 2007-02-26
Original language: en
Available languages: en