Demonstration of the Double Regenerative Burner technology to reduce GHG emissions from Steelmaking industry plant

PROJECT DESCRIPTION

BACKGROUND

The iron and steel industry is responsible for 30% of the greenhouse gas emissions from industry in Europe, making it the most-polluting industrial sector in terms of CO2 emissions. A significant volume of the CO2 emissions from integrated steel plants is related to natural gas consumption, of which about 45% comes from the use of natural gas to reheat furnaces. Reducing this consumption is essential to reduce the sector’s overall carbon footprint.

During thermo-reduction, which takes place during the transformation of iron oxides into cast iron, blast furnaces emit high volumes of a low calorific gas (named Blast Furnace Gas, BFG), containing a high proportion of carbon monoxide. The low calorific value of this gas drastically limits its use in any industrial application. In particular, when used in the steel industry’s standard recuperative burners, BFG must be mixed with a rich gas for process/metallurgical reasons: the very high flame temperatures required in the reheating furnaces cannot be reached using BFG alone. A typical composition of mixed gas used in a reheating furnace for steel slabs is 10% BFG with 90% natural gas.

OBJECTIVES

The LIFE DRB project would demonstrate, at the ArcelorMittal site in Ghent, Belgium, in a first industrial-scale application, the efficiency of an innovative patented burner technology: the Double Regenerative Burner (DRB). This technology would allow the pre-heating of BFG and air in an innovative combustion process within the burner, using an innovative fume-exhaust system installed inside the burner itself. This technology should have allowed a very high temperature of c.1 000 degrees Celsius to be reached for both BFG and combustion air for pre-heating. At this temperature, BFG can be used in the furnace-reheating process without the addition of any rich gas such as natural gas.

The project would design and implement a pair of the innovative 7MW Double Regenerative Burners at the reheating furnace for steel slabs at the ArcelorMittal integrated steel-making site.

Expected results: It was expected that use of DRB technology would result in:

A 9% reduction in natural gas consumption in steel-making plant rolling mills;

A 90% reduction of the use of natural gas in the reheating furnace;

Abatement of nitrogen oxide emissions below 150 mg/Nmc = 150 mg/Nm3 in DRB exhaust fumes;

A reduction in the related CO2 emissions from rolling mill sites;

A 90% increase in the quantity of BFG used to power reheating furnaces for steel slabs.

Once demonstrated, the DRB technology could have been replicable in all integrated steel plants that have blast furnaces and reheating furnaces for steel slabs. Applied at European scale, this technique could have resulted in yearly reductions of 30 461 661 gigajoules (GJ), corresponding to 1 716 164 tonnes of emitted carbon dioxide.

RESULTS

The project ended on 31/03/18, without having achieved its objectives. The project ended on 31/03/18, without having achieved its objectives.