RFCS Project GREENEAF

Sustainable EAF steel production

In the modern elec­tric arc fur­nace (EAF) more than 40% of ener­gy comes from che­mi­cal sources by fos­sil fuels: natu­ral gas is used in dedi­ca­ted bur­ner during the mel­ting of the scrap while coal (main­ly anthr­aci­te), lump in the bas­ket and pul­veri­zed by wall injec­tor, is used as foa­ming agent. In the frame of the Euro­pean Rese­arch Fund for Coal and Steel (RFCS), pro­ject GREENEAF, was car­ri­ed out with the objec­ti­ve to replace coal and natu­ral gas in EAF with char and sysn­gas pro­du­ced by bio­mass pyrolisis.

Gene­ral­ly spea­king, in the elec­tric fur­nace coal (and con­se­quent­ly char) is used as injec­ted pow­der or char­ged into the bas­ket. The syn­gas can be used for EAF burners.
The cha­rac­te­ristics of char and bio­gas, and the rela­ted pyro­ly­sis pro­cess, are tail­o­red in order to match the requi­re­ments for their uti­liza­ti­on in EAF. The fol­lo­wing acti­vi­ties have been car­ri­ed out within the project:

  • Bio­mass sel­ec­tion and clas­si­fi­ca­ti­on respect their ori­gin and cha­rac­te­ri­sa­ti­on activities
  • Tail­oring of bio­mass pyro­ly­sis: Labo­ra­to­ry tests to defi­ne the pyro­ly­sis kine­tics of the sel­ec­ted bio­mass, and on the basis of the­se results design of indus­tri­al pyro­ly­sis; then che­mi­cal and phy­si­cal cha­rac­te­riza­ti­on of char pro­du­ced by bio­mass pyro­ly­sis has been car­ri­ed out to defi­ne pyro­ly­sis plant pro­cess para­me­ters. About fif­teen tons of char has been pro­du­ced for indus­tri­al trials
  • EAF pilot plant expe­ri­men­ta­ti­on: First tests of char uti­liza­ti­on have been car­ri­ed out in the pilot Furnace
  • Indus­tri­al expe­ri­men­ta­ti­on: indus­tri­al tests with char have been car­ri­ed out
  • Simu­la­ti­on of syn­gas uti­liza­ti­on: due to the dif­fi­cul­ties to have syn­gas available clo­se to the steel plant syn­gas uti­liza­ti­on for EAF bur­ners has been simu­la­ted by CFD calculation.

The results obtai­ned have demons­tra­ted the tech­ni­cal fea­si­bi­li­ty of the used approa­ches while the eco­no­mic­al eva­lua­ti­on have show­ed the sus­taina­bi­li­ty of repla­cing the coal with char from bio­mass, in addi­ti­on to envi­ron­men­tal bene­fits due to CO2 reduc­tion, even if at the moment the­re is not a real asses­sed mar­ket of char­co­al for steel­ma­king purposes.

Green fuel for steel furnaces

Final Report

Bian­co, L.; Bar­ac­chi­ni, G.; Ciril­li, F.; Morico­ni, A.; Morico­ni, E.; Mar­cos, M.; Demus, T.; Ech­ter­hof, T.; Pfei­fer, H.; Bei­ler, C.; Gries­sa­cher, T.: Sus­tainable EAF steel pro­duc­tion (GREENEAF), EUR 26208, Publi­ca­ti­ons Office of the Euro­pean Uni­on, (2013), Luxem­bourg, ISBN 978–92-79–33614‑0

Logo ECThe rese­arch lea­ding to the­se results has recei­ved fun­ding from the Euro­pean Community’s Rese­arch Fund for Coal and Steel (RFCS) under grant agree­ment n° RFSR-CT-2009–00004.