RFCS Project GREENEAF2

Biochar for a sustainable EAF steel production

The pre­vious GREENEAF pro­ject (RFSR-CT-2009–00004) has demons­tra­ted the fea­si­bi­li­ty of uti­liza­ti­on of char, from bio­mass, as sub­sti­tu­te of coal into the EAF. The pre­sent pro­ject objec­ti­ve was to make the char use a stan­dard practice.
The­r­e­fo­re, the fol­lo­wing acti­vi­ties have been car­ri­ed out:

  • char labo­ra­to­ry cha­rac­te­riza­ti­ons to check the capa­bi­li­ty of the mate­ri­al to replace coal in indus­tri­al tri­als, both for char­ging and injec­tion procedures,
  • iden­ti­fi­ca­ti­on of most sui­ta­ble injec­tions systems
  • ana­ly­sis of EAF beha­viour in case of char and bio­mass use during long-time indus­tri­al trials
  • Life Cycle Assess­ment stu­dy, as regard to inven­to­ry issues.

Indus­tri­al tri­als of EAF char­ging con­firm­ed the fea­si­bi­li­ty of coal sub­sti­tu­ti­on and out­lined the rele­vant pro­cess aspects: bas­ket pre­pa­ra­ti­on to avo­id mate­ri­al bur­ning befo­re dis­so­lu­ti­on into mol­ten steel and EAF post com­bus­ti­on to reco­very the ener­gy con­tent of the char vola­ti­le matter.
In case of injec­tion tri­als, a wide ran­ge of pos­si­bi­li­ties has been exploi­ted: biochar, biochar mixed with fos­sil coal and vir­gin ligneous bio­mass. The best slag foa­ming, com­pa­ra­ble with the pul­ve­ri­sed fos­sil coal injec­tion has been obtai­ned with vir­gin biomass.
Out­lined ener­gy saving with EAF equip­ped for post com­bus­ti­on and tail­o­red char pro­duc­tion form low gra­de bio­mass show­ed that char uti­liza­ti­on is eco­no­mic­al­ly sustainable.

Logo ECThis rese­arch recei­ved fun­ding from the Euro­pean Community’s Rese­arch Fund for Coal and Steel (RFCS) under grant agree­ment n° RFSP-CT-2014–00003.