Dear Khun Bruno,
I would suggest you to give the cost centers following;
1) 1A32563600- HCl > If GEC is serviced directly to HCl unit
2) 1A32624000-DCPOl > If GEC is serviced directly to DCPOl unit
2) 1A32624200-ECH > If GEC is serviced directly to ECH unit
Anyway, if above cost centers can not specify you can use common cost center (1A3200000) that GEC cost will be allocated to 3 production cost centers by production cycle as well (10% to HCl,45% to DCPol,45% to ECH).