## 3 Results and Discussion
### Laboratory-Scale Profile (20 L)
Interestingly, the ohmic heating cell disruption method, used during S5, accounts for less than 1% of the total calculated impact. The efficiency of an electric-based extraction is mainly due to the application of an electric current during a short extraction period (5 min), with rapid and homogeneous heating, which is why this method has less of an impact than others, such as homogenisation or supercritical CO\({}_{2}\)[45]. Furthermore, K\(\ddot{\text{a}}\)ferb\(\ddot{\text{o}}\)[PERSON] et al. [33] reported that the use of electric fields decreased the environmental burden of phycocyanin extraction by 57-65% when compared to solvent-only extraction. In addition, the drying of residual biomass represents 3% of the total calculated impact and could be overcome for the use of wet pulp for further processing. Taking into account the main critical points identified, a sensitivity analysis has been carried out based on four alternative scenarios for the lab-scale process: (L1) the use of 20% less electricity; (L2) the use of the European electricity mix instead of Portugal; (L3) the use of the Swedish electricity mix (considered the cleanest in the European Union); and (L4) reduction of the biomass drying step by sending the residue to waste management (19.2 g batch\({}^{-1}\)). The results of the sensitivity analysis are shown in Figure 3.  
Figure 3: Sensitivity analysis from the laboratory-scale process, considering four alternative scenarios: (L1) the use of 20% less electricity; (L2) the use of Europe electricity mix instead of Portugal; (L3) the use of Swedish electricity mix; (L4) reducing the biomass drying step by sending the residue to waste management. Impact categories: global warming (GW), stratospheric ozone depletion (SOD), terrestrial acidification (TA), freshwater eutrophication (FE), marine eutrophication (ME), terrestrial ecotoxicity (TET), freshwater ecotoxicity (FET), marine ecotoxicity (MET), human carcinogenic toxicity (HCT), human non-carcinogenic toxicity (HNCT), fossil resource scarcity (FRS). By reducing the electricity consumption by 20% (scenario L1), the environmental load of the process was also reduced by 20%, which corroborates the critical point found in the baseline scenario, where electricity corresponds to most of the total impact. Moreover, the substitution of the Portuguese electricity mix with that of Europe (Scenario L2) leads to a reduction in the categories GW, TA, TET and FRS, while in the others some increases could be seen, highlighting that the impact of FE, ME, FET, MET and HCT increased by more than 100%, probably due to the lower share of renewable energy in Europe (22.1%) compared to Portugal (33.9%) [46]. In the third scenario (L3, Swedish energy emissions use), all factors decreased, on average by 74%. Sweden is considered the European country with the highest rate of renewable electricity (60.1%), mainly due to the use of hydropower (39.3%) [47], while in Portugal, although hydropower and wind account for a large share of energy consumption, coal and natural gas can increase the overall impact of this electricity mix [39]. Finally, by eliminating the residual biomass drying subsystem (scenario L4), and instead of using this waste as a by-product, sending it to waste management, the environmental burden of the process would decrease by 3%. However, due to the lack of studies on the use of this specific biomass as fertiliser, it is not possible to assume whether this reduction is a real advantage or a disadvantage. Considering the nitrogen content of the residue of _Cyanobium_ sp. spent biomass (12.1%) and reports about other species, such as _Arthrospirna platensis_, it could be assumed that a subproduct is more advantageous than sending this biomass to waste management [48].