## 3 Results and Discussion
### Laboratory-Scale Profile (20 L)
\begin{table}
\begin{tabular}{c c|c|c c c c c} \hline \hline \multirow{2}{*}{**Impact 1**} & \multirow{2}{*}{**Unit**} & \multirow{2}{*}{**Per Batch**} & \multirow{2}{*}{**Per Lite of Culture**} & \multicolumn{3}{c}{**Carotenoids**} & \multicolumn{2}{c}{**Phycobiliproteins**} \\ \cline{5-8}  & & & & **MA** & **EA** & **MA** & **EA** \\ \hline GW & kg CO2 eq & 197.3 & 9.86 & 5.12 & 1.79 & 4.74 & 8.08 \\ SOD & kg CFC11 eq & \(7.67\times 10^{-5}\) & \(3.84\times 10^{-6}\) & \(1.99\times 10^{-6}\) & \(6.96\times 10^{-7}\) & \(1.84\times 10^{-6}\) & \(3.14\times 10^{-6}\) \\ TA & kg SO2 eq & 1.04 & \(5.20\times 10^{-2}\) & \(2.70\times 10^{-2}\) & \(9.43\times 10^{-3}\) & \(2.50\times 10^{-2}\) & \(4.26\times 10^{-2}\) \\ FE & kg P eq & \(7.01\times 10^{-2}\) & \(3.50\times 10^{-3}\) & \(1.82\times 10^{-3}\) & \(6.35\times 10^{-4}\) & \(1.68\times 10^{-3}\) & \(2.87\times 10^{-3}\) \\ ME & kg N eq & \(4.65\times 10^{-3}\) & \(2.32\times 10^{-4}\) & \(1.21\times 10^{-4}\) & \(4.21\times 10^{-5}\) & \(1.12\times 10^{-4}\) & \(1.90\times 10^{-4}\) \\ TET & kg 1.4-DCB & 128.1 & 6.40 & 3.33 & 1.16 & 3.08 & 5.24 \\ FET & kg 1.4-DCB & 2.11 & \(10.57\times 10^{-2}\) & \(5.49\times 10^{-2}\) & \(1.92\times 10^{-2}\) & \(5.08\times 10^{-2}\) & \(8.65\times 10^{-2}\) \\ MET & kg 1.4-DCB & 2.99 & \(14.96\times 10^{-2}\) & \(7.77\times 10^{-2}\) & \(2.71\times 10^{-2}\) & \(7.19\times 10^{-2}\) & \(12.25\times 10^{-2}\) \\ HCT & kg 1.4-DCB & 4.50 & 0.22 & 0.12 & 0.04 & 0.11 & 0.18 \\ HNCT & kg 1.4-DCB & 118.5 & 5.93 & 3.08 & 1.07 & 2.85 & 4.85 \\ FRS & kg oil eq & 54.53 & 2.73 & 1.42 & 0.49 & 1.31 & 2.23 \\ \hline \hline \end{tabular}  
* Impact category: 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).  
\end{table} 
Table 4: Impact assessment results associated with the laboratory-scale process (20 L) per batch and per litre of culture, and the respective allocation for each co-product (mass allocation (MA) and economic allocation (EA)). Figure 2: Relative contribution (in %) per subsystem of the laboratory-scale process (20 L) to each impact category: 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). FRS impact. The same effect has also been observed for microalgae, which are the closest competitors to cyanobacteria in the pigment market. [PERSON] et al. [43] assessed the environmental impact of astaxanthin (carotenoid) production by _Haematococcus pluvialis_, and the LCA indicated that for GW, cultivation electricity accounts for 61% of the total impact, suggesting the replacement of the annular photobioreactor with artificial lights to a flat-panel, although still with artificial lighting. To reduce the impact of electricity use, the design of the photobioreactor is critical to achieving energy efficiency, along with the use of artificial lighting. [PERSON] et al. [30] showed that for _Arthospira platensis_, replacing an open raceway reactor with a tubular design decreases half of the system impact. On the other hand, the use of outdoor cultivation, which can reduce the impact caused by artificial lighting, could reduce productivity due to fluctuations in light availability [44]. With the analysis of each process subsystem, the main critical points could be identified. The energy demand of the freeze-drying process is expected to be responsible for the largest environmental load. In order to decrease the impact, improvements in the use of wet biomass and/or the modification of the drying procedure is needed.