Table 4.
Impact categories associated with the technology stages for PHB production (I—biomass process, II—pretreatment of biomass, III—delignification, IV—enzymatic hydrolysis, V—fermentation, and VI—PHB purification).
| Impact Category | Unit | I | II | III | IV | V | VI | Total |
|---|---|---|---|---|---|---|---|---|
| Carcinogens | kg C2H3Cl eq | 0.01 | 0.16 | 0.33 | 0.41 | 0.81 | 0.00 | 1.73 |
| Non-carcinogens | kg C2H3Cl eq | 0.02 | 0.36 | 0.70 | 0.85 | 1.72 | 0.00 | 3.65 |
| Respiratory inorganics | kg PM2.5 eq | 0.05 | 0.64 | 0.81 | 0.89 | 1.30 | 0.00 | 3.69 |
| Ionizing radiation | kBq Co-14 eq | 8.92 | 261.24 | 3449.01 | 4878.70 | 12,417.18 | 0.00 | 21,015.05 |
| Ozone layer depletion | kg CFC-11 eq | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Respiratory organics | kg C2H4 eq | 0.02 | 0.21 | 0.22 | 0.22 | 0.23 | 0.00 | 0.89 |
| Aquatic ecotoxicity | kg TEG water | 99.73 | 1609.53 | 3571.51 | 4454.37 | 9184.81 | 0.00 | 18,919.97 |
| Terrestrial ecotoxicity | kg TEG soil | 8.89 | 171.32 | 630.43 | 836.93 | 2046.04 | 0.00 | 3693.62 |
| Terrestrial acid/nutrification | kg SO2 eq | 1.66 | 22.69 | 23.68 | 24.13 | 26.51 | 0.00 | 98.67 |
| Land occupation | m2org arable | 0.00 | 0.07 | 0.41 | 0.56 | 1.68 | 0.00 | 2.71 |
| Aquatic acidification | kg SO2 eq | 0.23 | 3.13 | 3.54 | 3.73 | 4.70 | 0.00 | 15.32 |
| Aquatic eutrophication | kg PO4 P-lim | 0.00 | 0.01 | 0.05 | 0.07 | 0.19 | 0.00 | 0.32 |
| Global warming | kg CO2 eq | 37.04 | 507.79 | 580.04 | 612.45 | 783.51 | 0.00 | 2520.82 |
| Non-renewable energy | MJ primary | 529.61 | 7342.10 | 8794.46 | 9445.79 | 12,883.54 | 0.00 | 38,995.50 |
| Mineral extraction | MJ surplus | 0.00 | 0.23 | 1.10 | 1.49 | 3.55 | 0.00 | 6.37 |