Skip to main content

Table 1 Characteristics of selected biofuel options and their development status[2],[5],[11]-[13]

From: Benchmarking biofuels—a comparison of technical, economic and environmental indicators

  Raw materials Main conversion steps/plant concept By-productsa R&D Status of technical developmentb Plant capacityc Installed capacity | biofuel production worldwided Installed capacity | biofuel production EUd
Liquid biofuels
Biodiesel (FAME) Oil crops (e.g., rape, soya, palm), animal fats, waste oils (UCO, grease), algae and micro oils Oil extraction (mechanical/solvent), oil refining, trans-/esterification, biodiesel cleaning and upgrading Press cake/extraction meal, glycerine, salt fractions, fatty acids, oleochemicals Process optimisation with regard to e.g., oil quality, catalysts, auxiliary substitutionj Commercial TRL 9 2–350 MW 1,835 mn GJ a−1 | 624 mn GJ a−1 823 mn GJ a−1 | 336 mn GJ a−1
Hydrotreated vegetable oils (HVO) or hydroprocessed esters and fatty acids (HEFA) Oil extraction (mechanical/solvent), oil refining, hydrotreating of oil, isomerisation Extraction meal, fractions like naphtha, propane/butane, waxes Raw material diversification (e.g., algae, micro oils, hydrothermal oil), co-refiningk, process optimisation with regard to e.g., catalysts, H2 demand Commercial TRL 9 255–265 MW (150–1,220 MW) 102 mn GJ a−1 | n.a. 65 mn GJ a−1 | 46 mn GJ a−1 (estimation)
Bioethanol (conventional) Sugar (e.g., beets and cane) or starch (e.g., corn, wheat, rye) Sugar extraction or hydrolysis/saccharification, C6 fermentation, distillation, final dehydration From sugar based e.g., bagasse and vinasse From starch based e.g., gluten, DDGSf biogas/biomethane, technical CO2g Process optimisation with regard to e.g., upgrading stillages and by-products Commercial TRL 9 38–450 MW 2,403 mn GJ a−1 | 1,869 mn GJ a−1 179 mn GJ a−1 | 123 mn GJ a−1
Bioethanol (lignocellulose) Lignocelluloses (e.g., straw, bagasse, wood, switch grass) Pretreatment (e.g., hydrolysis, thermal, acid), saccharification, C6/C5 fermentation, distillation, final dehydration Intermediatesh like lignin, pentoses, fertiliser biogas (P&Hi), technical CO2 Upscaling, applications for lignin (e.g., conversion to fuel, chemicals or for P&H), pentoses, enzyme use and efficiency increase Demonstration TRL 7 0.5–5 MW (35–100 MW) 2,96 mn GJ a−1 | n.a., often only test campaigns 0,51 mn GJ a−1 | n.a., often only test campaigns
Synthetic biomass-to-liquids (BTL) Lignocelluloses (e.g., wood, straw, mischanthus), black liquor Pretreatment (e.g., mechanical, drying, pyrolysis, hydrothermal), gasification, gas treatment, synthesis (e.g., Fischer-Tropsch, FT), hydrocracking, distillation, isomerisation From FT: waxes, naphtha, P&H Upscaling overall concepts but downscaling of synthesis and upgrading units Process optimisation with regard e.g., to syngas treatment, efficiency increase, final fuel treatment Pilot for FT fuels TRL 6 0.8–5 MW (40–300 MW) 1 mn GJ a−1 | n.a., often only test campaigns No plants running
Gaseous biofuels
Biomethane/biogas Residuese (e.g., biowaste, manure, stillage) Silaging, hydrolysis (optional), anaerobic digestion, gas treatment and upgrading P&H, digestate, fertiliser fractions Process optimisation with regard to e.g., methane yields, enzyme use, gas treatment Commercial TRL 9 0.5–50 MW 60 GJ a−1 | n.a. 38 GJ a−1 | 36 GJ a−1 (estimation)
Biomethane/synthetic natural gas (SNG) Lignocelluloses (e.g., wood and straw) Pretreatment (e.g., mechanical, drying, gasification, gas treatment, synthesis (methanation), gas upgrading P&H Upscaling, process optimisation: with regard to e.g., syngas treatment, efficiency increase, adaption to decentralised concepts Demonstration TRL 7 1–10 MW (20–200 MW) Not realised outside Europe 0,092 mn GJ a−1 | n.a., often only test campaigns
  1. aUsually depending on process design.
  2. bAccording to technology readiness level (TRL) of the European Commission, which outlines in detail the different research and deployment steps (1 = basic principles observed, 2 = technology concept formulated, 3 = experimental proof of concept, 4 = technology validation in lab, 5 = technology validation in relevant environment, 6 = demonstration in relevant environment, 7 = demonstration in operational environment, 8 = system completed and qualified, 9 = successful mission operations) [14].
  3. cRelated to biofuel output—w/o brackets for current capacities, expected capacities in future in brackets (based on [5]).
  4. dValues for 2012 or 2013; n.a.—no information available for biofuel production.
  5. eMostly derived from sugar or starch-dominated substrates.
  6. fStillage for DDGS (distiller's dried grains with solubles).
  7. gTechnical CO2 can be used for food or chemical industries (e.g., CO2 for fizzy drinks and for synthesis).
  8. hCan be used as feedstock for another process or upgraded further.
  9. iP&H = (electrical) power and heat.
  10. jOne example of this is methanol substitution through bioethanol.
  11. kCo-refining in a mineral oil refinery.