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BIOREFINERY CONCEPT



This section of the blog contains general information about the biorefinery concept and the biorefining technologies.

Biorefinery definitions

IEA Bioenergy Task 42
Biorefinery is the sustainable processing of biomass into a spectrum of marketable products (food, feed, materials, chemicals) and energy (fuels, power, heat).
National Renewable Energy Laboratory
A biorefinery is a facility that integrates biomass conversion processes and equipment to produce fuels, power, and chemicals from biomass. The biorefinery concept is analogous to today's petroleum refineries, which produce multiple fuels and products from petroleum.

According to the first definition (widely accepted), biorefinery can be a concept, a process, a plant or even a cluster of facilities. The core is the conversion of biomass into several product streams and the integration of various technologies and processes in the most sustainable way.

Under the umbrella of this definition, facilities making a more traditional use of biomass (for instance, conventional biofuels plants and pulp and paper mills) can be considered as simple biorefinieries. This blog is focused on advanced biorefineries (2nd and 3rd generation) characterized for the use of sustainable feedstocks, application of innovative biorefining processes and, above all, high level of integration and flexibility.

Classification of the biorefineries

According to its products
Energy-driven biorefineries
The main goal is the production of one or more secondary energy carriers: fuels, power and/or heat. Process residues are upgraded and valorised to biobased products to maximise the economic profitability of the full biomass-to-products chain.
Product-driven biorefineries
The main goal is the production of one or more biobased products: chemicals, materials, food and/or feed. Process residues are used for the production of bioenergy to maximise the economic profitability of the full biomass-to-products chain.

According to its technological implementation status
1st Generation (Simple or Conventional)
Classical use of agricultural and forestal biomass (biomass rich on sugar: bioethanol; biomass rich on oil: biodiesel; wood biomass: paper). Low flexibility and integration.
2nd Generation (Advanced)
Lignocellulosic biomass as raw material. Utilization of the whole feedstock. Holistic approach. Intermediate flexibility and integration.
3rd Generation (Advanced)
Use of agricultural and organic waste streams. Algal biorefinery. High flexibility and integration.

According to its size
Small and medium-sized production facility
Located in rural areas. Local approach.
Large production facility
Linked to a network of decentralised primary processing plants.
Very large production facility
Located near a port and using mainly imported biomass.

According to its model
NOTE: Criterion is not homogeneous. Some of these systems refer to the type of feedstock while other focus on the technologies involved. The possibility to combine different biorefinery systems by linking different technologies is not taken into consideration.
Feedstock: lignocellulosic biomass. Biomass is fractionated into three components: cellulose, hemicellulose and lignin. Several final products can be obtained from them.
Whole crop biorefinery
Feedstock: cereals. Mechanical separation to remove the grain from the straw in order to carry out a full use of the crop.
Feedstock: green biomass. Initial fractionation by pressure to obtain two fractions: a nutrient-rich juice organic solution and a fibre-rich lignocellulosic press cake.
Two-platform concept biorefinery
Includes sugars and syngas platforms.
Conventional biorefinery
Based on existing industries (for instance, sugar or starch).
Thermochemical biorefinery
Based on a mix of several thermochemical processes.
Feedstock: aquatic biomass.
Liquid-phase catalytic processing biorefinery
Based on the production of functionalized hydrocarbons from biomass-derived intermediates.
Forest-based biorefinery
Based on the use of forest biomass for simultaneous production of paper, fibers, chemicals and energy.

Classification proposed by IEA Bioenergy Task 42 
Each individual biorefinery system can be classified using the following four main features:
1. Platforms / 2. Products / 3. Feedstock / 4. Processes
A biorefinery system is described as a conversion pathway from feedstock to products, via platforms and processes.
See examples in: The Biorefinery Fact Sheet (IEA Bioenergy Task 42).

Biorefinery Platforms


Feedstocks

Dedicated feedstocks
Sugar crops: sugar beet, sugar cane, sweet sorghum…
Further information can be found in: biofuelstp.eu/sugar_crops.html.
Starch crops: wheat, corn, rye…
Further information can be found in: biofuelstp.eu/starch_crops.html.
Oil-based crops: rapeseed, soya, palm oil…
Lignocellulosic crops: wood, Miscanthus, short rotation poplar and willow…
Further information can be found in: biofuelstp.eu/lignocellulosic-crops.html.
Green biomass: grasses, immature cereals, plant shoots…
Aquatic biomass: micro and macro algae.

Residues / Residuos
Oil-based residues: animal fat from food industries, used cooking oil from restaurants and households…
Lignocellulosic residues: crop residues, saw mill residues…
Organic residues and others: organic urban waste, manure, wild fruits and crops…

Biorefining Processes

Thermochemical
Combustion
Gasification
Blog posts about gasification (only in Spanish): Biomass to Liquid (1ª Parte / 2ª Parte / 3ª Parte).
Pyrolysis
Blog posts about pyrolysis (only in Spanish): Bio-oil (1ª Parte / 2ª Parte / 3ª Parte).
Torrefaction
Liquefaction
Supercritical

Biochemical
Fermentation
Anaerobic digestion
Aerobic digestion
Enzymatic

Chemical
Hydrolysis
Pulping
Esterification
Hydrogenation
Metathesis
Methanisation
Water Gas Shift reaction

Mechanical and physical
Extraction
Fiber separation
Mechanical fractionation
Pressing and disruption

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REFERENCES
1 “IEA Bioenergy Task 42 – Brochure”. Available online: www.iea-bioenergy.task42-biorefineries.com/upload_mm/8/5/4/2e500e0f-d19a-4f7f-9360-4e9d5e580b75_Brochure%20Totaal_definitief_HR%5B1%5D.pdf (accessed on 5th March 2016).
2 “NREL – What is a biorefinery?”. Available online: www.nrel.gov/biomass/biorefinery.html (accessed on 5th March 2016).
3 “IEA Bioenergy Task 42 – Factsheets Biorefineries”. Available online: www.iea-bioenergy.task42-biorefineries.com/en/ieabiorefinery/Factsheets.htm (accessed on 5th March 2016).
4 F Cherubini et al.: “Toward a common classification approach for biorefinery systems”. Published online in Wiley InterScience (www.interscience.wiley.com); DOI: 10.1002/bbb.172; Biofuels, Bioprod. Bioref. (2009).
5 “The European Biorefinery 2030 Vision”. Star-COLI BRI -Strategic Targets for 2020 – Collaboration Initiative on Biorefineries.
6 “Biorrefinerías. Situación Actual y Perspectivas de Futuro”Genoma España /CIEMAT.

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