This document provides an overview of biorefineries. It defines a biorefinery as a refinery that converts biomass into energy and other beneficial byproducts. The document then discusses the uses of biorefineries, how they function, and the types of biorefineries including classification based on platforms, products, feedstocks, and processes used. It also describes the major biorefinery platforms of thermochemical/syngas and biochemical/sugar, and important feedstocks like sugar, starch, and lignocellulosic materials. Gasification and types of gasifiers and fermentation of lignocellulosic feedstock are also summarized.

1. Biorefinery
S K Singh
Centre for Energy Studies
IIT Delhi

2. CONTENTS
● Introduction to Biorefinery
● Uses of Biorefinery
● Functioning of Biorefinery
● Types of Biorefineries
● Biorefinery Platforms and Feedstock
● Biorefinery Concept
● Gasification
● Types of Gasifiers
● Fermentation
● Fermentation of Lignocellulosic Feedstock
● References

3. Introduction to Biorefinery
● A biorefinery is a refinery that converts biomass to energy and other
beneficial byproducts such as chemicals.
● The International Energy Agency Bioenergy Task 42 defined biorefining as
"the sustainable processing of biomass into a spectrum of bio-based products
like food, feed, chemicals, materials and bioenergy like biofuels, power and/or
heat".

4. Uses of Biorefinery
● Contributes to national energy needs by producing a variety of fuels.
● Creation of new jobs, including rural areas
● Achieve the ultimate goal of reducing GHG emissions.
● Provides opportunity for economic growth for both the agricultural and forestry
sectors.
● Generates fuels, chemical commodities and bioproducts in an
environmentally sustainable manner.

5. Functioning of Biorefinery
● The biorefinery uses cellulose, hemicellulose, and lignin from agricultural,
forestry, and municipal waste sources and uses them as feedstocks for
producing a wide range of bio-products.
● These products are used in agri-business, energy production, transportation,
textiles, building products, pharmaceuticals, bioplastics and paper industries.

6. Types of Biorefineries
Biorefineries can be classified based on four main features:
● Platforms: Refers to key intermediates between raw material and final
products.
● Products: In this classification the main market must be identified.
● Feedstock : It refers to type of feedstock being used.
● Processes: Conversion process to transform biomass into a final product.

7. Biorefinery Platforms and Feedstock
● There are many type of Biorefinery platforms.
● Following are the major ones:
○ Thermochemical or syngas platform (for example- gasification)
○ Biochemical or sugar platform (for example- fermentation)
● The most important types of biomass feedstock for use in biorefineries are
sugar, starch and lignocellulosic materials.

8. Biorefinery Concept

9. GASIFICATION

10. Types of Gasifiers
● There are three main types of Gasifiers:
○ Fixed Bed: Passing velocity of gasifying agents through a fixed bed is relatively low.
○ Fluidized Bed : Passing velocity of gasifying agents is high enough to fluidize a bed containing
a small fraction of biomass.
○ Entrained (or suspension) flow gasifiers: In these gasifiers small particles of feedstock are
entrained in a gasifying agent.
● Different gasifier types require different feedstock quality with respect to
moisture and particle size.
○ The fixed bed gasifier requires a coarse biomass feed.
○ In fludized bed gasifiers, the particle diameter is normally in the range 0.1- 5 mm.
○ Entrained flow gasifiers normally require dried material.

11. FERMENTATION
● The fermentation in a biorefinery concept offers a versatile possibility to
convert the sugar containing polymers, cellulose and hemicellulose, to a
range of products.
● The main step in the fermentation process is the fermentation step in which
microorganisms are used to convert the sugar to a specific product.
● Benefits of microbial sugar conversion is that the microorganisms act as
specific catalysts that can produce a range of products.

12. Fermentation of Lignocellulosic Feedstock
● Lignocellulosic feedstock can also be fermented in more advanced
fermentation concepts.
● For that it first needs to be converted to a monosaccharide solution.
● Following steps need to be taken:
○ The lignocellulosic material is first mechanically degraded to increase the surface area.
○ Than it is hydrolysed
○ Than finally fermented

14. ● There are three different configurations of the enzymatic route:
○ SHF, separate hydrolysis and fermentation
○ SSF, simultaneous saccharification and fermentation
○ CBP, consolidated bioprocessing.
● In the fermentation process, it is of utmost importance that all sugar residues
are fermented with high product yield in order to use resources efficiently.
● After the fermentation step, the ethanol is recovered in a distillation step.

15. References
https://www.bioenergyconsult.com/biorefinery/
https://core.ac.uk/download/pdf/70603511.pdf
https://www.ctc-n.org/technologies/biorefinery
https://en.wikipedia.org/wiki/Biorefinery

16. Thank You