ENERGY FROM BIOMASS:

FUNDAMENTAL AND APPLICATIONS

Prapan Kuchonthara, Ph.D.
Department of Chemical Technology
Chulalongkorn University

March 13, 2024

Energy from Biomass : Fundamental and Applications

Department of Chemical Technology, Chulalongkorn University

https://www.menti.com/aley88bzedtx 2
 Energy from Biomass : Fundamental and Applications

Department of Chemical Technology, Chulalongkorn University

 Biomass gasification: fundamental, current, and future

Department of Chemical Technology, Chulalongkorn University

 Energy from Biomass : Fundamental and Applications

Department of Chemical Technology, Chulalongkorn University

 Biomass gasification: fundamental, current, and future

Biomass : Definition

Department of Chemical Technology, Chulalongkorn University

• Ecology: the amount of living matter in a given habitat, expressed either as the
weight of organisms per unit area or as the volume of organisms per unit
volume of habitat.
• Energy: organic matter, especially plant matter, that can be converted to fuel
and is therefore regarded as a potential energy source.

Renewable and Sustainable

Energy resource

Source: dictionary.com , www.canadianbiomassmagazine.ca 6

 Energy from Biomass : Fundamental and Applications

Department of Chemical Technology, Chulalongkorn University

 Energy from Biomass : Fundamental and Applications

Department of Chemical Technology, Chulalongkorn University

 Biomass gasification: fundamental, current, and future

Biomass categorization

Department of Chemical Technology, Chulalongkorn University

Woody Non-woody Other organic
biomass biomass wastes
Forest residues Agricultural
crops Animal waste
Fuel wood
Crop residues
Wood waste
Processing Sewage waste
Rotation forestry residues

Lignocellulosic materials Saccharides/Lipids/Protein

Segregation on the basis of nature 9

 Energy from Biomass : Fundamental and Applications

Lignocellulosic biomass : composition

Department of Chemical Technology, Chulalongkorn University

Typical wood composition

Source: Alonso et al., 2012, http://www.forestandrange.org 10

Biomass gasification: fundamental, current, and future

Biomass conversion to energy

Department of Chemical Technology, Chulalongkorn University

Thermochemical process
•Direct combustion
•Pyrolysis
•Liquefaction
•Gasification
Biological process
• Biomethanation
• Ethanol fermentation
Chemical conversion
• Biodiesel production

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Biomass gasification: fundamental, current, and future

Biomass : Fuel properties

Department of Chemical Technology, Chulalongkorn University

Moisture

Ash

Volatile
Biomass
Elemental composition

Heating value

Bulk density
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 Biomass gasification: fundamental, current, and future

Biomass : Proximate and Ultimate analyses

Department of Chemical Technology, Chulalongkorn University

Moisture (M) ∗ FC = 100 − (M + VM + ASH)
Proximate

Volatile matter (VM)

∗∗ O = 100 − (C + H + N + S)
Ash (A)

Fixed carbon (FC) *

Carbon (C)

Hydrogen (H)
Ultimate

Nitrogen (N)

Sulfur (S)

Oxygen (O) **

Source: หนังสือ พลังงานจากชีวมวลและวัสดุเหลือทิ้ง (2558) 13

 Biomass gasification: fundamental, current, and future

Elemental composition and heating value

Department of Chemical Technology, Chulalongkorn University

HHV = ?

Dulong’s equation (O<10%) : GCV (kJ/kg) = 338×%C + 1443(%H − %O/8) + 94×%S

Boie’s equation : GCV (kJ/kg) = 352×%C + 1162×%H −111×%O + 63×%N + 105×%S
NCV (kJ/kg) = GCV – 24.44(9×%H + %M)
Source: https://www.semanticscholar.org/paper/10-Biomass-Energy-Conversion-Capareda 14
 Biomass gasification: fundamental, current, and future

Thermochemical conversion - overview

Department of Chemical Technology, Chulalongkorn University

combustion

+O2/air (excess)

gasification

biomass
+O2/air (deficient)
pyrolysis

no air

liquefaction

Solvent, H2
(high pressure)
Source: หนังสือ พลังงานจากชีวมวลและวัสดุเหลือทิ้ง (2558) 15
Biomass gasification: fundamental, current, and future

Combustion

Department of Chemical Technology, Chulalongkorn University

Combustion is a chemical reaction between
hydrocarbon or any combustible compounds and
oxygen, giving CO2 and H2O as major products
and releasing energy (mainly heat)
• Be the oldest biomass conversion processes
• Produce energy in forms of heat and light
• Be a today dominant technology (>95%) of converting
biomass into energy directly (combustion)
• Produced heat is converted to other useful forms of energy
e.g. mechanical and electrical energy through heat engine
or turbines

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Biomass gasification: fundamental, current, and future

Combustion stoichiometric models

Department of Chemical Technology, Chulalongkorn University

• Combustion reaction:

𝑦 𝑧 𝑦
𝐶𝑥 𝐻𝑦 𝑂𝑧 + 𝑥 + − 𝑂2 ՜ 𝑥𝐶𝑂2 + 𝐻2 𝑂
4 2 2
Consequently, the stoichiometric oxygen (air) can be
determined.

Consider combustion of
• Methane (CH4)
• Cellulose (C6H10O5)
• Real biomass?
How much is theoretical air required?
Biomass gasification: fundamental, current, and future

Estimate stoichiometric combustion for some solid fuels

Department of Chemical Technology, Chulalongkorn University

Find a molecular formula for biomass as 𝐶𝑥 𝐻𝑦 𝑂𝑧 𝑁𝑎 𝑆𝑏
Biomass gasification: fundamental, current, and future

Combustion efficiency

Department of Chemical Technology, Chulalongkorn University

Thermal efficiency is defined as:
Thermal energy of flue gas
combustion efficiency (𝜂𝑐𝑜𝑚𝑏 ) = × 100
Chemical energy of fuel (LHV)

Practically, oxygen/air must be higher than that of a

theoretical value in order to achieve complete combustion

Equivalence ratio (ER, ) is a parameter indicating how

much oxygen/air is fed to combustion.
=1 means the theoretical oxygen/air supply.

𝑎𝑐𝑡𝑢𝑎𝑙 𝑎𝑖𝑟 𝑠𝑢𝑝𝑝𝑙𝑦 − 𝑡ℎ𝑒𝑜𝑟𝑒𝑐𝑡𝑖𝑐𝑎𝑙 𝑎𝑖𝑟 𝑑𝑒𝑚𝑎𝑛𝑑

% 𝑒𝑥𝑐𝑒𝑠𝑠 𝑎𝑖𝑟 = × 100
𝑡ℎ𝑒𝑜𝑟𝑒𝑐𝑡𝑖𝑐𝑎𝑙 𝑎𝑖𝑟 𝑑𝑒𝑚𝑎𝑛𝑑 19
 Combustion temperature
Biomass gasification: fundamental, current, and future

Limited air
Incomplete
combustion

air
Theoretical

Complete
combustion

Low-temp
Excess air

combustion
Excess air versus combustion temperature

ER

20

Department of Chemical Technology, Chulalongkorn University

Biomass gasification: fundamental, current, and future

Pyrolysis

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• Pyrolysis is a thermochemical decomposition with an absence of oxygen/air,
so-called cracking, devolatilization, carbonization, thermolysis.
• Products include gas, liquid and solid products.
• The process is irreversible and endothermic as a whole.
• Pyrolysis is considered as a early first step in several thermochemical
processes, such as combustion, gasification, liquefaction, taking place at
temperature around 300-650 C

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Biomass gasification: fundamental, current, and future

Types of pyrolysis

Department of Chemical Technology, Chulalongkorn University

Process residence heating Reaction Main
Conventional/Slow pyrolysis time rate temperat product
ure
Solid,
24 hr (<<1 K/s) 400
Slow Char
pyrolysis Char, oil,
Fast pyrolysis 5-30 min (<1 K/s) 600
gas
Fast (>500
<2s 500 Bio-oil
pyrolysis K/s)
Flash Bio-oiil,
<1s (>105 K/s) < 650
pyrolysis gas
Ultra fast/Flash pyrolysis

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 Energy from Biomass : Fundamental and Applications

Bio-oil property

Department of Chemical Technology, Chulalongkorn University

There are presently two fuel oil grades for fast pyrolysis bio-oil established by ASTM
(D7544)

Source: Standardisation of fast pyrolysis bio-oils, VTT Technical Research Centre of Finland 23
Biomass gasification: fundamental, current, and future

Liquefaction

Department of Chemical Technology, Chulalongkorn University

Direct liquefaction
• Single step conversion of solid fuels into liquid fuels in a presence of a
medium/solvent
• In case of biomass/waste with high moisture contents, water is used as a
medium. This process is also named “hydrothermal liquefaction”
Indirect liquefaction
• A multi-step process of converting solid fuels into liquid fuels through
syngas (CO+H2)
• Combined process between gasification and gas-to-liquid (GTL) process
• Product distribution can be controlled by type of catalyst and operating
conditions

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Energy from Biomass : Fundamental and Applications

Indirect liquefaction

Department of Chemical Technology, Chulalongkorn University

Gas cleaning and GTL
Gasification conditioning

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Energy from Biomass : Fundamental and Applications

Gasification

Department of Chemical Technology, Chulalongkorn University

Simple A process that converts a substance
definition: into gas

A process that converts solid fuels into

Well-known gaseous fuels or synthetic gas
definition: (SynGas) which consists mainly of H2,
CO, CO2, and (typically) traces of CH4

https://www.indiamart.com/proddetail/batliboi-75kwe-gasification-20225662462.html (Source: http://www.organicenergy.ca) 26

Energy from Biomass : Fundamental and Applications

Gasification product and elemental composition

Department of Chemical Technology, Chulalongkorn University

Moisture H2O(g)
+1/2O2 CO Carbon
Fixed carbon Char(s) +H O
2
Gas H2 Hydrogen
N2 Nitrogen
+1/2O2
Volatile Volatile(g) +H2O
Oxygen
Tar
H2S Sulfur

Ash Ash

Char reactions solid-gas reaction Slow reaction rate

Volatile reactions gas-gas reaction Low mass per volume

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Energy from Biomass : Fundamental and Applications

Gasification of coal vs biomass

Department of Chemical Technology, Chulalongkorn University

Gasifier design specification

Promote solid-gas reactions

Coal
of char and O2/steam

Promote gas phase reactions

Biomass
of volatile and O2/steam

Coal : High fixed carbon

Tar is a crucial problem in
Biomass : High volatile biomass gasification

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Energy from Biomass : Fundamental and Applications

Biomass Tar

Department of Chemical Technology, Chulalongkorn University

General Definition
A dark, thick, flammable liquid distilled from wood or coal,
consisting of a mixture of hydrocarbons, resins, alcohols, and
other compounds

Crucial Problems
• Pipline
Deposition • Engine
and corrosion • Turbine blade
• Fuel cells

Tar handling is a major challenge in biomass

gasification
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Energy from Biomass : Fundamental and Applications

Syngas quality

Department of Chemical Technology, Chulalongkorn University

Typical gasifier : Tar removal
Tar content 0.5-100 g/m3

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Energy from Biomass : Fundamental and Applications

Tar removal

Department of Chemical Technology, Chulalongkorn University

• Scrubber
Physical
• Absorption &
Approach
Adsorption

http://www.globalspec.com/

Catalyst
Chemical • Cracking
Tar CO+H2
Approach • Catalytic reforming
+H2O +Heat

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 Energy from Biomass : Fundamental and Applications

Chemical reactions in gasification

Department of Chemical Technology, Chulalongkorn University

Combustion

Boudouard

Water gas

CO shift or
Water-gas shift

Steam reforming

Source: Higman, C. and Van der Burgt, M. (2008) 32

 Energy from Biomass : Fundamental and Applications

Gasifying Agents

Department of Chemical Technology, Chulalongkorn University

Source: Report on THE STATUS OF BIOMASS GASIFICATION in Thailand and Cambodia (http://www.eepmekong.org)
 Energy from Biomass : Fundamental and Applications

Gasifier Design – Gasifier Types

Department of Chemical Technology, Chulalongkorn University

Updraft fixed bed Downdraft fixed bed Entrained flow

Bubbling fluidized bed Circulating fluidized bed Dual fluidized bed

SourceReview of technology for the gasification of biomass and wastes, E4tech (2009) 34
 Energy from Biomass : Fundamental and Applications

Pros & Cons of Gasifier Types

Department of Chemical Technology, Chulalongkorn University

Source: Report on THE STATUS OF BIOMASS GASIFICATION in Thailand and Cambodia (http://www.eepmekong.org) 35
 Energy from Biomass : Fundamental and Applications

Process Evaluation

Department of Chemical Technology, Chulalongkorn University

• The two most common criteria for gasification processes are coal gas
efficiency (CGE) and carbon conversion

Source: Higman, C. and Van der Burgt, M. (2008)

Energy from Biomass : Fundamental and Applications

Biomass to power (gasification)

Department of Chemical Technology, Chulalongkorn University

Gas engine
< 10MW

Syngas

Gas turbine
100-350MW

Steam
turbine

IGCC
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Energy from Biomass : Fundamental and Applications

Biomass conversion to energy

Department of Chemical Technology, Chulalongkorn University

Thermochemical process
•Direct combustion
•Pyrolysis
•Liquefaction
•Gasification
Biological process
• Biomethanation
• Ethanol fermentation
Chemical conversion
• Biodiesel production

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Energy from Biomass : Fundamental and Applications

Biogas (Bio-methane)

Department of Chemical Technology, Chulalongkorn University

• Biogas is a gas mixture of methane (CH4) and carbon
dioxide (CO2) that is generated when bacteria degrade
organic matter (biomass) in the absence of oxygen, in
a process known as anaerobic digestion

anaerobic
Organic matter CH4 + CO2 + H2 + NH3 + H2S
digestion

• Anaerobic digestion occurs in an anaerobic (oxygen-

free) environment through the activities of acid- and
methane-forming bacteria that break down the organic
material and produce biogas.

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 Energy from Biomass : Fundamental and Applications

Biomethanation (Biogas Production)

Department of Chemical Technology, Chulalongkorn University

Source: https://synodbioscience.files.wordpress.com/2014/07/biogas-production-in-india.jpg ; www.e-education.psu.edu/egee439/node/727 40
Energy from Biomass : Fundamental and Applications

Sources for Biogas Production

Department of Chemical Technology, Chulalongkorn University

• Municipal and animal waste, waste water, MSW, food and vegetable
processing waste, crops
0.37 m3 CH4
Carbohydrate
/kg dry matter

1.0 m 3 CH4
Protein
/kg dry matter

0.58 m3 CH4
Lipid
/kg dry matter

Chemical oxygen 0.35 m3 CH4

demand (COD) /kg COD removed
Waste water or
sludge
0.5-0.7 m3 CH4
Volatile solid (VS) /kg VS destroyed
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 Energy from Biomass : Fundamental and Applications

Design parameters

Department of Chemical Technology, Chulalongkorn University

• Selection of materials :
• Total solid (TS) : typically 8%
• Temperature : 20 – 35oC
• pH value : 6.8 – 7.2
• C/N ratio : 20:1 to 30:1
• Hydraulic residence time (HRT) : > 20 days @8%TS

Source: https://docplayer.net/23872162-Design-of-biogas-plant.html 42
 Energy from Biomass : Fundamental and Applications

Ethanol Fermentation

Department of Chemical Technology, Chulalongkorn University

First generation

Second generation

Source: http://aseancassava.info/bioethanol.asp 43
Energy from Biomass : Fundamental and Applications

Bioethanol

Department of Chemical Technology, Chulalongkorn University

Bioethanol as a fuel or an energy source is produced by a process known as
fermentation, in which microorganisms (usually yeast) converted sugar to
ethanol by using enzymes.

The fermentation reactions can be described as follows:

Glucose 2 Ethanol 2 CO2 Energy

Yeast Saccharomyces cerevisiae is the universal organism using starch and sugar
feedstocks
Theorectically, yield is 0.511 g ethanol/g glucose consumed. Around 90% can be
achieved under ideal conditions 44
 Energy from Biomass : Fundamental and Applications

Fermentation pathway

Department of Chemical Technology, Chulalongkorn University

Source: http://biology4alevel.blogspot.com/2015/08/91-anaerobic-respiration-ethanol.html 45
Energy from Biomass : Fundamental and Applications

Ethanol use in vehicles

Department of Chemical Technology, Chulalongkorn University

Biofuels, production, application and development/A.H. Scragg (2009) 46
Energy from Biomass : Fundamental and Applications

Ethanol from starch

Department of Chemical Technology, Chulalongkorn University

• The hydrolysis of starch to produce glucose
can be expressed by

180𝑛
Glucose = kg/kg of starch
160𝑛+18

When n becomes large, the value approaches 1.111

• Ethanol fermentation using glucose can be expressed by

1 kg of glucose produces 0.511 kg ethanol

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Energy from Biomass : Fundamental and Applications

Ethanol recovery

Department of Chemical Technology, Chulalongkorn University

• Distillation
• Ethanol and water forms an azeotropic mixture of 95% ethanol by
volume
• Azeotropic distillation using a ternary agent, e.g. benzene,
cyclohexane, was employed in the past to produce anhydrous ethanol

• Dehydration
• Molecular sieves (synthetic zeolite adsorbents) having pore size of 3 A
(water 2.8 A ,ethanol 4.4 A)
• Pressure Swing Adsorption (PSA)

48
 Energy from Biomass : Fundamental and Applications

Example of ethanol from cassava chip

Department of Chemical Technology, Chulalongkorn University

Source: An emerging leader and developer of Green Alternatives for Energy And Agricultural Food crops in Africa 49
Biomass gasification: fundamental, current, and future

Biodiesel Production

Department of Chemical Technology, Chulalongkorn University

• Biodiesel refers to a diesel-equivalent, processed fuel derived from
biological sources (such as vegetable oils), which can be used in
unmodified diesel-engine vehicles. It is thus distinguished from the
straight vegetable oils (SVO) or waste vegetable oils (WVO) used
as fuels in some diesel vehicles.
• Biodiesel refers to alkyl esters made from the transesterification of
vegetable oils or animal fats.
• Biodiesel is biodegradable and non-toxic, and typically produces
about 60% less net carbon dioxide emissions than petroleum-
based diesel.
50
 Energy from Biomass : Fundamental and Applications

Properties of vegetable oils (cf. Diesel Fuel)

Department of Chemical Technology, Chulalongkorn University

Source: B.K. Barnwal, M.P. Sharma / Renewable and Sustainable Energy Reviews 51
 Energy from Biomass : Fundamental and Applications

Properties of Biodiesel from various oils (cf. Diesel Fuel)

Department of Chemical Technology, Chulalongkorn University

Source: B.K. Barnwal, M.P. Sharma / Renewable and Sustainable Energy Reviews 52
Energy from Biomass : Fundamental and Applications

Biodiesel production - Reactions

Department of Chemical Technology, Chulalongkorn University

Transesterification

Catalyzed by acid or base (more effective) catalysts

Esterification

Catalyzed by acid catalysts (H2SO2 or HCl)

Interesterification and transesterification catalyzed by Enzyme catalysts

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Biomass gasification: fundamental, current, and future

Catalysts

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• Base or Alkali Catalyst
• Homogenous base catalysts : NaOH, KOH
• Low cost and high reaction rate at low temperature
• Difficult catalyst recovery and shorten equipment life due to high corrosive nature
• Heterogeneous solid base catalysts : ETS-10 (Na, K), CaO etc.
• Ease of recovery
• Slow reaction rate

• Acid Catalyst
• Homogenous acid catalyst : H2SO4, HCl, phosphoric, sulfonic acids
• Heterogeneous solid acid catalyst : zeolites, Amberlyst-15, naphion NR50, etc.

• Enzyme Catalyst
• Immobilized system : immobilized lipase
• Diffusion limitation, deactivation by alcohols, e.g. methanol or ethanol
Biomass gasification: fundamental, current, and future

Side reactions

Department of Chemical Technology, Chulalongkorn University

Saponification Excess FFA Soup formation

Hydrolysis

The soap inhibits separation of the methyl esters and glycerol

and contributes to emulsion formation during the water wash.
The FFA content up to 5% is still acceptable
 Biomass gasification: fundamental, current, and future

Pretreatment of High FFA Oil

Department of Chemical Technology, Chulalongkorn University

Source: https://www.itri.org.tw/eng/content/MSGPic01
 Biomass gasification: fundamental, current, and future

57

Department of Chemical Technology, Chulalongkorn University