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Overview of Technologies for Converting Waste Agricultural Biomass into Energy Training on Technologies for Converting Waste Agricultural Biomass into Energy Organized by United Nations Environment Programme (UNEP DTIE IETC) 23-25 September, 2013 San Jose, Costa Rica Surya Prakash Chandak Senior Programme Officer International environmental Technology Centre Division of Technology, Industry and Economics Osaka, Japan
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Overview of Technologies for Converting Waste Agricultural Biomass into Energy

Jan 25, 2016

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Overview of Technologies for Converting Waste Agricultural Biomass into Energy. Training on Technologies for Converting Waste Agricultural Biomass into Energy Organized by United Nations Environment Programme (UNEP DTIE IETC) 23-25 September, 2013 San Jose, Costa Rica. - PowerPoint PPT Presentation
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Page 1: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

Overview of Technologies for Converting

Waste Agricultural Biomass into Energy

Training onTechnologies for Converting Waste Agricultural Biomass into Energy

Organized by

United Nations Environment Programme (UNEP DTIE IETC)

23-25 September, 2013San Jose, Costa Rica

Surya Prakash ChandakSenior Programme Officer

International environmental Technology CentreDivision of Technology, Industry and Economics

Osaka, Japan

Page 2: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

CONTENT

Technology Classification

Direct Combustion

Densification

Thermo-chemical Conversion

Biological Conversion

Liquid Biofuels

Environmental Characteristics

Technology Selection

Technologies in Practice 2

Page 3: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

TECHNOLOGY CLASSIFICATION Direct combustion of raw biomass is the simplest

method of extracting energy with lowest cost

– Therefore is the most common method of conversion.

– However, such a use faces the worst features of biomass - bulk and inconvenience.

Therefore, before bio-energy is used for end-use activities, it may have to be converted from its primary form into a form that is more convenient for transport and use.

– This may involve simple physical processing before combustion or upgrading to a variety of convenient secondary fuels (solid, liquid or gas) by means of certain conversion processes. 3

Page 4: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

TECHNOLOGY CLASSIFICATION Methods of utilizing waste agricultural biomass

as a source of energy

WAB Resources

Conversion Processes

Intermediate Fuels

Biomass Fuels

Heat

Electricity

Mechanical Power

Direct Combustion / Gasification

HeatEngines

Generator

4RESOURCE TECHNOLOGY APPLICATION

Page 5: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

TECHNOLOGY CLASSIFICATION Different processes and technologies are

available for converting biomass to energy.

Could be categorized as:– Direct combustion of the raw biomass– Combustion after simple physical processing,

sorting, chipping, compressing, air-drying (beneficiation)

– Thermo-chemical processing Processes in this category include pyrolysis, gasification or

liquefaction;

– Biological processing Natural processes such as anaerobic digestion and

fermentation encouraged by the provision of suitable conditions giving useful secondary fuel (gaseous or liquid);

– Extraction Trans-esterification to produce biodiesel. 5

Page 6: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

TECHNOLOGY CLASSIFICATION

6

Figure 1.10: Methods of using biomass for energy

Combustion Gasification

Pyrolysis; Liquefaction; Hydrothermal

Upgrading

Digestion Fermentation Extraction Oilseeds

Steam Turbine

Gas turbine, combined cycle,

engine

Methanol,

hydrocarbons,

hydrogen

synthesis

Steam Gas Oil Gas Charcoal Biogas

Fuel Cell

Upgrading

Diesel

Gas Engine

Distillation

Ethanol

Esterification

Bio Diesel

Heat Electricity Fuel

Thermo-chemical Conversion Biochemical Conversion

Raw Material/Beneficiated Products Methods of using WAB for Energy

Page 7: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

TECHNOLOGY CLASSIFICATION Thermo-chemical conversion routes

7

ICE : Internal Combustion EngineECE : External Combustion EngineLGLF: Low-Grade Liquid FuelHGLF: High-Grade Liquid FuelLMJG: Low-Megajoule GasMMJG: Medium-Megajoule Gas

BI

OM

AS

S

Beneficiation

Upgrading / Conversion

Liquifaction

Gasification

Pyrolysis

Improvedsolidfuels

Char

LGLF

LMJG

HGLF

MMJG

Combustion Heat

Use in ICE Power

Use in ECE

Page 8: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

TECHNOLOGY CLASSIFICATION

8

Methods of using WAB for Energy

BENEFICIATION

Drying Dewatering Sizing Densification Separation Torrefaction

Baling Pelletization Briquetting

Page 9: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

DIRECT COMBUSTION Combustion of biomass has been widely used in

the past to generate heat– At present, it is making a comeback in many industrial

applications including generation of electricity,

Straightforward conversion of thermal energy into mechanical or electric power results in considerable losses– It is not possible to raise the ratio of thermal to

mechanical power above 60%. – However, if the low temperature waste heat can be

used productively, for instance for drying or heating purposes, much higher overall efficiencies can be obtained.

9

Page 10: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

DIRECT COMBUSTION Fuels and Combustion

Biomass combustion

10

Combustion Unit

Air and Fuel Combustion

Products

Heat Energy

Light

Volatile Matter

Hot Flue Gas

Flame Front

Entrained Air

Burning CharAsh

Wood

Conduction to Wood

Radiation to Wood

Radiation to

Surrounding

Convective Heat to Surrounding

EnergyCombustion of ProductsOxidizerFuel

Page 11: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

DIRECT COMBUSTION Biomass combustion

- Processes and temperatures in a burning piece of wood

11

Gaseous-phase combustion Diffusion flame, mostly Turbulent – a ‘free’ fire T > 1000C (probably T < 1000C) Simultaneous heat and mass transfer with chemical reaction; Surface combustion – a slow process 500C < T < 800C Problem same as in zone A but with sources/sinks due to pyrolytic reactions 200C < T < 500C Heat conduction in a medium with a moving boundary; Mitigation of moisture & gases; Uncertain properties T < 200C

Figure 6.1: Processes and temperatures in a burning piece of wood

Flame

D

Char

C

Pyrolytic Zone

B

Virgin Wood

A

Hea

t Flo

w

Gas

Flo

w

Page 12: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

Properties of Fuels– Solid.

DensityMoisture ContentVolatile Matter and Fixed CarbonSulfur ContentAsh Calorific Value

DIRECT COMBUSTION

12

Fuel Volatile Matter Fixed Carbon Ash

Paddy Husk 63.3 14.0 22.7

Bagasse 74.0 19.3 6.7

Wood 77 - 87 13 - 21 0.1 - 2.0

Lignite 43.0 46.6 10.4

Anthracite Coal 5.0 80 15

Page 13: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

DENSIFICATION Densification (briquetting or pelleting) is used to

improve characteristics of materials (especially low density biomass)– Productive transport,– Improved fuel characteristics.

Raw materials used include sawdust, loose crop residues, and charcoal fines.

The material is compacted under pressure– Depending on the material, the pressure, and the

speed of densification, additional binders may be needed to bind the material

13

Page 14: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

DENSIFICATION There are two main briquetting technologies

– Piston press– Screw press.

In the piston press the material is punched into a die by a ram with a high pressure.

In the screw press, the material is compacted continuously by a screw.

With the screw press generally briquettes of higher quality can be produced.

14

Page 15: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

THERMOCHEMICAL CONVERSION In thermochemical conversion, biomass is

subjected to appropriate temperatures and pressures and normally a restricted supply of oxygen

Pyrolysis is the basic thermochemical process to convert biomass into more valuable or more convenient products– In fact, it is the oldest method of processing one fuel

in order produce better one

Conventional pyrolysis involves heating the original material in the near-absence of air, typically at 300 - 500C, until the volatile matters has been driven off. 15

Page 16: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

THERMOCHEMICAL CONVERSION The residue is then the char (more commonly

known as charcoal)– Char has about twice the energy density of the

original fuel and burns at a much higher temperature

For many centuries, and in much of the world still today, charcoal is produced by pyrolysis of wood. – Depending on the moisture content and the efficiency

of process, 4 - 10 kg of wood are required to produce one kg of charcoal

16

Page 17: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

THERMOCHEMICAL CONVERSION With more sophisticated pyrolysis techniques,

the volatile matters can be collected– Careful choice of the temperature at which the

process takes place allows the control of the composition.

– The products formed are normally a gas, an oil-like liquid and charcoal

– The distribution of these products is dependent on the feedstock, temperature and pressure of reaction, the time spent in the reaction zone and the heating rate.

– High temperature pyrolysis (1000C) maximizes the production of gas (gasification) while lower temperature pyrolysis processes (<600C) have been used for the production of charcoal (carbonization).

– Another approach to produce liquid fuels and chemicals from biomass is direct catalytic liquefaction

17

Page 18: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

BIOLOGICAL CONVERSION Biological conversion consists of exposing

biomass to certain microorganisms.

The secondary fuels produced are the result of metabolic activity of the microorganisms.

Production of Ethanol and biogas are the two most common biological conversion processes.

Ethanol fermentation from carbohydrates is probably one of the oldest processes known to man. – Today, it is widely regarded as an important potential

alternative source of liquid fuels for the transport sector. 18

Page 19: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

LIQUID BIOFUELS Definition

- The term biofuels generally refers to liquid fuels made from biological sources, which include pure plant oil (PPO), bioethanol and biodiesel.

- Global biofuel production from year 2000 to 2011

19

0

10

20

30

40

50

60

70

80

90

100

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Bio

fuel P

rod

ucti

on

(M

illio

n L

iters

)

Year

Ethanol

Biodiesel

Page 20: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

LIQUID BIOFUELS Production and uses of liquid biofuels

20

First Generation (Conventional) BiofuelsBiofuel Type

Specific Names Biomass Feedstock Production Process

Uses

Vegetable/Plant Oil

Straight VegetableOil (SVO);Pure Plant Oil (PPO)

Oil crops(e.g. Rapeseed, Corn, Sunflower,Soybean,Jatropha,Jojoba,Coconut,Cotton,Palm,etc.)Algae

Cold pressing/extraction

Diesel engines,Generators,Pumping (all after modifications);Use for cooking and lighting, as possible;Transportation

Biodiesel

Biodiesel fromenergy crops

Cold pressing/extraction &trans-esterification

Diesel engines for power generation,Mechanicalapplications,Pumping;Transportation(diesel engines)

Rapeseed methylester (RME), fattyacid methyl/ethylester (FAME/FAEE)Biodiesel from waste; FAME/FAEE

Waste/cooking/frying oil/animal fat

Trans-esterification

BioethanolConventionalbioethanol

Sugarcane, Sweet sorghum, Sugar beet, Cassava Grains

Hydrolysis &fermentation Internal combustion

engine for motorized transport

Bio-ETBEEthyl Tertiary; Butyl; Ether

Bioethanol Chemical synthesis

Page 21: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

LIQUID BIOFUELS Production and uses of liquid biofuels

21

Second Generation BiofuelsBiofuel Type

Specific Names Biomass Feedstock

Production Process

Uses

BiodieselHydro-treatedbiodiesel

Vegetable oils and animal fat

Hydro-treatment

Internal combustionengine for motorized transport

BioethanolCellulosic bioethanol

Lignocellulosic material

Advanced hydrolysis& fermentation

Synthetic biofuels

Biomass-to-liquids(BTL):Fischer-Tropsch (FT) diesel; BiomethanolBiodimethyl-ether(Bio-DME)

Lignocellulosicmaterial

Gasification &synthesis

Bio-hydrogen

Lignocellulosicmaterial

Gasification &synthesis or biol.

Page 22: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

LIQUID BIOFUELS Production and uses of liquid biofuels

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Parameters 1st Gen. 2nd Gen.

Direct food vs. fuel competition Yes No

Feedstock cost per unit of production High Low

Land-use efficiency Low High

Feasibility of using marginal lands for feedstock production Poor Good

Ability to optimize feedstock choice for local conditions Limited High

Potential for net reduction in fossil fuel use Medium Medium-High

Potential for net reduction in greenhouse gas emissions Medium Medium-High

Readiness for use in existing petroleum infrastructure Yes Yes

Proven commercial technology available today Yes No

Simplicity of processes Yes No

Capital costs per unit of production Low High

Total cost of production High High

Minimum scale for economical production Medium High

Page 23: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

LIQUID BIOFUELS First, second and third generation biofuels

23

Biofuels

Ethanol Biodiesel

1st Generation 2nd Generation 1st Generation 2nd Generation 3rd Generation

Corn Cane Maize

Switchgrass Cellulosic Gasification

Palm Soybeans Rapeseed

Jatropha Gasification

Algae

Page 24: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

ENVIRONMENTAL PERFORMANCES Impacts of emissions from biomass combustion

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Component Biomass Sources Climate, environmental and health impactCarbon dioxide (CO2) Major combustion product

from all biomass fuelsClimate: Direct GHG. However, biomassis a CO2-neutral fuel

Carbon monoxide (CO)

Incomplete combustion of all biomass fuels

Climate: Indirect GHG through ozone formation. Health: Reduced oxygen uptake especially influences people with asthma, and embryos. Suffocation in extreme cases.

Methane (CH4) Incomplete combustion of all biomass fuels

Climate: Direct GHG. Indirect GHG through ozone formation.

Non Methane VolatileOrganic Components(NMVOC)

Incomplete combustion of all biomass fuels

Climate: Indirect GHG through ozone formation. Health: Negative effect on human respiratory system

Polycyclic AromaticHydrocarbons (PAH)

Incomplete combustion of all biomass fuels

Environment: Smog formationHealth: Carcinogenic effects

Particles Soot, char and condensed heavy hydrocarbons (tar) from incomplete combustion of all biomass fuels. Fly ash and salts

Climate and environment: Reversed greenhouse effect through aerosol formation. Indirect effects of heavy-metal concentrations in deposited particles.Health: Negative effect on the human respiratory system. Carcinogenic effects

Page 25: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

ENVIRONMENTAL PERFORMANCES Impacts of emissions from biomass combustion

25

Component Biomass Sources Climate, environmental and health impactNitric oxides(NOX = NO and NO2)

Minor combustion product from all biomass fuels containing nitrogen. Additional NOx may beformed from nitrogen in the air under certain conditions

Climate and environment: Indirect greenhouse effect through ozone formation. Reversed greenhouse effect through aerosol formation. Acid precipitation. Vegetation damage. Smog formation. Corrosion and material damage. Health: Negative effect on the human respiratory system. NO2 is toxic

Nitrous oxide (N2O)

Minor combustion product from all biomass fuels containing nitrogen

Climate: Direct GHG. Health: Indirect effect through ozone depletion in the stratosphere

Ammonia (NH3)

Small amounts may be emitted as a result of incomplete conversion of NH3 from pyrolysis/ gasification

Environment: Acid precipitation. Vegetation damage. Corrosion and material damage. Health: Negative effect on the human respiratory system.

Sulphur oxides(SOX = SO2 and SO3)

Minor combustion product from all biomass fuels containing sulphur.

Climate and environment: Reversed greenhouse effect through aerosol formation. Acid precipitation. Vegetation damage. Smog formation. Corrosion and material damage. Health: Negative effect on the human respiratory system, asthmatic effect

Page 26: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

ENVIRONMENTAL PERFORMANCES Impacts of emissions from biomass combustion

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Component Biomass sources Climate, environmental and health impactHeavy metals All biomass fuels contain

heavy metals to some degree, which will remain in the ash or evaporate

Health: Accumulate in the food chain. Some are toxic and some have carcinogenic effects

Ground levelozone (O3)

Secondary combustion product from atmospheric reactions, including CO, CH4, NMVOC and NOX

Climate and environment: Direct GHG.Vegetation damage. Smog formation.Material damage. Health: Indirect effect through ozone depletion in the stratosphere. Negative effect on the human respiratory system, asthmaticeffect

Hydrogen Chloride (HCl)

Minor combustion product from all biomass fuels containing chlorine

Environment: Acid precipitation. Vegetation damage. Corrosion and material damage. Health: Negative effect on the human respiratory system. Toxic

Dioxins and FuransPCDD/PCDF

Small amounts may be emitted as a result of reactions including carbon, chlorine, and oxygen in the presence of catalysts (Cu)

Health: Highly toxic. Liver damage. Central nervous system damage. Reduced immunity defense. Accumulate in the food chain

Page 27: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

ENVIRONMENTAL PERFORMANCES Carbon emissions

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Technology CO2 Emissions (Tonnes per GWh)Fuel

ExtractionConstruction Operation Total

Coal-fired 1 1 962 964AFBC* 1 1 961 963 IGCC** 1 1 748 751Oil-fired - - 726 726Gas-fired - - 484 484Geothermal <1 1 56 57Small hydro N/A 10 N/A 10Nuclear ~2 1 5 8Wind N/A 7 N/A 7Photovoltaic N/A 5 N/A 5Large hydro N/A 4 N/A 4Solar thermal N/A 3 N/A 3Wood -1509 3 1346 -160

Page 28: Overview of Technologies for Converting  Waste Agricultural Biomass into Energy

TECHNOLOGY SELECTION Analysis of the Options

SAT Methodology

Level of use

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RESOURCE

TECHNOLOGY

APPLICATION

Research Pilot Demonstration Commercial

GasificationPyrolysis

Biofuel applicationsBio-chemicals

Household energyBriquetting

Carbonization Combustion

Anaerobic Digestion