2. Overview
• Biomass and its potential for power
g
generation
• Types of biomass
• T h l
Technology for biomass utilization
f bi ili i
– Biomass conversion technologies
– Biomass gasification
– Engines
3. Climate change
Climate change
• Increase in green house gases emission possibly
leading to global warming and climate change
• Fossil fuels play a very important role in the
economies and lifestyles of people throughout
economies and lifestyles of people throughout
the world
• C th l b l
Can the global economy can be powered in ways
b di
that might have less impact on the environment
because they discharge less carbon dioxide?
b h di h l b di id ?
4. How do biofuels reduce green house
gas emissions?
• Bi
Biomass fuels as well as fossil fuels release carbon dioxide to the
f l ll f il f l l b di id t th
atmosphere when burnt.
• Fossil fuels produce CO2 from carbon which was stored in the earth
over several millions of years
l illi f
• if the biomass is produced sustainably, the growing trees and other
plants remove carbon dioxide from the atmosphere during
photosynthesis and store the carbon in plant structures.
h t th i d t th b i l t t t
• When the biomass is burned, the carbon released back to the
atmosphere will be recycled into the next generation of growing
plants.
l
• When biomass is used as fuel instead of fossil fuel, the carbon
contained in the fossil fuels remain in ground instead of being
released to the atmosphere.
• Fast‐growing trees can recycle carbon rapidly and will displace
fossil‐fuel use with every cycle.
5. Can CO2 growth rate be arrested by
afforestation alone?
• Forests that are not harvested does not continue
h h dd i
to accumulate carbon indefinitely.
• In mature forests photosynthesis nearly balances
the carbon that is released to the atmosphere by
respiration, oxidation of dead organic matter, and
fires and pests.
• If fossil fuels are to be used continuously, then
ever expanding afforestation would be needed to
prevent increasing levels of carbon dioxide in the
atmosphere.
6. What is biomass?
What is biomass?
• Biomass is any residue from plant or animal
i i id f l i l
matter.
• Sources
– Agricultural residues
– Energy plantation
– Biofuels
– Wastes from Argo industries
– Domestic and urban wastes
• Many of these will generate CO2 and other green
house gases even if left unutilized.
g
7. Types of biomass
Types of biomass
Biomass Components
– Sugars
– Oils
– Starch
– Cellulose
– Hemi‐cellulose
– Lignin
Leafy biomass – Mostly cellulosic + some starch +
f b l ll l h
some lignin
Woody biomass – 50 % cellulose + 25 % hemi‐
Woody biomass 50 % cellulose + 25 % hemi
cellulose + 25 % lignin
Seeds Starch and/or oils
Seeds – Starch and/or oils
8. Sources of biomass
Sources of biomass
• Kitchen wastes – fruits/vegetables/some starchy stuff
• Market wastes – similar to the above ‐ Contain large
amount of sugars/starch.
amount of sugars/starch
• Sewage – contains starch/more complex biodegradable
matter
• Urban solid wastes – contains some biodegradable
b lid i bi d d bl
matter and a larger amount of matter that can be
converted only by thermo chemical means (lignaceous,
plastics, etc)
l ti t )
• Agricultural wastes – contains a large amount of
matter that can be converted by thermo‐chemical
y
means
• Plantation residues – same as above
• Energy plantation/ wild growth
Energy plantation/ wild growth
9. Energy plantation
Energy plantation
• F t
Fast‐growing trees can recycle carbon rapidly and will
i t l b idl d ill
displace fossil‐fuel use with every cycle.
• There plantations, either managed or not managed,
p , g g ,
existing in India.
• Eucalyptus and casuarinas plantations for fuel wood and
paper and pulp industries are examples of managed
paper and pulp industries are examples of managed
plantations.
• Prosopis Juliflora is being utilized as biomass fuel in several
p g
parts of the country — an example of utilization of wild
growth.
• Bamboo under intensive cultivation can generate biomass
Bamboo, under intensive cultivation, can generate biomass
at a rate of more then 100 ton/ha/yr (Growmore Biotech,
Hosur, Tamil Nadu)
10. Availability of Bioamass in India
Availability of Bioamass in India
• Agricultural residues
i l l id
– Total Area: 143 M ha
– Crop production: 500 M T/ yr
– Residue generation: > 500 MT/ yr
g /y
– Surplus residues: 150 MT /yr
– Power potential: 20000 MW
Power potential: 20000 MW
• Other residues
–FForest residues
t id
– Waste land
11. National Biomass Resource Atlas of India
National Biomass Resource Atlas of India
• A l t i tl
An electronic atlas of India for excess biomass to enable
f I di f bi t bl
obtain local power potential
• Partners:
– Ministry of Agriculture (MoA, GOI) – their data base
– RRSSC (Regional Remote Sensing Centers of ISRO)
RRSSC (Regional Remote Sensing Centers of ISRO)
– Consultants and Apex Institutions appointed by MNRE, GOI
– Other institutions like Coir Board, Agricultural Universities, etc
•IISc – National Focal Point for acquiring assessing and processing
National Focal Point for acquiring, assessing and processing
the data from various sources into digital maps on a GIS format to
be used by industrialists, planners and others
12. Remote Sensing
Data
Taluka and
l k d (ISRO-RRSSC)
District Level MOA, Other
Project Partners Gov. Sources
Surveys
The Scheme
of the Work
Statistical NFP,
Database CGPL, IISc
Census, Other
Boards &
Discussion, Ageences
g
Interactive
Meetings with AIs,
Consultants
GIS B
Based
d
Interactive
Package
13. The Key-Aspects of the Work:
Key- Work:
1. The Statistical Data Analysis and Compilation.
y Compilation.
p
2. Graphical vectorisation for the base GIS layers.
layers.
3. Integration of remote sensing d t i t GIS l
3 I t ti f t i data into layers.
layers.
4. Strategies for crop identification – use of NDVI
(Vegetation Index) and AI (Artificial Intelligence)
techniques.
techniques.
5. Create a strategy for stand alone use for a variety of
users
6. Provide options for dynamic queries with graphical or
tabular outputs
14. The Main Features of the Package
g
• Statistical Data on crops, residues and estimate of surplus
residues taking account of the socially essential usage are
embedded as dynamic data.
data.
• About 40 crops all over the country, several of them having
p y, g
multiple residues are accounted for.
for.
• In a quick summary, 540 million tons/year of residue
leading to an excess of 120 to 140 million tons/year with
power potential of 15,000±1000 MWe is estimated having a
15,000±
scope of distributed generation in 1–6 MWe range.
range.
• Users can obtain the data from the Atlas, the nature of
,
crops, residues, power potential of each district over the
country and also the estimate for the talukas.
talukas.
17. Main Achievements of the Project
• A method of seamless integration of the data from all
essential sources to generate a single electronic document to
essential sources to generate a single electronic document to
be used as biomass resource atlas is developed and
demonstrated.
• Methods for Crop Identification from land‐use data and
remote sensing data for deriving coefficients from survey data
and obtaining assessment of biomass resource spatially are
and obtaining assessment of biomass resource spatially are
developed and used.
• The atlas available at http://lab.cgpl.iisc.ernet.in/Atlas/
• Also at MNRE web site
18. Biomass conversion technologies
Biomass conversion technologies
• Efficient utilization of biomass for energy
• Conversion of biomass to suitable forms of
Conversion of biomass to suitable forms of
fuel
• Di
Direct Combustion to generate thermal energy
C b i h l
• Advanced energy conversion devices
gy
19. Technology Routes for Biomass Conversion
Technology Routes for Biomass Conversion
Biomass characteristics are relevant for conversion
Biomass characteristics are relevant for conversion
• Biomethanation – Biogas
• Gasification Producer gas
Gasification ‐ Producer gas
• Direct combustion
• Liquid Fuels – Non edible oil from trees
Liquid Fuels – Non‐edible oil from trees
Alcohols from sugarcane and biomass
Pyrolitic oil through fast pyrolisis
oil through fast pyrolisis.
Liquid fuels through FT synthesis from PG
• Reciprocating engines and gas turbines with
Reciprocating engines and gas turbines with
liquid fuels, biogas and producer gas
20. Biomethanation
•Sugars + starch easily digested by bacteria (without or
with air)
• Vegetable and leafy wastes digested by bacteria
even though not so completely or easily (time
requirement) again, without or with air.
•Woody wastes difficult to be digested by bacteria
• Lignin requires fungi for digestion
21. Biomethanation route is well known for cattle dung and both China
a d d a a e a y a ge u be o p a ts o do est c a d
and India have vary large number of plants for domestic and
community applications, The design is simple - a feed system and
a extraction system – hydraulic residence time of 30 to 40 days at
ambient temperature. This functions well at tropical conditions with
liquid temperatures ~ 25 to 35 C
C.
Biomethanation plants for liquid residues, such as sewage and agro-
industrial effluents are well established
At lower temperatures, performance goes down.
High rate Biomethanation techniques (35 and 55 C operations) can
improve the performance These have not been attempted with
performance.
bovine dung since the market cannot sustain the capital investment
costs.
In the above cases the solids content is about 10 %.
Other processes with lower content of water is also available.
22. • 1 kg of solids with 4 to 9 times the water will produce
about 50 to 120 g (30 to 70 liters) of gas.
• The composition of the gas is: 50 to 55 % Methane, ~ 1000
to 5000 ppm Hydrogen sulfide and the remaining amount
~ 47 % carbondioxide
• For distillery effluents one uses anaerobic digestion
technique to reduce the BOD/COD of the effluent. These
q /
plants use generally high rate biomethanation processes.
• The composition of the gas is 60 to 65 % Methane, 2 to 5
%H d
Hydrogen sulfide and remaining ~ 33 % CO2.
lfid d i i
• The gas has a calorific value of 18 to 22 MJ/m3.
• A number of institutions are involved in research in this
area (eg. Agharkar Research Institute, IISc
23. Liquid Fuels from biomass
Liquid Fuels from biomass
• N
Non-edible oil f
dibl il from t trees
• Alcohols from sugarcane and other biomass containing
largely cellulose/ sugar
• Pyrolitic oil through thermal degradation process
• A large number of trees store in their seeds, starch or
oils. Some of these are non-edible. They can be used for
power generation.
• Th
These are R Rape seed oil, J
d il Jatropha, J j b M h
h Jojoba, Mohua, S l
Sal,
Pongemia, Cashew, Neem, Anderouba, Soumarouba.
• Indian government in collaboration with public sector
government,
undertaking and private partners, is taking initiative in
increasing the bio-oil production.
24. Biomass utilization for energy
(Thermal root)
B iom ass U tilisation
for Energy
Therm al Pow er Am b. Pr.
High Pr.
Boiler Steam turbine Gasifier
R/c engine Gas turbine
Mecha nica l Electricity
W a ter pum ping
Stoves Large Gasifier
Com bustors
Dom estic Industrial Gas Burner
25. Thermochemical conversion Technologies
Solids
(Combustion)
• Use combustion process – on a grate/ fluidized bed –
to provide hot gases to be used to raise high pressure
steam and then extract power from steam turbine –
generator route (standard)
(standard).
• The calorific value of dry biomass is 16 MJ/kg.
• The air-to-biomass ratio at stoichiometry is about 6.
air to biomass
(note for reference, the calorific value of fossil fuels is
about 42 MJ/kg and the stoichiometric air-to-fuel ratio
is 15)
• Several projects have been implemented with mixed
results
– L k of mechanism f collection and di t ib ti
Lack f h i for ll ti d distribution of bi
f biomass
residues
• Cost of energy critically depends on the biomass price.
26. Cogeneration potential in India
Cogeneration potential in India
India has several industries which has potential
g ( p )
for cogeneration. (ref: Teri report)
Industry Cogeneration potential (MW)
Sugar 5000
Paper 600
Cotton 500
Non‐agro‐industries 1400
Sugar industry is one large potential for
cogeneration.
27. Cogeneration in Sugar Industries in
India
• Sugar industry is one of the industries having
g p g
large potential for cogeneration.
• The fuel for power generation is generated in‐
house.
house
• The potential for power generation in sugar
industries in India is about 5000 MW
• The achieved potential is about 1000 MW
The achieved potential is about 1000 MW
28. Gasification
• For power levels less than 2 MWe, the cost can be cut down by
using gasification t h l i
i ifi ti technologies and using th gas i reciprocating
d i the in i ti
engines.
• Gasification of solid biomass occurs because of thermo-chemical
reactions at sub-stoichiometric conditions.
• Gas composition: CO = 20 %, H2 = 18 %,CH4 = 2 %, CO2 = 12 %,
H2O = 2 %, Rest =N2
• This gasification process captures between 78 to 82 % of the energy
in Biomass. Every kg of dry biomass generates 2.6 m3 of gas. The
gas has a calorific value of 4.5 to 5 MJ/m3. The stoichiometric air-to-
g
fuel ratio is 1.3 [note: 1 kg biomass needs 6 kg of air for combustion.
This is the same as the above calculation as follows: Biomass
requires 1.8 kg air for gasification. 2.8 kg of gas requires 2.8 times
1.4 kg air = 3.92 kg air – thus the total air required for combustion is
1.8 + 3.92 = 5.72, a value close to 6.0]
29. Gasification – contd.
Gasification contd
• When used in dual fuel mode in diesel engines,
the dry biomass and diesel required are about
0.9 to kg d
0 9 t 1 k and 60 t 75 ml per kWh
to l kWh.
• When used in producer gas engines, the dry
biomass required i about 0 8 t 1 3 k /kWh
bi i d is b t 0.8 to 1.3 kg/kWh.
30. The Gasification Process
The Gasification Process
Biomass when heated looses volatiles leaving fixed
Biomass when heated looses volatiles leaving fixed
carbon (about 20–25 %)
The volatile matter reacts with air providing energy for
p g gy
biomass heating and to raise the temperature of gases
b h d h f
to about 1200–1400°C.
The hot gases thus produced, which contains CO2 and
The hot gases thus produced, which contains CO2 and
H2O react further with the fixed carbon to generate CO
and H2.
These are endothermic reduction reactions and brings
These are endothermic reduction reactions and brings
down the temperature to about 600–700°C.
The IISc open top reactor has a second stage of
oxidation‐reduction process to minimize the tar in the
id ti d ti t i i i th t i th
product gases and to improve the carbon conversion.
31. Work at IISc
Work at IISc
Novel reactor design
N l t d i
Air is drawn from the top and from the air nozzles –
• Uniform distribution Air (~ 50-70%)
Biomass
A
Broader high temperature zone Broader than in Stratific ation (upward
closed-top.
Enough residence time propagation of flame front)
B
A
Air
B
Grate
o Hot gases
1200 - 1400 C o
(700 - 800 C)
• Consistent high quality gas over the turn down ratio
• Varying biomass quality – can accept a variety of agro residues
The ratio of air flow rate from the nozzle to the top depends on the fuel
properties – size, density; the char consumption rate, etc
32. Gas cleaning ‐
Gas cleaning process
• Gas has to be cooled and cleaned for end use application
Gas has to be cooled and cleaned for end use application
T and P levels of 100 ppm and 1000 ppm respectively in the raw gas at 350
T and P levels of 100 ppm and 1000 ppm
– 650°C
650°
– Cooling and cleaning is achieved by using a number of components
– These are cyclones and cooling devices by spraying water in scrubbers
– Further cleaning is achieved using chilled scrubbers
Further cleaning is achieved using chilled scrubbers
With this gas cleaning process it is possible to restrict the
contaminants to ppb levels
contaminants to ppb levels
• Water is the only medium used for cooling and
cleaning process. Water treatment process
cleaning process Water treatment process
enables reusing of water
33. Gasification Elements
Gasification Elements
1 5
4 6
2 3 1
0
8
7 9 11 12
Components
• The reactor
• N
Necessary cooling and cleaning system
li d l i t
- to meet the end use requirements
34. Comparison of steam and gasification
root for electricity generation
Steam Gasification
Elements Boiler, steam turbine
Boiler steam turbine Gasifier, IC engine
Gasifier IC engine
Technology Well established Reasonably matured
Skills required for Low to medium Medium
operation
Installation cost 4 – 4.5 crores/ MWe 5 ‐ 6 crores/ MWe
Efficiency Reasonably high at High efficiency can be
several 100 MW level, achieved at low power
but low at lower power
but low at lower power levels
levels
35. Research on gasification process
Research on gasification process
• Single particle behaviour in various
p
atmospheres
• Behaviour of packed beds
• G ifi modeling
Gasifier d li
• Gas cleaning processes
gp
• Water treatment
36. Research on Gasification process –
Single particle
Reactants : (a) CO2 (b) H 2O (c) air (d) O2
Kinetic and
CO2 diffusion
t b ~ d 1.03
1
0
dependence
CO 2
tc/ρ(s m3/kg)
Kinetic and
H2 O
-1
H 2O diffusion
10
t b ~ d1.2 -1.3
0
dependence
air
t b ~ d 1 .9 air diffusion limited
-2
0
10
O2
T = 1273 K tb ~ d 2
O2 diffusion limited
0
10 -3
1 10
Conversion time for char reaction with
d 0 (mm)
1. CO2 is 3-4 times that of H 2O
2. H2O is comparable to air at dp > 8
mm
37. Basic Research packed bed
Basic Research – packed bed
With increase in mass flux the front velocity initially increases and then reduces
‐ This fixes the turn down ratio of the gasification system
‐ Superficial mass flux and ash properties are used as design
parameters
38. Power generation using producer gas
Using R/C engines
Dual – Fuel Engine
80% gas & 20% diesel
Gas Engine
100% gas
39. Research on Engines
Research on Engines
• Basic Research – Experimental & Modeling
• Development of gas carburetion system
p g y
• Reliability tests - Long duration trails
• Collaborative work with Cummins India
– Adaptation of Natural gas engines
– Laboratory trails & Field monitoring
• Collaborative work with engine manufacturers
40. How is PG different from NG in
engine?
• Th air-to-fuel ratio of PG is 1.3:1, whereas for
The i t f l ti f i 131 h f
NG it is 17:1 – this calls for a different carburetor
• PG has higher octane rating, therefore can be used
rating sed
in engines with higher Compression ratio
• The flame speed of PG is higher ~ 20%; calls for
a different ignition timing setting
• The energy density of PG is lower ~ 20%, this
20%
causes de-rating of the engine power
• The flame temperature is lower by about 300 K, K
implies different operating condition in the engine
cylinder and turbocharger
y g
41. Analysis of Producer Gas Engine
y g
Reasons for
de-rating with
PG
Energy density
gy y Sub-optimal –
p
Reactant:Product
R t tP d t
PG < NG Turbocharger
< 12%
by 20 - 23%
Properties of Gaseous Fuel
p
Fuel Fuel Air/Fuel Mixture, Φ, Limit SL (Limit), SL Peak Product/
+ LCV, @ (Φ =1) MJ/kg cm/s Φ =1, Flame Reactant
Air MJ/kg Lean Rich Lean Rich cm/s Temp, K Mole Ratio
H2 121 34.4
34 4 3.41
3 41 0.01
0 01 7.17
7 17 65 75 270 2400 0.67
0 67
CO 10.2 2.46 2.92 0.34 6.80 12 23 45 2400 0.67
CH4 50.2 17.2 2.76 0.54 1.69 2.5 14 35 2210 1.00
C3H8 46.5 15.6 2.80 0.52 2.26 - - 44 2250 1.17
C4H10 45.5 15.4 2.77 0.59 2.63 - - 44 2250 1.20
PG 5.00 1.35 2.12 0.47 1.60 10.3 12 50 1800 0.87
a b c d
42. Typical Applications
Application Requirement
Rural Electrification •Short duration ~ 4 – 6 hour/day, low PLF
•High plant availability > 95%
i h l il bili
•Load reasonably constant
Industrial - Captive
p •Continuous operation – 24 hr x 6/7 day a week
p y
•High plant availability > 90%
•Large load fluctuations
Independent Power •Continuous operation – 24 hr x 7 day a week
Producer – grid lined •High plant availability > 90%
•Ability to take fluctuations in the grid (in India)
y g ( )
Producer gas engine can meet each of the above applications
43. Emission
1 Load ~ 80-90% 2
0.8 1.6
CO
NO, g/MJ
CO, g/MJ
0.6 1.2
g
g
0.4 NO
0.8
0.2 0.4
0 0
0 4 8 12 16 20 24
Time Cycle, Hour
47. Some Case Studies
Some Case Studies
• Gasification technology is commercially deployed
in India with mixed performance in the field
• A few manufacturers in India provides gasifiers
for industrial use
for industrial use
• While it has been proved in the field on
commercial operations, optimal use still to be
i l ti ti l till t b
achieved
• Biomass collection and distribution still to be
p
developed
48. Grid connected 100 kWe biomass
gasification power plant in Karnataka
• 08
0.8 MWe of gasification power plant connected
f ifi i l d
to the grid in Karnataka as a part of Biomass
Energy for Rural India a program under
E f R l I di d
GoK/UNDP/MNRE
• The project is being implemented in five village
clusters with a total of 26 villages in the state of
Karnataka, India
K k I di
• The project had six gasifier based power plants
composed of two 100 kWe and one 200 kWe in
different villages
52. Heat treatment –Tahafet, Hosur
Heat treatment Tahafet Hosur
• Eight furnaces and temperatures vary from
600 C to 1000 C
• Each furnace is fitted with two burners having
air to fuel ratio control and also a PID
air to fuel ratio control and also a PID
controller to oversee the operations. The
industry operates on three shifts for about 6
h hf f b
days in a week
• Typical LDO consumption per day = 1500‐2000
53. Heat treatment .. contd
Heat treatment contd
• 300 k /h
300‐kg/hr capacity installed
it i t ll d
• All the eight furnaces are
connected to the gasifier
connected to the gasifier
using WESMAN make dual‐
fuel burner. The temperatures
in the individual furnaces are
i th i di id l f
maintained independently.
• With 8 furnaces connected
With 8 furnaces connected
presently to gasifier saving is
about 2000 litres/day.
• Average fuel consumed per
day 5.2 ton of coconut shells,
woodchips
• Total operating hours ~35000
55. Performance using briquetted fuels
Performance using briquetted fuels
• Agro residue briquettes tested at 20 % ash
– Same gasification system can handle 1 to 20 % ash
g y
– Gas quality acceptable for engine
– SFC consumption similar on ash free basis
SFC consumption similar on ash free basis
• Fuel quality requirement
– Thermal stability of the briquette important
– Density and binding an important property
Density and binding an important property
56. Future Directions and possible areas of
cooperation
• Fuel cells for increased efficiency
l ll f i d ffi i
– High temperature fuel cells operating directly on
producer gas.
d
• Liquid fuel generation (FT process) for generation
transportation fuels.
i f l
– Work in progress at IISc and IIT Guahati
• Hydrogen from biomass
– Generation of hydrogen rich syngas and hydrogen
separation.
– Work in progress at IISc
