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1
RICE HUSK UTILIZATION IN THE MEKONG, RIVER DELTA, VIETNAM
PHAM THI MAI THAO
Angiang University
The 2nd International Conference on Sustainability Science in Asia
March 2 - 4, 2011, Hanoi, Vietnam
2
Contents
1 – Introduction
2 – Objectives
3 – Scenario Development
4 – Life Cycle GHG assessments
5 – Conclusions
3
Huge amount of rice husks is generated and most of them are illegally
dumped into canals and rivers
Currently, open burning of rice husks has increased causing severe fire
accidents and respiratory diseases
Therefore, if they are utilized as energy source, not only GHG
mitigation but also improvement of local environment can be
achieved
1 Introduction
Problems from rice husk generation
4
2 Objectives
Evaluate LC-GHG emissions of the 18 developed scenarios
The obtained results can answer the following questions:
How much GHG emissions can be mitigated by using rice husk?
Which technology shows higher mitigation potential?
Which stage of the process contributes to the total GHG
emissions?
5
Area: 3.4 thousand km2
Adm. division: 1 city, 1 town, and 9 districts
Population: 2.2 million people
Density: 625 persons per km2
Rural population: 71.75 %
Total agricultural area: 75% of total land area
Rice area: 520 thousand ha (three seasons)
Rice production: 3.10 million t/y
Rice husk generation: 620 thousand t/ySource: Angiang, 2007
VIETNAM
VIETNAM
VIETNAMVIETNAM
3 Scenario development
Study area - Angiang province
6
18 scenarios were developed based on (1) current demand and supply of rice husks and (2) rice husk and rice husk briquette use technologies
S: scenario; B - briquette; a - medium scale (5 MW); b - large scale (30 MW) of power plants
3 Scenario settings
Coal, LPG, fuel wood
National electricity
Diesel oilFue
l rep
lace
men
t
Cooking Brick burningCombustion
(power)Gasification
(power)Pyrolysis
Rice huskBriquette
S1, S1B1, S1B2, S1B3S2a,b, S4a,b,
S2Ba,b, S4Ba,bS3a,b, S5a,b, S6, S7
Steam Gases
Heat Electricity Bio-oil
7
For the rice husk scenarios
For the briquette scenarios
Fuel allocations
Baseline Scenario 1
Scenario 2 (a, b)
Scenario 3 (a, b)
Scenario 4 (a, b)
Scenario 5 (a, b)
Scenario 6
Scenario 7
0
20
40
60
80
100
Perc
enta
ge, %
9
26
65
74
26
9
26
65
9
26
65
100 100
9
26
65
100
CookingBrick makingOpen burningCombustionGasificationPyrolysis
Baseline Scenario 1B1
Scenario 1B2
Scenario 1B3
Scenario 2B (a, b)
Scenario 3
Scenario 4B (a, b)
Scenario 5, 6, 7
0
20
40
60
80
100
Perc
enta
ge, %
9
26
65
80
20
9
26
65
74
26
9
26
65
100
CookingBrick makingCombustionOpen burninga - 5 MW; b – 30 MW
8
4 Life Cycle - GHG emissions
9
(1) COOKING
Cook stove
Combustion
Rice husk
Heat energy
Non-CO2 GHGs
(a)
(d)
Legend(a) - IPCC default value
(b) - Literature review(d) - Calculated taking into account of efficiencies
(b)
Stove production & disposal
Out of boundary
14 Boundary settings and data preparation
Emission replacement: Coal, LPG, fuel-wood combustion
Emission source: Rice husk/briquette combustion
Transportation
Walk, bicycle or wood boat
Out of boundary
Replacement of Coal, LPG, Fuel wood
A B
Total emission reduction, (A-B)
GHG
(d)
10
CombustionPower Plant
Rice husk Transportation
Combustion RH(d)
Legend(a) - IPCC default value(b) - Literature review(c) - Interview data(d) - Calculated data
Boiler
Steam
Turbine/Engine
Emission replacement: National electricity
(a) (b)
Non- CO2 GHGs
Residual Oil
(b)
GHGs(a) (b)
Diesel
(c)
GHGs
(a)(b)
Diesel production
GHGs
Residual oil production
(b)(b)
Construction & Disposal
GHGsOut of boundary
(b)
Plant operation
10%(b) Replacement of National Electricity
GHGs
Electricity(d)
(d)Total
emission reduction
= Emissions - Emissions
Emission source: Transportation, rice husk combustion in power plant, start-up
(2) COMBUSTION POWER PLANT
Construction and disposal emissions are included and discussed in total emission mitigation potential section
14 Boundary settings and data preparation
11
(3) GASIFICATION POWER PLANT
Gasification power plant
Rice husk Transportation
Combustion RH
Legend(a) - IPCC default value(b) - Literature review(c) - Interview data(d) - Calculated data
Gasifer
Gases
Turbine/Engine
Air
14 Boundary settings and data preparation
(b)
Non- CO2
GHGs
Emission replacement: National electricity
(c)
Diesel
(a)
GHGs
(b)
Diesel production
GHGs
(b)
Construction & Disposal
GHGs
Out of boundary(b)
Emission source: Transportation, rice husk gas combustion in power plant
Total emission reduction
= Emissions - Emissions
(d)
(b)
(d)
Replacement of National Electricity
GHGs
Plant operation
Electricity
10%
Construction and disposal emissions are included and discussed in total emission mitigation potential section
12
(4) PYROLYSIS PLANT
(d)
Pyrolysis Plant
Rice husk Transportation
Combustion RH
Legend(a) - IPCC default value(b) - Literature review(c) - Interview data(d) - Calculated data
Reactor
Crude bio-oil
Catalytic reactor
14 Boundary settings and data preparation
Emission replacement: Diesel oil
Diesel
(a)
GHGs
(b)
(b)Catalyst
(b)
Nitrogen gas
(b)Electricity Plant
operation
(d)
(b)
(b)
(b)
Diesel production
Electricity generation
Catalyst production
Nitrogen production
GHGs
(b)Construction & Disposal
GHGs
Out of boundary
(d)
(d)
Replacement
of Diesel
GHGs
Upgraded Bio-oil
Total emission reduction = Emissions - Emissions
Emission source: Transportation, Nitrogen gas and catalyst production, electricity consumption
Construction and disposal emissions are included and discussed in total emission mitigation potential section
13
Bri
qu
ette
p
rod
uct
ion
Nat
ion
al g
rid
ele
ctri
city
p
rod
uct
ion
14 Boundary settings and data preparation
(c)
ElectricityElectricity generation
GHGs
(d)
Out of boundaryMachine production
& disposal
PO
WE
R P
LA
NTAnthra-
cite coal
(b)
Legend(a) - IPCC default value
(b) - Literature review
Diesel
Natural gas
(b)
(b)
(b)
Electricity
Hydro power
37%
8.1%
19.6%
35.3%
(b)
(a)GHGs
(b)
Anthracite coal production
(b)
Diesel oil production
(b)
Natural gas production
(b)
GHGs
Replacement of RH, Coal, LPG, Fuel wood
GHGs
(d)
Rice husk Briquetting machine
Briquette
Legend(c) - Interview data(d) - Calculated data
(d)
Vietnamese elect. Emissions (*)
CO2eq : 0.459 kg/kWh
(*) Calculated based on energy consumption and total generated electricity (2007)
To product 1kg briquette need 1.05 kg rice husk 0.13 kWh electricity
14
24 GHG emissions per 1 kWh electricity
Rice husk combustion power plants: combustion Rice husk gasification power plants: fuel transportation Briquette combustion power plants: briquette production
0.0050.006
0.066
0.032
0.077
0.050
0.000
0.020
0.040
0.060
0.080
0.100
S2a S2Ba S2b S2Bb S3a S3b
Combustion Start-up Transportation Briquette production
GH
Gs
em
iss
ion
, k
gC
O2
eq/k
Wh
0.400
0.500 5 MW 5 MW30 MW 30 MW0.459
Combustion Gasification
National electricity
Main stage contributes to total GHG emissions per 1 kWh electricity
15
34 GHG emission change from baseline
The maximum mitigation potential from S2Bb (0.22 million t/y) accounts for 0.23% of the GHG emissions
in Vietnam (98.6 million t/y) [1]
Total net generated electricity Maximum: 721 GWh/y from S4Bb; Minimum: 198 GWh/y from S2a
It can supply from 17 - 60% of total electricity consumption in Angiang province (1,2000 GWh/y) [2]
[1] (UNDP, 2008); [2] (Angiang Department of Electricity, 2009)
-4.0
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
Cooking Brick making Briquette productionPower generation Bio-oil generation Open burningElectricity replacement Diesel oil replacement Cooking fuel replacementTotal GHG change
S1
S1B
1
S1B
2
S1B
3
S2a
S4a
S4B
aS
2Ba
S2b
S4b
S2B
bS
4Bb
S3a
S5a
S3b
S5b
S6
S7
30 MW5 MW 5 MW 30 MW
Ba
se
lin
e
Inc
rea
se
, 10
5 t/y
De
cre
as
e, 1
05 t
/yCooking Combustion Gasification Pyrolysis
16
All scenarios give GHG emission mitigation potentials, the innovative technologies
show higher mitigation potentials than the conventional uses
5 Conclusions
Among the cooking scenarios: GHG mitigation potentials of rice husk and
briquette are not significantly large
Among power generation scenarios
S2Bb using briquettes in large-scale combustion power plants (30 MW)
keeping current rice husk demand shows the highest GHG emission
mitigation potential
S3b using excess rice husk for small-scale gasification also shows larger
mitigation potential
Among pyrolysis scenarios: S6 using excess rice husk shows larger GHG
emission reduction than the scenario using all rice husk generated (S7)
The effective options for GHG mitigations are to use excess rice husk for large-scale
power generation through combustion or gasification keeping current rice husk
demand
17
On going to construct rice husk power plants financed by
Swedish government
Reuse catfish oil for bio-oil generation
Biogas generation from animal residue and wastewater
treatment’s sludge
6 Projects for developingbioenergy production and utilization in Angiang
18
Thank you very much for your attention!