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Eawag: Das Wasserforschungs-Institut des ETH-Bereichs
Land and water demand of biofuel and implications for food production and
market supply in China
Hong YangSwiss Federal Institute for Aquatic Science and
Technology
2
Questions to answer
- Why is China interested in biofuel?
- How much land and water is needed for biofuel?(land and water footprint of biofuel)
- What are implications of biofuel for China‘s food supply and price?
3
1. Overview
0
50
100
150
200
250
300
1985 1990 1995 2000 2001 2002 2003 2004 2005 2006 2020
quan
titiy
, mill
ion
tons
production of crude oil
total petroleum import
total petroleum export
China‘s petroleum balance, 1980-2006, projection for 2020
By 2020, over 70% of petroleum supply will rely on import.
4
1. Overview
Composition of petroleum balance
1995 2006
Agri.7%
Industry58%
Construction2%
Transport & post18%
Service2%
Domestic4%
others9%
Agri.
Industry
Construction
Transport & post
Service
Domestic
others
Agri.6%
Industry43%
Construction5%
Transport & post31%
others6%Domestic
6%
Service3% Agri.
Industry
Construction
Transport & post
Service
Domestic
others
5
1. Overview
0
5000
10000
15000
20000
25000
30000
35000
40000
1985
1990
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
Nu
mb
er o
f ve
hic
les,
100
0
Other vehicles
Total private vehicles
Numbe of vehicles, 1985-2006
Number of private vehicle increased from 2.5 million to 23 million between 1995-2006. Others only increased by 5 million. On average, there are only 1.8 private vehicles per 100 persons. The potential demand is enormous.
6
0
300000
600000
900000
1200000
1500000
1800000
2004 2005 2006 2007
Eth
an
ol
pro
du
ctio
n (
ton
)
- Bioethanol was in trial in 2002 and a commercial supply became available in 2004. Currently, about 80% of China‘s fuel ethanol uses maize as feedstock.
- Biodiesel production is so far very small compared with bioethanol.
1. Overview
Biofuel development in China, 2004-2007
7
2. Water and land requirement of biofuel (footprint)
where WRB is the water requirement of biofuel in m3/L, d is the density of a certain biofuel in kg/L, C is the feedstock biofuel conversion ratio in kg/kg (the amount of feedstock needed to produce a kilogram of biofuel).
where CWR is the crop water requirement (m3/kg), ET is the seasonal evapotranspiration (m3/ha), and Y is the crop yield (kg/ha). (GIS-based EPIC model)
CWR = ET/Y
WRB = d x C X CWR
8
2. Water and land requirement of biofuel
where LRB is the land requirement of biofuel (m2/L), the constant 10000 is used to convert ha to m2.
Y
CdLRB
10000
Bioethanol: 1000 kg = 1262 litersBiodiesel: 1000 kg = 1136 liters
9
2. Water and land requirement of biofuel
Biofuel
Type
Feedstock Feedstock biofuel
conversion ratio
Crop
yield
Specific
water
demand
Water
footprint of
biofuel
Land
footprint of
biofuel
kg kg-1 (ton/ton) kg ha-1 m3 kg-1 m3 l-1 m2 l-1
Bioethanol Maize 3 5001 0.844 2.01 4.75
Bioethanol Cassava 6 16226 0.555 2.64 2.93
Bioethanol Sugarcane 15 62563 0.124 1.47 1.9
Bioethanol Sugarbeets 14 20196 0.202 2.24 5.49
Bioethanol Sweet potato 10 20968 0.23 1.83 3.78
Biodiesel rapeseeds 3.27 1595 2.02 5.82 18.05
Biodiesel soybeans 5.57 1741 3.203 15.7 28.16
Average water and land footprint of biofuel produced with different feedstock crops
Bioethanol: 1000 kg = 1262 litersBiodiesel: 1000 kg = 1136 liters
10
3. Biofuel development plan and land and water requirement - Projection
- In 2007, the Medium and Long-term Development Plan for Renewable Energy in China was released. The production targets are:
- 2.2 million tons by 2010– Of which, 0.2 million ton biodiesel
- 12 million tons by 2020– Of which, 2 million tons biodiesel
- Biofuel will account for about 15% of the transportation fuel by 2020.
11
3. Projection
Year
Biofuel
(million
ton)
Feedstock
crop
Feedstock
use
(million
ton)
Area for
biofuel
crops
(1000 ha)
% of total
crop area
Total
water
requirem
ent (km3)
Fertilizer
use???
Projected
feedstock
production
(million ton)
2010
Ethanol 2 Maize 6 1112 0.72 5.1 148
Cassava 12 735 0.47 6.7 7
Sugarcane 30 477 0.31 3.7 86
Sugarbeet 28 979 0.63 5.7 8.6
Biodiesel 0.2 Soybean 1.2 686 0.44 3.8 16
Rapeseed 0.66 361 0.23 1.3 13
2020
Ethanol 10 Maize 30 5562 3.59 25.3 170
Cassava 60 3676 2.37 33.3 8
Sugarcane 150 2387 1.54 18.6 99
Sugarbeet 140 4897 3.16 28.3 10
Biodiesel 2 Soybean 12 6857 4.42 38.4 18
Rapeseed 6.6 3607 2.33 13.3 15
Land requirement: 0.84-1.8 million haWater requirement: 5-10.5 km3
Land requirement: 6-12.4 million ha (5-10% of cultivated land) Water requirement: 31.9-71.7 million ha
12
4. Implications of biofuel development for food supply and prices
Trend in maize production, average price and net export (quantity), 2000-2007
-
20
40
60
80
100
120
140
160
2000 2001 2002 2003 2004 2005 2006 2007
Qu
anti
ty,
mil
lio
n t
on
800
900
1000
1100
1200
1300
1400
1500
1600
1700
Do
mes
tic
pri
ce,
RM
B/t
on
Production
Net export
Price
13
4. Implications of biofuel development for food supply and price
- The average commercial rate of maize in China is about 70%. 30% of the production does not leave the farm gate.
- 1% reduction in total production will translate to about 1.43% reduction in supply at the market.
- The current scale of biofuel production consumes about 4% of the total maize production of the country. This could have led to a roughly 6% of reduction in the maize availability at the market for other uses.
Enough to induce a price hike?.
Amplified effects
14
Thank you!
Yang, H., Zhou, Y., Liu, J.G., 2009. Land and water requirements of biofuel and implications for food supply in China. Energy Policy, 37: 1876-1885.
15
3. Energy balance of biofuel
Average energy balance:
NEV = (Ee + Ep)-(Ef + Ec)
- Where NEV is net energy value, - Ee is the energy credit of ethanol, - Ep is the energy credits of co-products, - Ef is the energy input in the production, - Ec is the energy used in ethanol conversion
process. (All the above variables are expressed in GJ/ton).
(Direct energy consumption)
16
3. Energy balance of biofuel
-5.0
-3.0
-1.0
1.0
3.0
5.0
7.0
9.0
11.0
Province
Net
en
erg
y va
lue
(GJ/
ton
)
Net energy value of maize based ethanol production in individual provinces
Source of input data: National farm household survey.