Presentation on theme: "Eawag: Das Wasserforschungs-Institut des ETH-Bereichs Land and water demand of biofuel and implications for food production and market supply in China."— Presentation transcript:
Eawag: Das Wasserforschungs-Institut des ETH-Bereichs Land and water demand of biofuel and implications for food production and market supply in China Hong Yang Swiss 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 Chinas food supply and price?
3 1. Overview Chinas 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
5 1. Overview 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 -Bioethanol was in trial in 2002 and a commercial supply became available in 2004. Currently, about 80% of Chinas 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 m 3 /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 (m 3 /kg), ET is the seasonal evapotranspiration (m 3 /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 (m 2 /L), the constant 10000 is used to convert ha to m 2. Bioethanol: 1000 kg = 1262 liters Biodiesel: 1000 kg = 1136 liters
9 2. Water and land requirement of biofuel Average water and land footprint of biofuel produced with different feedstock crops Bioethanol: 1000 kg = 1262 liters Biodiesel: 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 Land requirement: 0.84-1.8 million ha Water 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
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 Net energy value of maize based ethanol production in individual provinces Source of input data: National farm household survey.