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, , projection for 2020 By 2020, over 70% of petroleum supply will rely on import.
4 1.Overview Composition of petroleum balance
5 1. Overview Numbe of vehicles, Number of private vehicle increased from 2.5 million to 23 million between 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 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,
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 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: million ha Water requirement: km3 Land requirement: million ha (5-10% of cultivated land) Water requirement: million ha
12 4. Implications of biofuel development for food supply and prices Trend in maize production, average price and net export (quantity),
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., Land and water requirements of biofuel and implications for food supply in China. Energy Policy, 37:
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.