Transcript Carbon sequestration by means of Ocean Iron Fertilization

RENEWABLE / ALTERNATIVE / SUSTAINABLE ENERGY : ANALYZING THE OPTIONS
Carbon Sequestration
By means of
Ocean Iron Fertilization
Igal Levine, Alon Henson and Yotam Asscher
June 2010
What is Ocean Iron Fertilization?
Could this be a solution ?
Introduction
Carbon sequestration by means of Ocean Iron Fertilization
1.
Perform a CO2 emissions analysis to Ocean Iron
Fertilization (OIF).
2.
Examine the global potential of Ocean Iron
Fertilization
Introduction
Carbon sequestration by means of Ocean Iron Fertilization
Methodology
Closing the
loop
Raw
Materials
Life Cycle
Analysis
Product use
Manufacture
Distribution
Introduction
Carbon sequestration by means of Ocean Iron Fertilization
Iron Life cycle scheme
Ore
Extraction
CO2
Removal
Iron
Fertilization
Pretreatment
Transport
CO2 Analysis
Carbon sequestration by means of Ocean Iron Fertilization
How much Iron is needed per Carbon?
Fe/C molar ratio
Value used in LCA : 4x10-4 , From the subantartic ocean
Directions Mesoscale Iron Enrichment Experiments 1993-2005: Synthesis and Future P. W. Boyd, et al. Science 315, 612 (2007)
Introduction
Carbon sequestration by means of Ocean Iron Fertilization
Iron ore production
Value used in LCA : 10 kg CO2e/ton
JOURNAL OF CLEANER PRODUCTION VOLUME 18, ISSUE 3, FEBRUARY 2010, PAGES 266-274
CO2 Analysis
Carbon sequestration by means of Ocean Iron Fertilization
Pretreatment - From Iron ore to Iron sulphate
Reaction
Fe2O3 + 2H2SO4 → 2FeSO4 + 2H2 + 1.5O2
FeO + H2SO4 → FeSO4 + H2 + 0.5O2
Fe3O4 + 3H2SO4 → 3FeSO4 + 3H2 + 2O2
Average specific
energy [kJ/ton]
CO2 e [kg]
4.2x106
1.3x103
Overall reaction energy
[kJ/mol]
Specific Energy
[kJ/ton]
297.7
5.3x106
157.6
2.8x106
258.4
4.6x106
But what about the process?
CRC handbook chapter 5 section 12
CO2 Analysis
Carbon sequestration by means of Ocean Iron Fertilization
Modeling the process
Fe2O3 + 4SiO2 + 11C → 2FeSi2 + 11CO
Overall reaction energy
1.6x103 [kJ/mole]
Specific Energy
2.9x107 [kJ/ton]
CO2 e [kg]
8.7x103
Overall ferrosilicon production
2.2x104 [kg CO2 e]
Reaction / Production
40%
Overall pretreatment
1.3x103x2.5=3.2x103 [kg CO2 e]
Int J Life Cycle Assess (2009) 14:480–489
CO2 Analysis
Carbon sequestration by means of Ocean Iron Fertilization
9
Transportation
Value used in this LCA : 36g CO2e/ton-km
CO2 Analysis
Carbon sequestration by means of Ocean Iron Fertilization
Transportation
Transportation distance : 10,000km
CO2 Analysis
Carbon sequestration by means of Ocean Iron Fertilization
CO2 Balance
Quantity of Iron
1 ton
Transportation distance
10,000 km
Production
Transportation
Pretreatment
10 [kg CO2]
3.6x102 [kg CO2]
3.2x103 [kg CO2]
Total
3.6x103 [kg CO2]
CO2 Sequestered [kg]
2x106
CO2 sequestered / CO2 emitted ~ 103
CO2 Analysis
Carbon sequestration by means of Ocean Iron Fertilization
Global Potential of Ocean Iron Fertilization
1. Upper Limit of ocean carbon uptake
2. Phosphate and Iron demand for ocean iron
fertilization
Global potential
Carbon sequestration by means of Ocean Iron Fertilization
What will be the best location for Ocean Iron Fertilization?
GLOBAL BIOGEOCHEMICAL CYCLES, VOL. 14, NO. 3, PAGES 957-977, SEPTEMBER 2000
Global potential
Carbon sequestration by means of Ocean Iron Fertilization
How much carbon can we sequester up to 2100?
Phosphorous net annual production in Southern oceans
6.6x1011 mole of Phosphorous
Phosphorous available until 2100 assuming linear correlation
6.0x1013 moles of Phosphorous
Redfield molar ratio for carbon : phosphorous
1 Carbon : 106 Phosphorous
Carbon sequestration until 2100
6x1015 moles of carbon
Global potential
Carbon sequestration by means of Ocean Iron Fertilization
How much Iron will we need?
Global maximum uptake of CO2 – theoretical model
(Caldeira 2010)
6x1015 moles of CO2
Amount of Iron needed for maximum theoretical uptake
1.4x108 ton
Global amount of Iron production per year (2007)
1.1x109 ton
Global amount of Iron production until 2100
1.0x1011 ton
Iron needed / Iron production
0.1%
CO2 emitted due to fertilization process
5.1x1011 Kg = 1.2x1013 moles of CO2
Journal of Climatic Change “Can ocean iron fertilization mitigate ocean acidification?” L. Cao, K. Caldeira 2010
Global potential
Carbon sequestration by means of Ocean Iron Fertilization
A big improvement?
Results (year 2100)
model
Atm.
CO2
[ppm]
Atm. Change in
carbon storage
Ocean. Change in
carbon storage
[PgC]
[PgC]
Pre-industrial
280.0
0
0
A2_emis
965.3
1457.1
540.9
A2_emis+OIF
832.6
1175.8
822.2
change in atmosphere and/or ocean carbon storage is relative to the preindustrial values
2.8x1017g = 6x1015
moles of CO2
Journal of Climatic Change “Can ocean iron fertilization mitigate ocean acidification?” L. Cao, K. Caldeira 2010
Global potential
Carbon sequestration by means of Ocean Iron Fertilization
Summary
1. LCA of iron fertilization shows that carbon emitted in the process of
fertilization is ~1000 times less than the carbon sequestered by
fertilization between the years 2008-2100 (Caldeira).
2. The estimates done in the LCA were done using the most stringent
Fe/C uptake ratio, hence in terms of CO2 emissions, the process is
favorable.
3. Further research should be done in order to asses the ecological
impact of iron fertilization in the southern ocean.
(Acidification of deep ocean, Nutrient depletion)
3. OIF reduces atmospheric concentration but does not eliminate the
CO2 problem.
Summary
Carbon sequestration by means of Ocean Iron Fertilization
The end…
Acknowledgments
Prof. David Cahen
Dr. Ron Milo
Alon Shepon
Prof. Uri Pick
Dr. Hezi Gildor
Summary
Questions?
Carbon sequestration by means of Ocean Iron Fertilization