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

Goals Perform a CO2 emissions analysis to Ocean Iron Fertilization (OIF). Examine the global potential of Ocean Iron Fertilization Introduction Carbon sequestration by means of Ocean Iron Fertilization

Methodology Introduction Life Cycle Analysis Raw Materials Manufacture Distribution Product use Closing the loop Life Cycle Analysis Introduction Carbon sequestration by means of Ocean Iron Fertilization

Iron Life cycle scheme CO2 Analysis Ore Extraction Pre-treatment Iron Fertilization Ore Extraction Pre-treatment CO2 Removal Transport CO2 Analysis Carbon sequestration by means of Ocean Iron Fertilization

How much Iron is needed per Carbon? Fe/C molar ratio Green : mixed layer phytoplankton Red : suspended biogenic particles Brown : sinking biogenic particles Blue : remineralization of particles A-E : different regions ML mixed layer 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 CO2 Analysis 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

Overall reaction energy [kJ/mol] Average specific energy [kJ/ton] Pretreatment - From Iron ore to Iron sulphate Reaction Overall reaction energy [kJ/mol] Specific Energy [kJ/ton] Fe2O3 + 2H2SO4 → 2FeSO4 + 2H2 + 1.5O2 297.7 5.3x106 FeO + H2SO4 → FeSO4 + H2 + 0.5O2 157.6 2.8x106 Fe3O4 + 3H2SO4 → 3FeSO4 + 3H2 + 2O2 258.4 4.6x106 Average specific energy [kJ/ton] CO2 e [kg] 4.2x106 1.3x103 But what about the process? CRC handbook chapter 5 section 12 CO2 Analysis Carbon sequestration by means of Ocean Iron Fertilization

Modeling the process CO2 Analysis Fe2O3 + 4SiO2 + 11C → 2FeSi2 + 11CO Overall reaction energy Specific Energy CO2 e [kg] 1.6x103 [kJ/mole] 2.9x107 [kJ/ton] 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 9 Carbon sequestration by means of Ocean Iron Fertilization

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 sequestered / CO2 emitted ~ 103 CO2 Balance Quantity of Iron 1 ton Transportation distance 10,000 km Production Transportation Pretreatment Total 10 [kg CO2] 3.6x102 [kg CO2] 3.2x103 [kg CO2] 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 Upper Limit of ocean carbon uptake 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? Plate 3a shows the magnitude of the seasonal difference for phosphate integrated over the top 100 m of the ocean and multiplied by a C:P ratio of 106. This map represents spring- summer new production 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 Plate 3a shows the magnitude of the seasonal difference for phosphate integrated over the top 100 m of the ocean and multiplied by a C:P ratio of 106. This map represents spring- summer new production 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? Global potential Results (year 2100) model Atm. CO2 [ppm] Atm. Change in carbon storage [PgC] Ocean. Change in carbon storage Pre-industrial 280.0 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 pre-industrial 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 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). 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. 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) OIF reduces atmospheric concentration but does not eliminate the CO2 problem. Summary Carbon sequestration by means of Ocean Iron Fertilization

The end… Questions? Acknowledgments Prof. David Cahen Dr. Ron Milo Alon Shepon Prof. Uri Pick Dr. Hezi Gildor Questions? Summary Carbon sequestration by means of Ocean Iron Fertilization