CO 2 SEQUESTRATION THROUGH EARLY AGE CONCRETE CARBONATION

Transcription

1 CO 2 SEQUESTRATION THROUGH EARLY AGE CONCRETE CARBONATION Sean Monkman, PhD VP Technology Development CarbonCure Technologies Anna Maria XIII Anna Maria, Florida 8 November 2012

2 CEMENT DEMAND IS GROWING 6 G t Cement Other developing countries India Higher than it has ever been, and projected to rise ever higher Perhaps 600% growth from 1990 to China 0 OECD, industrial nations Year Source: WWF/Lafarge 2

3 CEMENT PRODUCTION AND CO 2 EMISSIONS 40% 0.65 t CO 2 60% Specific CO 2 emissions tion Calcinat Clinker 865 kg CO 2e / t Cement 650 kg CO 2e / t 0.25 t additions Co ombustion 1.13 t 075t t 0.75 Raw clinker clinker Material 0.1 t coal Source: adapted from presentation by Kevin Cail 3

4 CARBON CYCLE CO 2 Limestone Cement Fresh Concrete 4

5 OUTLINE Carbonation background Historical perspective The Technology Demonstration data 5

6 OUTLINE Carbonation background Historical perspective The Technology Demonstration data 6

7 CHEMICAL REACTIONS C3S (alite) + 3H + 3Ca 2+ + SiO OH - C2S (belite) + 2H + 2Ca 2+ + SiO OH - CO 2 (g) CO 2 (aq) CO 2 (aq) +HO 2 H 2 CO 3 (aq) H 2 CO 3 (aq) HCO - 3 (aq) + H + HCO (aq) CO 3 (aq) H Cement Dissolution (Ca 2+ Supply) + CO 2 Dissociation (CO -2 3 Supply) = Ca +2 (aq) + CO 3-2 (aq) CaCO 3 (s) Precipitation (CO 2 Storage) ) 7

8 HYDRATION VS CARBONATION Cement CaCO 3 Calcium hydroxide Silicate hydrate Calcium silicate hydrate 8

9 CO 2 INTO CONCRETE IS TRADITIONALLY A PROBLEM Carbon dioxide reaction with a mature concrete microstructure can be associated with durability issues Shrinkage Reduced pore solution ph Carbonation induced corrosion However, process applies CO 2 to fresh concrete rather than mature concrete 9

10 OUTLINE Carbonation background Historical perspective The Technology Demonstration data 10

11 CARBON UTILIZATION BEFORE 11

12 NEW APPROACH Developed after research into carbonation curing at McGill University Goal: achieve the material benefits of carbonation curing Improved strength Reduced absorption Improved resistance to chloride permeability Improved freeze-thaw performance Goal: carbon dioxide absorption into the concrete Closing the loop Permanent CO 2 storage in the concrete product Green positioning in the marketplace Value added 12

13 OUTLINE Carbonation background Historical perspective The Technology Demonstration data 13

14 CARBONATION CURING INTEGRATION Traditional mould design Modified core bar source: 14

15 CARBONATION CURING INTEGRATION Modified core bar Gas delivery system source: 15

16 TECHNOLOGY OFFERINGS Rapid installation with low CAPEX Plug and play Utilizes the existing production setup Same plants Same materials Same practices Realize cost savings and environmental marketing benefits 16

17 OUTLINE Carbonation background Historical perspective The Technology Demonstration data 17

18 15 SEC CARBONATION 30 Control Compress sive Strength (MPa) CO2 +6% +13% +20% 0 5% reduced dbinder mix CO2 15 sec, 75 g hr 7 d 28 d 57 d Test Age 18

19 IMPROVING THE 15 SEC INJECTION TIME 15 sec of gas injection slows down the production cycle. An economically viable process needs to have minimal impact on the business as usual cycle. Must confine the gas injection to the 5-7 seconds that t concrete is in the mould. 19

20 SHAW -CONVENTIONAL MIX AND CURING ive Strength (MPa) Ti Trial l8 Control Mix 81 CO2 Mix 82 CO2 Compress % + 5.1% % % % + 8.0% 0 Mix 81 CO 2 50 g in approximately 6 seconds Mix 82 CO 2 68g in approximately 6 seconds day 7 day 28 day Test Age 20

21 SHAW -REDUCED CURING TEMPERATURE Compress sive Strength (MPa) Mix 61 Control Mix 61 CO2 0 regular mix Curing reduced 10 C CO 2 65 g in approximately 7 seconds day 7 day 28 day Test Age 21

22 SHAW -REDUCED CEMENT CONTENT Compress sive Strength (MPa) Mix 62 Control Mix 62 CO2 0 5% reduced dcement mix Normal curing CO 2 65 g in approximately 7 seconds day 7 day 28 day Test Age 22

23 BASALITE -WATER C COMPENSATION 3500 Basalite Batch 602 (+11% water) (psi) Compressiv ve Strength Control Carbonated +40% +30% 0 3 day 7 day 21 day 28 day Test Age CO 2 50 g in approximately 5 seconds Used 16 block datasets for 21 & 28 days, (conclusions are statistically significant) 23

24 SENSITIVITIES Water content Consistent product look Compaction properties Achieving consistent product mass Keeping perforations clear How much CO 2 is absorbed? 2 24

25 QUICK AND DIRTY KINETICS CO2 Content (% %) R² = Carbonation Time (s) 25

26 THANK YOU CarbonCure Technologies Source: City of Vancouver, Cisco and Pulse Energy 26