Facilitating CO 2 capture at a cement plant Dr Dennis R Van Puyvelde Chemeca 2013, Brisbane 29 Sep 2 Oct 2013
Background
Emissions from Cement Production Direct Emissions/ Pyroprocessing Limestone emissions CaCO 3 CaO+CO 2 535 kg CO 2 / t-clinker Fuel emissions C n H m +y O 2 n CO 2 +m/2 H 2 O 175 to 542 kg CO 2 / t-clinker Represents approx. 90% of total emissions for producing cement. Globally, direct emissions are over 2 billion tonnes CO 2 pa Reference: IEAGHG (2008), Kline (2012)
Emissions from Cement Production Indirect Emissions Electricity consumption on site for Conveying Grinding Mixing Bagging Transport emissions
Emissions Reduction Strategies Energy Efficiency More efficient process Reduction in electricity consumption Alternative Fuels Switching to gas and/or biomass Clinker Substitution Slag from steel production Carbon Capture & Storage Oxyfiring Studies underway Can technically be done but requires further research Post combustion Previous studies show this is feasible Demonstration in Norway Possibly 44% of total 56% of reductions Reference: ECRA (2007), ECRA (2012), AkerSolutions (2013)
Emissions Reduction Strategies Contribution of CCS Over 56% of emission reductions Between 450 and 900 Mt CO 2 pa by 2050 CEO for HeidelbergCement Northern Europe: We have a vision that our product in a life-cycle perspective will be carbon neutral by 2030, and we believe that carbon capture from cement production is an important part of and long step toward achieving this vision. Reference: IEA (2012) - Energy Technology Perspectives
Aim To identify opportunities where the waste heat from cement processing may be used to meet the energy requirements for post combustion capture.
Absorber Stripper Post Combustion Capture Process Cleaned Flue Gases CO2 Flue Gases from kiln HX Reboiler Steam Amine based capture Regeneration energy of 4.0 GJ/ t CO 2 at 120 C for monoethaleneamine
Heat Losses from Cement Production Cement Plant Component Author Preheater Kiln Cooler Total Engin et al (2005) 0.71 (315 C) 0.56 (308 C) 0.21 (215 C) 1.48 Radwan (2012) Gahzi (1997) Gardiek (1983) 0.75-1.25 0.2-0.55 0.4-0.65 1.35-2.45 0.74 0.96-1.70 0.87 1.18-2.05
Methodology
Methodology (1)
Methodology (2) Assumptions Base case heat losses based on data by Engin, 2005 Reboiler duty needs to be provided above 120 C A temperature approach of 10 C Only 50% of theoretically recoverable heat is assumed to be available for this process Daily kiln capacity of 3,000 t clinker Regeneration energy for MEA solvent is 4.0 GJ/ t-co 2
Methodology (3) Example (base case) Heat losses of 0.56 GJ/t-clinker and that this heat is available from the kiln wall at 310 C. The Theoretically Recoverable Energy is 310 C 130 C = 0.35 GJ/t-clinker. 310 C 25 C The available heat is 0.177 GJ/t-clinker (50% assumption). The total available heat per day is obtained by multiplying the daily kiln capacity of 3,000 t-clinker per day by the available heat. This equals 531 GJ. The regeneration of solvent is taken as 4 GJ/t-CO 2. Dividing the available heat by the regeneration heat provides an estimate of the amount of CO 2 that can be recovered. this equals 531/4 = 133 t CO 2 per day. In the base case, a world average kiln is considered which produces 0.865 t-co 2 / t-clinker. The direct daily emissions from this kiln are 2,595 t-co 2. The percentage of recoverable CO 2 is then 133/ 2,595 = 5.1% So while the Heat Losses from Kiln to Atmosphere for the base scenario are 0.56 GJ/ t-clinker, only 0.177 GJ/t-clinker (approximate a third) is available for PCC by applying the above conditions. Each scenario is calculated as above but using the specific conditions for that scenario (heat losses, solvent, fuel).
Results
CO 2 captured (tpd) CO 2 captured (% of total produced) Results (1) Heat Losses 500 450 400 350 300 250 200 150 100 50 0 0.56 (kiln only) 1.27 (kiln and precalciner) 1.48 (kiln, precalciner and air cooler) Total Heat Losses from Cement Plant (GJ/t-clinker) 2.00 (greater kiln losses) 20% 18% 16% 14% 12% 10% 8% 6% 4% 2% 0% CO2 captured (tpd) Percent CO2 Captured
CO 2 captured (tpd) CO 2 captured (% of total produced) Results (2) Solvent Performance 600 25% 500 20% 400 15% 300 10% 200 100 5% 0 4 3 2.5 2 1 Regeneration heat of solvent (GJ/t CO 2 ) 0% CO2 captured (tpd) Percent CO2 Captured
CO 2 captured (% of total produced) Results (3) Fuel/ Cement Manufacturing Process 7% 6% 5% 4% 3% 2% 1% 0% Dry kiln (gas fired) Semi dry kiln (gas fired) Dry kiln (coal fired) World average Wet kiln (coal fired) Kiln configuration and fuel used Percent CO2 Captured
Opportunities for the use of Waste Heat
CO 2 captured (tpd) CO 2 captured (% of total produced) Opportunities for the use of Waste Heat Base Case 2000 1800 100% 90% 1600 1400 1200 1000 800 600 400 200 80% 70% 60% 50% 40% 30% 20% 10% 0 Base Dry kiln & gas fired (from 0.865 t-co2/t-clinker down to 0.71) Additional heat losses (from 0.56 up to 2 GJ/clinker) Improved Solvent (from 4 GJ/t-CO2 down to 2.5) Functionalised Ionic Liquids 0% Effect of cumulatative improvements CO2 captured (tpd) Percent CO2 Captured Capture of 133 tpd (5.1% of total emissions)
CO 2 captured (tpd) CO 2 captured (% of total produced) Opportunities for the use of Waste Heat Switch to dry kiln and gas firing 2000 1800 100% 90% 1600 1400 1200 1000 800 600 400 200 80% 70% 60% 50% 40% 30% 20% 10% 0 Base Dry kiln & gas fired (from 0.865 t-co2/t-clinker down to 0.71) Additional heat losses (from 0.56 up to 2 GJ/clinker) Improved Solvent (from 4 GJ/t-CO2 down to 2.5) Functionalised Ionic Liquids 0% Effect of cumulatative improvements CO2 captured (tpd) Percent CO2 Captured Capture of 133 tpd (6.2% of total emissions)
CO 2 captured (tpd) CO 2 captured (% of total produced) Opportunities for the use of Waste Heat Utilise Additional Heat Losses 2000 1800 100% 90% 1600 1400 1200 1000 800 600 400 200 80% 70% 60% 50% 40% 30% 20% 10% 0 Base Dry kiln & gas fired (from 0.865 t-co2/t-clinker down to 0.71) Additional heat losses (from 0.56 up to 2 GJ/clinker) Improved Solvent (from 4 GJ/t-CO2 down to 2.5) Functionalised Ionic Liquids 0% Effect of cumulatative improvements CO2 captured (tpd) Percent CO2 Captured Capture of 474 tpd (22.2% of total emissions)
CO 2 captured (tpd) CO 2 captured (% of total produced) Opportunities for the use of Waste Heat Improve Solvent Performance 2000 1800 100% 90% 1600 1400 1200 1000 800 600 400 200 80% 70% 60% 50% 40% 30% 20% 10% 0 Base Dry kiln & gas fired (from 0.865 t-co2/t-clinker down to 0.71) Additional heat losses (from 0.56 up to 2 GJ/clinker) Improved Solvent (from 4 GJ/t-CO2 down to 2.5) Functionalised Ionic Liquids 0% Effect of cumulatative improvements CO2 captured (tpd) Percent CO2 Captured Capture of 758 tpd (35.5% of total emissions)
CO 2 captured (tpd) CO 2 captured (% of total produced) Opportunities for the use of Waste Heat Next Generation Solvents 2000 1800 100% 90% 1600 1400 1200 1000 800 600 400 200 80% 70% 60% 50% 40% 30% 20% 10% 0 Base Dry kiln & gas fired (from 0.865 t-co2/t-clinker down to 0.71) Additional heat losses (from 0.56 up to 2 GJ/clinker) Improved Solvent (from 4 GJ/t-CO2 down to 2.5) Functionalised Ionic Liquids 0% Effect of cumulatative improvements CO2 captured (tpd) Percent CO2 Captured Capture of 1,895 tpd (89.0% of total emissions)
CO 2 captured (tpd) CO 2 captured (% of total produced) Opportunities for the use of Waste Heat Combined Effects 2000 1800 100% 90% 1600 1400 1200 1000 800 600 400 200 80% 70% 60% 50% 40% 30% 20% 10% 0 Base Dry kiln & gas fired (from 0.865 t-co2/t-clinker down to 0.71) Additional heat losses (from 0.56 up to 2 GJ/clinker) Improved Solvent (from 4 GJ/t-CO2 down to 2.5) Functionalised Ionic Liquids 0% Effect of cumulatative improvements CO2 captured (tpd) Percent CO2 Captured Enough energy to capture from 5.1% to 89.0% of total emissions
Conclusions
Conclusions Deep CO 2 reductions from cement require CCS. Two capture options Oxyfiring Post Combustion Waste heat may be utilised to regenerate solvent Up to 35.5% can be captured now, rising to 89% with next generation capture technology Further work required to develop practical approaches of utilising this heat
Contact dennis.vanpuyvelde@globalccsinstitute.com 0423 024 550