SCHLEGEL Thomas

11th ILA Congress Potential reduction of CO2 emissions & associated abatement costs in the European Lime industry: 

11th ILA Congress Potential reduction of CO2 emissions & associated abatement costs in the European Lime industry G. FLAMENT, Th SCHLEGEL May 17th, 2006

Content of the presentation: 

Content of the presentation Introduction Reduction through process changes (case studies) Reduction through fuel switch Reduction through carbon capture and sequestration (CCS) Conclusion

Introduction: 

Introduction KEY STATEMENTS CONCERNING THE LIME SECTOR : « Emission reductions are possible by use of more efficient kilns and through improved management of existing kilns, using similar techniques as the cement industry (e.g. precalciners, improved burners, high efficient cooling systems) Emission reductions (5  10% of total emissions) are possible by energy efficiency measures at payback periods of 3 years or less » « Switching to low fossil carbon fuels can further reduce CO2 emissions » « Reduce the consumption of lime in various processes » LHOIST CHALLENGES SERIOUSLY THESE STATEMENTS

Costs of CO2 reduction through process changes: 

Costs of CO2 reduction through process changes Case study nr. 1: adding a preheater to an existing 500 tlime/day long RK Technical parameters : Fuel consumption down : from 7.5 GJ/tlime to 5.7 GJ/tlime Electricity consumption up : + 10 kWh/tlime Maintenance cost up : + 0.50 €/tlime Energy costs : Fuel : 2.5  4.0 €/GJ Electricity : 0.055 €/kWh Financial parameters : Depreciation time for CAPEX : 10 years Discount rate : 9% Inflation rate : 2% Taxation rate on profits : 25  40%

Equilibrium costs of CO2 reduction through major process changes: add a preheater to an existing long RK: 

Equilibrium costs of CO2 reduction through major process changes: add a preheater to an existing long RK DPB = 3 years if CO2 at  80 €/t DPB = 3 years if CO2 at  100 €/t

Costs of CO2 reduction through process changes: 

Costs of CO2 reduction through process changes Case study nr. 2: replacement of an existing 500 tlime/day long RK (Ø stone feed : 230 mm) by a new fine lime PFR kiln (Ø stone feed : 2090 mm) with the same capacity Technical parameters : Fuel consumption down : from 7.5 GJ/tlime to 3.7 GJ/tlime Electricity consumption up : + 15 kWh/tlime Maintenance cost down : - 1.0 €/tlime Stone feed : in principle cost increase as the fraction (220 mm) is not burnt into into lime, but, for the present calculation, cost increase = 0 Energy costs : Identical to those used in the previous case study Financial parameters : Identical to those used in the previous case study

Equilibrium costs of CO2 reduction through major process changes: replace a long RK by a PFR kiln: 

Equilibrium costs of CO2 reduction through major process changes: replace a long RK by a PFR kiln DPB = 3 years if CO2 at  40 €/t DPB = 3 years if CO2 at  60 €/t

Summary – equilibrium costs of CO2 reduction through process changes (at payback time of 3 years): 

Summary – equilibrium costs of CO2 reduction through process changes (at payback time of 3 years)

Potential to reduce CO2 - Process changes: 

Potential to reduce CO2 - Process changes Percentage of lime produced in various types of kilns : Rotary kilns  94% Rotary kilns  25%

EU(25) – Potential to reduce CO2 – Process changes: 

EU(25) – Potential to reduce CO2 – Process changes EXTREME ASSUMPTION : stop all rotary kilns Switch the soft and medium burnt lime production to PFR kilns and maintain the production of hard burnt / sintered products in mix feed shaft kilns THEORETICAL POTENTIAL OF CO2 REDUCTION WITHIN EU(25):  7% of the actual emissions (i.e.  2.2 Mt/year) providing the fuel distribution in the PFR kilns would remain the same as today LIMITS : Massive investments and increased operating costs for a limited improvement  only justified if kCO2 >> 50 €/t Very high costs relative to product price High consumption rate of natural resources since small fraction (f < 20 mm) cannot be burnt into lime

Cost of CO2 reduction through fuel switch: 

Cost of CO2 reduction through fuel switch ANY INCREASE OF THE SPREAD (NATURAL GAS TO SOLID FUEL PRICES) LEADS TO AN INCREASE OF THE CO2 ABATEMENT COSTS

Slide12: 

Potential to reduce CO2 - fuel switch Average CO2 emission factor of the national fuel mix [kg CO2/GJ] :  98  75  60

EU(25) – Potential to reduce CO2 – Fuel switch: 

EU(25) – Potential to reduce CO2 – Fuel switch THEORETICAL POTENTIAL OF CO2 REDUCTION WITHIN EU(25):  7% of the actual emissions (i.e.  2.0 Mt/year) EXTREME ASSUMPTION : replace solid and liquid fuels by natural gas (except for mix feed NSK)

Slide14: 

Potential to reduce CO2 - fuel switch LIMITS : Very high costs (> 80 €/tCO2 at actual natural gas prices) relative to current lime prices (with an increasing trend due to the increasing price of gas), Supply of natural gas is not available everywhere (lime plants are often located in remote areas), Change in product quality (hard burnt lime), Limited availability of biomass, and Strong demand from other sectors for biomass with prices considerably influenced by public tax incentives (e.g. electricity production),

Use of biomass in lime kilns: 

Use of biomass in lime kilns PFR kiln Long RK Preh. RK Single Shaft kilns LIME Modern cement kilns POWER 20% 40% 60% 80% 100% Stand alone biomass fired Old coal fired Advanced Super Critical Pulverised fuel Energy efficiency of various processes Using biomass in shaft kilns to produce lime is a least twice as efficient than using the same biomass for generating power Lobbying on EU and national level should be done to enhance the use of biomass in the most efficient processes and improve the less efficient processes rather than « wasting » the biomass

Typical marginal abatement cost curve (combination of fuel switches and process changes): 

Energy savings Typical marginal abatement cost curve (combination of fuel switches and process changes) The position of the asymptote varies from one company to another depending on the energy mix and the population of kilns Fuel switch At 2003 gas prices Process changes At 2006 gas prices

Reduction through stripping / sequestration: 

Reduction through stripping / sequestration PRINCIPLE : Strip the CO2 from the flue gas of the lime kilns (CCO2 = 15  30%), compress it (at 110 bars), transport it and inject it in depleted oil or gas reservoirs, coal beds, … SELECTED TECHNOLOGY FOR THE SEPARATION : Post-combustion Thermal energy :  4 GJ/tCO2 Power :  180 kWh/tCO2 CO2 removed CO2 avoided

Reduction through stripping / sequestration: 

Reduction through stripping / sequestration COSTS : Separation : ~ 50 € / tCO2 removed or ~ 100 € / tCO2 avoided Transportation (in pipelines) : 0.5  2 €/tCO2/100 km Sequestration : 3  5 €/tCO2 (based on actual publications) LIMITS : High thermal and electrical energy requirements Ecobalance questionable Emerging techniques Infrastructure for transportation / storage does not exist nowadays in Europe Irrealistic costs relative to current lime prices

Conclusion: 

Conclusion THE LIME INDUSTRY IN EUROPE HAS A VERY LIMITED ABILITY TO REDUCE ITS CO2 EMISSIONS (max. : 7  10%) EVEN AT HIGH COSTS (never less than 30 €/tCO2 and up to 100 €/tCO2) as : the process is already largely optimised, the fuel switch is largely influenced by factors that are independant from the lime industry A MORE RADICAL REDUCTION OF CO2 EMISSIONS WOULD ONLY BE POSSIBLE THROUGH STRIPPING / SEQUESTRATION, WHICH IS NOT A PROVEN TECHNIQUE NOWADAYS AND LEADS TO COSTS, THAT ARE ABOVE 100 €/tCO2 AND ARE UNREALISTIC RELATIVE TO THE PRICE OF LIME TODAY THE CO2 DIMENSION WITH ALL ITS UNCERTAINTIES IS FULLY INCLUDED INTO NORMAL BUSINESS DECISION BUT INVESTMENT DECISIONS PURELY DRIVEN BY CO2 REDUCTION ARE NOT ECONOMICALLY JUSTIFIABLE

Appendix: 

Marginal cost of CO2 emission abatement : ratio between the estimated costs of a project aiming at reducing CO2 and the estimated CO2 emission reductions Equilibrium carbon price : CO2 price for which it would be equivalent to buy CO2 on the allowances market or to take internal measures to reduce CO2 emissions with a defined pay-back time Appendix