Overview of talk

1. CO2 balances and mitigation costs of CHP systems with CO2 capture in pulp and paper millsKenneth MöllerstenInternational Institute for Applied Systems Analysis (IIASA)

2. Overview of talk Background: - Opportunities for cost-effective CO2 reductions through energy measures in Swedish pulp and paper mills CO2 capture and storage: - How far can pulp and paper mills go in the direction of low-CO2 production? - Economic evaluation of CO2 capture and storage

3. Reduction options: • Emissions from the mills • Decreased energy consumption • Fuel switch • CO2 capture and storage (CCS) • Emissions from marginal electricity production reduced in case of • Decreased on-site electricity consumption • Increased on-site electricity production

4. Reduction potential in SwedenAssuming marginal electricity from natural gas-fired CC power plants Measure Potential % of 1990 (MtCO /yr) Swedish 2 emissions Conventional technologies 3 5 % - Improved performance of steam power cycles - Electricity conservation - Substitution of oil for biofuels Black liquor gasification 2.5 5 % CO2 capture and storage 10 16% ~90 % of carbon in black liquor andbark 15.5 26 % Source: Möllersten K, (2002). Opportunities for CO2 reductions and CO2-lean energy systems in pulp and paper mills

5. Biomass energy with CO2 capture and storage CO2 CO2 Biofuels Energy products (Forest Products) CO2 to underground storage

6. Marginal electricity from coal-fired power plants Marginal electricity from NGCC COR [US$/tCO2] COR [US$/tCO2] Capital valuation: Industrial Societal K 200 200 L L C F 100 100 K D G L L C M M F D K G M M F K G F 8 4 E E A A G 4 C 8 E D Reduction potential [MtCO2/y] C A E Reduction potential [MtCO2/y] D A A:Reduced process steam requirements: Utilisation of surplus steam for additional power production, C:Electricity conservation: TMP, D:Electricity conservation: Pumps, fans, mixers, and other motor systems, E:Increased utilisation of installed steam turbine capacity, F:Adjusting steam turbine capacity to present process steam demand, G:Wood powder-fired superheater after Tomlinson boiler, K:Electricity production from waste heat, L:Conversion of lime kilns to biofuels, M:Substituting fuel oil for biofuels in steam production. Reduction potential and cost of reduction - conventional technologies

7. Capital valuation: * Industrial + Societal COR [US$/tCO2] Marginal electricity from coal-fired power plants J * 100 N * I * H + J * + N + I H + Reduction potential [MtCO2/yr] 10 2 6 COR [US$/tCO2] Marginal electricity from NGCC H * 100 I * * N * J H + + N I + + J Reduction potential [MtCO2/yr] 10 6 2 H:Black liquor integrated gasification combined cycle, I: Black liquor integrated gasification combined cycle with pre-combustion CO2 capture and sequestration, J: Black liquor integrated gasification with pre-combustion CO2 capture and sequestration, methanol production and combined cycle, N:Recovery and bark boilers with flue gas CO2 capture and sequestration. Reduction potential and cost of reduction - emerging technologies

8. CO2 capture in pulp and paper mills Focus: • Energy efficiency of technologies • CO2 balance • Capture cost, transportation and storage cost

9. CO2 capture technologies Post-combustion capture Air Energy Flue gas Black liquor Biomass Boiler and turbines CO2 capture CO2-lean flue gas CO2 Heat & electricity Compressor

10. CO2 capture technologies Pre-combustion capture ASU Energy Black liquor Biomass O2 H2 or H2 and CO CC CO2 Capture CO shift (optional) Pressurised gasifier Flue gas Heat & electricity CO2 Compressor CO-shift: CO + H2Ovap → CO2 + H2 +44.5 MJ/Molco

11. Storage options Underground geological formations • Depleated gas & oil wells • Deep aquifers • Deep coal beds • Enhanced oil recovery The deep oceans

12. Studied mills • “Ecocyclic pulp mill” reference mill (STFI, 2000) • 1550 t pulp/day • Late 1990’s state-of-the-art technologies in all departments • Market pulp mill – “MPM” • Process steam is 24% lower than the 1994 Swedish average • Integrated pulp & paper mill – “IPPM” • Process steam is 5% lower than the 1994 Swedish average • Same pulp wood input. IPPM has higher heat and electricity demand

13. System for detailed study • recovery boiler case Simulations with Aspen+

14. System for detailed study - gasification case

15. Performance MPM

16. Performance IPPM

17. CO2 captured and stored (tCO2/ADt) Net electricity export (MWh/ADt) CO2 emissions (tCO2/ADt) Market pulp mill 1.5 0.5 (ref. case 1.0) -1.3 Integrated mill 2.2 0.5 (ref. case 0.5) -2.2 “Global” CO2 emissions compared to reference (NGCC marginal power production) Conclusion: In addition to pulp and paper, the mills could potentially • Export electricity, AND • Remove substantial amounts of CO2 from the atmosphere on a net basis

18. Economic evaluation Cost of CO2 capture and storage (USD/tCO2)= Annual incremental cost / Annually captured CO2 Where: Annual incremental cost = + Delta capital cost + Delta O&M + Delta electricity * Price electricity + Delta biomass * Price biomass + Cost of CO2 transportation and storage • 11% Discount rate

19. Economic evaluation Estimated capital costs - example: pre-combustion CO2 capture

20. Scale issues in CO2 transportation • Pipeline - results from IEA model: • Tanker ~ 15-20 USD/t CO2

21. Cost of capture and storage: Dependence on technology and transportation distance

22. Conclusions • Evaluated energy efficiency, CO2 balances, and cost-effectiveness of biomass-based CHP systems with CCS in pulp and paper mills • 2. Steep CO2 reductions can be achieved through CCS • 3. Systems based on black liquor and biomass gasification have several advantages: • - energy efficiency • - self-sufficiency in electricity and biomass • - a lower cost of CO2 capture • Last conclusion confirmed by economic assessment using price scenarios for CO2, biomass, and electricity (2020 –2070)