High Efficiency Low Emissions Coal Use: Global challenges and Opportunities. Dr Andrew Minchener OBE General Manager IEA Clean Coal Centre

Transcription

1 High Efficiency Low Emissions Coal Use: Global challenges and Opportunities Dr Andrew Minchener OBE General Manager IEA Clean Coal Centre

2 The IEA Clean Coal Centre We are an international organisation, endorsed by the International Energy Agency. We provide independent, objective information on how to use coal more effectively, efficiently and cleanly, to minimise its environmental impact while providing cost effective energy

3 What does the IEA Clean Coal Centre specifically do? Our output includes: comprehensive assessment reports on all aspects of clean coal technology webinars based primarily on the assessment reports, technical workshops on key clean coal issues, a major Clean Coal Technologies Conference web based dissemination services Increasingly, we are implementing various capacity building activities in developing countries and industrialising nations. These outreach initiatives support knowledge transfer on a wide range of coal related energy and environmental issues, particularly for power generation

4 Examples of the IEACCC outreach activities Focus initially has been on Thailand and China, followed by support to several initiatives in India Specialist assistance to UNEP, US Department of State, UNECE and World Bank/GEF Carried out dissemination and outreach programme in China to support UK FCO Prosperity Fund programme Worked with IEA on another FCO funded capacity building project in SE Asia, to assess options to reduce carbon intensity within the power sector

5 Scope of presentation Projections for global coal use Regional considerations Policy issues, performance standards and financing prospects The way forward for cleaner coal technologies (in terms of carbon emission intensities and non-ghg emissions) HELE and its global importance Current coal power developments and deployment Longer term options Use of coal as a resource to produce premium products CCS/CCUS possibilities

6 Sustainable energy for the future: the energy trilemma Energy security Environment & climate protection Economic competitiveness and equity

7 Rhetoric versus reality? Coal sector faced with unprecedented level of opposition Much of it is irrational, non-scientific based, wrapped in selfserving unsubstantiated rhetoric, but Campaign is well organised and geared to maximum exploitation of the digital media Reality does not resonate with such a vision for the future Coal has to be a part of the global energy mix but it needs to ensure that it can meet the three parts of the energy trilemma Future appears to be positive in Asia, while Africa and parts of the Middle East show promise Expectation is that coal will be used for decades to come in significant quantities with a focus on those non-oecd regions

8 Projection of world coal demand & share of coal in world primary energy demand by scenario (IEA WEO 2015)

9 Coal is important in many regions and can be used effectively in many sectors Asia is focus for the world s energy markets, especially in developing countries. Coal has a far greater market share than gas in the power sector, which will continue. USA has seen decrease in coal use due to impact of shale oil, with associated shale gas production, However, high cost shale oil production raises concerns about economic sustainability, while methane leakage is an as yet unresolved climate issue. European Commission is driving forward a low CO 2 agenda, based on renewables and energy efficiency, plus gas as a back-up. This has cost and security of supply issues, plus gas leakage concerns. New and intended power capacity (Platts 2014) ASIA/USA/EUROPE

10 Projections can be changed Introduction of high efficiency coal power plant will reduce CO2 emissions intensity Subsequent introduction of CCS/CCUS will maintain the advantages of coal while making ever greater reductions in CO2 emissions intensity

11 Coal based aspirations towards lower carbon intensity High Efficiency Low Emissions (HELE) coal technology is available now and being deployed commercially, such as in Germany, India, Japan, Korea, USA and most especially in China Development work is underway to establish advanced HELE systems that will provide a step change improvement to over 50% cycle efficiency for current systems, with corresponding reductions in carbon intensity HELE can be applied now and can readily link with CCS when required Major transformational technology development programmes are underway to further address carbon emission limitations of existing systems

12 HELE clean coal technologies are a key step towards near zero emissions from coal Focus on technologies to reduce both GHG and non-ghg (NOx, SO 2, PM) emissions. Reducing coal consumption (higher steam T&P) Technologies for cleaner coal generation (2) Reducing non-ghg emissions (3) Carbon Capture and Storage (to be added in due course) Turbine Condenser Generator Water Mill Coal Steam Boiler Flue gas Pollutants to be reduced De-NOx SO 2, NOx, Particulate matter Mercury (in due course) EP De-S CO 2 Storage CO 2 CO 2 Capture N 2, H 2 O

13 Near term: What should be the way forward for the coal power sector? Introduce HELE technologies rather than subcritical units Examine all subsystems to see potential for improvement and implement changes where cost effective (as demonstrated on the Waigaoqiao No.3 power plant in China) Step up the case for coal Medium term: Establish advanced USC systems with state of the art non-ghg emissions control (at least two options to consider) Longer term: Take forward options for alternative systems In several cases link in and integrate the coal utilisation process with promising novel and improved CCUS techniques

14 The IEA HELE roadmap Plan for coal power under the IEA 2DS to increase the proportion of high efficiency coal plants built in place of inefficient, polluting units HELE technologies currently include USC, A-USC, and IGCC (in principle), and Average global coal efficiency is currently 35% ~40% world power generation is coal: huge CO 2 savings possible by using HELE technologies Only 50% of coal plant built last year was SC focus need to be to promote use of HELE plant in the developing world and raise average efficiency Adoption of CCS (once proven)will also be less demanding for HELE plant

15 CO2 reduction potential of coal fired power plants through increased efficiency (VGB Powertech 2013) Increasing global average coal plant efficiency by 4 7%pts equates to 15-20% reduction in coal CO 2 emissions, or ~1 2 Gt globally New technologies can further raise the efficiency ceiling Upgrades will be required for existing plant

16 IEA CCC study on potential HELE impacts in Asia Projected increase in coal power capacity Chart 1: Coal power in 10 Asian economies by region and technology (GWe) Projected CO 2 emissions reductions from subcritical to USC Chart 2: Annual reduction in CO2 emissions from new coal power due to use of HELE in place of subcritical technology (MtCO2) 0 All countries, current & China planned current & planned India current & Other planned East Asia current & planned Subcritical Supercritical Ultrasupercritical 0 All ten countries China India Other East Asia Emmissions if all new plant was subcritical Emissions with technology mix currently planned Emissions if all new plant is ultrasupercritical

17 Fundamentals of coal-fired power generation have remained unchanged for some time but. Rankine cycle pulverised coal fired power plant

18 Increasing the flexibility of coal-fired power plants Electricity output from renewable energy plants fluctuates, so fossil-fired power plants are having to operate more flexibly This presents considerable challenges, both now and for the future

19 Impact on power production due to unreliability of renewables August 2014 (MHPS 2014)

20 Increasing the flexibility of coal-fired power plants Electricity output from renewable energy plants fluctuates, so fossil-fired power plants are having to operate more flexibly This presents considerable challenges, both now and for the future, which are being met by coal power plants Generally worthwhile replacing control and instrumentation systems in older plant to increase efficiency and flexibility Such retrofits can give faster ramp rates and lower minimum loads

21 Impact of wind on coal unit cycling

22 Changes to coal plants to increase flexibility

23 Firing systems bituminous coals Range of operation without support can be extended to lower loads by: Mill size and burner changes loads down to 25% on two mills Loads even of 15% on one mill achievable in corner-fired tangential systems, as at Heilbronn Unit 7 Burner operating range - design with four mills for hard coal (Brüggemann and Marling, 2012) Heilbronn power station, Germany Photo: Kreuzschnabel Wikimedia Commons

24 Firing systems lignite Range of operation, normally down to 50% on older units, 40% on recent units, can be extended to lower loads: For lignite 35% looks possible with 3 mills in service through air supply and mill adjustments and additional means LEFT Vattenfall s lignite-fired Schwarze Pumpe plant, where firing down to 37% has been demonstrated Studies show lignite drying may allow ~30% load RIGHT RWE s WTA lignite drying plant at Niederaussem

25 Boiler pipework improvements for greater flexibility Increasing ramp rate through reducing thermal gradients by: Using new steels to allow reduced metal thicknesses Increasing number of headers External steam heating and hot storage systems Reducing the minimum load by, for example: Evaporator design, such as rifled tubing in new boilers Economiser or feedwater heater bypasses

26 Turbine and water/steam systems achieving greater integrity Features available for faster response, greater resilience and reduced losses include: Steam cooling of thick-walled outer casings Use of sliding pressure (whole plant aspect) Turbine bypass, so rate of steam temperature change can be managed during start-up and shut-down USC steam turbine at J-POWER s Isogo Unit 1, Japan

27 Turbine and water/steam systems achieving flexibility Methods for short-term additional power and frequency control: Turbine throttling, condensate throttling Feedwater heater by-pass Thermal storage (feedwater tanks with hot and cold water displacement) HP stage by-pass for frequency control over whole load range

28 Waigaoqiao No.3 coal power plant (Shanghai Shenergy Energy Technology 2008)

29 Waigaoqiao No. 3 power plant in China Emissions (mg/m 3 ) Dust: 0.7 SO 2 : 15.1 NOx: 17.2 Year Year to date Net efficiency (%) (%) Specific coal consumption (gce/kwh) Annual load rate (%) rate (%)

30 There is scope to make a step change in plant efficiency

31 China s power sector latest great leap forward Detailed design for mounting the high and intermediate pressure steam turbine modules at the same level as the boiler steam headers outlets, with the lower pressure turbine modules in the conventional turbine house. Independent international experts have shown that this reduces the use of expensive steel pipework while offering a potential cycle efficiency of some 48.9%, which would result in CO2 emissions comfortably below those applicable for gas fired plant

32 Towards >50% cycle efficiency with advanced USC technology Metals used in boiler and turbine hot spots: Steels well proven in USC at 600ºC Nickel based alloys proving capable in A-USC at 700ºC

33 Ongoing improvements to coal fired power plants Increased operational flexibility Higher efficiency Lower conventional emissions

34 What can we get if we combine both improvements? The re-design of the turbine layout, if applied on a 1350 MWe unit with a very high efficiency steam turbine operating at USC steam parameters of 600/620ºC combined with other efficiency improvements, would reach 48.9% net electrical efficiency (LHV). This has been independently verified by Siemens, GE and Chinese local manufacturers. There are plans to demonstrate this concept and other innovations on the PingShan II USC plant, which is expected to be operational by 2018 Advanced USC based on use of nickel alloys to ensure 700ºC steam temperature could achieve > 50% efficiency (net, LHV basis), with the technology demonstrated from 2021 onwards by Japanese companies Should the two technology options be combined the net electrical efficiency would be over 52%

35 Efficiency, coal consumption and CO2 emissions for various advanced coal power technologies in China (WWF European Policy Office 2016) Note:1. Net coal consumption is based on standard coal with LHV of 7000 kcal/kg or kJ/kg 2. All the data are based on design conditions 3. CO2 emissions are based on the gross energy output of the coal fired unit

36 Where else do we go from here? Fuel cell (FC) is an emerging technology that can potentially be applied to towards-zero emission, high-efficiency coal power plants. Coal-based FC power systems are under development but there is some way to go before the first commercial coal-fed FC power plant can be built CLC has a number of technical advantages (e.g., CO 2 separation takes place during combustion, expensive air separation unit is not required, etc) and challenges (e.g., reactive and stable oxide carriers, reliable solids transport system, efficient heat integration). The technology is still at an early stage of development sco2 power cycle can potentially replace a steam Rankine cycle in a wide variety of power generation applications. Significant progress has been made recently and the development of a sco2 cycle coal power system is underway

37 IGCC prospects (MHPS 2015) Original four demonstration units in EU and USA did not perform in line with expectations, despite major inspirational actions by operators and designers. More recently, in Japan, Nakoso IGCC industrial pilot and commercial prototype units established between 2001 and 2007 have achieved very favourable results. The air blown option has been established at 250MWe scale and is now operated on a commercial basis. Two 500MWe units are being designed. Technology is considered suitable both for near term applications and longer term hydrogen fuelled gas turbines/fuel cell prospects

38 Fuel cells High temperature MCFC and SOFC offer the best opportunity for thermal integration with coal gasification systems

39 Integrated gasification fuel cell (IGFC) systems

40 Performance comparison of IGFC variants Atmospheric pressure IGFC Pressurised IGFC Efficiency (%) CO 2 emission (kg/mwh) water consumption (litre/mwh) capital cost (2007$/kW) LCOE (cents/kwh)

41 Fuel cell power plants demonstration Cell to stack to module buildup The 58.8 MWe Gyeongg fuel cell power plant in South Korea

42 Chemical looping combustion (CLC) Chemical looping combustion/gasification Alstom s 550 MWe CLC power plant

43 Coal-Direct Chemical Looping power plant with CCS

44 Alternatives to steam Rankine cycles Kalina cycle organic Rankine cycle (ORC)

45 Oxyfuel gas turbines Several possible cycles for oxyfuel turbine with syngas/ng: Recycled H 2 O cooled (e.g. Clean Energy Systems) or CO 2 cooled Allam cycle CES Highlight: 8 Rivers Capital Allam cycle High P combustion (~300 bar) produces supercritical CO 2 for turbine 50 MWt NG pilot under construction by NET Power With gasification: 50.3% LHV achievable more than SCPC w/o CCS Zero cost of CO 2, 15% reduction in COE over SC plant w/o CCS

46 Supercritical CO2 alternatives to steam Rankine cycles A 10 MWe sco 2 power turbine and a 10 MWe steam turbine Closed Loop sco 2 recompression Brayton cycle

47 Need for HELE technologies Reality is that developing countries are going to use coal, as their driver is security of supply and economic competitiveness Many OECD countries will continue to use coal although they will likely have more balanced energy portfolios It is essential to support more efficient coal-fired power, as it's the only realistic way to bring down CO2 emissions in developing countries in the near term HELE clean coal technology is commercially available now and being deployed commercially, such as in Germany, Japan, USA but more especially in China The development work to establish advanced systems that will provide a step change improvement to well over 50% cycle efficiency is a very exciting prospect

48 The power of high efficiency coal HELE coal-fired power generation mitigates more CO2 emissions than renewables per dollar of investment (WCA 2015) Given the higher capital costs of renewable technologies and their lower load factors, in most regions, conversion to HELE technologies represents the lowest cost CO2 abatement alternative (WCA 2015) Increasing the use of high-efficiency, low-emissions (HELE) coal technologies will meet the dual objectives of providing power and realizing environmental and social responsibility (Shenhua 2016)

49 New coal chemical industry supply chain is extensive but comes with challenges Concerns re high capital costs and uncertainty of forward oil prices, which has been emphasised recently Concerns re water availability in some countries Need to optimise both high efficiency operation and the production of top quality products Ensuring these needs are addressed represents a key part of process approval procedures

50 Economic challenges These large scale projects represent a massive upfront capital investment to cover the coal conversion plant itself and the associated infrastructure. The production cost of the coal can be reasonably well estimated and normally is relatively stable. In contrast, the costs of oil and gas, from which the end products can also be made, have always been more volatile. Consequently, the overall profitability is very difficult to estimate, for the 50 year lifetime of the process since there will be times when oil/gas-based end products are more competitive than the coal based versions. As such, the financial stability of the coal based conversion technologies projects is always vulnerable to changes in oil and gas prices.

51 Environmental considerations Chinese applications Standard coal consumption Water consumption CO2 emissions tonnes/tonnes ICL Coal to olefins Coal to ethylene glycol tonnes/1000 Nm3 Coal to SNG

52 Future fuels from coal Coal can be upgraded to provide a range of chemical products including liquid and gaseous fuels

53 China is driving coal to chemicals China does not yet have a commercial scale coal to chemicals and fuels sector established, but it does have the necessary framework in place at large scale Besides options just considered, there are others being trialled at industrial pilot scale However like all previous attempts worldwide, China is struggling to reconcile national strategic requirements with international market forces That said, China has established long term plans The energy optimisation challenges can be solved, while the government can underpin the economic uncertainties on strategic grounds The biggest issue may yet be environmental sustainability

54 Extraction of coal bed and coal mine methane About 50% of available methane can typically be extracted from a coal seam but this can be increased to 90% by further injection of steam and/or nitrogen Methane can be used for : Small scale power production for domestic and industrial use Motor fuel As a source of methane to be added into natural gas pipelines

55 CCS, a proven technology in use around the world, has a key role to play in curbing CO2 emissions Large-scale CCS projects in operation around the world Source: Global CCS Institute, The Global Status of CCS: 2015 Summary Report, November 2015 In 2010 the G8 called for 20 large-scale CCS projects to be operating by 2020 There are 15 large-scale CCS projects in operation currently In 2016 and 2017, further such projects are due to come on stream This will mean 22 projects in operation or under construction three times as many as at the start of the decade However, the total CO2 capture capacity of the 22 projects will be only around 40 Mtpa It is clear that more needs to be done, especially to demonstrate the cumulative positive impact of establishing a HELE coal power generation system that incorporates CCS/CCUS

56 Thank you for listening! I am happy to answer questions now, while I am at the Conference or by . <andrew.minchener@iea-coal.org>