Opportunities Dr Andrew Minchener OBE General Manager IEA Clean - - PowerPoint PPT Presentation

High Efficiency Low Emissions Coal Use: Global challenges and Opportunities

Dr Andrew Minchener OBE General Manager IEA Clean Coal Centre

The IEA Clean Coal Centre

We are an international organisation, endorsed by the International Energy

• Agency. We provide independent,
• bjective information on how to use

coal more effectively, efficiently and cleanly, to minimise its environmental impact while providing cost effective energy

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

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

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
• f 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

Susta Sustainab inable ene le energ rgy y for th for the futu e future re: th : the e en ener ergy gy trilemma trilemma Energy security Economic competitiveness and equity Environment & climate protection

Rhetoric versus reality? Coal sector faced with unprecedented level of

• pposition
• Much of it is irrational, non-scientific based, wrapped in self-

serving 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

Projection of world coal demand & share of coal in world primary energy demand by scenario (IEA

EA WEO WEO 2015)

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 CO2 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

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

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

Flue gas Turbine Mill Boiler De-NOx EP De-S Generator Condenser Steam Water Coal CO2 Storage Pollutants to be reduced

• SO2, NOx,
• Particulate matter
• Mercury (in due course)

CO2 CO2 Capture

(2) Reducing non-GHG emissions (3) Carbon Capture and Storage

(to be added in due course)

Reducing coal consumption

(higher steam T&P)

Technologies for cleaner coal generation

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, SO2, PM) emissions.

N2, H2O

What should be the way forward for the coal power sector? Near term:

• 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

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 CO2 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

• Increasing global average coal plant efficiency by 4–7%pts equates to 15-20%

reduction in coal CO2 emissions, or ~1–2 Gt globally

• New technologies can further raise the efficiency ceiling
• Upgrades will be required for existing plant

CO2 reduction potential of coal fired power plants through increased efficiency (VGB Powertech 2013)

Projected CO2 emissions reductions from subcritical to USC IEA CCC study on potential HELE impacts in Asia Project Projected ed i inc ncre rease ase in in co coal al po power ca wer capa pacity city

200 400 600 800 1000 1200 1400 1600 1800 2000

All countries, current All countries, current & planned China current China current & planned India current India current & planned Other East Asia current Other East Asia current & planned

Chart 1: Coal power in 10 Asian economies by region and technology (GWe)

Subcritical Supercritical Ultrasupercritical 1000 2000 3000 4000 5000 6000 7000 All ten countries China India Other East Asia

Chart 2: Annual reduction in CO2 emissions from new coal power due to use of HELE in place of subcritical technology (MtCO2)

Emmissions if all new plant was subcritical Emissions with technology mix currently planned Emissions if all new plant is ultrasupercritical

Fundamentals of coal-fired power generation have remained unchanged for some time but…….

pulverised coal fired power plant Rankine cycle

• 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 Increasing the flexibility of coal-fired power plants

Impact on power production due to unreliability

• f renewables August 2014 (MHPS 2014)

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

Impa Impact ct of

• f wi

wind nd on

• n coa

coal l un unit c it cycling ycling

Changes to coal plants to increase flexibility

• 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 Firing systems – bituminous coals

Heilbronn power station, Germany

Photo: Kreuzschnabel Wikimedia Commons

Burner operating range - design with four mills for hard coal (Brüggemann and Marling, 2012)

• Range of operation, normally down to 50% on older units, 40%
• n 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

Firing systems – lignite

RIGHT RWE’s WTA lignite drying plant at Niederaussem

– Studies show lignite drying may allow ~30% load

• 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:

Boiler pipework – improvements for greater flexibility – Evaporator design, such as rifled tubing in new boilers – Economiser or feedwater heater bypasses

• 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 Turbine and water/steam systems – achieving greater integrity

USC steam turbine at J-POWER’s Isogo Unit 1, Japan

• Methods for short-term additional power and

frequency control: Turbine and water/steam systems – achieving flexibility

– 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

• ver whole load range

Waigaoqiao No.3 coal power plant

(Shanghai Shenergy Energy Technology 2008)

Waigaoqiao No. 3 power plant in China Emissions (mg/m3) Dust: 0.7 SO2: 15.1 NOx: 17.2

Year ear 2008 2008 2009 2009 2010 2010 2011 2011 2012 2012 2013 2013 Net efficiency (%) 42.73 43.53 43.97 44.50 44.40 44.35 Specific coal consumption (gce/kWh) 287.4 282.2 279.4 276.0 276.1 276.8 Annual load rate (%) 75 75 74 81 77 78

Yea ear 2008 2008 2009 2009 2010 2010 2011 2011 2012 2012 2013 2013 2014 2014 2015 2015 to to da date te Net efficiency (%) 42.7 43.5 44.0 44.5 44.4 44.4 44.9 Specific coal consumption (gce/kWh) 287.4 282.2 279.4 276.0 276.1 276.8 272.9 Annual load rate (%) 75 75 74 81 77 78 76

There is scope to make a step change in plant efficiency

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

Towards 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

Ongoing improvements to coal fired power plants

• Increased operational flexibility
• Higher efficiency
• Lower conventional emissions

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
• ther 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%

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 29307.6kJ/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

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., CO2 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

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

• perated 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

Fuel cells

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

Integrated gasification fuel cell (IGFC) systems

Performance comparison of IGFC variants

At Atmospher mospheric ic pr press essur ure e IGFC IGFC Pr Press essuris urised ed IGFC IGFC Efficiency (%) 49.4 56.2 CO2 emission (kg/MWh) 1.36 1.36 water consumption (litre/MWh) 877 782 capital cost (2007$/kW) 2000 1800 LCOE (cents/kWh) 8.8 7.9

Fuel cell power plants demonstration

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

Chemical looping combustion (CLC)

Alstom’s 550 MWe CLC power plant Chemical looping combustion/gasification

Coal-Direct Chemical Looping power plant with CCS

Alternatives to steam Rankine cycles

Kalina cycle

• rganic Rankine cycle (ORC)

Oxyfuel gas turbines

Several possible cycles for oxyfuel turbine with syngas/NG: Recycled H2O cooled (e.g. Clean Energy Systems) or CO2 cooled Highlight: 8 Rivers Capital Allam cycle

• High P combustion (~300 bar) produces supercritical CO2 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 CO2, 15% reduction in COE over SC plant w/o CCS

Allam cycle CES

Closed Loop sCO2 recompression Brayton cycle

Supercritical CO2 alternatives to steam Rankine cycles

A 10 MWe sCO2 power turbine and a 10 MWe steam turbine

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

• ver 50% cycle efficiency is a very exciting prospect

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)

New New co coal che al chemical i mical ind ndust ustry sup ry supply cha ply chain i in is s ex exte tensive nsive bu but co t comes wi mes with th ch challeng allenges es

• 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

• f process approval procedures

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.

Environmental considerations

Ch Chine inese e applica pplications tions Stan tandar dard d coa coal l cons consumption umption Water ter cons consumption umption CO CO2 2 em emis ission ions tonnes/tonnes ICL

4.39 13 5.0

Coal to olefins

6.68 33 5.5

Coal to ethylene glycol

2.55 14 2.0

tonnes/1000 Nm3 Coal to SNG

2.83 6.58 2.5

Future fuels from coal Coa Coal l ca can n be be upg upgra rade ded d to to pr provide

• vide a

a ra rang nge e of

• f ch

chemica emical l pr prod

• duc

ucts ts includ including li ing liqu quid id an and d ga gaseo seous us fue fuels ls

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

• n strategic grounds
• The biggest issue may yet be environmental sustainability

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

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
• r 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

Thank you for listening!

I am happy to answer questions now, while I am at the Conference or by email. <andrew.minchener@iea-coal.org>