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Mitsubishi Hitachi Power Systems

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Dry lignite utilization towards improving flexibility and competitiveness of lignite power plants

Drylig workshop 2017

M. Agraniotis

C. Bergins

E. Kakaras

08.06.2017

© 2017 Mitsubishi Hitachi Power Systems, Ltd.

Proprietary and Confidential Information. This document or information cannot be reproduced, transmitted, or disclosed without prior written consent of Mitsubishi Hitachi Power Systems,Ltd.

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� Presentation of MHPSE

� Background and Motivation

� Overview of lignite pre-drying and firing technologies

� Selected results from Drylig project

� Summary

Contents



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Mitsubishi Hitachi Power Systems, Ltd. (MHPS)

� Start of Joint Venture: 1 February 2014

Mitsubishi Hitachi Power Systems, Ltd. (MHPS)

� HQ Location: Yokohama, Japan

� Number of MHPS Group companies: 58

(8 in Japan, 50 overseas)

� Total workforce: approx. 20,500 (consolidated)

� Major operations/ businesses:

� Thermal Power Generation Systems

� Geothermal Power Generation Systems

� Environmental Systems

� Fuel Cells

� Capital: 100 billion Yen / 1.05 billion USD

(USD/JPY: 95)

Mitsubishi Hitachi Power Systems, Ltd.

Mitsubishi Hitachi Power Systems Europe

65% 35%

100%



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MHPS – Business Activities/ Products

Gas Turbines

Gas Turbine Combined Cycle (GTCC) Power Plants

Boilers

Integrated Coal GasificationCombined Cycle (IGCC) Power Plants

Environmental Plants SCR (DeNOX) Systems / Flue Gas desulfurization

Generators

Boiler & Turbine Generation Plants Geothermal Power Plants Steam TurbinesPower Generating Plant Peripheral Equipment



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Coal-Fired Power Plants – Main Business Activities

Plants/Components

� Power Train

� Utility Steam Generators

� Industrial Steam Generators for

all fuels (incl. CHP)

� Firing Systems

� Flue Gas Cleaning Systems

� Steam Turbines



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New Technologies for Energy Generation and Storage

Geothermal Energy

� Generating electric power using energy from underground hot water

� Leading geothermal turbine supplier in the world

High Temperature Heat Pump (HTHP)

� Utilization in the industrial field

� Process steam generated from district heating, substantial raise of energy efficiency

Liquid Air Energy Storage (LAES)

� Liquified air is being used as an energy storage in the GWh scale

� Calculated storage efficiency over 70%

� Short construction and lead times; rapid implementation possible

Power-to-Fuel (PtF)

� Methanol synthesis from CO2 and Hydrogen; processing of methanol into various fuels

� Suitable for large-scale power plants, steelworks, chemical plants, refineries, cement

factories

Solid Oxide Fuel Cells (SOFC)

� High operating temperature (approx. 1,000 degree Celsius); effective utilization of

exhaust heat

� High durability

� Fuel flexibility (using natural gas, oil or coal as fuel)



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� Summary

Contents



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� Severe market situation for new build

coal power plants in Europe

� No new builds are foreseen in the

overall European market with specific

exceptions (Poland, Balkan area,

Turkey)

� Eurelectric statement towards carbon

neutral power supply in 2050: No coal

new builds after 2020

� Current market demand: retrofits of

existing coal power plants (new BREF)

� No further research activities on USC

plants, CCS, oxy-fuel

Lignite utilizationCurrent market situation



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� Flexibility – reduction of

minimum load

� Industrial scale CHP

� Other industrial processes,

furnaces (niche markets)

� Medium to long term applications

� Coal to Liquids, Chemicals

Lignite utilizationMarket potential

Examined within Drylig

� Promoting use of indigenous fossil sources for production of fuels and chemicals replacing imported fuels

� In the case of using RES electricity in synthesis processes (e.g. hydrogen from electrolysis) new products with lower carbon footprints can be produced

� Short to medium term applications favouring dry lignite utilization



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Flexibile operation of thermal plantsWhich are the requirements?

max.

min.(old)

min.(new)

Reduction of minimum load

Reduction of startup cost and startup time

Increase of load change speed

Maximum load extension

old new Minimum load reduction

(-) Lower efficiency = higher specific

cost

(+) Continuous sales of grid services

(+) Savings in auxiliary fuels

(+) Avoiding start-up and additional

thermal fatigue

Non regret strategy for flexibility!

Improvement of startup

(-) Loss of operational hours and

income

(+) auxiliary fuel savings

(+) faster startup



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� Summary

Contents



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MHPSE‘s experience with dry lignite utilization (previous projects, studies, commercial proposals)

2012 Jänschwalde (Germany)

Commercial Proposal for a retrofit of 250 MWe boiler. Installation of a start-up system with dry lignite firing

Flexibility / reduction of minimum load

YearName of project / proposal / study

Project DetailsScope of dry lignite

utilisation

1975

1984

1991

2003

Megalopolis 3 (Greece)

Elbistan A (Turkey)

Megalopolis 4 (Greece)

Elbistan B (Turkey)

New builts:

300 MWegross

320 “

300 “

360 “

Effective utilization of extreme low lignite qualities (improvement of flame stability)

1997Frankfurt (Oder) (Germany)

CHP boiler (105 t/h) Cost effective district heat production through CHP technology

2000 - 2008 Boxberg (etc.) (Germany)Several studies for 100% dry lignite fired boilers

Increase of efficiency, reduction of CO2emissions / oxyfuel ready

2009 Jänschwalde (Germany)Feasibility study for a new built 250 MWe Oxyfuel PP (tender not published)

“

2002Niederaussem K (Germany)

New built, 1010 MWegross with dry lignite firing for start-up

Start-up, min. load, (demonstration ofintegration with RWE‘s WTA dryer)



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Lignite pre-drying Overview industrial scale lignite drying technologies

Tubular dryer Rotary dryer

Fan beater mill(MHPSE‘s NV ®, DGS®

mill)

Fluidised bed dryers (WTA, DDWT, others)



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Drying systems (utilizing steam)Tubular dryer

� mature, reliable technology, (more than 50 years old)

� increased operating costs (wear and tear), due to large mechanical rotating parts

� extensive coal pretreatment required (crushing, seeving)

process flow coal side process flow water/steam side

Source: www.rwe.com

+

-

-



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Drying systems (utilizing steam)Fluidised bed dryers : WTA

Source: www.rwe.com

� RWE‘s licensed technology

� An industrial scale prototype (110t/h dry lignite production) in commercial operation since 2014

� Most advanced technology in terms of overall efficiency WTA prototype

dryer at Niederaussem PP

First integration option: steam bleed utilisation Second integration option: vapor compression

+



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Drying systems (utilizing flue gas)Rotary Dryer

� Simple robust, reliable design

� Proven technology for a broad variety

of fuels

� Low CAPEX solution

+

+



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Drying systems (utilizing flue gas)Fan beater Mills (DGS ®, NV ®)

� Solution comparable with rotary dryers

� Simple robust, reliable design

� Proven technology for a broad variety of

fuels

� Low CAPEX solution +

+



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Lignite firing systems

� High water content

� High ash content

� Low heating value

� Low ash melting temperature in some cases �� high slagging

potential

0

20

40

60

80

0 10 20 30

LHV [MJ/kg]

Lignite

with low

heating

value

Lignites

Subbituminous

Bituminous

(Semi-) Anthracite

BiomassVolatiles [% by wt. (waf)]

3

6

9

12

15

18

15 25 35 45 55 65 75

Water content [% by wt.]

bc

d

aLHV

[MJ/kg]a-d: different

firing systems



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Pre-dried lignite utilization for extreme low quality fuelsDirect firing with partial vapor discharge - case: Elbistan B

120.7m

110.3m

0.0m

vapour ESP

vapourline

dry lignitelines

3

6

9

12

15

18

15 25 35 45 55 65 75Water content [% by wt.]

bc

d

aLHV

[MJ/kg]



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Pre-dried lignite utilization for low quality fuelsHybrid firing (combination of direct + indirect) - case: Niederaußem K

� 1010 MWegross, 580/600 °C, 290bar

� Commissioned 2002, more than 10 years operation of pre-dried lignite firing system

� Integration of WTA prototype fluidised bed dryer in the power plant steam cycle

Dryer

Dry lignitestorage

Raw lignite

Mill

Air

Feed water

Bleed steam

DustVapour

Vapour

Condensate

Transport& Cooling



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Pre-dried lignite utilization in Combined Heat and Power PlantsIndirect Firing - case: Frankfurt/Oder

� Replacement of the overall firing system from oil to dry lignite (fuel switch)

� Successful project implementation by installation of DS ® burners

� Considerable fuel savings by replacement of Heavy Oil through pre-dried lignite

� Use of carbon biomass fuels together with dry lignite dust also possible

CHP plant Frankfurt/Oder100 MWth (1998)



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� Summary

Contents



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Case study: Retrofit of existing lignite PP External lignite dryer and indirect firing towards flexibility increase

� Addition of slip stream drying with a) flue gas b) excess heat (different technology options)

� Slight efficiency increase by decreasing flue gas temperature

� Excess heat from air preheater allows slip stream drying for daily 6-8 hours part load operation

FGD

FGC

Air

Cooling tower

or stack

Separation,

Cooling,

Storage

Raw

coalAir to

burners

Indirect

firingDirect

Firing

ESP



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Case study: Retrofit of existing lignite PPExternal lignite dryer and indirect firing towards flexibility increase



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Case study: Retrofit options of a new build lignite PP

External lignite dryer and indirect firing towards flexibility increase

� The integration of a fluidized bed drying technology with

inert gas loop was investigated for different cases

� Dry lignite utilization improves net efficiency in all cases

� Significant increase of flexibility at total substitution of

expensive oil

� The application of 30 % dried lignite is possible with low

technical efforts resulting to flexibility and efficiency

improvements

� An overproduction of dry lignite is possible, for combustion

in other power plants or industrial furnaces

Boiler scheme: 660 Mwe gross Ptolemais V unit



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� MHPSE’s long and broad experience on power plants utilizing dry lignite

(first references in the 60s-70s).

� Despite the severe market environment for new builds, existing

thermal power plants continue to play a key role for the stability of the

electricity system �� need for flexibility

� Not all drying technologies optimized for all applications. Evaluation

based on each application field necessary.

� Lignite pre-drying systems currently investigated towards increase of

flexibility (reduction of minimum load) in existing and new built lignite

boilers.

� Step by step development of solutions for specific cases (cooperation

with clients in the framework of commercial studies and R&D projects).

Summary



Mitsubishi Hitachi Power Systems

Thank You

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