ME4103 Michael Ryan 11323146 4BM

A THERMODYNAMIC AND COMBUSTION ANALYSIS OF EDENDERRY
POWERSTATION FUELLED BY 100% BIOMASS USING CARBON
CAPTURE AND STORAGE
by
MICHAEL RYAN
A project submitted in partial fulfilment of the requirements for the degree of
B.E. in Mechanical Engineering
NATIONAL UNIVERSITY OF IRELAND, GALWAY
15/04/2016
Project Supervisor: Dr Rory Monaghan

ii
Abstract
CAPTURE AND STORAGE
MICHAEL RYAN
2016
Advisor: Dr Rory Monaghan
Degree: Honours Bachelor of Engineering, Mechanical
This project aims to demonstrate the opportunities and challenges associated with
the use of carbon capture and storage in an industrial power generation capacity.
Furthermore, it will demonstrate the challenges associated with fuelling the modern
powerstation at Edenderry, Co. Offaly on 100% biomass, specifically short rotation
coppice willow (SRCW). A Matlab model for the existing peat burning plant will
be developed and used as a validation means for the subsequent analysis on biomass
combustion and latterly biomass combustion with carbon capture and storage. The
CCS method used is a post combustion system that uses amine to separate carbon
dioxide from the flue gas. The impact of increasing the percentage of flue gas CO2
capture will be demonstrated. The associated socio-environmental factors for the
growth of approximately 27000 hectares of SRCW, enough to fuel the 128MW
facility at Edenderry on an annual basis, will be explored. Finally, a levelised cost
of electricity study will be undertaken to demonstrate the inertial effects of
‘business as usual’ when it comes to cheap fossil fuel power generation versus
cleaner but more expensive renewable options.

iii
I. Acknowledgments
I would firstly like to thank Dr Rory Monaghan for his guidance, expertise and
understanding throughout the year as I sometimes floundered with this project. He
was always readily available and approachable. I would like to thank Peter Gillespie
and the staff at Edenderry powerstation for taking time out of their busy schedules
to grant me an in-depth plant tour. I would also like to take the chance to thank
Peter for always being so helpful in our many email correspondences throughout
the year as I got to grips with the technical aspects of the powerplant. I would also
like to make special mention to postgraduates Paul Burke and David Connolly for
being there for me throughout the year in both an academic and personal capacity.
Special thanks to David for the tips on the writing of this report and to Paul for the
Matlab expertise. On the subject of Matlab, I would like to express my sincere
gratitude to the authors of the XSteam tables. No doubt my life was made a lot
easier with this fantastic resource. Finally, I would like to pass on my thanks to Jim
Gittinger at Babcock and Wilcox for his courteous, efficient and informative
guidance on the topic of all things fluidised boilers. From a generic email sent, I
received such an enthusiastic and helpful reply that it would be remiss of me not to
make a mention of it here.

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II. Plagiarism Declaration
11323146 Ryan Michael
Student Number Family Name Other Names
CAPTURE AND STORAGE
I declare that:
1. I have read and understood both the NUI Galway Code of Practice on
Plagiarism and “Plagiarism – a guide for engineering and I.T. students in NUI,
Galway”.
2. I am the original author of all work included in this report, except for
material which has been fully and properly acknowledged using a standard
referencing method.
4. The material in this report has not been presented for assessment in any
other course in this university or elsewhere.
5. I have taken all reasonable care to ensure that no other person has been able
to copy any part of this report either in paper or electronic form.
11/04/16
Signature Date

v
III. Nomenclature
Symbol Description Units
CCS Carbon capture and storage -
SRCW Short rotation coppice willow -
BFB Bubbling fluidised bed -
MC Moisture content -
Gt C Billion metric tonnes of carbon tonnes CO2
Eha Energy per hectare of SRCW GJ
Ereq Annual energy requirement for Edenderry powerstation GJ
tha Tonnes of SRCW per hectare planted tonnes
HPT High pressure turbine -
IPT Intermediate pressure turbine -
LPT Low pressure turbine -
FWP Feedwater pump -
γC Carbon composition of a fuel -
γH Hydrogen composition of a fuel -
γS Sulphur composition of a fuel -
γN Nitrogen composition of a fuel -
γO Oxygen composition of a fuel -
γH2O Water composition of a fuel -
γASH Ash composition of a fuel -
WTOT Total system work out kW
Ein Power into steam cycle in the form of heat energy/sec kW
ηth Thermal efficiency -
ηT Turbine isentropic efficiency -
ηP Pump isentropic efficiency -
ṁ wf Mass flow rate of working fluid kg/sec
ṁ fuel Mass flow rate of fuel kg/sec
ṁ bleed Bleed mass flow rate kg/sec
CVfuel Calorific value for given fuel MJ/kg
Vflue Volume of flue gas/kg fuel burned m3
/kgfuel
FF Fuel factor m3
/MJ

vi
Pout Net plant power output MW
ṁ flue Mass flow rate of flue gases kg/sec
V̇flue Volume flow rate of flue gases m3
/sec
ρ Density kg/m3
f Working fluid bleed fraction -
M(x) Molar mass of element x g/mol
ηcap Flue gas CO2 capture efficiency -
Rc Emissions ratio of carbon -
Tli
Inlet temperature of lean amine °C
Tlo
Outlet temperature of lean amine °C
Tri
Inlet temperature of rich amine °C
Tro Outlet temperature of rich amine °C
CH2O Specific heat capacity of water kJ/kg.K
M(CH2O) Molar heat capacity of water kJ
CCO2
Specific heat capacity of CO2 kJ/kg.K
M(CCO2
) Molar heat capacity of CO2 kJ
LV Latent heat of vaporisation of water kJ/kg
hstrip Enthalpy required for stripping reaction per mole CO2 kJ/kg
hchange Enthalpy required to change state of one mole of H2O kJ/kg
Nsol Number of moles in amine-CO2 solution -
Nevp Moles of CO2 captured per mole of H2O evaporated -
Qstrip Heat required for stripping reaction J
Q100_130 Heat required to break amine-CO2 bonds J
Q85_100 Heat required to increase temp of rich solution to 100°C J
Qevp Heat required to evaporate water from the system J
Qccs Total heat required to capture CO2 from solution J
Cheat Specific heat energy (of system) kJ/kg
ṁ SRCW Mass flow rate of SRCW fuel kg/sec
ṁ Co2SRCW
CO2 mass flow rate from SRCW combustion kg/sec
ηcapflu
% of flue gas captured -
syear Seconds in a year sec

vii
CF Capacity factor of Edenderry -
r Discount rate (LCOE analysis) -
T Number of years of plant operation -

viii
Contents
I. Acknowledgments .............................................................................................. iii
II. Plagiarism Declaration ...................................................................................... iv
III. Nomenclature.................................................................................................... v
Table of Figures ..................................................................................................... xi
Table of Tables....................................................................................................... xi
Table of Equations ................................................................................................ xii
1. Introduction......................................................................................................... 1
1.1 Project Motives ............................................................................................. 1
1.2 Project Specifications.................................................................................... 2
1.3 Project Approach........................................................................................... 2
1.3.1 Conduct Literature Review .................................................................... 2
1.3.2 Selection of Suitable Indigenous Biomass Source................................. 2
1.3.3 Land Requirement for Growing of SRCW to Fuel 128MW Facility .... 2
1.3.4 Visit to Edenderry Powerstation ............................................................ 3
1.3.5 Development of Computational Thermodynamic Model ...................... 4
1.3.6 Assess the Impact of CCS on the Efficiency of the Plant...................... 4
1.3.7 Testing and Validation of Model ........................................................... 4
1.3.8 Levelised Cost of Electricity.................................................................. 4
2. Literature Review................................................................................................ 5
2.1 Introduction…............................................................................................... 5
2.2 Analysis……................................................................................................. 5
2.2.1 Biomass.................................................................................................. 5
2.2.2 Biomass Combustion ............................................................................. 6
2.2.3 BFB ........................................................................................................ 8
2.2.4 CCS ........................................................................................................ 9

ix
2.3 Discussion………. ...................................................................................... 10
2.4 Conclusion……… ...................................................................................... 11
3. Methodology ..................................................................................................... 12
3.1 Schematics……………............................................................................... 12
3.1.1 Plant Steam Cycle ................................................................................ 12
3.1.2 CCS ...................................................................................................... 15
3.2 Live Steam Parameters................................................................................ 17
3.3 Land Requirement....................................................................................... 18
3.4 Thermodynamic Analysis: Steam Cycle..................................................... 19
3.5 Calorific Value Calculation ........................................................................ 21
3.6 Flue Gas Mass Flow Rate Determination ................................................... 22
3.7 Thermodynamic Analysis: Parasitic Operators........................................... 23
3.7.1 Preheating Feedwater........................................................................... 23
3.7.2 Heat Requirement for CCS Process..................................................... 24
3.7.3 CCS Compression Power Requirement ............................................... 27
3.8 Matlab Technical Approach........................................................................ 28
3.9 Total Specific Heat Energy in System ........................................................ 29
3.10 Tonnes of CO2 Captured Per Annum........................................................ 29
3.11 Levelised Cost of Electricity..................................................................... 29
4. Results............................................................................................................... 32
4.1 Land Requirement....................................................................................... 32
4.2 Calorific Values Determination .................................................................. 32
4.3 HPT, IPT and LPT Work ............................................................................ 32
4.4 Thermal Efficiency of Peat Combustion without CCS............................... 33
4.5 Flue Gas Mass Flow Rate Calculation........................................................ 34
4.6 T-s Plot of Cycle ......................................................................................... 35
4.7 Bleed Mass Flow Rate Fraction for Feedwater Preheating......................... 35

x
4.8 Thermal Efficiency of SRCW Combustion without CCS .......................... 35
4.9 Thermal Efficiency of SRCW Combustion with CCS................................ 37
4.10 Tonnes of CO2 Captured Annually........................................................... 38
4.11 Levelised Cost of Electricity..................................................................... 38
5. Discussion ......................................................................................................... 40
5.1 Breakdown of Turbine Work ...................................................................... 40
5.2 Levelised Cost of Electricity....................................................................... 40
5.3 Flue Gas Capture Level............................................................................... 42
5.4 Reduction in Efficiency of SRCW Cycle.................................................... 42
5.5 Validity of Matlab Model............................................................................ 43
5.6 CCS Analysis ……………………………………………………………...43
6. Concluding Remarks......................................................................................... 44
7. References......................................................................................................... 45
Appendix A: Main Matlab Code........................................................................... 51
Appendix B: CO2 Thermodynamic Properties Handbook (1st
Edition)................ 57
B1: Example of Entropy Tables........................................................................ 57
B2: Example of Enthalpy Tables ...................................................................... 58
Appendix C: LCOE Spreadsheets......................................................................... 59
C1: Milled Peat……… ..................................................................................... 59
C2: SRCW…………......................................................................................... 60
C3: SRCW with CCS........................................................................................ 60

Table of Figures
Figure 1 Kaevrner BFB Boiler [19] ........................................................................ 8
Figure 2 Post combustion, amine based CCS [27]................................................ 10
Figure 3 Steam cycle schematic............................................................................ 12
Figure 4 CCS plant layout..................................................................................... 15
Figure 5 Graphically determining bleed mass flow rate....................................... 34
Figure 6 Live steam cycle plot.............................................................................. 35
Figure 7 Determining thermal efficiency with SRCW as fuel.............................. 36
Figure 8 Increasing levels of flue gas capture increases compressor work .......... 37
Figure 9 Impact of CCS on thermal efficiency..................................................... 37
Figure 10 LCOE results for the three operating conditions .................................. 39
Table of Tables
Table 1 Steam cycle plant description .................................................................. 12
Table 2 Edenderry Emissions Data....................................................................... 14
Table 3 CCS Processes labelled............................................................................ 15
Table 4 CCS plant description .............................................................................. 16
Table 5 Working fluid live parameters ................................................................. 17
Table 6 Chemical Composition of the two solid fuels.......................................... 21
Table 7 Molar masses for elements of interest...................................................... 25
Table 8 CCS parameters........................................................................................ 26
Table 9 Table of variables for LCOE calculations................................................ 31
Table 10 Dulong equation-derived calorific values.............................................. 32
Table 11 Matlab generated values for turbine work across all three turbines ...... 33
Table 12 Matlab obtained flue gas mass flow rates.............................................. 34
Table 13 LCOE Results compared to empirical data............................................ 39

xii
Table of Equations
Equation 1………………………. ........................................................................ 19
Equation 2…………………….. ........................................................................... 19
Equation 3……………….. ................................................................................... 20
Equation 4…………………………………………………………………… ..... 20
Equation 5……………………. ............................................................................ 20
Equation 6………………… ................................................................................. 20
Equation 7………………… ................................................................................. 20
Equation 8………………… ................................................................................. 20
Equation 9……………….. ................................................................................... 20
Equation 10………………….. ............................................................................. 20
Equation 11………………. .................................................................................. 20
Equation 12………………… ............................................................................... 20
Equation 13……………….. ................................................................................. 21
Equation 14………………………. ...................................................................... 21
Equation 15………………… ............................................................................... 21
Equation 16………………………………………………………. ...................... 21
Equation 17……………………………………………………………………….22
Equation 18…………….. ..................................................................................... 23
Equation 19…………………….. ......................................................................... 23
Equation 20……………….. ................................................................................. 23
Equation 21……………………. .......................................................................... 24
Equation 22 ........................................................................................................... 24
Equation 23……………………….. ..................................................................... 25
Equation 24…………………… ........................................................................... 25
Equation 25…………………………… ............................................................... 26
Equation 26…………………………………. ...................................................... 26
Equation 27………………….. ............................................................................. 26
Equation 28 ........................................................................................................... 27
Equation 29……………… ................................................................................... 27
Equation 30……………………………………………… ................................... 27
Equation 31…………………………… ............................................................... 28

xiii
Equation 32………………… ............................................................................... 29
Equation 33………………………………… ....................................................... 29

1
1. Introduction
1.1 Project Motives
The Paris Accord of December 2015 is the first universally ratified protocol on
climate change. It reflects the growing concern, awareness and support for
atmospheric carbon reduction efforts. Pilot CCS schemes are now underway in the
huge global emitters of China, India and the USA. Clean coal, hydro-power and
nuclear energy are further reducing the impact of traditional fossil fuel driven
pollution that has facilitated a mean global temperature increase of 0.9°C since 1905
[1]. If, as expected, the mean global temperature increases to the 2°C mark by 2050,
the following knock on events are likely:
 41% of the world’s land is dryland; these include all terrestrial regions
where water scarcity limits the production of crops, forage, wood and other
ecosystem provisioning services. These house 2 billion people [2]. A rise in
temperatures will see 2 billion people adversely impacted.
 A 1.5m rise in sea levels which could displace up to 18 million people in
Asia, the Netherlands and various other low-lying, at risk coastal regions [3]
 A conversion of reflective ice caps to absorptive seawater, further enhancing
the warming up effect. [4]
The motivation for this research project is to demonstrate the net positive impact
carbon neutral resources such as biomass can have. This impact is further enhanced
when paired to a carbon capture and storage technology. CCS is a means for
reducing CO2 emissions from both new and existing powerplants. Upwards of 90%
of flue gas CO2 can be captured [5]. This project champions an overall net negative
electricity generation source and discusses the challenges and opportunities for such
an approach. The concept of a carbon negative electricity generation method is one
where the net carbon emissions from combustion, transport, processing etc are less
than those taken in from the technology such as CCS and the carbon taken in during
the plants lifespan.

2
1.2 Project Specifications
 Determine suitable indigenous biomass source for combustion
 Determine land requirement for said biomass source
 Develop Matlab model of Edenderry powerplant
 Conduct thermodynamic analysis of cycle
 Conduct combustion analysis of milled peat vs biomass
 Identify suitable carbon capture technology
 Generate Excel model to determine the LCOE for the three different cycles
1.3 Project Approach
1.3.1 Conduct Literature Review
It was crucial to assess the state of the art in both biomass electricity generation and
CCS. A comprehensive literature review has been completed and is included in
Section 2 of this document.
1.3.2 Selection of Suitable Indigenous Biomass Source
The work of G. Doonan [6] put forward the recommendation that willow would be
the most suitable indigenous energy crop to grow in the temperate Irish climate. A
key element of this project was to address the issue of Ireland’s dependence on
imported fuel for electricity generation. In order to shield against future hikes in
coal, oil and gas prices, the necessity for an indigenous fuel supply was set as a goal
for this project. The positive knock on effects with regards to job creation and rural
community sustainability were also taken into account in this regard. The technical,
chemical and ecological reasons for the selection of SRCW will be discussed in
subsequent sections.
1.3.3 Land Requirement for Growing of SRCW to Fuel 128MW Facility
Edenderry power station has an annual power requirement of 7.7x 109
MW [7].
According to the Irish Forestry and Forest Products Association, there are currently
1000 hectares of SRCW growing in Ireland [8]. This equates to 273 x 106
MW of

3
energy. As will be shown in subsequent calculations, a total of 27000 hectares is
needed to provide enough fuel to power the plant at Edenderry. This equates to 364
kilotonnes of SRCW yield per annum. This tonnage of SRCW would prevent the
release of some 340 kilotonnes of carbon into the atmosphere [7].
1.3.4 Visit to Edenderry Powerstation
On the 19th
February, 2016, a visit was arranged to the site in Edenderry. Peter
Gillespie, Operations & Maintenance Manager at Edenderry Power Ltd, delivered
an in-depth technical presentation and tour where the many facets of power
generation with milled peat and biomass were outlined. The visit highlighted the
following:
 Edenderry plant is currently equipped to operate on 100% biomass. All fuel
supply mechanisms, conveyors and pumps have been installed with a future
biomass operating level of at least 50% in mind. However, obstacles to this
are unknowns such as repeatable and quantifiable chemical compositions of
biomass, both indigenous and imported and also a shortage of biomass for
fuel currently being grown in Ireland
 The BFB technology used at Edenderry is suitable for the combustion of
many types of fuels, including biomass such as SRCW. In fact, it is the most
versatile boiler technologies on the market today, able to handle fuels with
MC’s of 50%. This technology will be discussed in depth in the next section
of this report
 The efficient running of the Edenderry plant is somewhat hampered by the
presence of wind power supplying the national grid. As there has to be a
steady supply level at all times in the Irish market, and because wind is
constantly varying, many of the peaking plants dispersed throughout the
country, Edenderry included, are in a state of constant dynamic energy
provision.
 Edenderry currently imports almost 55% of its biomass. This is a reflection
on the lack of support and incentives that haven’t been created for
landowners to grow biomass crops such as willow and miscanthus.

4
1.3.5 Development of Computational Thermodynamic Model
There were a number of critical parameters that had to be met in the development
of the Matlab model for the cycle. Firstly, the output efficiency had to reflect the
real life efficiency of Edenderry powerplant as it stands. This figure is 38.4% [7].
As many steam parameters as possible were taken from the real life scenario to
enhance the accuracy of the model. The more technical aspects of the model will
be discussed subsequently.
1.3.6 Assess the Impact of CCS on the Efficiency of the Plant
The percentage of flue gas CO2 captured, compressed and transported versus the
net parasitic effect on both output plant efficiency and work was analysed and
determined graphically.
1.3.7 Testing and Validation of Model
Using baseline efficiency figures as a guide, all other output variables would be
compared to existing literature to ensure validity. Feedwater preheating, using bled
steam from the IPT, is used to give the feedwater entering the feedwater pump a
temperature of 170°C. This loss of working fluid from the cycle, and the consequent
loss in turbine work, was a key computational model element. The balancing act
between reducing pump work with the high feedwater temperatures, and the loss of
working fluid and turbine work was something, when correctly facilitated, which
ensured the validity of the model. This technicality will be discussed in greater
detail in subsequent sections of this report. Another aspect of model validation was
overall turbine work and the division of the same. Please refer to Table 11 for
further details.
1.3.8 Levelised Cost of Electricity
An industry standard of accurately comparing varying forms of electricity
generation. Values are generated in cents/kWh in this report. Please refer to
Sections 3.11 and 4.11.

5
2. Literature Review
2.1 Introduction
In order to fully appreciate the state of the art in biomass combustion, CCS and
BFB boiler technology, a comprehensive review of existing technical literature was
carried out. Within this section, it will be shown that BFB boiler technology offers
the greatest flexibility with regards to the variety of fuels that can be burned within.
It will be shown that post-combustion, amine based capture technology offers the
most cost effective solution to the burgeoning technology that is CCS. Finally, the
use of biomass in an industrial capacity to generate electricity and/or heat will be
discussed and reviewed.
2.2 Analysis
2.2.1 Biomass
Biomass is becoming an increasingly attractive and viable alternative to fossil fuels.
It can be broken down into three main sections: 1) Energy Crops, 2) Forest Residues
and 3) Agricultural Wastes. For the purposes of this project, it was deemed vital to
long term sustainability and fuel provision security that the crop used would be
indigenous. Ireland currently has an energy dependency of 90% on imported
sources, mainly coal and gas. Many studies have been conducted, [9]–[11], on the
potential for biomass, specifically SRCW, as energy crops. However, increasing
global demand for food as a result of an increasing global population means that
the amount of land available to grow energy crops is not vast. However, researchers
at the University of Illinois [12] believe that the use of second generation crops,
such as miscanthus, switchgrass or SRCW will not directly impinge upon the land
requirement too severely. Second generation crops are those that provide fuel from
plant stems and leaves rather than fruit or grains, unlike ethanol for example which
is made from corn.

6
Here in Ireland, the case for a bio-crop such as SRCW is much more
straightforward. Referencing a study already mentioned in this report by the IFFPA,
there has been on average 14000 hectares of land approved by the government for
planting in the years 2009-2013, with a peak of 19000 hectares approved in 2010
[8]. SRCW is a highly resilient crop that grows well here in Ireland. It is native to
northern temperature zones and thrives in cool and wet conditions. It experiences
rapid juvenile growth and has the ability to coppice, or re-sprout, from the stool left
in the ground after harvest. Growth within the first year can be 6-8m [13]. Taking
some of the land approved for forestry planting would allow for minimal intrusion
on existing agricultural land. Willow is a carbon neutral crop. The carbon released
during combustion is offset by that captured via photosynthesis during the crops
lifetime. In fact, one hectare of SRCW can capture approximately 0.12 tonnes of
carbon annually [13]. Biomass emits just 60g of CO2 per kilowatt hour of electricity
produced. Comparatively, the figures for coal and gas are 1000g and 400g,
respectively. Furthermore, maintenance and fertilisation of the crop is low. SRCW
has a very low nitrogen requirement. Intensively managed grassland has a
requirement for 900 kg N/ha over three years. By comparison, this figure can be as
low as 150 kg N/ha for SRCW [13].
SRCW has been found to have bio-regenerative properties; areas with corrupt water
tables, wastewater and/or sewage have seen regeneration and quality
improvements. A field experiment conducted by Yoder et al [14], found that the use
of willow as part of filter strip plantings controlled soil erosion and chemical runoff
from agronomic crops. Willow can be harvested six to eight times on a three year
cycle with an overall plantation lifespan of 19-25 years, upon which time the
coppice can be removed and the land returned to conventional cropping.
2.2.2 Biomass Combustion
Processing requirements for turning SRCW into a viable and usable fuel source are
not intensive. SRCW can be harvested in a number of ways: direct chip harvesting,
whole rod harvesting or billet harvesting. This is not an agricultural project so the
harvesting techniques will not be discussed in great detail. However, an important
point to note is that selection of harvesting technique can have knock on effects
further down the combustion chain. Direct chip harvesting converts the plant into

7
chips, facilitating for quicker drying times. It also negates the need for resizing
further down the line. Whole rod, as the name suggests, is the process of harvesting
full lengths of the plant and placing in storage for drying. The advantage of this is
less deterioration of the willow itself, but drying times are longer and there is further
work needed further down the line to convert to chips. Billet harvesting falls
between the two techniques, with bigger chips but not full length rods.
In order to be considered a viable fuel source, the moisture content of SRCW must
be in the 20-35% range [13]. Freshly harvested chip has a moisture content of 50%,
similar to that of milled peat. These figures were obtained with adherence to the
British standard BS-EN-14774-1. Once, these MC targets are reached the chip is
transported onsite and placed in fuel storage silos. It is then transported to the boiler
via conveyors.
The use of SRCW will decrease NO2 emissions due to the lower nitrogen levels
versus milled peat [15]. However, the formation of harmful chlorine and alkaline
compounds can result from the higher chlorine levels found in SRCW. The ash
content of SRCW is lower than that of peat. The presence of volatile organic matter
in SRCW can cause increased fouling and slagging within the boiler. Another issue
with SRCW, and biomass in general, is higher quantities of sodium and potassium
which can quicken the deterioration of the boiler tubes [16].
In Section 2.2.3 BFB technology will be discussed, but with regards to biomass
combustion within the boiler, a key issue is sand agglomeration, or a glassing effect.
SRCW has a higher calorific value versus milled peat. Normal bed temperature in
Edenderry is 920°C. However, a concern for the operations staff and engineers at
the plant is the potential for a 100% biomass combustion scenario to increase this
bed temperature to levels above 1000°C. The lower CV value of peat ensures that
boiler temperatures remain constant. The relative composition unpredictability of
biomass presents many challenges and needs to be constantly monitored. The
benefits to be gleaned from the use of biomass in an electricity generation capacity
are numerous. However, there is little argument that their use speeds up the
deterioration process of critical boiler components [17].

8
2.2.3 BFB
Bubbling fluidised bed boilers are the most fuel flexible technology in existence
today. Pena et al [18] highlight the advantage of BFB being its ability to burn
reactive fuels with relatively low heating values and high moisture levels. As the
technology has progressed and become more popular, higher efficiencies and lower
emissions have been achieved. Figure 1 below shows the basic layout of a modern
BFB boiler.
Figure 1 Kaevrner BFB Boiler [19]
The premise of this technology is to ensure uniform temperature distribution
throughout the entire boiler. Non-fluidised boilers tend to have a temperature peak
at the bed where the combustion occurs. This can lead to inefficiency and in-
complete combustion. Combustion air passing through the holes at the bottom of
the bed, or bubble caps, must do so at a pressure that is capable of fluidising the bed

9
material [20]. High internal mass and heat transfers within the particles of the bed
material ensure the even spreading of both pressure and temperature distributions
within the boiler, effectively eliminating the concept of incomplete combustion.
The swirling motion of the particles also has the effect of circulating all the
combustible molecules further enhancing the efficiency of the system.
Davidson et al [21] discuss the importance of the rising bubbles through the bed
material. By treating the bed material as a moving fluid, hence the term fluidised,
fluid dynamic principles on bubble formation, transition and break down within a
stream can be applied thus increasing the theoretical knowledge as to what is going
on at an elemental level.
2.2.4 CCS
Carbon capture and storage is the process whereby CO2 is removed from carbon
sources like the flue stack of power plants. Figure 2 below shows the basic layout
of a post combustion, amine based capture system. It then undergoes compression
in order to place the CO2 into its supercritical state at 7.31 MPa and 38°C [22]. The
aim of this technology is to reduce the amount of atmospheric CO2. The largest sink
for the storage of CO2 is the ocean. It is a natural and sustainable energy sink. The
ocean contains 40,000 Gt C. By comparison, the atmosphere has 750 Gt C and the
terrestrial biosphere has 2200 Gt C [23]. Research conducted by the SEAI on the
potential for carbon storage in a number of offshore locations was carefully
analysed [24]. There is no doubt that on a technical level, there are opportunities
for atmospheric carbon mitigation through pioneering technologies such as CCS.
However, there remains many teething issues. The parasitic load required to operate
the amine pumps, CO2 compressors and additional ancillary devices has been
shown to reduce net plant output by 20%. The removal of as much as eleven
percentage points in efficiency terms are also routinely noticed [25].
However, increasingly impressive commercial attempts being made to make CCS
work in an industrial environment. Mills et al [26] at the IEA Clean Coal Centre
complied a detailed summary of CCS demonstration plants currently in operation
around the world. At the 800MW facility in Gaobeidian, China, 1% of the flue gas,
or 2500 m3
/hour of CO2, is being captured, refined and shipped to a local

10
carbonation facility for soft drinks at a quality of 99.9%. The energy required per
tonne of CO2 captured at the plant is 3GJ while the amount of amine solution
required to capture the same amount is 1.35kg.
A similar plant at Shidongkou in China is capturing 3-4% of its flue gases at the
same food grade quality of 99.9%. This facility is now capturing approximately 120
kilotonnes of CO2 annually at a cost of US$35 per tonne. The approach being taken
by many of those in industry is to capture a portion of the flue gases. It is simply
not feasible at present to capture anything more than 10%.
Berstad et al [27] at the SINTEF Energy Centre in Norway outline the parameters
of CO2 in a compression, transport and storage capacity. As stated previously, in
order for CO2 to attain the supercritical state required for transport and storage, it
needs to be pressurised to 7.38 MPa at a temperature of 31°C. The water content
allowed for pipeline transport is 0.4 x10−3
kg/m3
. The extremely volatile H2S, or
hydrogen sulphide, that occurs naturally in most combustible sources, is limited to
100 ppm.
Figure 2 Post combustion, amine based CCS [27]
2.3 Discussion
Sustainable and indigenously sourced biomass used in an electricity generation
context, paired with CCS, offers a viable and alternative approach to global

11
atmospheric carbon mitigation efforts. Within this literature review a number of key
points have been highlighted and will now be discussed in more detail.
The security, availability and widespread use of coal as the primary source of fossil
fuel derived electricity and heat is likely to continue until the end of this century at
the very least [28]. The recent collapse in oil prices, dropping to levels below US$30
a barrel for the first time in decades, has set back the argument for renewables. The
gap between the commercially feasible fossil fuels and the comparatively
unfeasible renewables has grown in recent months. In 2009, when the price of oil
was in excess of US$140 a barrel, global calls were made for investment and
research into alternative technologies. The results of this push can be seen today in
the list of CCS demonstration plants summarised by Mills et al.
Unfortunately, the ‘business as usual’ approach by many elements of society will
see the importance of net carbon negative technologies to be introduced. Biomass
paired with CCS is one such technology. The development of fluidised boiler
technology over the past forty years in terms of emissions, efficiency and fuel
flexibility offers a real and exciting opportunity for cleaner electricity and heat
provision in the coming decades.
2.4 Conclusion
To conclude, this section has demonstrated the concept of carbon negative
electricity generation; the means of attaining it sustainably and the technologies that
must be invested in to increase its development further. It has been shown that there
is now a concerted global push towards meaningful atmospheric carbon mitigation.
However, such technology presents many technical, commercial and socio-
economic challenges that will require many years of development before they can
be deemed true viable alternatives to the traditional fossil fuelled offerings.

12
3. Methodology
3.1 Schematics
3.1.1 Plant Steam Cycle
A Feedwater Pump
B BFB Boiler
C HPT
D IPT
E LPT
F Condenser
G Feedwater preheater
Table 1 Steam cycle plant description
Makeup Water
Flue Gas to CCS and stack
Flue Gas
recirculated as
combustion
control
measure
Working
fluid
Figure 3 Steam cycle schematic

13
Please note that in Figure 3 the red section of the schematic represents the flue gas
steam and the black represents the working fluid. The feedwater pump operates at
168 bar, delivering water at 255°C to the Kaevrner triple condenser, two cylinder
boiler. The bed temperature of the boiler is 920°C. The base material is sand and
some high temperature additives that aid combustion further. Saturated vapour exits
the boiler and enters the high pressure turbine where it produces less than 30% of
the net 128MW of electricity that Edenderry produces.
It then undergoes a reheat at 40 bar which takes it back up to the temperature at
high pressure turbine inlet. This superheated vapour then enters the intermediate
pressure turbine and contributes less than 20% of net plant output. The exhaust from
the medium pressure turbine then exits directly into the low pressure turbine. More
than 50% of the 128MW nameplate capacity of Edenderry comes from the LPT.
These figures on the breakdown of work at the plant were provided courtesy of
Peter Gillespie at Edenderry Power Ltd. It will be shown in Table 11 in Section 4.3
how these real life values compare to the computationally obtained results. This
comparison will be used as another validation parameter to ensure the accuracy of
the model and the results being obtained.
The working fluid, now a vapour/liquid mix, enters the condenser where it is chilled
to below 30°C at 30mBar. The working fluid then, paired with makeup water,
passes through feedwater heaters and the cycle begins again.
Meanwhile, flue gas exits the boiler at atmospheric pressure and 165°C. It passes
through an electrostatic precipitator and a further abatement process to achieve the
emissions figures listed in Table 2 overleaf. Due to the critical temperature required
at the boiler bed (920°C) to avoid sand agglomeration or glassing, it is vital to have
a means of combustion control that is fast acting and effective. This is achieved by
having a recirculated flue gas stream as shown in Figure 3. If temperatures in the
boiler begin to creep up, the recirculated stream is introduced to the combustion
chamber to slow down the combustion process and reduce the boiler temperature.
This is possible due to the reduced oxygen content of the flue gas.

14
Emissions Type Legal Limits [29] Plant Figure
Dust/ Particulate Matter 5 mg/m3
-100
mg/m3
50 mg/m3
Nitrogen Oxides
(NOx)
100 mg/m3
-600
mg/m3
325 mg/m3
Sulphur Oxides
(SOx)
100 mg/m3
- 400-
2000 mg/m3
600 mg/m3
Table 2 Edenderry Emissions Data
The legal limits used for emissions of this type shown in Table 2, were taken from
the EU Directive 2001/80/EC on Large Combustion Plants [30] in the fluidised
combustion section for a powerplant in the region of 100-300MW. Emissions levels
for biomass combustion are always taken at the upper limit of the recommended
band due to their more environmentally friendly origins [29]. From the above table
it is clear to see the plant operates well within the current remit of 100-300MW
electricity provision.
With the addition of CCS a number of changes will be made to what happens to the
flue gas but the main steam cycle will remain the same, save for additional bled
steam requirement to provide heat addition to the rich amine solution. These
changes are discussed in Section 3.1.2.

15
3.1.2 CCS
Figure 4 CCS plant layout
Balloon Technical Description
1 Flue gas leaving boiler at 165°C and 1 bar
2 89% of flue gas remain uncaptured. See Section 4.9
3 11% of flue gases enter CCS heat exchanger number 1
4 Flue gas now at 25°C; enters absorber
5 Leaves absorber column as rich amine solution
6 Solution compressed by rich pump
7 Solution preheated in heat exchanger 2
8 Solution now at 130°C having passed through bled steam
9 CO2 leaves desorber column in pure stream
10 Lean amine solution leaves desorber as liquid at 100°C
11 Lean amine solution enters absorber having passed through heat
exchanger 2
12 CO2 passes through condenser and enters 1st
compression
13 CO2 enters second compression stage
14 CO2 enters 3rd
and final compression stage
15 CO2 exits having achieved supercritical state (7.31MPa and 31°C)
Table 3 CCS Processes labelled
Bled steam

16
Machine Label Description
A Heat exchanger 1
B Absorber column
C Rich solution pump
D Heat exchanger 2
E Heat exchanger 3
F Desorber column
G Condenser
H CO2 compressor 1
J CO2 compressor 2
K CO2 compressor 3
Table 4 CCS plant description
Figure 4 shows the layout of a basic post combustion, amine-based CCS. The flue
gases exit to the atmosphere at 1 bar and 165°C. As mentioned before, the power
requirement to capture 100% of flue gas is simply not feasible in the current climate.
The parasitic load would render the plant commercially obsolete. This load includes
the heat energy requirement to heat the rich amine solution as well as the
mechanical power required to drive the CO2 compressors [31]. So for this case, 11%
of the flue gases will be considered. The theoretical approach to defining the
fraction of flue gas mass flow captured is outlined in Section 3.6 while the results
are presented in Section 4.9.
Post combustion, amine-based CCS works in the following way. CO2-rich flue gas
enters the absorption column as shown at 25°C. The flue gas leaves the boiler at
165°C. Despite being open to the atmosphere and therefore losing the vast majority
of this heat, there is a requirement for the flue gas to pass through a heat exchanger
to ensure the temperature entering the CCS stage is at 25°C. Two moles of amine
reacts with each mole of CO2 that passes through the column. This reaction process
has an efficiency of 90%. The now amine rich solution is passed though the heat
exchanger together with the lean amine solution coming from the de-absorption
column and undergoes preheat before passing into the de-absorption column. Bled
off working fluid heats the solution to 130°C, supplying the enthalpy required to

17
break the CO2-amine bonds. In this process, one mole of H2O evaporates for every
mole of CO2 captured. The now lean amine solution leaves the desorber, passes
through another heat exchanger and comes out as liquid at 100°C. At this stage the
CO2 leaves the desorber in a pure stream and enters the first compressor stage.
Further heat exchanging is required before the gas can be compressed in multiple
stages to 7.38MPa and 31°C.
3.2 Live Steam Parameters
Table 5 below details the exact conditions of the working fluid at it moves
throughout the cycle of the plant.
Balloon
Number
(Figure 3)
Stage Condition Pressure
(bar)
Temperature
(°C)
1 Pump Inlet Saturated liquid 6.5 170
2 Pump exit boiler
inlet
Saturated liquid 168 255
3 HPT inlet Saturated vapour 168 540
4 HPT exit Saturated vapour 40 340
5 After reheat/
MPT Inlet
Saturated vapour 40 540
6 LPT inlet Saturated vapour 20 435
7 LPT exit Liquid/vapour mix 30x10−3 50
8 Compressor exit Saturated liquid 6.5 <50
6ccs CCS bleed flow Saturated vapour 20 435
6fw Feedwater
preheating bleed
Saturated vapour 20 435
Table 5 Working fluid live parameters
The heat energy needed to increase the temperature from under 50°C to 170°C is
provided by the feedwater preheaters using bled steam from the turbines. Please
refer to Figure 6 where the data tabulated above is displayed graphically.

18
3.3 Land Requirement
As mentioned earlier, there was a requirement for the biomass to be sourced
indigenously. In a future where energy provision security and reliability will prove
ever more crucial, this was a necessity. SRCW is suitable to the temperature climate
here in Ireland and it can stimulate existing, and provide new, forms of rural
employment.
There were a number of key elements to providing the biomass required to fuel the
128MW facility in Edenderry.
 Do not impinge upon exiting farmland; be that grasslands, crops for human
consumption and crops for agricultural use.
 Do not adversely impact local ecosystem. A study by the International Panel
for Sustainable Resource Development found that the introduction of certain
crops into areas previously deemed non-suitable lead to an abundant
overuse of nitrogen and phosphorus in soils that caused hypoxia in rivers
and streams locally [32]. However, the benefit of SRCW is its low nitrogen
dependence and hence avoidance of this phenomenon.
 Dependence on crop(s) with proven track record of strong growth in
temperate Irish climate. As Styles et al [33] concluded, SRCW requires less
intensive cultivation, less fertilisation and less harvesting intensity due to
two year growing cycle. It must be noted that on this latter point that the
yield for SRCW in comparison to miscanthus, for example, is not inferior
as a result [34].
 Dependence on crops that are realistically and financially suitable for Irish
growers. There is no point in stating how potentially great SRCW can be if
there are no land owners willing or able to grow it. The study by Jones et al
[35] shows that with additional government incentives, a stable indigenous
market (ie demand such as fuelling Edenderry) and increased awareness of
the many advantages of SRCW; low cultivation, harvesting requirement and

19
waste water treatment potential, the required 30000 hectares for fuelling
Edenderry exclusively with SRCW can be achieved.
The land requirement was based upon the Dulong equation-derived calorific values
[36] for peat and SRC, the annual required energy input, Ereq, of 7.7 PJ and the
number of tonnes of SRCW per hectare, tha, which in this case is 13 tonnes [37]
Eha = tha ∗ CVfuel ∗ 1000 Equation 1
The total land required was derived from equation 2 below.
Landreq =
Ereq
Eha
Equation 2
According to a commercial study [8] , there have been on average 14600 hectares
of land approved for planting in the years 2009-2013, with a high of 19000 hectares
approved by the Irish government in 2010. In Section 3.1 of this report, it will be
shown that the annual land requirement to fuel Edenderry to be roughly 27000
hectares. It is clear to see that with sustainable and correct planning, the shortfall
could be made up in a number of years without unduly impacting on agricultural
land used for livestock, feedstock and crops for human consumption.
3.4 Thermodynamic Analysis: Steam Cycle
To analyse and model the biomass-fired plant, the properties of the steam cycle had
to be found at all stages. Thanks to the help and support of the staff at the plant
during the onsite visit at the beginning of the year, some of the important
thermodynamic conditions of the various cycle stages were already known before
any analysis began. In the Matlab model of the cycle, an online script of the steam
tables, XSteam, was used extensively. This resource allowed for any
thermodynamic property of a given state to be found once at least two properties of
that state were known.

20
In the cycle itself, the overall efficiency, η, of the plant was found by using equation
3 below.
ηth =
WTOT
Ein
Equation 3
WTOT was determined by subtracting the work required to drive the pumps and
compressors from the work outputted by the turbines. See equation 4 below.
WTOT = [(WHPT + WIPT + WLPT) − (WFWP)] ∗ ṁ wf Equation 4
The total energy into the cycle, Ein, was determined by using equation 5 below. The
calorific value, CV, is calculated in Section 3.5 of this report.
Ein = ṁ fuel ∗ CVfuel Equation 5
Equations 6-9 below show how the work across each stage was calculated. It must
be noted at this point that the isentropic efficiencies of pumps and turbines were not
factored in at this time. Pump and turbine work was assumed adiabatic and
reversible. Refer to Figure 3 in this document for the enthalpy subscripts at each
stage.
WFWP = h2 − h1 Equation 6
WHPT = h3 − h4 Equation 7
WIPT = h5 − h6 Equation 8
WLPT = h6 − h7 Equation 9
Isentropic pump efficiency, 𝜂 𝑝, was taken at 0.7 while isentropic turbine efficiency,
𝜂 𝑡, was taken at 0.9. In order to determine the real work done by the turbine and the
pump, equations 10-13 were used.
WFWPs = h2s − h1 Equation 10
WHPTs = h3s − h4 Equation 11
WIPTs = h5s − h6 Equation 12

21
WLPTs = h6s − h7 Equation 13
In order to determine the real enthalpy, hxs, the following equations were used in
conjunction with the known isentropic pump and turbine efficiencies. All variables
below are known except for the required hxs.
ηt =
h3−h4
h3−h4s
Equation 14
ηp =
h2−h1
h2s−h1
Equation 15
3.5 Calorific Value Calculation
Table 6 below shows the chemical composition of SRCW and milled peat. The data
was obtained from a variety of published journals [17], [38], [39].
Variable SRCW Milled Peat
γC 0.554 0.4374
γO 0.325 0.3897
γN 0 0.05
γS 0.03 0
γASH 0.064 0.1121
γH 0.054 0.058
Table 6 Chemical Composition of the two solid fuels
In order to calculate the calorific value of the two fuels, equation 16 (Dulong
Equation) below was used. It is not practical to include differing subscripts on all
equations. For the purposes of practicality assume that equations are used twice to
find CV values for both SRCW and peat.
CVfuel = 34000γC + 144000(γH − 0.125γO) + 9440γS Equation 16

22
3.6 Flue Gas Mass Flow Rate Determination
The European standard EN 12952-15 [40] was used as a base throughout the
following calculations to accurately determine the flue gas mass flow rate of milled
peat and SRCW. It is not practical to include differing subscripts on all equations.
For the purposes of practicality assume that equations are used twice to find values
for both SRCW and milled peat.
Graham et al at E.on, Vattenfall and Kema [41] outline the validated approach for
determining the flue gas mass flow rates in solid fuel combustors. The accurate
determination of the flue gas mass flow rates was crucial in defining the parasitic
impact CCS capture would have on the plant. As discussed earlier, it is not practical
nor commercially feasible at present to capture 100% of flue gas CO2. Instead,
plants such as Shidongkou No. 2 in Shanghai and Staudinger Unit 5 in Germany
capture no more than 5% of flue gas CO2. The facility at Shanghai uses 3GJ/tonne
CO2 captured [26]. This is a substantial quantity of energy for a 5% capture rate.
Nonetheless, there is justification for CCS. Any technology that can permanently
reduce flue gas CO2 by any noticeable measure must be pursued.
Figure 9 in Section 4.9 shows the impact the increasing percentage of flue gas CO2
captured has on overall plant efficiency. In order to determine such a relationship,
the flue gas mass flow rate from the burning of milled peat and SRCW had to be
determined. This section is concerned with this requirement.
The first step was to determine the volume of flue gas emitted per unit mass (kg) of
fuel used. This was done using equation 17 (equation A.5N on page 85 of EN
12952-15) below.
Vflue = −0.06018(1 − γash − γH2O) + 0.25437(Ein + 2.4425γH2O) Equation 17

23
The next step outlined in the standard was to determine the fuel factor of both
SRCW and peat. This was done using equation 18 below. Two separate values for
peat and SRCW were obtained.
𝐅𝐅 =
𝐕𝐟𝐥𝐮𝐞
𝐂𝐕𝐟𝐮𝐞𝐥
Equation 18
The next step involved defining the volume flow rate.
V̇flue =
Pout∗FF
ηth
Equation 19
Finally, the mass flow rate could be determined by multiplying by the density of air
at 1atm and 435K (flue gas pressure and temperature) which was a value of
0.815kg/m3
.
ṁ flue = V̇flue ∗ ρ Equation 20
3.7 Thermodynamic Analysis: Parasitic Operators
This thermodynamic analysis was divided into two key areas:
 Heat requirement to preheat feedwater to 255°C
 Heat requirement to overcome amine-CO2 bonds in desorber
 Work requirement to drive the three-stage CO2 compression system
3.7.1 Preheating Feedwater
In order to determine the power needed to preheat the feedwater to the parameters
laid out in Table 5, it was first necessary to determine the bleed rate of steam
required from the working cycle. Please refer to Appendix A: Main Code where
the code used for this procedure is shown. The heat into the feedwater heater was
simply taken as the enthalpy change across the feedwater heater, as shown and
labelled in Figure 3.

24
Qfw = h1 − h8 Equation 21
The total mass flow rate of the working fluid is a known parameter [7] and so once
the bleed mass flow rate was identified, the power requirement for the feedwater
preheaters could be found. The bleed mass flow rate was identified by analysing
the data whereby the bleed rate was iteratively looped for values from 1kg/sec to
100kg/sec. The bleed mass flow rate that eventually gave out an overall efficiency
value close to the known 38.1% thermal efficiency was used. The Matlab technical
approach will be discussed in greater detail in Section 3.8 of this report.
In order to determine the model thermal efficiency, equations 3-5 were used with
the addition of the mass flow rate reduction fraction going into the low pressure
turbine due to the bleed rate after the intermediate pressure turbine. Equation 22
below shows the modified approach.
WTOT = {[ṁ wf ∗ (WHPT + WIPT)] + [ṁ bleed ∗ WLPT)]} − [(WFWP ∗ ṁ wf) + (ṁ bleed ∗ Qfw)]
Equation 22
The overall thermal efficiency (equation 3) of the plant operating on peat and
biomass could then be determined. All other variables were set: calorific value,
work of turbines and pumps and the mass flow rate of the fuels into the boiler.
Therefore it was possible to constrain the iterative loop to finding the bleed flow
fraction with just one unknown. This was possible as the unknown had a value lying
within a known range. The data from this range of values was analysed and the
bleed mass flow rate that eventually generated an overall thermal efficiency closest
to 38.1% was used. The results on this analysis are included in Section 4 of this
report. The work output from the HPT and IPT remained the same as the bleed took
place after the IPT. Therefore, only the mass flow rate through the LPT, and hence
output work, was affected.
3.7.2 Heat Requirement for CCS Process
A number of base variables required for the combustion analysis of both peat and
SRCW are summarised in Table 7 overleaf.

25
Variable Value (g/mol)
M(C) 12
M(O) 16
M(N) 14
M(H) 1
M(H2O) 18
M(CO2) 44
M(Amine) 61
ηcap 0.9
Rc 3.67
Table 7 Molar masses for elements of interest
The principles of operation of the post-combustion, amine based CO2 capture used
in this model are outlined in Section 3.1.2 of this report and will not be repeated
here. Please refer to this section before proceeding herein. The following formulae
are the generic case. In reality they are used twice, once for peat and once for
SRCW. It is not practical to include two sets of equations with differing subscripts.
The reader may take these as the base formulae with generic variables attached for
the purposes of efficient report writing. The first step in this combustion analysis
was to define the number of moles captured per second from combustion of a given
fuel.
M(CO2) =
ṁ fuel∗Rc∗γc
ηcap
Equation 23
There is a requirement for two moles of amine for every mole of CO2 captured.
M(Amine) = M(CO2) ∗ 2 Equation 24
Table 8 overleaf shows the common parameters used for both peat combustion-
based and SRCW combustion-based CO2 capture. Please refer to nomenclature.

26
Variable Value
Tli
100
Tlo
25
Tri
10
Tro
85
CH2O 4.180
M(CH2O) 0.075
CCO2
0.846
M(CCO2
) 0.037
LV 2.257e3
hstrip 84.44
hchange 40.63
Table 8 CCS parameters
The total number of moles in the amine-CO2 solution is found using equation 25
below. The value was found to be 17.81.
Nsol =
2∗M(Amine)
0.3
M(H2O)
Equation 25
The heat requirement to increase temperature of rich solution to 100°C is outlined
in equation 26 below.
Q85_100 = Nsol ∗ M(CH2O) ∗ (Tli
− Tro
) Equation 26
The heat requirement to evaporate the water from the solution is outlined in
equation 27 below. Nevp are the amount of moles of H2O evaporated per mole of
CO2 captured.
Qevp = Nevp ∗ hchange Equation 27

27
The heat requirement to overcome the amine-CO2 bonds is outlined in equation 28
below. The temperature required to break these bonds, Tbreak, is 130°C.
Q100_130 = [(Tbreak − Tli
) ∗ ( Nsol − Nevp) ∗ M(CH2O)] + [Nevp ∗ M(CCO2
)]
Equation 28
The heat requirement for the stripping reaction is outlined in equation 29 below.
Qstrip = Nevp ∗ hstrip Equation 29
The total heat input required for the entire CCS process is shown below in equation
30 below.
QCCS = Qstrip + Q100_130 + Qevp + Q85_100 Equation 30
In order to determine the power requirement, or parasitic load, of the CO2 capture
process, the total heat requirement, QCCS, is multiplied by the fraction of flue gas
mass flow rate the system will be capturing. There are two separate flue gas mass
flow rates for peat and SRCW due to their differing combustion characteristics.
These mass flow rates, calculated in Section 3.6 of this report, are summarised
below in Table 12.
3.7.3 CCS Compression Power Requirement
There are a number of online resources available for defining the thermodynamic
properties of CO2 at a given pressure and temperature [42]–[44]. These are fantastic
tools for referencing the required properties. However, such resources should be
used as a comparison tool only. Another approach engineers, researchers and
scientists take is to use an equation of state such as the Redlich-Kwong Law.
Wedebrock et al at the University of South Florida [45] and Campbell et al [46]
outline such an approach. However, this type of analysis presents challenges in the
form of discrepancies that occur as the CO2 transitions from the subcritical to the
supercritical state. The method that has become an industry standard and the method
used in this report is the use of the published CO2 tables of Anwar and Carroll [47].

28
Please see Appendix B1 and B2 for table extracts, it is not practical to include all
300 pages of tables.
Interpolation is required to determine a required property at a given pressure and
temperature. Equation 31 shows the formula used for this step.
y = (
y1−y2
x1−x2
) (x − x1) + y1 Equation 31
It is useful to note that the tables with values that have minus signs attached
represent exothermic properties.
3.8 Matlab Technical Approach
There were a number of critical parameters that could only be determined iteratively
using Matlab. These were:
 Bleed mass flow rate for feedwater preheaters
 Fraction of flue gas captured and resulting impact upon plant efficiency
 Bleed rate required to provide heat to CCS process and hence work required to
drive compressors.
For each iterative loop incorporated in the code, values were taken with known
limits and then compared to known real life data to ensure validity. For example,
the fraction of flue gas captured for the burning of peat would go from a nominal
value of 0kg/sec to a maximum of 150.4095kg/sec, the maximum flue gas mass
flow rate for peat as shown in Table 12. The impact this had upon the overall plant
efficiency, and a realistic value requirement for plant efficiency in order for it to be
commercially sustainable, was taken at ten percentage points below the known
plant efficiency of 38.1%. Therefore, there was room to capture as much CO2 in the
manner demonstrated as would result in a net plant efficiency drop of 10%. The
data gathered was then graphed in Excel.

29
3.9 Total Specific Heat Energy in System
The nameplate capacity of Edenderry powerstation is 128MW. This translates to
128 x103
kJ/sec. The mass flow rate of the working fluid is 100kg/sec. By using
these two known variables, it is possible to determine the specific heat energy of
the system using equation 32 below.
P = ṁ wf ∗ Cheat Equation 32
By manipulating equation 32 above, a value for Cheat is determined at 1280 kJ/kg.
3.10 Tonnes of 𝐂𝐎 𝟐 Captured Per Annum
Equation 33 below was used to determine the total CO2 captured every year in the
SRCW burning cycle that uses post combustion CCS at the percentage of capture
determined in the analysis. The capacity factor was determined by the averaged
amount of downtime the plant at Edenderry has experienced over the past five years.
This was found to be 0.83.
(ṁ Co2SRCW
)(ηcapflu
)(syear)(CF) Equation 33
3.11 Levelised Cost of Electricity
The levelised cost of electricity is the price per unit electricity must be sold at over
the duration of a powerplants lifetime. Equation 34 below is used to determine this
useful and powerful comparative tool.
ΣT [(CapT + CarbonT + FuelT + O&MT + DecomT + CO2(Trans + Stor)T )(1 + r)]−T
)
ΣT (Elec GenT )(1 + r)−T)
Equation 34

30
A number of these variables were obtained from peer reviewed journals [48], [49],
others from government websites [50]–[52] and [53] while others still could be
determined theoretically. (1 + r)−T
is the discount factor. It places a time value on
money and lessens over time. It simulates the lessening value of today’s money in
the future due to inflation effects. The values are listed in Table 9 below.
Variable Value Source
Years of operation 50 Nominally selected
Nameplate capacity 128 MW Known
Capacity factor 0.83 Calculated
Capital cost $800,000,000 Research
Capital cost-CCS $880,000,000 Calculated from above
Annual energy produced 7.7 PJ Known
O&M $110/kW per annum Research
O&M-SRCW $140/kW per annum Research
O&M-CCS $160/kW per annum
Construction time 7 Research
Peat plant efficiency 0.381 Known
SRCW plant efficiency 0.33 Calculated
SRCW with CCS plant
efficiency
0.271
Calculated
Annual fuel consumption -
SRCW
1,000,000 tonnes
Calculated
Annual fuel consumption - peat 770,000 tonnes Calculated
CO2 emitted per annum -peat 880,000 tonnes Calculated
CO2 emitted per annum -
SRCW
550,000 tonnes*
Calculated
CO2 capture efficiency 0.9 Known
Carbon tax $20 Research
CV peat 7.705 MJ/kg Calculated
CV SRCW 11.241 MJ/kg Calculated

31
Table 9 Table of variables for LCOE calculations
*This figure of 550,000 tonnes is an absolute figure of tonnes of CO2
emitted. However SRCW is a carbon neutral fuel due to its ability to absorb
CO2 during its growing cycle. Hence, there is no carbon cost associated with
the burning of SRCW.
Table 9 above lists the variables required for the LCOE calculation and the origins
of the same. An excel spreadsheet was created and the LCOE for each the following
was created:
1) Basic peat burning cycle without CCS
2) Basic SRCW burning cycle without CCS
3) SRCW cycle with CCS.
In order to compare each electricity generation form from a level base, the analysis
was conducted on the basis that the plant was not yet constructed and would run for
50 years once operational. A nominal increase of 10% was applied to all CCS
related costs as outlined in the literature cited in this section. Please refer to
Appendix C: LCOE Spreadsheets for images of the calculator created for this
analysis.
Peat fuel cost $10 per tonne Research
SRCW fuel cost $70 per tonne Research
CCS costs (storage and
transport)
$13/tonne captured Research
Discount Rate 0.1 Research
Decommission Cost $3,500,000 Research
Decom Costs-CCS $4,000,000 Calculated from above

32
4. Results
4.1 Land Requirement
Ereq= 7.7x106
GJ/annum
tha= 13 tonnes
Eha= 273.59 GJ
Landreq =
7.7x106
GJ/annum
273.585 GJ/ha
Landreq = 28144.817 Ha/annum
4.2 Calorific Values Determination
Using the Dulong equation (equation 16) and the data summarised in Table 6, the
CV of the two fuels of interest could be determined.
Fuel Calorific value (MJ/kg)
Milled peat 7.705
SRCW 11.241
Table 10 Dulong equation-derived calorific values
4.3 HPT, IPT and LPT Work
As shown in Section 3.9 of this report, the specific heat of the system as a function
of known nameplate capacity and known working fluid mass flow rate is found to
be 1280 kJ/kg. Table 11 overleaf summarises the Matlab generated data.

33
Turbine Specific Energy-
Δh (kJ/kg)
Turbine Work
(*𝐦̇ 𝐰𝐟) (kW)
% of Total
Work
HPT 335.0066 33500 26.5
IPT 211.8899 21189 16.5
LPT 731.5658 73157 57
Table 11 Matlab generated values for turbine work across all three turbines
The total turbine work generated computationally sums to 127.846 MW. This figure
is within 0.0013% of the real life nameplate capacity of the plant.
4.4 Thermal Efficiency of Peat Combustion without CCS
There were a number of different operating conditions considered for this report:
 Basic steam cycle with milled peat combustion
 Basic steam cycle with SRCW combustion
 Basic steam cycle with SRCW combustion with addition of post combustion
CCS.
Separate thermal efficiencies had to be defined for each of these operating
conditions. As a base level, and as a model validation parameter, the efficiency of
the basic peat burning cycle was first analysed and compared to the real life value
of 38.1% in the process described in Section 3.7.1. The actual figure attained
computationally was 37.97%.
Below shows the results of the first sixteen loops whereby the bleed mass flow rate
goes from 1kg/sec to 16kg/sec. The intersection point of the real thermal efficiency
and the computationally obtained data outputs the required mass flow rate. The
graph illustrates the decrease in efficiency with respect to increasing bleed rate.

34
Figure 5 Graphically determining bleed mass flow rate
4.5 Flue Gas Mass Flow Rate Calculation
Fuel Flue Gas Mass Flow Rate (kg/sec)
SRCW 150.4095
Milled Peat 183.4756
Table 12 Matlab obtained flue gas mass flow rates
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
0 2 4 6 8 10 12 14 16
ThermalEfficiency
Bleed Mass Flow Rate (kg/s)
Thermal Efficiency vs Bleed Mass Flow Rate
Impact of Bleed Fraction
on Efficiency
Known Efficiency
Required Mass Flow Rate

35
4.6 T-s Plot of Cycle
Figure 6 Live steam cycle plot
4.7 Bleed Mass Flow Rate Fraction for Feedwater Preheating
The results in this section are closely related with those obtained in Section 4.4.
Referring to Figure 5, the intersection of the real life and computational data occurs
at a bleed flow rate of 12 kg/sec, or a bleed fraction, f, of 0.12. This is the required
mass flow rate to deliver the 2303 kJ/kg of specific energy to the preheaters to
increase the temperature of the feedwater from below 50°C to 170°C.
4.8 Thermal Efficiency of SRCW Combustion without CCS
By using the known thermal efficiency for the burning of peat in Edenderry, it was
possible to validate the model and find the required bleed mass flow rate to feed
heat to the preheaters. With model validation achieved, it was then possible to

36
translate this approach to determining the efficiency of 100% SRCW combustion
at the plant.
Figure 7 Determining thermal efficiency with SRCW as fuel
From Figure 7, the efficiency of the plant operating with 100% biomass is 33.78%.
The slight reduction in plant efficiency can be attributed to a number of combustion
variables that will be discussed in greater detail in Section 5 of this report.
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0 2 4 6 8 10 12 14 16 18 20 22 24
ThermalEfficiency
Bleed Mass Flow Rate
SRCW Efficiency (without CCS)
SRCW Efficiency
Series2

37
4.9 Thermal Efficiency of SRCW Combustion with CCS
Figure 8 Increasing levels of flue gas capture increases compressor work
Figure 8 above demonstrates the increase in the parasitic CCS load requirement as
the percentage of CO2 captured increases. This parasitic load is made up of two
main components: 1) The heat required for the rich solution and 2) The work
required to drive the compressors. This cumulative load is demonstrated here.
Figure 9 Impact of CCS on thermal efficiency
0.00E+00
5.00E+03
1.00E+04
1.50E+04
2.00E+04
2.50E+04
3.00E+04
3.50E+04
4.00E+04
0 20 40 60 80 100
CompressorWork(kW)
% Flue Gas
% Flue Gas Captured vs CCS Work Requirement
Series1
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0 20 40 60 80 100
SRCWCombustionThermalEfficiency
% of Flue Gas Captured
% of Flue Gas Captured vs Thermal Efficiency
% Captured vs
Efficiency
28.1% Efficiency Cut
Off
Series3
11

38
Figure 9 demonstrates the linear reduction in thermal efficiency of the SRCW cycle
as the percentage of CO2 captured increases. A ten percentage point drop in overall
plant efficiency versus the original peat based cycle was shown to be the absolute
maximum drop allowed. A higher capture rate would render the plant commercially
obsolete. The intersection point of the two curves indicates the maximum capture
level would be 11%. The thermal efficiency of the SRCW cycle with CCS is 28.1%.
4.10 Tonnes of 𝐂𝐎 𝟐 Captured Annually
This definition of flue gas mass flow rate captured shown in Section 4.9 presents
the following values for tonnes of CO2 captured per annum:
ṁ SRCW = 24.42 kg/sec
ṁ Co2SRCW
= 16.23 kg/sec
Tonnes of CO2 captured per annum:
(16.23)*(0.11)*(365)*(24)*(3600)*(0.83) = 46,760 tonnes of 𝐂𝐎 𝟐 per annum
Based on current prices of carbon tax per tonne CO2 [54] of €20, this represents a
saving of €935,000 per annum for just an 11% capture rate.
The values for the variables outlined in Table 9 were inputted into an Excel
spreadsheet and summed iteratively from 1 year to 50 years using equation 34.
Please see Figure 10 overleaf.

39
Figure 10 LCOE results for the three operating conditions
From Figure 10, the following is obtained:
Process Type LCOE (cents/kWh) Empirical LCOE (cents/kWh)
Milled Peat 16.36 8-11 [53], [55]
SRCW 20.82 11-15 [56], [52]
SRCW with CCS 31.23 N/A
Table 13 LCOE Results compared to empirical data
The reasons for the calculated LCOE being higher than the empirical results are
Irish market dependant and will be discussed in greater detail in Section 5 of this
report.
16.35764664
20.81964544
31.25595414
0
5
10
15
20
25
30
35
LCOE(cents/MWh)
Milled Peat
SRCW
SRCW with CCS

40
5. Discussion
The model has been created, the data analysed, tabulated and graphed. The results
have been referenced against empirical datasets to ensure their validity. In this
section the results will be examined and the model motives probed.
5.1 Breakdown of Turbine Work
Analysis of the Matlab model quickly showed that the LPT was responsible for the
majority share of the 128MW that the plant produces. The onsite visit on the 19th
February corroborated this result where a control room reading indicated the LPT
was providing 51% of the total plant work at that instant. The Matlab modelled
developed for this report indicated this figure to be 57%.
The result is interesting yet credible. The superheated vapour entering the HPT, and
the MPT after reheat, remains at an elevated temperature throughout. In other
words, there is not a massive emphasis placed upon maximum heat extraction but
rather optimum steam quality to preserve the first two high performance turbines.
Any water droplets present in the fluid stream at this stage and blade erosion would
be expedited. The minimal heat extraction that occurs at these stages reflects in
lower work outputs by both turbines. In the last stage, the exhaust from the IPT
simply exits straight into the LPT. An emphasis is placed upon maximum heat
extraction. The LPT inlet temperature is 435°C and outlet temperature is 50°C. This
represents the highest temperature drop across any of the three turbines which in
itself represents the highest enthalpy change. The higher the change in enthalpy
within a system, the more specific energy transference is occurring. This in turn
means the most work is being done.

41
The results obtained are interesting. To the uninformed observer, the values
generated appear to diverge from empirical data. However, there are a number of
crucial reasons for this disparity. First of all, the cost of fuel in the Irish context is
more than that of other countries. The plant visit was eye-opening with regards to
the politics of electricity generation with peat. There are many groups actively
involved in the perseverance of Irish bogs and would rather see them untouched.
This presents many difficulties for Edenderry Power Ltd that has culminated in
price hikes over the past number of years as the government needs to be seen to be
doing something to appease the many stakeholder groups involved. The newly
ratified Paris Accord will see a cohesive approach to tackling atmospheric carbon
levels. This approach will see increases in carbon tax and this report has facilitated
for such an increase. This is reflected in the LCOE generated for peat.
With regards to the LCOE of SRCW, a number of parameters were involved in the
calculations that constrained the competitiveness to a large extent. The absolute
requirement that the biomass crop be sourced indigenously was the main cause of
this. A low uptake for willow plantations in this country is a result of non-
competitive government incentives and a small market in which the produce can be
sold. An Irish farmer cannot at present make as much of a living from a hectare of
willow as from a hectare of corn or wheat. These are the simple economics of the
situation at present. In order to reverse this, prices for indigenous willow will have
to be higher in order to be attractive for Irish landowners. The result is that the fuel
cost for SRCW will be far higher than peat at present.
Finally, SRCW with CCS is merely a theoretical pipedream and there doesn’t exist
a single commercial example of it in any capacity at present. The motivation and
theory for such a cutting edge setup would facilitate for a dramatic reduction in
global atmospheric carbon levels were it to become commonplace. The LCOE
generated is substantially higher than that of peat and the contrast is even more
drastic when compared to a technology like clean coal, which has an LCOE of
approximately 10cents/kWh [57]. However, the cost savings on carbon captured
and the subsequent reduction in carbon tax would amount to approximately €46.75
million over a typical 50 year plant lifespan, based on the figures calculated in this
report.

42
5.3 Flue Gas Capture Level
From the outset, there was a resolve to limit the impact on efficiency of CCS to ten
percentage points below the current peat burning efficiency of 38.1%. This gave a
working range in which to iteratively increase the percentage of flue gas captured
by the CCS process until an efficiency of 28.1% was reached. Figure 9 above
displays this graphically. 0.11 was the fraction of flue gas deemed acceptable in this
case. This capture level still renders the plant a net carbon negative source of
electricity generation which was the original objective of this research project. The
remaining 89% of the flue gas will be exhaust to the atmosphere. However, due to
the fact that the combustion involves carbon neutral biomass, the consideration for
a 100% capture rate is not of concern. In fact, as has been stated earlier in this report,
such is the parasitic load CCS has on the output of a plant, every current CCS
project around the globe at present captures no more than 10% of the flue gas CO2.
5.4 Reduction in Efficiency of SRCW Cycle
Edenderry Power Ltd. have noticed a number of changes in maintenance intervals
since the percentage of biomass being used at the plant for power generation has
increased. Biomass has been found to be more problematic that peat, owing to its
chemistry [16]. Boiler tube corrosion due to higher levels of alkaline halides,
sodium, potassium and chlorine has resulted in more frequent cleaning, and in some
cases overhauling, of key pipe infrastructure.
Furthermore, hugely expensive boiler fouling caused by the high levels of sodium
and potassium and the higher temperatures caused by the higher calorific value fuel,
have resulted in a complete boiler overhaul by manufacturers- Finnish company
Kaevrner. All of this activity has resulted in an incremental drop in the capacity
factor of the plant which is reflected in the slightly lower efficiency value of

43
33.78%. However, these adverse effects of biomass combustion are hugely offset
by the impressive reduction in carbon emissions.
5.5 Validity of Matlab Model
The accuracy of the model is evident in a number of the output variables mentioned
for analysis in this report. The total power generated from the three turbines sums
to 127.846MW, or within 0.0013% of the nameplate 128MW Edenderry outputs.
The requirement for bled steam to heat the feedwater entering the feedwater pump
was a crucial yet complicated variable to execute correctly yet its inclusion further
enhanced the creation of a coherent and credible model. The final bled mass flow
rate of 12kg/sec was, once found, included as a standard variable in all subsequent
analysis on both the SRCW cycle and the SRCW with CCS cycle. The SRCW
model with CCS was therefore the most complicated to execute given that it
included two bleed rates for the CCS rich solution requirements and for the
preheating of the feedwater.
5.6 CCS Analysis
In the model included in this report, three CO2 compressor stages are used. It is
found that increasing the number of compressor stages, thereby reducing the
requirement for massive enthalpy changes across individual stages, reduces the
amount of overall parasitic load of the CCS compression system. Bolea et al [58]
discuss the possibility of intercooling compression thereby having an element of
heat recovery included thereby reducing compressor work. In the model generated
for this analysis, a token heat recovery amount of 0.65 was selected to reflect some
heat recovery between compression stages. This author would like to highlight this
section of the model as being one open for further investigation.
There is however, a limit to the number of compressor stages that can be included.
The increase in the number of stages is linked to reaching the isothermal limit of
compression work [59]. Furthermore, on a practical level, the increase in the

44
number of compressor stages exponentially increases the complexity of the plant
resulting in increased maintenance costs, breakdowns and monitoring equipment.
6. Concluding Remarks
A project to model the 128MW, peat-burning facility at Edenderry, Co. Offaly was
undertaken. The model incorporated three distinct processes that were however
intrinsically linked by a number of key variables. Initially, the base peat burning
cycle was analysed. A cycle efficiency of 37.97% was generated while a net work
output of 127.846MW was produced. This first cycle was used to determine the
bled steam mass flow rate requirement for the feedwater preheaters. This bleed rate
was determined to be 12kg/s. Next, the biomass burning cycle was analysed using
the same bled steam mass flow rate as before. The plant efficiency was found to be
33.78%. However, fuel usage decreased by 23% due to the higher calorific value of
the fuel. Finally, the SRCW cycle with CCS was analysed. There were a number of
parasitic loads placed on the system; heat requirement for the rich solution to break
the amine-CO2 bonds and the work requirement to drive the CO2 compressors. It
was not feasible or indeed possible to capture 100% of the flue gas so an iterative
loop was set up to investigate the percentage that could be captured that would result
in a maximum ten percentage point drop in overall plant efficiency. This approach
generated a capture rate of 11% at a cycle efficiency of 28.1%. Approximately
46000 tonnes of CO2 would be prevented from entering the atmosphere annually at
this capture level, creating Europe’s first carbon negative electricity generation
source. The objectives set out within this research report have been met and the
opportunities and challenges for the burgeoning technology that is carbon capture
and storage have been demonstrated.

45
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51
Appendix A: Main Matlab Code
%FYP Michael Ryan, 11323146
%Thermodynamic and Combustion Analysis of Edenderry Powerplant
with 100% Biomass
clear all
clc
close all
PowerOut = 128e3; %Electric power output required of the plant
(kW)
CVP = 7.7e3;%calorific value of peat kJ/kg (Dulong Equation)
CVW = 11.241e3;%calorific value of SRCW kJ/kg (Dulong Equation)
TnP = 1000000000;%kg required per annum of peat
TnW = 770000000;%kg required per annum of SRCW
CF = 0.83; %Capacity factor based on plant availability over past
5 years
syear = 24*60*60*365;%seconds in a year
mdotp = TnP/syear;%mass flow rate of milled peat required per
second (kg/s)
mdotw = TnW/syear;%Mass flow rate of SRCW required per second
(kg/s)
Eannual = 7.7E12; %Annual energy requirement of Edenderry 7.7PJ
rho = 0.815; %density of water (kg/m^3)
%The following are the thermodynamic conditions at each stage of
the cycle
Npump = 0.7; %Isentropic efficiency of the feedwater pump
Nt = 0.9; %Isentropic efficiency of the turbines
%Feedwater pump exit conditions
P2 = 168;
T2 = 255;
s2 = XSteam('s_pt',P2,T2);
h2 = XSteam('h_pT',P2,T2);
v2 = XSteam('v_pt',P2,T2);
x2 = XSteam('x_ph',P2,h2);
%Feedwater pump inlet conditions-saturated liquid
P1 = 6.5;
s1s = s2; %assuming isentropic efficiency
T1s = XSteam('Tsat_s',s1s);
h1s = XSteam('h_pt',P1,T1s); %assuming isentropic efficiency
h1 = (0.3*h2)+(0.7*h1s);
T1 = XSteam('T_ph',P1,h1);
s1 = XSteam('sL_p',P1);
v1 = XSteam('vL_p',P1);
%HPT inlet steam parameters
P3 = 168; %combustion pressure
T3 = 540; %combustion temperature
h3 = XSteam('h_pt',P3,T3);
%HPT exit steam parameters

52
P4 = 40;
T4 = 340;
%IPT Inlet steam parameters- Still superheated vapour condition
P5 = P4;
T5 = T3;
%MPT exit/ LPT inlet steam parameters
P6 = 20;
s6s = s5;
h6s = XSteam('h_ps',P6,s6s);
T6s = XSteam('T_ph',P6,h6s);
h6 = h5-(Nt*(h5-h6s)); % Isentropic pump efficiency of 0.9 applied
T6 = XSteam('T_ph',P6,h6); % Isentropic pump efficiency of 0.9
applied
s6 = XSteam('s_ph',P6,h6); % Isentropic pump efficiency of 0.9
applied
%LPT exit steam parameters
P7 = 0.03;
T7 = 50;
TT2 = XSteam('Tsat_p',P2);%Sat temperature at 168bar
ss2 = XSteam('sL_p',P2);%Entropy of sat liquid at 168bar
TT3 = TT2;
ss3 = XSteam('sV_p',P2);%Entropy of sat vapour at 168bar
T8 = XSteam('Tsat_p',P7);%Sat temperature at 0.03bar
s8 = XSteam('sV_p',P7);%Entropy of sat vapour at 0.03bar
h8 = XSteam('hL_t',T8);%Enthalpy of sat liquid after condenser
s9 = XSteam('sL_p',P7);%Entropy of sat liquid at 003bar
T9 = XSteam('Tsat_p',P7);%Sat temperature at 0.03bar
%close the T-s curve, back to state 1
s10 = s1;
T10 = T1;
y = h3-h4; %enthalpy change across HPT-representative of fraction
of overall work done
z = h5-h6; %as above for IPT
w = h6-h7; %as above for LPT
%Determining mdotbleed required for preheating feedwater
FeedQ = h1-h8; %Heat needed to preheat feedwater (kJ/kg)
mdotwf = 100; %Live steam mass flow rate (kg/s) #SEAI data on
Edenderry

ME4103 Michael Ryan 11323146 4BM

ME4103 Michael Ryan 11323146 4BM

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