Page 47 - Impiantistica Novembre-Dicemvre 2015
P. 47
Emissions to the atmosphere of green-house gases,pofarftoicsusillarfulyelsC,Ow2illemis-• IGCC plant based on MHI (Mitsubishi Heavy
sions from use need Industries) dry feed air blown gasification and
pre-combustion capture using Selexol solvent
to be reduced to avoid the risks of cli- scrubbing.
mate change. The sector which emits The pulverised coal plant without capture is ba-
sed on a single boiler, a net output of around 1000
tion, which macocsot uCnOts2 is power and heat genera- MWe and state-of-the-art steam conditions (27
for 42% of global emissions MPa, 600-620 °C) as used in new large coal fired
power plants in Europe and Japan. The pulverised
r[1e]d. uCcOed2 emissions from power generation can be coal plants with post combustion and oxy-com-
by increasing generation efficiency, use bustion capture have the same coal feed rate but
lower net power outputs of 820-840 MWe due to
of lower-carbon fuels such as natural gas, use of the energy consumption for capture. The coal feed
rate of the IGCC plants is determined by the fuel
renewable energy (wind, solar, hydro etc.) and nu- feed rate of the two gas turbines, which are state
of the art 50 Hz F-class turbines suitable for high
clear energy and by Carbon Capture and Storage hydrogen content gas.
The net power outputs of the IGCC plants are in
(CCS). CCS can be applied to coal, gas, oil and the range of 800-880 MWe, i.e. similar to the pul-
verised coal plants with capture.
biomass based power plants.
This paper concentrates on coal based power
plants, which account for 75% of global CO2 emis-
sions from power generation [1].
IEA (International Energy Agency) has contracted
Amec Foster Wheeler to undertake a study to
provide an up-to-date assessment of the perfor-
mance and costs of coal-based power generation
and hydrogen production plants based on the
cthormeebulesatidoinn,goCxyO-2cocmapbtuusretiotnecahnndoplorgei-ecso,mi.be.usptoiosnt This paper includes an assessment
of three coal gasification hydrogen
capture [2]. The study, which is summarised in this production plants with CCS, all based on
GE oxygen blown gasification and Selexol
paper, provides a baseline for possible subsequent
solvent scrubbing
studies on other capture processes, CCS in indu-
Hydrogen plants
stries other than power and hydrogen generation
Coal gasification plants with CCS could also pro-
and costs of CCS in other countries. duce hydrogen, which can be used as a carbon-
free fuel for separate power plants, CHP (Combi-
It should be noted that the focus of this paper is to ned Heat and Power) plants and distributed energy
consumers. Intermediate storage of hydrogen,
provide an up-to-date technical and economic as- such as in underground salt caverns, could be
included to accommodate variations in end-user
sessment of coal-fired power and hydrogen plants demand. This could potentially be an attractive op-
tion for decarbonisation of power plants operating
with CCS. The study does not aim to provide a at lower capacity factors, which are needed to ac-
commodate the variability of power demand and
definitive comparison of different technologies or variable renewable power generation technologies.
This paper includes an assessment of three coal
technology suppliers because such comparisons gasification hydrogen production plants with CCS,
all based on GE oxygen blown gasification and Se-
are strongly influenced by specific local constraints lexol solvent scrubbing:
• plant with high net electricity co-production,
and by market factors, which can be subject to ra-
including two 130 MWe E-class gas turbines;
pid changes. • plant with intermediate net electricity co-pro-
Plant descriptions duction, including two 77 MWe F-class gas
turbines;
Power plants • plant with low electricity co-production, inclu-
This paper assesses the design, performance and ding a PSA (Pressure Swing Adsorption off-
gas fired boiler.
costs of the following coal based power generation
plants:
• supercritical pulverised coal power plant wi-
• tshuopuetrcCrOitic2 aclapputulvreer(isreefderecnocael plant); plant with
power
post combustion capture based on Cansolv
solvent scrubbing;
• supercritical pulverised coal power plant using
oxy-combustion;
• IGCC (Integrated Gasification Combined
Cycle) plant based on General Electric (GE)
slurry feed oxygen blown gasification and
pre-combustion capture using Selexol solvent Sensitivity cases
scrubbing;
• IGCC plant based on Shell dry feed oxygen All of the baseline power and hydrogen plants are
blown gasification and pre-combustion captu- bbeasaeddeoqnua9te0%forCeOa2rlycaCpCtuSrep. laTnhtiss is expected to
but in the lon-
re using Selexol solvent scrubbing;
Impiantistica Italiana - Novembre-Dicembre 2015 45
