Page 50 - Impiantistica Novembre-Dicemvre 2015

Capital cost
The capital costs of the plants are summarised in
table 2 and breakdowns of the total plant costs are
given in figure 1 and figure 2.
Including capture increases the specific cost per
1kW18e%byfo9r1%thefoIrGthCeCpuclavseeriss,edcocmoaplacreadsetsoatnhde1p1u0l--
verised coal reference plant. This cost increase is
partly due to the cost of additional plant required for
capture and partly due to the reduced net power
output per unit of thermal capacity, e.g. boiler size.
There is no significant difference between the spe-
cific capital costs of the post combustion capture
(PCC) and oxy-combustion plants.
The main cost of additional plant for oxy-combu-
stion is the cost of the Air Separation Unit (ASU).
The ocxoys-tcoofmthbeus“tCioOn2pclaonmtpthreasnsiionnt”huenpitoisst higher in
the
stion plant because the volume of gas to be com-
pressed is greater, due to the presence of impu-
rities, and due to the cost of
Unit (CPU) which removes the
is included in the it“CcoOu2ldcoamlsoprbeesscioonn”siduenritedcotostbine
figure 2, although
a type of “CO2 capture” unit.
Fig. 1 - Specific Total Plant Cost of pulverised coal plants
Fig. 2 - Specific Total Plant Cost of IGCC plants
48 Impiantistica Italiana - Novembre-Dicembre 2015
The specific capital costs of the three IGCC cases
are similar. The MHI air blown gasifier plant has hi-
gher costs for gasification, syngas treating and Acid
Gas Removal (AGR), which is to be expected due
to the higher volume of the fuel gas but it avoids the
cost of a large ASU (the MHI gasifier plant includes
a small ASU which provides nitrogen for coal fee-
ding but the vendor included this in the cost of the
gasification unit).
Levelised costs of electricity and
CO2 avoidance cost
Levelised Costs of aErleecsthriocwityn(LinCtOaEb)lean3daCndO2fiAgvuorei-
dance Cost (CAC)
3. The costs of the IGCC plants are higher than tho-
se of the pulverised coal combustion plants, mainly
combu-
because of higher capital costs and higher fixed
operating and maintenance (O + M) costs, particu-
larly maintenance costs.
timhepuCrOitie2 sP.rTohceesCsPinUg Hydrogen co-production
plants
A summary of the performance of the baseline
hydrogen / power co-production plants is given in
table 4. The “Net efficiency to hydrogen” in this ta-
ble is calculated by assuming that the net power
output displaces electricity generated by a GE ga-
sification IGCC plant ewffiitchieCnOci2ecsaopftcuorea.l It should be
noted that while the fired power
plants are higher on an LHV basis than on an HHV
(High Heating Value basis, hydrogen plants have a
significantly higher efficiency on an HHV basis.
Capital costs and LCOH are shown in table 5. For
the calculation of LCOH, the electricity co-product
is valued at 114.4 €/MWh, i.e. the production cost
of the corresponding IGCC case (GE gasifier). Si-
milarly, the capital cost associated with electricity
production in the IGCC plant is subtracted from the
capital cost of the co-production plants to give the
specific capital cost of hydrogen production. The
highest efficiency and lowest cost of hydrogen pro-
duction are achieved by the plant with the lowest
amount of electricity co-production, which is based
on feeding the PSA off-gas to an on-site boiler.
Plant design sensitivity cases
Near-zero emission plants
The performance and costs of the plants with near-
zero emissions are summarised in table 6, which
also shows the change in efficiencies and costs
compared to plants with 90% capture. Increasing
tchieencpyeracnedntaingcereCasOe2s abatement reduces the effi-
the capital cost and LCOE.
The largest increase in LCOE is for the biomass co-
firing case and the lowest is for the oxy-combustion