CAPEX
The total capital cost of retrofitting an amine unit to an existing emission source will in addition to the cost of the CC plant itself consist of various integration costs. The integration costs are substantial and may vary signif-icantly from case to case depending on the scope included. The following typical cost elements may be included in retrofit projects in addition to the CC plant costs:
• Boiler for generating low pressure steam to CC plant or modification of steam turbine/new steam tur-bine to allow for steam extraction to CC plant
• CO₂ compression and dehydration or CO₂ liquefaction plant
• Liquid CO₂ tank farm and export facilities
• Extensive heat integration
• Additional flue gas cleaning e.g. desulfurization plant
• Utilities such as cooling tower, water treatment plant, etc.
• Owners cost, contingency
Because of the different scope included and the general uncertainty on cost estimation significant scatter is seen in CAPEX estimates reported in the literature for retrofit cases. Moreover, because only few CC projects have been realised there is a general lack of as built capital cost data.
Table 2Table 3
lists the public available cost data for the two existing large-scale post combustion retrofit projects Boundary Dam and Petra Nova. To supplement also recent cost estimates for a retrofit case study for401 Amine post combustion carbon capture technology
Saskpower's Shand power plant and the Norwegian National CCS Demonstration project. For these projects, the cost data is based on significant level of engineering and therefore of higher credibility than miscellaneous high-level studies in the literature.
Table 3. Cost of specific amine CC retrofit projects based on engineering estimates or actual costs. * Realised cost for total project is 1.5 bill USD but the total project also included other works e.g. power plant refurbishment. ** although realised, the reported cost is an engineering estimate, total project cost is reported to 1 bill. USD, but includes pipeline cost. ***costs adjusted to 2018 level using 2% escalation rate similar as in study.
Project Boundary Dam Petra Nova Shand
feasibil-ity study Klemets-rud
Feasibility study Concept study Concept study
Emission
As shown in
Table 3
, the scope included in the capital cost is not identical. All cases however include costs for integration and CO₂ compression/liquefaction, which are major addons. Total actual cost of the Boundary Dam project has been reported to 1.5 billion USD, but about half of this was related to refurbishing of old coal-fired boiler including new turbine and generator as well as an amine based desulphurisation plant. The Petra Nova total actual project cost has been reported to about 1 billion USD, which is more than the predicted engineering cost. The cost also included utilities and a steam plant. The Norwegian projects include CO₂ liquefaction and liquid CO₂ storage tanks for 4 days production as well as CO₂ export pier, which is more costly than CO₂ com-pression for pipeline transport. Also, the Norwegian projects included extensive heat integration with heat pumps, steam compression and waste heat recovery units.To obtain a more equal basis for the CAPEX the scope and cost adjustments to the Norwegian projects as shown in
Table 4
have been applied. The CAPEX reported for CC retrofit will then include CO₂ capture plant, CO₂ compression to pipeline pressure, utility systems (cooling water, electricity, steam, etc.), integration costs (hook-up to main plant) and owners cost.Table 4. Specific CAPEX of CC retrofits with estimated scope adjustments.
Project
Bound-ary Dam Petra
Nova Shand
study Klemetsrud CCS Norcem CCS Scope
EUR/USD 0.10 EUR/NOK 0.10 EUR/NOK
Rubin et al. [35] compared cost estimates of 6 different case studies for new built coal fired power plants (ca-pacity 3-4 MTPA, generic cases) with amine CC and found that the specific CAPEX varied from 1600 to 2300 USD/kWe generating capacity, which translates to approximately 2.1-2.9 mill EUR/(t CO₂ out-put/h). This is lower than any of the cases reported in
Table 3
, but the capture capacity is significantly higher, and the case covers newbuilt.The Global CCS Institute has released an update on its predicted global cost of carbon capture in 2017 [36]. This shows estimates on cost of carbon capture implemented in different industries. For coal fired boilers specific capital costs of 1.6 mill EUR/(t CO₂ output/h) for CC installation can be deduced. This includes compression and transport of CO₂ and is related to newbuilt power station in USA with capacity of 480-550 t CO₂ output/h.
It is clear from the studies referenced above that many desktop studies of generic plants provide substantially lower CAPEX estimates compared to specific projects where the costs are based on some level of engineering.
Also, the fact that most desktop studies concern newbuilt facilities will contribute to significantly reduced inte-gration costs.
Figure 6
shows a comparison of the different CAPEX estimates inTable 4
and in the referenced studies vs.the CC plant installed capacity. It is apparent that the effect of scale on specific CAPEX shown in
Figure 6
is quite pronounced even if the two data points from generic studies are omitted. However, it is also clear from the scatter inFigure 6
that the CAPEX of CC retrofit project is difficult to generalise and there will be consid-erable uncertainty on such generalised cost estimates. The CAPEX estimates for 2020 in the Data Sheets are based on the cost level indicated inFigure 6
.401 Amine post combustion carbon capture technology
Figure 6. Specific CAPEX cost of complete CC plant installations including CO₂ compression, integration and utility costs vs. CC plant capacity (data from Table 4).
Figure 7
shows a rough estimate of the share of total CAPEX for a retrofit CC project that is related to respec-tively the capture plant, utilities incl. flue gas supply, CO₂ compression, Owner's cost and heat integration e.g.turbine refurbishment, steam plant and waste heat recovery. The estimate is amongst other based on data from [28].
Figure 7
can be used to correct the CAPEX estimate if not all scope is relevant to the investigated CC project.Figure 7. Estimated CAPEX distribution of a complete CC plant retrofit installation based on data from [28].
OPEX
Fixed O&M for amine CC includes staffing, maintenance, service agreements. As the amine CC plant will be an addon to an existing facility, the need for additional operating staff is reduced. 7 to 15 additional staff (depend-ing on size and the site’s exist(depend-ing organisation) for O&M is expected for a commercial plant includ(depend-ing CO₂ com-pression and drying. Other fixed O&M such as service agreements and maintenance. Annual fixed O&M is cal-culated as 3% of CAPEX.
Variable OPEX for amine CC plants are dominated by cost of heat and electricity. Many reported variable OPEX in the literature includes cost of energy. Excluding heat and electricity (listed separately) the variable OPEX is mainly related to costs of make-up of amine, caustic soda for flue gas pre-treatment, waste disposal costs and the variable part of maintenance costs.
The cost of make-up amine may range from 1.5-12 EUR/kg depending on the specific amines applied. The con-sumption rate is as provided in
Table 1
. Based on this, a cost of 2 EUR/(t CO₂) is included in variable O&M.Other consumables such as caustic soda, activated carbon, etc. are required in minor quantities. These consum-ables will typically constitute less than 1% of OPEX. Disposal cost of chemical waste from reclaimer is typically also comparatively small. A cost of 0.5 EUR/(t CO₂) is included in variable O&M to cover all these small consum-ables.
Uncertainty
The uncertainty on cost data for larger scale plants i.e. > 20 t CO₂ output/h, is relatively significant today as few of these plants have been erected. Although several large-scale projects have been in the planning, no large CC installations have been erected in Denmark or EU hence there will also be uncertainty related to the permitting process.
In a 2050 perspective there will be significant uncertainty predicting the performance and cost of technology as it will depend on how and when the market will develop. As the cost data at 2020 level is based on first-of-a-kind plants, it is however likely that costs will decrease substantially in the future.