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Integrally geared CO2 compressor for CCS

Compression of captured CO2 from about 1 bar to 110-150 bar dense phase, 50 to 10,000 t/d: stage-by-stage power with intercooling, dense-phase pump, trains, and cost per tonne from McCollum & Ogden, cross-checked against an 8-stage integrally geared design.

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Open Jack

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  • CurrencyEUR 2023
  • Battery limitinstalled
  • 68 documented assumptions
  • Updated2 Nov 2026

Mass and energy balance

What the asset draws and delivers for the case and load you choose.

Reference case

Share of the year the compressor runs at nominal flow. 80 % is the McCollum & Ogden value; it is the lever project mode sets from the capture unit upstream.

Flows

  • In: Captured CO2—
  • In: Electricity for the compressor drive and pump—

Asset

Integrally geared CO2 compressor for CCS (to dense phase)

  • Out: Dense-phase CO2—

Annual quantities at the current usage.

Captured CO2 entering the compressor, in tonnes per day: the capacity the catalogue binds on and the flow project mode chains from capture. Default 2,700 t/d (MHI Compressor, Padeswood). Petra Nova is about 5,000 t/d. Below 1,000 t/d the cost correlation is extrapolated.

Shaft power
— MW
Number of trains
— -
Number of stages (integrally geared)
— -
CO2 mass flow
— kg/s

CAPEX

Specific cost at this size, what backs it, and how it behaves with scale.

Specific CAPEX at this size

—

Reference size 1,000 t/d

McCollum 2006, p. 5

Model value: McCollum & Ogden 2006 compressor and pump correlations, escalated from 2005 dollars to 2023 euros. Customized: the specific cost of your own quote at the flow you set, used as is (a quote is not scaled again); it is then no longer sourced.

Specific CAPEX by cO2 throughput

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  1. Ex-factory
  2. Installed· this figure
  3. Fully financed
CAPEX at the battery limit—
Working capital, contingencyproject level

Included

  • Equipment
  • Installation, civil works and engineering

Not included

  • Working capital
  • Contingency

Added at project level

  • Working capital layer, from the project settings
  • Contingency, from the project settings

Project figures

Values passed to project mode when this asset is added to a project.

Concept sketch, not to scale · drag to rotate

Captured CO2 in
—
Electricity for the compressor drive and pump in
—
Dense-phase CO2 outMain product
—
CAPEX to the battery limit
—
Fixed O&M
—
Variable O&M, excluding feedstocks
0 EUR/year
Asset lifetime
30 years

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Levelised cost of compression

A standalone indicator for a quick read. Project mode recomputes it for the whole system.

—

  • Compression cost: capital—
  • Compression cost: O&M—
  • Compression cost: electricity—

Linked to the balance above

Share of the year the compressor runs at nominal flow. 80 % is the McCollum & Ogden value; it is the lever project mode sets from the capture unit upstream.

Pressure of the captured CO2 at the compressor inlet. 1 bar (0.1 MPa) is McCollum's value; amine strippers deliver about 1.5 bar.

Dense-phase pressure delivered to the pipeline or the injection well. 150 bar (15 MPa) is McCollum's value; Petra Nova delivers 130 bar. The pump takes over from 73.8 bar, the critical pressure.

Price paid for the drive electricity. Default: Eurostat, EU27 non-household band ID, excluding VAT, first half of 2025.

Levelised cost of compression by capacity factor

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Benchmarks

This model's figures against published references and reference cases.

Specific energy, kWh/t

140.3 Daud 2019, Table 1

Number of stages (integrally geared), -

8 Daud 2019, p. 4

Intercooling temperature, C

38 Daud 2019, p. 4

Reference cases at this size and usage

Log in to compare the reference cases.

All results

Every model output at the current settings, grouped, with the sensitivity charts.

43 outputs · 7 groups · 15 also shown above, dimmed

Compression cost

6
Levelised cost of compression
ComputingEUR/t
Compression cost: capital
ComputingEUR/t
Compression cost: O&M
ComputingEUR/t
Compression cost: electricity
ComputingEUR/t
Electricity share of the cost
Computing%
Capital-charge load penalty
Computingratio

Energy

9
Specific energy
ComputingkWh/t
Compressor specific energy
ComputingkWh/t
Pump specific energy
ComputingkWh/t
Shaft power
ComputingMW
Compressor power
ComputingkW
Dense-phase pump power
ComputingkW
Pump share of power
Computing%
Daud et al. specific energy
ComputingkWh/t
Specific energy vs Daud et al.
Computingratio

Stages and trains

8
Number of trains
Computing-
Power per train
ComputingMW
Number of stages (integrally geared)
Computing-
Pressure ratio per property band
Computing-
Overall pressure ratio
Computing-
Stage 1 power
ComputingkW
Stage 5 power
ComputingkW
Last band share
Computing%

Heat and cooling

4
Heat rejected in the intercoolers
ComputingMW
Heat rejected a year
ComputingMWh/yr
Intercooling temperature
ComputingC
Margin above the critical temperature
ComputingK

CAPEX

7
Total CAPEX
ComputingEUR
Specific CAPEX
ComputingEUR/(t/d)
CAPEX scale exponent applied
Computing-
Compressor CAPEX
ComputingEUR
Pump CAPEX
ComputingEUR
CAPEX per kW of shaft power
ComputingEUR/kW
Cost escalation factor
ComputingEUR/USD

Flows

4
CO2 mass flow
Computingkg/s
CO2 compressed a year
Computingt/yr
Operating hours
Computingh/yr
Electricity a year
ComputingMWh/yr

Yearly costs

5
Capital recovery factor
Computing1/yr
Annualised CAPEX
ComputingEUR/yr
O&M a year
ComputingEUR/yr
Electricity cost a year
ComputingEUR/yr
Total yearly cost
ComputingEUR/yr

Sensitivities

5 charts
Compression cost components vs capacity factor

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Levelised cost of compression vs throughput

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CAPEX and shaft power vs throughput

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Specific energy by discharge pressure

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Levelised cost of compression vs electricity price

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Sources

68 documented assumptions · 8 sources

About

Calculator context

Compressor that takes captured CO2 from about 1 bar (1 to 1.5 bar, the outlet of an amine stripper) to the 110-150 bar dense phase of a CCS pipeline or injection well. The calculator gives the levelised cost of compression in EUR per tonne of CO2, without the value of the CO2 itself, plus the shaft power, the energy per tonne, the number of trains and stages, and the heat the intercoolers reject.

Thermodynamics. The method is McCollum & Ogden (UC Davis, 2006), Part I. The gas is compressed up to 73.8 bar, the critical pressure of CO2, in five bands of equal pressure ratio, each with its own compressibility factor and ratio of specific heats, and cooled back to 40 C before every band. Above 73.8 bar a pump takes over in the dense phase (630 kg/m3, efficiency 0.75). The reference case sets the isentropic efficiency of the stages: 0.75 (McCollum) or 0.85, the upper end of the range studied by Daud et al. (2019) for an 8-stage integrally geared machine. The physical stage count of an integrally geared compressor is shown apart, at the 1.78 stage ratio of Daud et al. The power is not recomputed on it, since the tabulated properties belong to the five bands. Trains are limited to 40 MW (IEA GHG PH4/6). A 75 MW single machine (Everllence RG) would need fewer trains.

Check against an independent design. Daud et al. print 79 MW of compression for 156.4 kg/s from 1.5 to 151 bar, about 140 kWh/t. This model gives 80-105 kWh/t over its range, lower because a pump does the last stage and the band properties are averages. The page shows the ratio. Shaft energy only: motor and gearbox losses are not added.

CAPEX and cost. Compressor and pump costs are the McCollum correlations (adapted from Hendriks 2004 and IEA GHG), in 2005 dollars, escalated to 2023 euros with the CEPCI (797.9 / 468.2) and the ECB 2023 rate. The compressor cost per kg/s falls as the train flow to the power -0.60, so the specific CAPEX falls with size until a second train is added. The source plots its curve from 1,000 t/d: from 50 to 1,000 t/d the same law is extrapolated and the CAPEX there is indicative. The source does not say what its capital cost includes; it is read as installed equipment. The levelised cost uses the source's CRF of 0.15, an O&M of 4 % of CAPEX a year and the electricity price you set (Eurostat EU27 industrial band by default). With the source inputs at 1,000 t/d the model reproduces McCollum Fig. 4 to the cent: 8.52 capital, 2.27 O&M and 6.81 power, in US$2005 per tonne.

Out of scope: dehydration (the water knocked out and the dryer are not costed, no sourced figure found), aftercooling below 31 C before the pump (so the heat rejected is a lower bound), and the value of the CO2. Chains with amine capture upstream and CO2 liquefaction or a pipeline downstream on the t/d CO2 flow.

Model

129 variables — inputs, calculations and outputs, with their dependencies.

129 variables shown of 129
VariableValueUnitDepends on
2700t/d—
80%—
1——
1bar—
150bar—
0.1246EUR/kWh—
0——
14500EUR/(t/d)—
VariableFormulaUnitDepends on
if((<=)+(<=)+(>)+(<=)+(*>=)+(<=)+(<)+(>)+(<)+(>)+(<=)+(<)>,,)bool
*MPa
*MPa
/max(,)-
/-
if(==,,)ratio
/t/h
**/(*)kW
**(/(-))*(^((-)/)-)kW
**(/(-))*(^((-)/)-)kW
**(/(-))*(^((-)/)-)kW
+kW
/kg/s
**(*^+*^(-)*ln())USD
*/+USD
(+)*EUR
/EUR/(t/d)
/(+)*%
**t/yr
VariableFormulaUnitDepends on
/max(,)-
^(/)-
*/(*)kg/s
**(/(-))*(^((-)/)-)kW
**(/(-))*(^((-)/)-)kW
++++kW
max(,ceil(/))-
//MW
ceil(ln()/ln())-
***(-)/(***)kW
/MW
*/kWh/t
*/kWh/t
*/kWh/t
/max(,)*%
/max(,)*%
/MW
-C
-K
**h/yr
***t/yr
*/MWh/yr
*/MWh/yr
//EUR/USD
if(>=,,clamp(,,))EUR/(t/d)
if(>=,,)-
*EUR
**EUR
-EUR
/max(,)EUR/kW
1/yr
*EUR/yr
*EUR/yr
**EUR/yr
++EUR/yr
/(*)ratio
/*EUR/t
/EUR/t
/EUR/t
++EUR/t
/max(,)*%
*/(*/)kWh/t
/ratio

Assumptions

68 assumptions used in the calculations

  • Lower limit in the input guards.

    Market range Exact by definition.

    0
    Numerical constant

  • Unit multiplier in the guards, the train count and the Customized switch.

    Market range Exact by definition.

    1
    Numerical constant

  • Protects divisions against a zero denominator.

    Market range Exact by definition.

    0
    Numerical constant

  • Converts a percent into a fraction.

    Market range Exact by definition.

    0.01
    Numerical constant

  • Converts a fraction into a percent; upper limit of a percent input.

    Market range Exact by definition.

    100
    Numerical constant

  • Converts bar into MPa (1 bar = 0.1 MPa), the pressure unit of the McCollum equations.

    Market range Exact by definition.

    0.1
    Numerical constant

  • Bar per MPa in the McCollum pump power equation (the '10' of the source).

    Market range Exact by definition.

    10
    Numerical constant

  • Kilograms per tonne (the '1000' of the McCollum power equations).

    Market range Exact by definition.

    1000
    Numerical constant

  • Hours per day (the '24' of the McCollum power equations).

    Market range Exact by definition.

    24
    Numerical constant

  • Seconds per hour (the '3600' of the McCollum compressor power equation).

    Market range Exact by definition.

    3600
    Numerical constant

  • Hours in a year.

    Market range Exact by definition.

    8760
    Numerical constant

  • Days in a year (McCollum: m_year = m x 365 x CF).

    Market range Exact by definition.

    365
    Numerical constant

  • kW per MW.

    Market range Exact by definition.

    1000
    Numerical constant

  • kWh per MWh.

    Market range Exact by definition.

    1000
    Numerical constant

  • Converts kelvin into degrees Celsius.

    Market range Exact by definition.

    273.15
    Numerical constant

  • The '36' of the McCollum pump power equation: m3 x bar per hour per kW (1 kW = 36 m3.bar/h).

    Market range Exact by definition.

    36
    McCollum 2006, p. 4

  • Reference case 1: McCollum & Ogden 2006 compressor, isentropic stage efficiency 0.75.

    Market range Not applicable.

    1
    Selector code

  • Reference case 2: high-efficiency integrally geared stages, isentropic efficiency 0.85, the upper end of the range studied by Daud et al. 2019.

    Market range Not applicable.

    2
    Selector code

  • Pressure at which the compressor hands over to the dense-phase pump: the critical pressure of CO2 (McCollum: compressor 0.1-7.38 MPa, pump 7.38-15 MPa).

    Market range Fixed by CO2 properties.

    7.38MPa
    McCollum 2006, p. 2

  • Critical pressure of CO2. A discharge pressure at or below it is not dense phase, so the input guard refuses it.

    Market range Physical constant.

    73.8bar
    NIST WebBook

  • Critical temperature of CO2 (about 31 C). The intercooler outlet at 40 C sits above it: the CO2 leaving the last stage is supercritical and must be cooled further to reach the 630 kg/m3 pump density.

    Market range Physical constant.

    304.18K
    NIST WebBook

  • Number of compression stages over which McCollum splits the CO2 properties (5 bands of Z and k, Mohitpour optimal ratio). It sets the thermodynamics; the physical stage count of an integrally geared machine is shown apart.

    Market range No independent range cited.

    5-
    McCollum 2006, p. 2

  • Gas temperature at the inlet of every stage, after intercooling (40 C).

    313.15K
    McCollum 2006, p. 2

  • Isentropic efficiency of each compressor stage, reference case 1.

    0.75ratio
    McCollum 2006, p. 2

  • Isentropic efficiency of each stage, reference case 2 (high-efficiency integrally geared stages).

    0.85ratio
    Daud 2019, pp. 4-5

  • Universal gas constant.

    Market range Physical constant.

    8.314kJ/(kmol.K)
    McCollum 2006, p. 2

  • Molar mass of CO2.

    Market range Physical constant.

    44.01kg/kmol
    McCollum 2006, p. 2

  • Average compressibility factor of CO2 in stage 1 (McCollum band 0.1-0.24 MPa, 356 K average).

    Market range No independent range cited.

    0.995-
    McCollum 2006, p. 2

  • Average ratio of specific heats Cp/Cv of CO2 in stage 1 (McCollum band 0.1-0.24 MPa).

    Market range No independent range cited.

    1.277-
    McCollum 2006, p. 2

  • Average compressibility factor of CO2 in stage 2 (McCollum band 0.24-0.56 MPa, 356 K average).

    Market range No independent range cited.

    0.985-
    McCollum 2006, p. 3

  • Average ratio of specific heats Cp/Cv of CO2 in stage 2 (McCollum band 0.24-0.56 MPa).

    Market range No independent range cited.

    1.286-
    McCollum 2006, p. 3

  • Average compressibility factor of CO2 in stage 3 (McCollum band 0.56-1.32 MPa, 356 K average).

    Market range No independent range cited.

    0.97-
    McCollum 2006, p. 3

  • Average ratio of specific heats Cp/Cv of CO2 in stage 3 (McCollum band 0.56-1.32 MPa).

    Market range No independent range cited.

    1.309-
    McCollum 2006, p. 3

  • Average compressibility factor of CO2 in stage 4 (McCollum band 1.32-3.12 MPa, 356 K average).

    Market range No independent range cited.

    0.935-
    McCollum 2006, p. 3

  • Average ratio of specific heats Cp/Cv of CO2 in stage 4 (McCollum band 1.32-3.12 MPa).

    Market range No independent range cited.

    1.379-
    McCollum 2006, p. 3

  • Average compressibility factor of CO2 in stage 5 (McCollum band 3.12-7.38 MPa, 356 K average).

    Market range No independent range cited.

    0.845-
    McCollum 2006, p. 3

  • Average ratio of specific heats Cp/Cv of CO2 in stage 5 (McCollum band 3.12-7.38 MPa).

    Market range No independent range cited.

    1.704-
    McCollum 2006, p. 3

  • Largest compressor train: above it, the flow is split into parallel trains.

    Market range 40 MW (IEA GHG PH4/6) to 75 MW (Everllence RG, vendor claim).

    40000kW
    McCollum 2006, p. 3

  • Density of CO2 in the dense-phase pump.

    Market range No independent range cited.

    630kg/m3
    McCollum 2006, p. 4

  • Efficiency of the dense-phase pump.

    Market range No independent range cited.

    0.75ratio
    McCollum 2006, p. 4

  • Pressure ratio per stage of an 8-stage integrally geared CO2 compressor, used to count the physical stages up to the cut-off pressure.

    Market range No independent range cited.

    1.78-
    Daud 2019, p. 4

  • Intercooling temperature of the Daud et al. integrally geared design, a benchmark for the 40 C of McCollum.

    Market range No independent range cited.

    38C
    Daud 2019, p. 4

  • Compression power printed by Daud et al. for their 8-stage integrally geared case, used for the independent specific-energy check.

    Market range No independent range cited.

    79MW
    Daud 2019, Table 1

  • CO2 flow of the Daud et al. case.

    Market range No independent range cited.

    156.4kg/s
    Daud 2019, p. 4

  • First coefficient of the compressor capital cost correlation (per kg/s of train flow).

    Market range No independent range cited.

    130000USD2005/(kg/s)
    McCollum 2006, p. 5

  • Exponent of the first term of the compressor cost correlation, on train flow in kg/s.

    Market range No independent range cited.

    -0.71-
    McCollum 2006, p. 5

  • Second coefficient of the compressor capital cost correlation, multiplied by ln(Pcut-off/Pinitial). It carries about 98 % of the compressor cost.

    Market range No independent range cited.

    1400000USD2005/(kg/s)
    McCollum 2006, p. 5

  • Capacity exponent of the compressor cost: the McCollum term mtrain x mtrain^-0.60 grows as mtrain^0.40, so the cost per t/d falls as flow^-0.60 within one train. The second term (mtrain^0.29) and the pump cost (almost linear) weigh about 3 % at the nominal size.

    Market range No independent range cited.

    0.4-
    McCollum 2006, p. 5

  • Variable part of the dense-phase pump capital cost.

    Market range No independent range cited.

    1110000USD2005/MW
    McCollum 2006, p. 5

  • Fixed part of the dense-phase pump capital cost.

    Market range No independent range cited.

    70000USD2005
    McCollum 2006, p. 5

  • Chemical Engineering Plant Cost Index, 2005 annual average: base year of the McCollum costs.

    Market range No independent range cited.

    468.2-
    CEPCI 2005

  • Chemical Engineering Plant Cost Index, 2023 annual average: target year of the costs.

    Market range No independent range cited.

    797.9-
    CEPCI 2023

  • Converts 2023 dollars into 2023 euros.

    Market range Exact annual average.

    1.0813USD/EUR
    ECB 2023

  • Capital recovery factor applied to the total capital cost.

    Market range No independent range cited.

    0.151/yr
    McCollum 2006, p. 6

  • Reference capacity factor of the source; the capital charge per tonne is shown as a penalty relative to it.

    Market range No independent range cited.

    0.8ratio
    McCollum 2006, p. 6

  • Yearly O&M as a share of the total capital cost.

    Market range No independent range cited.

    0.041/yr
    McCollum 2006, p. 6

  • Lower guard of the specific CAPEX clamp. The model gives about 9,000-160,000 EUR per t/d over the slider, so the guard never binds there.

    Market range Not applicable.

    1000EUR/(t/d)
    Model guard

  • Upper guard of the specific CAPEX clamp; never binds inside the slider range (checked at the corners).

    Market range Not applicable.

    500000EUR/(t/d)
    Model guard

  • Method: five-band polytropic stage work from the CO2 inlet pressure to the critical pressure (7.38 MPa) with intercooling to 40 C between stages, trains of at most 40 MW, a dense-phase pump from 7.38 MPa to the discharge pressure, then the levelised cost of compression = (CRF + O&M factor) x CAPEX / tonnes a year + electricity x price. Reproduces McCollum Fig. 4 at 1,000 t/d (8.52 capital, 2.27 O&M, 6.81 power, US$2005/t) with the source inputs.

    Market range Not applicable.

    —
    Model scope

  • Out of scope: dehydration. The water knocked out in the intercoolers and the glycol or molecular-sieve dryer needed for pipeline specification are neither costed nor counted in the flows (no sourced figure found). The CO2 mass in equals the mass out.

    Market range Not applicable.

    —
    Model limits

  • The pump density of 630 kg/m3 implies the CO2 is cooled below its critical temperature (31 C) after the last stage; that aftercooling duty is not added to the heat rejected, which is a lower bound (Daud et al. 2019 note the heat removed exceeds the isentropic work at high pressure).

    Market range Not applicable.

    —
    Model limits

  • The compressor cost correlation is plotted by the source from 1,000 to 25,000 t/d. Between 50 and 1,000 t/d the calculator extrapolates the same power law: the CAPEX there is indicative.

    Market range Not applicable.

    —
    Model limits

  • Battery limit: the source gives the compressor and pump capital cost (adapted from Hendriks 2004 and IEA GHG PH4/6) without listing what it includes. It is read as installed equipment, so project mode adds working capital layers and contingency only.

    Market range Not applicable.

    —
    CAPEX boundary

  • Service life exported to project mode as the replacement interval of the compressor train.

    Market range No independent range cited.

    30years
    NETL QGESS 2010

  • Default of the electricity price input.

    0.1246EUR/kWh
    Eurostat 2025-S1

  • Independent benchmark of the compression energy per tonne: Daud et al. compression power divided by their CO2 flow (79,000 kW / (156.4 kg/s x 3.6 t/h per kg/s)).

    Market range No independent range cited.

    140.3kWh/t
    Daud 2019, Table 1

  • Number of stages of the Daud et al. integrally geared design, benchmark for the physical stage count.

    Market range No independent range cited.

    8-
    Daud 2019, p. 4

  • Reference size of the CAPEX scale law: the smallest flow at which the source plots its cost. The calculator also outputs the reproduction of the source at this flow when inputs are set to 1,000 t/d, 1 to 150 bar and 0.065 USD/kWh.

    Market range Not applicable.

    1000t/d
    McCollum 2006, p. 8