ISO 27928
(Main)Carbon dioxide capture, transportation and storage — Carbon dioxide capture — Performance evaluation methods for CO2 capture connected to a CO2 intensive plant
Carbon dioxide capture, transportation and storage — Carbon dioxide capture — Performance evaluation methods for CO2 capture connected to a CO2 intensive plant
1. Scope: This document is a part of a series of standards for carbon dioxide (CO2) capture. It specifies methods for measuring, evaluating and reporting the performance of CO2 capture plant connected to a CO2 intensive plant, and which separate CO2 from the CO2 intensive plant exhaust gas in preparation for subsequent transportation and geological storage. In particular, it provides a common methodology to calculate specific key performance indicators for the CO2 capture plant, requiring the definition of the boundaries of a typical system and the measurements needed to determine the KPIs. 2. Policy of work: The series of standards for carbon dioxide capture will be done based on the following fundamental policies: (1) The standards and requirements being developed in the series will depend on the maturity of the content and its practical use to stakeholders. (2) Standards in the series will build on the previous standards. (3) Standards for CO2 capture lend themselves better to a series of individual standards rather than a single comprehensive standard because of the maturity of the technologies and the process differences in power and different Energy Intensive Industries (EII).
Capture, transport et stockage du dioxyde de carbone — Capture du dioxyde de carbone — Méthodes d'évaluation des performances pour la capture du CO2 des installations à fortes émissions de CO2
General Information
Standards Content (Sample)
FINAL DRAFT
International
Standard
ISO/FDIS 27928
ISO/TC 265
Carbon dioxide capture,
Secretariat: SCC
transportation and geological
Voting begins on:
storage — Carbon dioxide capture
2025-09-10
— Performance evaluation methods
Voting terminates on:
for CO capture connected to a CO
2025-11-05
2 2
intensive plant
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Reference number
ISO/FDIS 27928:2025(en) © ISO 2025
FINAL DRAFT
ISO/FDIS 27928:2025(en)
International
Standard
ISO/FDIS 27928
ISO/TC 265
Carbon dioxide capture,
Secretariat: SCC
transportation and geological
Voting begins on:
storage — Carbon dioxide capture
— Performance evaluation methods
Voting terminates on:
for CO capture connected to a CO
2 2
intensive plant
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
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BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
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INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
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TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
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TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
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ii
ISO/FDIS 27928:2025(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 2
3 Terms, definitions, abbreviated terms and symbols . 2
3.1 Terms and definitions .2
3.2 Abbreviated terms .7
3.3 Symbols .7
4 Establishing the CO capture plant boundary . 8
4.1 CO capture plant connected to a CO intensive plant .8
2 2
4.2 Boundary of the CO capture plant, CO intensive plant and utilities .8
2 2
5 Definition of basic CO capture plant performance .10
5.1 General .10
5.2 CO streams .11
5.3 CO capture rate of the CO capture plant .11
2 2
5.4 Flow rate of the product CO stream from a CO capture plant . 12
2 2
5.5 Properties of product CO stream from a CO capture plant . 12
2 2
5.5.1 General . 12
5.5.2 Amount of product CO stream . 12
5.5.3 Compositions of product CO stream . 12
5.5.4 Quality control of product CO stream . 13
6 Definition of utilities and consumption calculation .13
6.1 General . 13
6.2 Thermal energy . 13
6.2.1 Definition of thermal energy . 13
6.2.2 Consumption calculation .14
6.3 Cooling water .14
6.3.1 Definition of cooling water .14
6.3.2 Industrial water .14
6.3.3 Waste water .14
6.4 Definition of electrical energy consumption evaluation. 15
6.5 Absorbent, adsorbent and chemical compounds consumptions. 15
7 Guiding principles — Basis for CO capture plant performance assessment .15
7.1 General . 15
7.2 Test boundary and required measurements .16
7.3 Test plan .16
7.3.1 Preparation .16
7.3.2 CO intensive plant and CO capture plant conditions .17
2 2
7.3.3 Conduct of test .18
7.3.4 Calculation and results .18
8 Instruments and measurement methods . 19
8.1 General requirement .19
8.1.1 General .19
8.2 Measurement method .19
8.2.1 Inlet gas containing CO .19
8.2.2 Product CO stream at the CO conditioning outlet .21
2 2
8.2.3 Thermal energy measurements.21
8.2.4 Electric power consumption measurement . 22
8.2.5 Measurement of pressure and temperature . 22
8.2.6 Data collection and handling . 22
9 Evaluation of key performance indicators .23
iii
ISO/FDIS 27928:2025(en)
9.1 General . 23
9.2 Specific electrical energy consumption (SEC). 23
9.3 Specific thermal energy consumption (STEC) .24
9.4 Specific material consumption (SMC) .24
10 Quantification and verification of the CO capture .24
10.1 General .24
10.2 Quantification . . .24
10.3 CO leakage . 25
10.4 Verification . . 25
Annex A (informative) General information for the instrument and measurement methods .26
Annex B (informative) KPI evaluation sheet.28
Bibliography .30
iv
ISO/FDIS 27928:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
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This document was prepared by Technical Committee ISO/TC 265, Carbon dioxide capture, transportation
and geological storage.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO/FDIS 27928:2025(en)
Introduction
It is very important to reduce atmospheric carbon dioxide (CO ) emissions in order to meet climate change
mitigation targets. The inclusion of carbon dioxide capture and storage (CCS) among the variety of available
emission reduction approaches enhances the probability of meeting these targets at the lowest cost to the
global economy. CCS captures CO from industrial and energy-related sources and stores it underground in
geological formations. It can capture CO emissions from carbonaceous fuel-based combustion processes,
including power generation, and is at present the most effective technology capable of dealing directly with
emissions from several CO intensive industries, such as steel, cement etc.
As a standard for CO capture, ISO 27919-1 presents an evaluation method of key performance indicators
(KPIs) for post-combustion CO capture (PCC) from a power plant. On the other hand, this document covers
an evaluation method of KPIs for CO capture from various CO intensive plants. It is noted that these two
2 2
standards, ISO 27919-1 and ISO 27928, are mutually independent, similar terms and symbols used in both
the standards are valid only in the respective standards. CO intensive plants suggest industries such as
steel, cement, ferro alloys, aluminium and other metals. It is also intended for CCS enabled hydrogen as well
as refineries, chemical processing industries such as fertilizer. The CO capture plant takes in the exhaust
gas from the CO intensive plant without further integration, i.e. not impacting on the production of the CO
2 2
intensive plant.
CO intensive industries are characterized by the production of significant volumes of CO as a by-product.
2 2
In many cases, the CO amounts are comparable or even larger than the amount of the main product. The
two largest of such industries, steel and cement manufacture, are responsible for 7 % to 8 % each of global
CO production. Typically, the CO intensive industries produce large amounts of CO at each production site,
2 2 2
often in the range from some hundred thousand to million tonnes per annum. CO intensive industries, such
as steel, cement, etc. are using carbon or carbon-containing raw materials, which often cannot readily be
replaced. For example, cement needs limestone and silicon metal needs carbon as the chemical reductant.
In steel production, the dominant CO sources are the iron-making blast furnace and the steel converter,
while other production steps (ore sintering, rolling mills, etc.) are producing smaller amounts. A modern,
integrated steel plant, making finished steel bars, beams or plates from iron ore emits around two tonnes
of CO per tonne of finished product. In contrast, steel produced from scrap in an electric arc furnace emits
about 350 kg CO per tonne of steel. However, scrap availability is seriously limited. The exhaust gases from
the blast furnace have extra high content of CO (typically a volume fraction of 25 %) and high pressure
[2 atmospheres (atm) to 4 atm]. The steel converter produces intermittently smaller amounts of flue gas
with some lower CO content and at ambient pressure. Other CO producing steps on the way from iron
2 2
ore to finished products typically produce flue gases with lower CO content (10 % to 15 %), like most fuel
combustion and at ambient pressure.
CO capture on the blast furnace exhaust gas can take advantage of the high CO content, pressure and
2 2
volume of this exhaust gas, typically 75 % of the total CO from the integrated mill. This has been pilot tested
with pressure swing adsorption (PSA) on a semi-industrial blast furnace. The adsorbents were zeolites and
active carbon. The results showed low energy consumption.
In cement production, there are two main steps producing CO :
a) Calcination of limestone by heating the main raw material, limestone to 900 °C, after grinding the rock
limestone to a fine powder. Heating of the materials occurs in counter current flow with hot exhaust
gases from step 2. The process equipment can vary from plant to plant.
b) Clinker burning of a mixture of burnt lime from step 1 together with silica containing raw materials
occur in a long, rotary kiln. The kiln is normally fired from the material exit end with solid, liquid or
gaseous fuel (e.g. coal, oil, gas, biomass and waste). The clinker mix is heated up to 1 450 °C and the
clinker is semi-fused to round plum size pellets. A part of the exhaust gases is sent to step a); the rest is
sent to the exhaust gas stack. The clinker leaving the rotary kiln passes through a clinker cooler, where
combustion air is pre-heated for the kiln.
In lime production, the CO generation includes only this first step.
vi
ISO/FDIS 27928:2025(en)
After calcination and clinker burning, the clinker is ground together with other mineral raw materials into
cement powder, used to make concrete; the biggest volume of construction material globally by far.
The limestone calcination generates 60 % of the total CO produced. The exhaust gas from the rotary kiln
combustion carries the remaining 40 %; giving a total of 0,8 to 0,9 tonnes of CO per tonne of clinker. The
exhaust gas contains typically 20 % to 22 % of CO , moisture and dust. The remaining gas compounds are
mostly N , O and NOx with smaller amounts of other compounds depending on the fuel used. The CO
2 2 2
capture process is located downstream of conventional contaminant controls of the exhaust gas, and is
expected to have minimal, if any, influence on the quality of the cement clinker produced.
Silicon metal (a typical use is in solar panels) is smelted in large bucket shaped furnaces with three large
diameter electrodes in through the top. The top of the furnace is semi-closed for operational reasons. Raw
materials (typically quartz and carbon) are fed through the top. Extreme high temperatures are generated
in the centre of the furnace. This causes the quartz to melt, react with carbon and form a bottom pool of
silicon metal, which then is intermittently tapped out. The furnace reactions also generate large volumes of
exhaust gases; a mixture of carbon monoxide and silicon monoxide (CO and SiO). As the exhaust gas is cooled
down and contacts air at the top of the furnace, these gas components are oxidized into CO and silica dust
(SiO ). The silica particle size typically less than 10 microns in size (particle size as for cigarette smoke) is
filtered off and sold as a by-product. The resulting plant exhaust contains varying and low concentrations of
CO and air. Recycling off gas back to the furnace top before connecting the exhaust gas to the CO capture
2 2
plant can result in higher CO concentrations, facilitating the CO capture.
2 2
Even if the furnace producing silicon metal is fed exclusively with renewable electricity, the production
emits around four tonnes of CO per tonne of silicon metal produced.
Aluminium production is done in long rows of electrolysis cells fed with aluminium oxide (Al O ) powder
2 3
into a melted fluoride bath. The electricity is fed through bottom (cathode) and top (anode) electrodes.
Produced melted aluminium metal gathers in the bottom and is intermittently tapped off. Under the top
carbon electrode, CO gas evolves containing over 95 % CO ; the remainder being fluorides. This cell gas is
2 2
collected from the long row of cells and then mixed with large volumes of air from building above the cell
row (the hall). This gaseous mixture also contains traces of fluorides leaked from the cells. The diluted cell
gas is then sent to water washing, to avoid harming the environment. After mixing with the hall air and after
water wash, the gas contains 1 % to 2 % CO ; rest air and moisture.
Aluminium electrolysis produces around 1,5 tonnes of CO per tonne of aluminium product.
To capture CO the cell gas can be diverted to a CO capture unit before mixing it with the hall gas and then
2 2
sent to washing with water.
CCS enabled hydrogen (commonly referred to as “Blue” Hydrogen) is produced by the reforming of short-
chain hydrocarbons (typically methane). The product CO from this reaction is captured and exported for
permanent storage.
Feedstock gas is purified and mixed with steam, before passing through one or multiple reforming reactor(s),
producing a stream consisting primary of hydrogen, CO , carbon monoxide (CO) and water. This stream is
then passed through a water-gas shift reactor, where residual CO is converted to CO and hydrogen, and then
cooled to remove water. The result is a syngas made up almost entirely of CO and hydrogen, at a pressure of
1)
approximately 25 bar to 30 bar.
CO is then captured from this syngas stream and exported for storage. Depending on the plant’s
configuration and reformer design, CO can also be captured from plant’s fired heater and reformer flue
gases. Hydrogen is typically purified using a pressure swing adsorption (PSA) unit, from which the rejected
“tail gas” is combusted to produce process heat or steam.
Modern CCS enabled hydrogen flowsheets are capable of capturing in excess of 95 % of all carbon within the
feedstock hydrocarbon gas.
For other CO intensive industries, beyond steel, cement, silicon, aluminium and CCS enabled hydrogen, see
relevant textbooks. The intended user of this document includes CO intensive plant owners and operators,
5 2
1) 1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
vii
ISO/FDIS 27928:2025(en)
project developers, technology developers and vendors, regulators, and other stakeholders. This document
provides a common basis for estimating, measuring and evaluating the performance of a CO capture plant
connected to a CO intensive plant.
viii
FINAL DRAFT International Standard ISO/FDIS 27928:2025(en)
Carbon dioxide capture, transportation and geological
storage — Carbon dioxide capture — Performance evaluation
methods for CO capture connected to a CO intensive plant
2 2
1 Scope
1.1 This document specifies methods for measuring and evaluating the performance of CO capture
connected to a CO intensive plant, and which separates CO from the CO intensive plant exhaust gas in
2 2 2
preparation for subsequent transportation and geological storage. In particular, this document provides a
common methodology to calculate key performance indicators (KPI) for the CO capture plant. In particular,
this document provides a common methodology to calculate key performance indicators (KPI) for the CO
capture plant. To determine the KPIs, the boundaries of the CO capture plant need to be defined and the
necessary parameters need to be measured.
1.2 This document covers the CO capture plant capturing CO from CO containing exhaust gas connected
2 2 2
to CO intensive plants. The connection of a CO -capture plant to a CO intensive plant is anticipated to have
2 2 2
negligible impact on the product quality or the quantities produced by the CO intensive plant. This is in
contrast with the integration of CO -capture plants with power plants which usually results in a reduction
of the power plant output. For the CO intensive industry, it is important that product quality remains the
same after connection of the CO -capture plant, in order for the industry to continue to meet customer
requirements.
The CO capture technologies covered by this document are able to operate without interfering with the
operations of the CO intensive plant. Frequently used CO capture technologies are chemical absorption
2 2
(e.g. liquid amine) and solid adsorption [e.g. pressure swing adsorption (PSA), temperature swing adsorption
(TSA)]. Other CO capture concepts are membranes, cryogenic and other capture technologies. The CO
2 2
capture plant can be installed for treatment of the full volume of exhaust gas from the CO intensive plant
or a fraction of the total (i.e. a slipstream). Captured CO is then conditioned, e.g. dried and compressed or
liquefied, as determined by the conditions needed for transportation and storage. The transportation can be
either through a pipeline or through an intermediate storage facility waiting for shipment; either by tanker
car, train or ship.
The system includes interfaces between the CO capture plant and the CO intensive plant as well as the CO
2 2 2
transportation and storage system.
1.3 This document is intended to describe the following KPIs:
a) CO capture rate;
b) specific electrical energy consumption (SEC);
c) specific thermal energy consumption (STEC);
d) specific material consumption (e.g. absorbent or adsorbent) (SMC).
The calculations are based on measurements at the boundary of the CO capture plant, particularly of energy
and other utilities consumption.
ISO/FDIS 27928:2025(en)
1.4 This document includes the following items:
a) the CO capture plant boundary (see Clause 4), which defines the boundaries of the CO capture plant
2 2
and identifies which streams of energy and mass are crossing these boundaries to identify the key
streams that are applicable for their particular case.
b) the basic performance of CO capture plant (see Clause 5), which defines the parameters that describe
the basic performance of the CO capture plant;
c) the utilities and consumption calculation (see Clause 6), which lists the utility measurements required
and provides guidance on how to convert utility measurements into the values required for the KPIs;
d) the guiding principles (see Clause 7), the basis for CO capture plant performance assessment, which
describes all guidelines to prepare, set-up and conduct the tests;
e) the instruments and measurement methods (see Clause 8), which lists the standards available for the
relevant measurements issues and considerations to take into account when applying measurement
methods to CO capture plants;
f) the evaluation of key performance indicators (see Clause 9), which specifies the set of KPIs to be
determined and their calculation methods.
1.5 This document does not provide guidance for benchmarking, comparing or assessing KPIs of different
technologies or different CO capture projects. HSE is not included.
2 Normative references
There are no normative references in this document.
3 Terms, definitions, abbreviated terms and symbols
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Terms and definitions
3.1.1
absorbent
substance able to selectively absorb liquid or gas components in its bulk phase
3.1.2
accuracy
measurement accuracy
closeness of agreement between a measured quantity value and a true quantity value of a measured entity
[SOURCE: ISO/IEC Guide 99:2007, 2.13, modified — the admitted term "accuracy of measurement" has been
deleted, "measurand" has been replaced with "measured entity" in the definition and Notes 1, 2 and 3 to
entry have been deleted.]
3.1.3
adsorbent
substance able to selectively adsorb liquid or gas components on its surface
ISO/FDIS 27928:2025(en)
3.1.4
auxiliary unit
unit providing electricity or thermal (heating or cooling) or other utilities for the CO capture plant
3.1.5
carbon dioxide capture and storage
CCS
process consisting of the separation of CO from industrial and energy-related sources, transportation and
injection into a geological formation, resulting in long term isolation from the atmosphere
Note 1 to entry: CCS is often referred to as carbon capture and storage. This terminology is not encouraged because it
is inaccurate: the objective is the capture of carbon dioxide and not the capture of carbon. Tree plantation is another
form of carbon capture that does not describe precisely the physical process of removing CO from industrial emission
sources.
Note 2 to entry: The term “sequestration” is also used alternatively to “storage”. The term “storage” is preferred.
Note 3 to entry: Long term means the minimum period necessary for CO geological storage to be considered an
effective and environmentally safe climate change mitigation option.
Note 4 to entry: The term carbon dioxide capture, utilization (or use) and storage (CCUS) includes the concept that
isolation from the atmosphere can be associated with a beneficial outcome. CCUS is embodied within the definition
of CCS to the extent that long term isolation of the CO occurs through storage within geological formations. CCU is
carbon capture and utilization (or use) without storage within geological formations.
Note 5 to entry: CCS should also ensure long term isolation of CO from oceans, lakes, potable water supplies and other
natural resources.
[SOURCE: ISO 27917:2017, 3.1.1, modified — Note 2 to entry has been modified.]
3.1.6
chemical absorption
process in which CO is absorbed by chemical reaction
3.1.7
CO capture
separation of CO in such a manner as to produce a concentrated stream of CO that can readily be
2 2
transported for storage
3.1.8
CO captured
CO in the product CO stream (3.1.31) produced by a CO capture plant that produces a CO stream (3.1.14)
2 2 2 2
from exhaust gases
3.1.9
CO capture plant boundary
boundary
performance evaluation boundary of a CO capture plant
3.1.10
CO capture rate
CO removal efficiency of the CO capture plant calculated as the quotient of the CO volume flow rate in the
2 2 2
product CO stream (3.1.14) divided by the CO volume flow rate in the inlet gas steam
2 2
Note 1 to entry: CO capture rate is expressed as a percentage.
3.1.11
CO conditioning
processes needed before transportation to make the CO stream (3.1.14) leaving the capture plant
meeting downstream specifications, e.g. drying (dehydration) purification, compression, liquefaction and
dehydration
ISO/FDIS 27928:2025(en)
3.1.12
CO intensive industry
industry producing significant volumes of CO as a by-product
3.1.13
CO intensive plant
plant producing significant volumes of CO as a by-product
3.1.14
CO stream
gas stream containing CO , crossing the CO capture plant boundary (3.1.9)
2 2
Note 1 to entry: In ISO 27917, a CO stream is defined instead as a “stream consisting overwhelmingly of carbon
dioxide”.
3.1.15
cooling duty
net enthalpy rejected to a cooling media
3.1.16
cooling energy
enthalpy removed by the cooling method
3.1.17
dehydrator
moisture removal system or equipment
3.1.18
deNOx
process or equipment used to remove nitrogen oxides (NOx) from the exhaust gas
3.1.19
effluent
liquid discharged to the environment or wastewater (3.1.42) treatment facility
3.1.20
heat duty
net enthalpy required from a heat media cycling forth and back with the thermal energy source
3.1.21
impurity
non-CO substance that is part of the CO stream (3.1.14) that may be derived from the source materials or
2 2
the capture process, or added as a result of co-mingling for transportation, or released or formed as a result
of sub-surface storage or leakage of CO
[SOURCE: ISO 27917:2017, 3.2.12, modified — Notes 1 and 2 to entry have been deleted.]
3.1.22
inlet gas stream
input gas stream to be treated by CO capture plant coming from the CO intensive plant (3.1.13)
2 2
3.1.23
interface
mechanical, thermal, electrical or operational common boundary between two elements of a system
[SOURCE: ISO 10795:2019, 3.132, modified — the term "I/F" has been deleted.]
3.1.24
key performance indicator
KPI
measure of performance relevant to the CO capture plant connected to a CO intensive plant (3.1.13)
2 2
ISO/FDIS 27928:2025(en)
3.1.25
measurement point
point of connection between the CO capture plant and inlet, outlet and product gas stream as well as with
utilities
Note 1 to entry: The measurement point sits at the CO capture plant boundary (3.1.9).
3.1.26
outlet gas stream
outlet CO leaner gas stream of which the CO concentration has been reduced after passing through a CO
2 2 2
capture plant
3.1.27
permanent plant instrument
instrument installed in the CO intensive plant (3.1.13) and capture plant for control and monitoring
3.1.28
plant reference condition
stable operating condition of the CO intensive plant (3.1.13) with the rated or the ordinary production
operation
3.1.29
post-combustion CO capture
PCC
capture of carbon dioxide from exhaust gas stream produced by carbonaceous fuel combustion
[SOURCE: ISO/TR 27912:2016, 3.51, modified — “fuel air combustion” has been modified to “carbonaceous
fuel combustion”.]
3.1.30
pre-treatment
part of the CO capture (3.1.7) which conditions the inlet gas as required for CO to be separated, in respect
2 2
of the temperature, the pressure and impurities concentrations
Note 1 to entry: Treatment can include, if necessary, deNOx, exhaust (flue) gas desulfurization (FGD), and particulate
matter (PM) reduction.
3.1.31
product CO stream
CO stream (3.1.14) produced by a CO capture plant including any conditioning process
2 2
3.1.32
redundant instrument
duplicate instrument necessary to plant functioning in case of failure of similar instruments for measurement
of the same parameters
3.1.33
reference condition
condition for a reference point where results of performance evaluation can be adjusted for the purpose of
comparability in the reporting of the results and benchmarking
3.1.34
regeneration
process to regenerate an absorbent (3.1.1) or adsorbent (3.1.3) activity after use to its operationally effective state
3.1.35
renewable energy
energy from a source that is not depleted by extraction, such as solar energy (thermal and photovoltaic),
wind power, hydropower and biomass
ISO/FDIS 27928:2025(en)
3.1.36
specific electrical energy consumption
SEC
C
se
electrical energy consumed to capture and conditioning (e.g. compress, liquify, purify, dehydrate) a mass
unit of CO
3.1.37
specific material consumption
SMC
C
sm
amount of materials (e.g. absorbent (3.1.1), adsorbent (3.1.3) or chemical) consumed to capture and compress
or liquefy a mass unit of CO
3.1.38
specific thermal energy consumption
STEC
C
ste
thermal energy (3.1.39) consumed to capture and compress or liquefy a mass unit of CO
3.1.39
thermal energy
enthalpy transported by the heating media cycling forth and back between the heat supply sources or by the
heat generating media like fuels through the distribution network
3.1.40
uncertainty
measurement uncertainty
non-negative parameter characterizing the dispersion of the quantity values being attributed to a measured
entity, based on the information used
Note 1 to entry: Measurement uncertainty includes components arising from systematic effects, such as components
associated with corrections and the assigned quantity values of physical properties, as well as the definitional
uncertainty. Sometimes estimated systematic effects are not corrected for; associated measurement uncertainty
components are incorporated instead.
Note 2 to entry: The parameter may be, for example, a standard deviation called standard measurement uncertainty
(or a specified multiple of it), or the half-width of an interval, having a stated coverage probability.
Note 3 to entry: Measurement uncertainty comprises, in general, many components. Some of these may be evaluated
by Type A evaluation of measurement uncertainty from the statistical distribution of the quantity values from a series
of measurements and can be characterized by standard deviations. The other components, which may be evaluated
by Type B evaluation of measurement uncertainty, can also be characterized by standard deviations, evaluated from
probability density functions based on experience or other information.
Note 4 to entry: In general, for a given set of information, it is understood that the measurement uncertainty is
associated with a stated quantity value attributed to the measured entity. A modification of this value results in a
modification of the associated uncertainty.
Note 5 to entry: “Type A evaluation of measurement uncertainty” is defined as an evaluation of a component of
measurement uncertainty by a statistical analysis of measured quantity values obtained under defined measurement
conditions. “Type B evaluation of measurement uncertainty” is defined as an evaluation of a component of measurement
uncertainty determined by means other than a Type A evaluation of measurement uncertainty”.
[SOURCE: ISO/IEC Guide 99:2007, 2.26, modified — the term "measurement of uncertainty has been deleted",
“measurement standards” has been changed to “physical properties” in Note 1 to entry, "measurand" has
been replaced with "measured entity" in Note 4 to entry and Note 5 to entry has been added.]
3.1.41
utility
substance or ancillary service needed in the operation of a process, such as steam, electricity, cooling water
(CW), demineralised water, compressed air, nitrogen, refrigeration, and effluent (3.1.19) disposal
ISO/FDIS 27928:2025(en)
3.1.42
waste water
excess water allowed to run to waste from the water circuit
3.2 Abbreviated terms
CCS carbon dioxide capture and storage
CCUS carbon dioxide capture, utilization (or use) and storage
CW cooling water
FGD exhaust (flue) gas desulfurization
KPI key performance indicator
NOx nitrogen oxides
PM particulate matter
PSA pressure swing adsorption
SEC specific electrical energy consumption kWh/t
SMC specific material (e.g. absorbent or adsorbent) consumption kg/t
SOx sulfur oxides
STEC specific thermal energy consumption GJ/t
TSA temperature swing adsorption
3.3 Symbols
C specific electrical energy consumption kWh/t
se
C specific material (e.g. absorbent or adsorbent) consumption kg/t
sm
C specific thermal energy consumption GJ/t
ste
P
total electrical power requirement of a CO capture plant MW
CO capture
q
mass flow rate of CO in a product CO stream t/h
mCO
2 2
q
average consumption rate of material at a CO capture plant kg/h
mmaterial
q
volume flow rate of CO in the inlet gas stream on a dry basis at the standard
VrCO in
2 3
m /h
temperature (273,15 K) and pressure (100 kPa) conditions
q
volume flow rate of CO in the outlet gas stream (stream #3) on a dry basis at
VrCO out
2 3
m /h
the standard temperature (273,15 K) and pressure (100 kPa) conditions
q
volume flow rate of the inlet gas stream on a dry basis at the standard temper-
Vr inletgasin
m /h
ature (273,15 K) and pressure (100 kPa) conditions
q
volume flow rate of CO in the product CO stream on a dry basis at the standard
VrproductCO
2 2 3
m /h
temperature (273,15 K) and pressure (100 kPa) conditions
q
volume flow rate of the product CO stream on a dry basis at the standard tem-
VrproductCOstream
2 2 3
m /h
perature (273,15 K) and pre
...
ISO/DISFDIS 27928:2025(en)
ISO/TC 265/WG 1
Secretariat: SCC
Date: 2025-08-27
Carbon dioxide capture, transportation and geological storage —
Carbon dioxide capture — Performance evaluation methods for
CO2 capture connected to a CO2 intensive plant
First edition
Date: 2025-05-16
ISO/CD 27928
FDIS stage
2 © ISO 2023 – All rights reserved
ISO/FDIS 27928:2025(en)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO'sISO’s member body in the country of the requester.
ISO Copyright Office copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Email: E-mail: copyright@iso.org
Website: www.iso.org
Published in Switzerland.
iii
ISO/FDIS 27928:2025(en)
Contents
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 2
3 Terms, definitions, abbreviated terms and symbols . 2
3.1 Terms and definitions . 2
3.2 Abbreviated terms . 7
3.3 Symbols . 7
4 Establishing the CO capture plant boundary . 8
4.1 CO capture plant connected to a CO intensive plant . 8
2 2
4.2 Boundary of the CO capture plant, CO intensive plant and utilities . 8
2 2
5 Definition of basic CO capture plant performance . 12
5.1 General. 12
5.2 CO streams . 12
5.3 CO capture rate of the CO capture plant . 12
2 2
5.4 Flow rate of the product CO stream from a CO capture plant . 13
2 2
5.5 Properties of product CO stream from a CO capture plant . 14
2 2
6 Definition of utilities and consumption calculation . 15
6.1 General. 15
6.2 Thermal energy . 15
6.3 Cooling water. 16
6.4 Definition of electrical energy consumption evaluation . 17
6.5 Absorbent, adsorbent and chemical compounds consumptions . 17
7 Guiding principles — Basis for CO capture plant performance assessment . 18
7.1 General. 18
7.2 Test boundary and required measurements . 18
7.3 Test plan . 19
8 Instruments and measurement methods . 21
8.1 General requirement . 21
8.2 Measurement method . 22
9 Evaluation of key performance indicators . 25
9.1 General. 25
9.2 Specific electrical energy consumption (SEC) . 26
9.3 Specific thermal energy consumption (STEC) . 26
9.4 Specific material consumption (SMC) . 27
10 Quantification and verification of the CO capture . 28
10.1 General. 28
10.2 Quantification . 28
10.3 CO leakage . 28
10.4 Verification . 28
Annex A (informative) General information for the instrument and measurement methods . 29
Annex B (informative) KPI evaluation sheet . 31
Bibliography . 33
iv
ISO/FDIS 27928:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 265, Carbon dioxide capture, transportation and
geological storage.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO/FDIS 27928:2025(en)
Introduction
It is very important to reduce atmospheric carbon dioxide (CO ) emissions in order to meet climate change
mitigation targets. The inclusion of carbon dioxide capture and storage (CCS) among the variety of available
emission reduction approaches enhances the probability of meeting these targets at the lowest cost to the
global economy. CCS captures CO from industrial and energy-related sources and stores it underground in
geological formations. It can capture CO emissions from carbonaceous fuel-based combustion processes,
including power generation, and is at present the most effective technology capable of dealing directly with
emissions from several CO intensive industries, such as steel, cement etc.
As a standard for CO capture, ISO27919-1 has been published, which presentedISO 27919-1 presents an
evaluation method of key performance indicators (KPIs) for post-combustion CO capture (PCC) from a power
plant. On the other hand, this document covers an evaluation method of KPIs for CO capture from various CO
2 2
intensive plants. It is noted that these two standards, ISO27919ISO 27919-1 and ISO27928ISO 27928, are
mutually independent, similar terms and symbols used in both the standards are valid only in the respective
standards. CO intensive plants suggest industries such as steel, cement, ferro alloys, aluminium, and other
metals. It is also intended for CCS enabled hydrogen as well as refineries, chemical processing industries such
as, fertilizer, etc. The CO -capture plant will taketakes in the exhaust gas from the CO -intensive plant without
2 2
further integration, i.e. not impacting on the production of the CO -intensive plant.
CO intensive industries are characterized by the production of significant volumes of CO as a by-product. In
2 2
many cases, the CO amounts are comparable or even larger than the amount of the main product. The two
largest of such industries, steel and cement manufacture, are responsible for 7 % to 8 % each of global CO
production. Typically, the CO intensive industries produce large amounts of CO at each production site, often
2 2
in the range from some hundred thousand to million tonnes per annum. CO intensive industries, such as steel,
cement, etc. are using carbon or carbon-containing raw materials, which often cannot readily be replaced. For
example, cement needs limestone and silicon metal needs carbon as the chemical reductant.
In steel production, the dominant CO sources are the iron-making blast furnace and the steel converter, while
other production steps (ore sintering, rolling mills, etc.) are producing smaller amounts. A modern, integrated
steel plant, making finished steel bars, beams or plates from iron ore emits around 2two tonnes of CO per
tonne of finished product. In contrast, steel produced from scrap in an electric arc furnace emits about 350 kg
CO per tonne of steel. However, scrap availability is seriously limited. The exhaust gases from the blast
furnace have extra high content of CO (typically a volume fraction of 25 vol %) and high pressure ([2
atmospheres (atm) to 4 atm.).]. The steel converter produces intermittently smaller amounts of flue gas with
some lower CO content and at ambient pressure. Other CO producing steps on the way from iron ore to
2 2
finished products typically produce flue gases with lower CO content (10 % to 15 %), like most fuel
combustion and at ambient pressure.
CO capture on the blast furnace exhaust gas can take advantage of the high CO content, pressure and volume
2 2
of this exhaust gas, typically 75 % of the total CO from the integrated mill. This has been pilot tested with
pressure swing adsorption (PSA) on a semi-industrial blast furnace. The adsorbents were zeolites and active
carbon. The results showed low energy consumption.
In cement production, there are two main steps producing CO :
a) a) Calcination of limestone by heating the main raw material, limestone to 900 °C, after grinding
the rock limestone to a fine powder. Heating of the materials occurs in counter current flow with hot
exhaust gases from step 2. The process equipment can vary from plant to plant.
b) b) Clinker burning of a mixture of burnt lime from step 1 together with silica containing raw
materials occur in a long, rotary kiln. The kiln is normally fired from the material exit end with solid, liquid
or gaseous fuel (e.g. coal, oil, gas, biomass and waste). ClinkerThe clinker mix is heated up to 1 450 °C and
the clinker is semi-fused to round plum size pellets. A part of the exhaust gases is sent to step a); the rest
vi
ISO/FDIS 27928:2025(en)
is sent to the exhaust gas stack. The clinker leaving the rotary kiln passes through a clinker cooler, where
combustion air is pre-heated for the kiln.
In lime production, the CO generation includes only this first step.
After calcination and clinker burning, the clinker is ground together with other mineral raw materials into
cement powder, used to make concrete; the biggest volume of construction material globally by far.
The limestone calcination generates 60 % of the total CO produced. The exhaust gas from the rotary kiln
combustion carries the remaining 40 %; giving a total of 0,8 to 0,9 tonnes of CO per tonne of clinker. The
exhaust gas contains typically 20 % to 22 % of CO , moisture and dust. The remaining gas compounds are
mostly N , O and NOx with smaller amounts of other compounds depending on the fuel used. The CO capture
2 2 2
process is located downstream of conventional contaminant controls of the exhaust gas, and is expected to
have minimal, if any, influence on the quality of the cement clinker produced.
Silicon metal (a typical use is in solar panels) is smelted in large bucket shaped furnaces with three large
diameter electrodes in through the top. The top of the furnace is semi-closed for operational reasons. Raw
materials (typically quartz and carbon) are fed through the top. Extreme high temperatures are generated in
the centre of the furnace. This causes the quartz to melt, react with carbon and form a bottom pool of silicon
metal, which then is intermittently tapped out. The furnace reactions also generate large volumes of exhaust
gases; a mixture of carbon monoxide and silicon monoxide (CO and SiO). As the exhaust gas is cooled down
and contacts air at the top of the furnace, these gas components are oxidisedoxidized into CO and silica dust
(SiO ). The silica particle size typically less than 10 microns in size (particle size as for cigarette smoke) is
filtered off and sold as a by-product. The resulting plant exhaust contains varying and low concentrations of
CO and air. Recycling off gas back to the furnace top before connecting the exhaust gas to the CO capture
2 2
plant can result in higher CO concentrations, facilitating the CO capture.
2 2
Even if the furnace producing silicon metal is fed exclusively with renewable electricity, the production emits
around 4four tonnes of CO per tonne of silicon metal produced.
Aluminium production is done in long rows of electrolysis cells fed with aluminium oxide (Al2O3) powder into
a melted fluoride bath. The electricity is fed through bottom (cathode) and top (anode) electrodes. Produced
melted aluminium metal gathers in the bottom and is intermittently tapped off. Under the top carbon
electrode, CO gas evolves containing over 95 % CO ; the remainder being fluorides. This cell gas is collected
2 2
from the long row of cells and then mixed with large volumes of air from building above the cell row (the hall).
This gaseous mixture also contains traces of fluorides leaked from the cells. The diluted cell gas is then sent to
water washing, to avoid harming the environment. After mixing with the hall air and after water wash, the gas
contains 1 % to 2 % CO ; rest air and moisture.
Aluminium electrolysis produces around 1,5 tonnes of CO per tonne of aluminium product.
To capture CO the cell gas can be diverted to a CO capture unit before mixing it with the hall gas and then
2 2
sent to washing with water.
CCS enabled hydrogen (commonly referred to as “Blue” Hydrogen) is produced by the reforming of short-
chain hydrocarbons (typically methane). The product CO from this reaction is captured and exported for
permanent storage.
Feedstock gas is purified and mixed with steam, before passing through one or multiple reforming reactor(s),
producing a stream consisting primary of hydrogen, CO , carbon monoxide (CO) and water. This stream is then
passed through a water-gas shift reactor, where residual CO is converted to CO and hydrogen, and then cooled
vii
ISO/FDIS 27928:2025(en)
to remove water. The result is a syngas made up almost entirely of CO and hydrogen, at a pressure of
1)
approximately 25 bar to 30 bar pressure.
CO is then captured from this syngas stream and exported for storage. Depending on the plant’s configuration
and reformer design, CO can also be captured from plant’s fired heater and reformer flue gases. Hydrogen is
typically purified using a pressure swing adsorption (PSA) unit, from which the rejected “tail gas” is combusted
to produce process heat or steam.
Modern CCS enabled hydrogen flowsheets are capable of capturing in excess of 95 % of all carbon within the
feedstock hydrocarbon gas.
For other CO intensive industries, beyond steel, cement, silicon, aluminium and CCS enabled hydrogen, see
relevant textbooks. The intended user of this document includes CO intensive plant owners and operators,
project developers, technology developers and vendors, regulators, and other stakeholders. This document
provides a common basis for estimating, measuring and evaluating the performance of a CO capture plant
connected to a CO intensive plant.
1) 5 2
1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
viii
ISO/FDIS 27928:2025(en)
Carbon dioxide capture, transportation and geological storage —
Carbon dioxide capture — Performance evaluation methods for CO2
capture connected to a CO2 intensive plant
1 Scope
1.1 This document specifies methods for measuring and evaluating the performance of CO capture
connected to a CO intensive plant, and which separates CO from the CO intensive plant exhaust gas in
2 2 2
preparation for subsequent transportation and geological storage. In particular, this document provides a
common methodology to calculate key performance indicators (KPI) for the CO capture plant. It’s
requiringIn particular, this document provides a common methodology to calculate key performance
indicators (KPI) for the definition ofCO capture plant. To determine the KPIs, the boundaries of a typical
systemthe CO capture plant need to be defined and the measurements ofnecessary parameters
neededneed to determine the KPIsbe measured.
1.2 This document covers the CO capture plant capturing CO from CO containing exhaust gas connected
2 2 2
to CO intensive plants. The connection of a CO -capture plant to a CO -intensive plant is anticipated to have
2 2 2
negligible impact on the product quality or the quantities produced by the CO -intensive plant. This is in
contrast with the integration of CO -capture plants with power plants which usually results in a reduction of
the power plant output. For the CO -intensive industry, it is important that product quality remains the same
after connection of the CO -capture plant, in order for the industry to continue to meet customer requirements.
The CO capture technologies covered by this document are able to operate without interfering with the
operations of the CO intensive plant. Frequently used CO capture technologies are chemical absorption (e.g.
2 2
liquid amine) and solid adsorption [e.g. pressure swing adsorption (PSA), temperature swing adsorption
(TSA)]. Other CO capture concepts are membranes, cryogenic and other capture technologies. The CO
2 2
capture plant can be installed for treatment of the full volume of exhaust gas from the CO intensive plant or a
fraction of the total (i.e. a slipstream). Captured CO is then conditioned, e.g. dried and compressed or liquefied,
as determined by the conditions needed for transportation and storage. The transportation can be either
through a pipeline or through an intermediate storage facility waiting for shipment; either by tanker car, train
or ship.
The system includes interfaces between the CO capture plant and the CO intensive plant as well as the CO
2 2 2
transportation and storage system.
1.3 This document is intended to describe the following KPIs:
a) a) CO capture rate;
b) b) Specificspecific electrical energy consumption (SEC));
c) c) Specificspecific thermal energy consumption (STEC));
d) d) Specificspecific material consumption (e.g. absorbent/ or adsorbent) (SMC)).
The calculations are based on measurements at the boundary of the CO capture plant, particularly of energy
and other utilities consumption.
1.4 This document includes the following items:
a) 1) Thethe CO capture plant boundary (see 4Clause 4),), which defines the boundaries of the CO
2 2
capture plant and identifies which streams of energy and mass are crossing these boundaries to identify
the key streams that are applicable for their particular case.
ISO/FDIS 27928:2025(en)
b) 2) Basicthe basic performance of CO capture plant (see 5Clause 5),), which defines the
parameters that describe the basic performance of the CO capture plant.;
c) 3) Utilitiesthe utilities and consumption calculation (see 6Clause 6),), which lists the utility
measurements required and provides guidance on how to convert utility measurements into the values
required for the KPIs.;
d) 4) Guidingthe guiding principles (see 7Clause 7)- Basis), the basis for CO capture plant
performance assessment, which describes all guidelines to prepare, set-up and conduct the tests.;
e) 5) Instrumentsthe instruments and measurement methods (see 8Clause 8),), which lists the
standards available for the relevant measurements issues and considerations to take into account when
applying measurement methods to CO capture plants.;
f) 6) Evaluationthe evaluation of key performance indicators (see 9Clause 9),), which specifies the
set of KPIs to be determined and their calculation methods.
1.5 This document does not provide guidance for benchmarking, comparing or assessing KPIs of different
technologies or different CO capture projects. HSE is not included, but should be the operators
responsibility.
2 Normative references
There are no normative references in this document.
3 Terms, definitions, abbreviated terms and symbols
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
3.1 Terms and definitions
3.1.1 3.1.1
absorbent
substance able to selectively absorb liquid or gas components in its bulk phase
3.1.2 3.1.2
accuracy
measurement accuracy
closeness of agreement between a measured quantity value and a true quantity value of a measured entity
[SOURCE: ISO/IEC Guide 99]
3.1.3
[SOURCE: ISO/IEC Guide 99:2007, 2.13, modified — the admitted term "accuracy of measurement" has been
deleted, "measurand" has been replaced with "measured entity" in the definition and Notes 1, 2 and 3 to entry
have been deleted.]
3.1.3
adsorbent
substance able to selectively adsorb liquid or gas components on its surface
ISO/FDIS 27928:2025(en)
3.1.33.1.4 3.1.4
auxiliary unit
unit providing electricity or thermal (heating and/or cooling) and/or other utilities for the CO capture plant
3.1.43.1.5 3.1.5
carbon dioxide capture and storage
CCS
process consisting of the separation of CO2 from industrial and energy-related sources, transportation and
injection into a geological formation, resulting in long term isolation from the atmosphere
Note 1 to entry: CCS is often referred to as Carbon Capturecarbon capture and Storagestorage. This terminology is not
encouraged because it is inaccurate: the objective is the capture of carbon dioxide and not the capture of carbon. Tree
plantation is another form of carbon capture that does not describe precisely the physical process of removing CO2 from
industrial emission sources.
Note 2 to entry: The term "“sequestration"” is also used alternatively to "“storage".”. The term "“storage"” is preferred.
Note 3 to entry: Long term means the minimum period necessary for CO2 geological storage to be considered an effective
and environmentally safe climate -change -mitigation -option.
Note 4 to entry: The term carbon dioxide capture, utilization (or use) and storage (CCUS) includes the concept that
isolation from the atmosphere can be associated with a beneficial outcome. CCUS is embodied within the definition of
CCS to the extent that long term isolation of the CO2 occurs through storage within geological formations. CCU is Carbon
Capturecarbon capture and utilization (or use) without storage within geological formations.
Note 5 to entry: CCS should also ensure long term isolation of CO from oceans, lakes, potable water supplies and other
natural resources.
[SOURCE: ISO 27917:2017, 3.1.1, modified -— Note 2 to entry has been modified.]
3.1.53.1.6 3.1.6
chemical absorption
process in which CO is absorbed by chemical reaction
3.1.63.1.7 3.1.7
CO capture
separation of CO in such a manner as to produce a concentrated stream of CO that can readily be transported
2 2
for storage
3.1.73.1.8 3.1.8
CO captured
CO in the product CO stream (3.1.31(3.1.31)) produced by a CO capture plant that produces a CO stream
2 2 2 2
(3.1.14(3.1.14)) from exhaust gases
3.1.83.1.9 3.1.9
CO capture plant boundary
boundary
performance evaluation boundary of a CO capture plant
3.1.93.1.10 3.1.10
CO capture rate
CO removal efficiency of the CO capture plant calculated as the quotient of the CO volume flow rate in the
2 2 2
product CO stream (3.1.14(3.1.14)) divided by the CO volume flow rate in the inlet gas steam
2 2
Note 1 to entry: CO2 capture rate is expressed as a percentage.
ISO/FDIS 27928:2025(en)
3.1.103.1.11 3.1.11
CO conditioning
processes needed before transportation to make the CO stream (3.1.14(3.1.14)) leaving the capture plant
meeting downstream specifications, e.g. drying (dehydration) purification, compression, liquefaction and
dehydration.
3.1.113.1.12 3.1.12
CO2 intensive industry
industry producing significant volumes of CO as a by-product
3.1.123.1.13 3.1.13
CO intensive plant
plant producing significant volumes of CO as a by-product
3.1.133.1.14 3.1.14
CO stream
gas stream containing CO , crossing the CO capture plant boundary (3.1.9(3.1.9))
2 2
Note 1 to entry: In ISO 27917 defines as, a CO2 stream is defined instead as a “stream consisting overwhelmingly of
carbon dioxide”.
3.1.143.1.15 3.1.15
cooling duty
net enthalpy rejected to a cooling media
3.1.153.1.16 3.1.16
cooling energy
enthalpy removed by the cooling method
3.1.163.1.17 3.1.17
dehydrator
moisture removal system and/or equipment
3.1.173.1.18 3.1.18
deNOx
process or equipment used to remove nitrogen oxides (NOx) from the exhaust gas
3.1.183.1.19 3.1.19
effluent
liquid discharged to the environment or wastewater (0(3.1.42)) treatment facility
3.1.193.1.20 3.1.20
heat duty
net enthalpy required from a heat media cycling forth and back with the thermal energy source
3.1.203.1.21 3.1.21
impurity
non-CO substance that is part of the CO stream (3.1.14(3.1.14)) that may be derived from the source
2 2
materials or the capture process, or added as a result of co-mingling for transportation, or released or formed
as a result of sub-surface storage and/or leakage of CO
[SOURCE: ISO 27917:2017, 3.2.1112, modified - Note— Notes 1 and 2 to entry hashave been deleted.]
3.1.213.1.22 3.1.22
inlet gas stream
input gas stream to be treated by CO capture plant coming from the CO intensive plant (3.1.13(3.1.13))
2 2
ISO/FDIS 27928:2025(en)
3.1.223.1.23 3.1.23
interface
mechanical, thermal, electrical, or operational common boundary between two elements of a system
[SOURCE: ISO 10795:2019, 3.132], modified — the term "I/F" has been deleted.]
3.1.233.1.24 3.1.24
key performance indicator
KPI
measure of performance relevant to the CO capture plant connected to a CO intensive plant (3.1.13(3.1.13))
2 2
3.1.243.1.25 3.1.25
measurement point
point of connection between the CO capture plant and inlet, outlet and product gas stream as well as with
utilities
Note 1 to entry: This The measurement point sits at the CO2 capture plant boundary (3.1.9.).
3.1.253.1.26 3.1.26
outlet gas stream
outlet CO leaner gas stream of which the CO concentration has been reduced after passing through a CO
2 2 2
capture plant
3.1.263.1.27 3.1.27
permanent plant instrument
instrument installed in the CO intensive plant (3.1.13(3.1.13)) and capture plant for control and monitoring
3.1.273.1.28 3.1.28
plant reference condition
stable operating condition of the CO intensive plant (3.1.13(3.1.13)) with the rated or the ordinary production
operation
3.1.283.1.29 3.1.29
post-combustion CO capture
PCC
capture of carbon dioxide from exhaust gas stream produced by carbonaceous fuel combustion
[SOURCE: ISO/TR 27912:2016, 3.1.51, modified –— “fuel air combustion” washas been modified to
“carbonaceous fuel combustion”.]
3.1.293.1.30 3.1.30
pre-treatment
part of the CO capture (3.1.7(3.1.7)) which conditions the inlet gas as required for CO to be separated, in
2 2
respect of the temperature, the pressure and impurities concentrations
Note 1 to entry: Treatment can include, if necessary, deNOx, exhaust (flue) gas desulfurization (FGD,), and particulate
matter (PM) reduction.
3.1.303.1.31 3.1.31
product CO stream
CO stream (3.1.14(3.1.14)) produced by a CO capture plant including any conditioning process
2 2
3.1.313.1.32 3.1.32
redundant instrument
duplicate instrument necessary to plant functioning in case of failure of similar instruments for measurement
of the same parameters
ISO/FDIS 27928:2025(en)
3.1.323.1.33 3.1.33
reference condition
condition for a reference point where results of performance evaluation can be adjusted for the purpose of
comparability in the reporting of the results and benchmarking
3.1.333.1.34 3.1.34
regeneration
process to regenerate an absorbent (3.1.1(3.1.1)) or adsorbent (3.1.3(3.1.3)) activity after use to its
operationally effective state
3.1.343.1.35 3.1.35
renewable energy
energy from a source that is not depleted by extraction, such as solar energy (thermal and photovoltaic), wind
power, hydropower and biomass
3.1.353.1.36 3.1.36
specific electrical energy consumption
SEC
C
se
electrical energy consumed to capture and conditioning (e.g. compress, liquify, purify, dehydrate etc.)) a mass
unit of CO
3.1.363.1.37 3.1.37
specific material consumption
SMC
C
sm
amount of materials (e.g. absorbent (3.1.1(3.1.1),), adsorbent (3.1.3(3.1.3)) or chemical) consumed to capture
and compress/ or liquefy a mass unit of CO
3.1.373.1.38 3.1.38
specific thermal energy consumption
STEC
C
ste
thermal energy (3.1.39(3.1.39)) consumed to capture and compress/ or liquefy a mass unit of CO
3.1.383.1.39 3.1.39
thermal energy
enthalpy transported by the heating media cycling forth and back between the heat supply sources or by the
heat generating media like fuels through the distribution network
3.1.393.1.40 3.1.40
uncertainty
measurement uncertainty
non-negative parameter characterizing the dispersion of the quantity values being attributed to a measured
entity, based on the information used
Note 1 to entry: Measurement uncertainty includes components arising from systematic effects, such as components
associated with corrections and the assigned quantity values of physical properties, as well as the definitional
uncertainty. Sometimes estimated systematic effects are not corrected for; associated measurement uncertainty
components are incorporated instead.
Note 2 to entry: The parameter may be, for example, a standard deviation called standard measurement uncertainty (or
a specified multiple of it), or the half-width of an interval, having a stated coverage probability.
Note 3 to entry: Measurement uncertainty comprises, in general, many components. Some of these may be evaluated by
Type A evaluation of measurement uncertainty from the statistical distribution of the quantity values from a series of
measurements and can be characterized by standard deviations. The other components, which may be evaluated by Type
ISO/FDIS 27928:2025(en)
B evaluation of measurement uncertainty, can also be characterized by standard deviations, evaluated from probability
density functions based on experience or other information.
Note 4 to entry: In general, for a given set of information, it is understood that the measurement uncertainty is associated
with a stated quantity value attributed to the measured entity. A modification of this value results in a modification of the
associated uncertainty.
Note 5 to entry: “Type A evaluation of measurement uncertainty” is defined as an evaluation of a component of
measurement uncertainty by a statistical analysis of measured quantity values obtained under defined measurement
conditions. “Type B evaluation of measurement uncertainty” is defined as an evaluation of a component of measurement
uncertainty determined by means other than a Type A evaluation of measurement uncertainty”.
[SOURCE: ISO/IEC Guide 99:2007, 2.26, modified –— the term "measurement of uncertainty has been
deleted", “measurement standards” in Note 1 washas been changed to “physical properties” in Note 1 to entry,
"measurand" has been replaced with "measured entity" in Note 4 to entry and Note 5 wasto entry has been
added.]
3.1.403.1.41 3.1.41
utility
substance or ancillary service needed in the operation of a process, such as steam, electricity, cooling water
(CW), demineralised water, compressed air, nitrogen, refrigeration, and effluent (3.1.19(3.1.19)) disposal
3.1.413.1.42 3.1.42
waste water
excess water allowed to run to waste from the water circuit
3.2 Abbreviated terms
CCS carbon dioxide capture and storage
CCUS carbon dioxide capture, utilization (or use) and storage
CW cooling water
FGD exhaust (flue) gas desulfurization
KPI key performance indicator
NOx nitrogen oxides
PM particulate matter
PSA pressure swing adsorption
SEC specific electrical energy consumption [kWh/t]
SMC specific material (e.g. absorbent/ or adsorbent) consumption [kg/t]
SOx sulphursulfur oxides
STEC specific thermal energy consumption [GJ/t]
TSA temperature swing adsorption
3.3 Symbols
C specific electrical energy consumption [kWh/t]
se
C specific material (e.g. absorbent/ or adsorbent) consumption [kg/t]
sm
ISO/FDIS 27928:2025(en)
C specific thermal energy consumption [GJ/t]
ste
𝑃 𝑃 total electrical power requirement of a CO capture plant
2 [MW]
CO capture CO capture
2 2
𝑞 𝑞 mass flow rate of CO in a product CO stream
2 2 [t/h]
𝑚 CO 𝑚 CO
2 2
𝑞 𝑞 average consumption rate of material at a CO2 capture plant [kg/h]
𝑚 material 𝑚 material
𝑞 𝑞 volume flow rate of CO in the inlet gas stream on a dry basis at the standard
𝑉𝑟 CO in 𝑉𝑟 CO in
2 2 3
[m /h]
temperature (273,15 K) and pressure (100 kPa) conditions
𝑞 𝑞 volume flow rate of CO in the outlet gas stream (stream #3) on a dry basis at
𝑉𝑟 CO out 𝑉𝑟 CO out
2 2 3
[m /h]
the standard temperature (273,15 K) and pressure (100 kPa) conditions
𝑞 𝑞 volu me flow rate of the inlet gas stream on a dry basis at the standard
𝑉𝑟 inlet gas in 𝑉𝑟 inlet gas in
[m /h]
temperature (273,15 K) and pressure (100 kPa) conditions
𝑞 𝑞 volum e flow rate of CO in the product CO stream on a dry basis at the
2 2
𝑉𝑟 product CO 𝑉𝑟 product CO
2 2 3
[m /h]
standard temperature (273,15 K) and pressure (100 kPa) conditions
𝑞 𝑞 volume flow rate of the pr oduct CO stream on a dry basis at the standard
𝑉𝑟 product CO stream 𝑉𝑟 product CO stream
2 2 3
[m /h]
temperature (273,15 K) and pressure (100 kPa) conditions
𝜂 𝜂 CO capture rate
2 [%]%
CO CO
2 2
𝛷 𝛷 thermal energy consumption of a CO capture plant
2 [kJ/h]
th capture th capture
𝜑 𝜑 volume concentration of CO in the inlet gas stream on a dry basis
2 [%]%
CO in_cap CO in_cap
2 2
𝜑 𝜑 v olume concentration of CO in the product CO stream on a dry basis
2 2 [%]%
CO product CO product
2 2
4 Establishing the CO capture plant boundary
4.1 CO2 capture plant connected to a CO2 intensive plant
A CO capture plant connected to a CO intensive plant is characterized as follows:
2 2
a) a) ReceivesIt receives exhaust gas from one or more CO intensive plants. Pre-treatment may be
conducted within the CO intensive plant(s), within the CO capture plant, or a combination of both;.
2 2
NOTE Depending on local regulatory demand or technology, this will vary. If reported, KPIs needs to be
specified against the specific location of the boundary.
b) b) ReceivesIt receives utilities and energy supply from other sources than the CO capture plant;.
c) c) The load control of CO capture plant is linked to the operation of the CO intensive plant with
2 2
the agreement of both parties.
4.2 Boundary of the CO capture plant, CO intensive plant and utilities
2 2
Figure 1Figure 1 presents a typical boundary of a CO capture plant connected to a CO intensive plant. The
2 2
boundary of a CO capture plant includes the following interfaces and the bold red line with “Scope” is a
reference line to indicate to the reader the items to be considered and the range.
a) a) Interface with the CO intensive plant (stream #1): Important elements at this interface include
exhaust gas (downstream of any existing environmental control systems),
b) b) Interface with supply of utilities (streams #4, #5, #6, #7 and #8): It includes electrical energy
and thermal energy to the CO capture plant. Only the utility consumption affecting the performance
ISO/FDIS 27928:2025(en)
evaluation of the CO capture plant should be included in the consumption calculations (see 6See
Clause 6).).
c) c) Interface of the outlet gas stream (stream #3): The destination of outlet of the CO capture plant
(outlet gas side) including the environment is out of scope for this document. Waste streams such as
effluent (e.g. waste water), solid waste (e.g. catalysts and filters sludges) and those generated from
consumables inlet should also be included in consumables outlet, calculating consumption and utility
requirements if present (see 6. (See Clause 6)).
d) d) Interface with CO transportation infrastructure (stream #2): It is the last flange at the outlet
piping of product CO stream from the CO conditioning, if applied.
2 2
e) e) Interface with any auxiliary units generating a CO stream, e.g. a steam boiler. This CO stream
2 2
should be included either a) into the inlet gas stream from the CO intensive plant (stream #1) or b) into
the outlet gas stream (stream #3) depending on how the generated CO is being handled.
The performance evaluation boundary of a CO capture plant connected to a CO intensive plant is depicted as
2 2
a thick blue line with “#13 boundary” in Figure 1Figure 1.
ISO/FDIS 27928:2025(en)
Key
1 inlet gas stream 8 consumables outlet
2 product CO2 stream 9 CO2 intensive plant
3 outlet gas stream 10 CO2 capture
4 electrical energy 11 CO2 conditioning
5 thermal energy 12 scope
6 cooling energy 13 boundary
7 consumables inlet
1 inlet gas stream
2 product CO2 stream
3 outlet gas stream
4 electrical energy
5 thermal energy
ISO/FDIS 27928:2025(en)
6 cooling energy
7 consumables inlet
8 consumables outlet
9 CO intensive plant
10 CO capture
11 CO2 conditioning
12 scope
13 boundary
Figure 1 — Block diagram of the boundary of CO capture connected to a CO intensive plant
2 2
NOTE 1 The inlet gas streams entering the CO2 capture plant do not necessarily represent all of the CO2 containing
exhaust gas generated by the CO2 intensive plant or auxiliary units. The CO2 capture plant can be designed for partial
capture, with a share of the exhaust gas from the CO intensive plant routed to the CO capture plant for treatment.
2 2
CO conditioning for the product CO stream (#2) is normally necessary to meet the specifications of the
2 2
downstream intermediate storage or transport. CO conditioning consists typically of dehydration and
compression. It is to be regarded as an integral and necessary part of the CO capture plant, hence utility
consumption in CO conditioning should be included in the overall utility consumption in 6Clause 6.
Items related to definition of 3Clause 3 and basic CO capture plant performance (see 5Clause 5)) are included
in Table 1Table 1. These include inlet CO richer gas stream (#1) entering the CO capture plant from the CO
2 2 2
intensive plant and streams (#2 an
...
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