Carbon Utilization Infrastructure, Markets, and Research and Development: A Final Report (2024)
Chapter: Appendix H: CO2 Stream Impurities and CO2 Purity Requirements for Transport and Utilization
H
CO2 Stream Impurities and CO2 Purity Requirements for Transport and Utilization
This appendix collects information about impurities commonly present in gas streams and those of greatest concern for CO2 conversion processes. Table H-1 lists various impurities and their concentrations in flue gas streams from different types of CO2 capture facilities. It is provided for reference on the impurities that may be present in CO2 destined to be transformed into products. Table H-2 describes trace impurities by CO2 source. Table H-3 lists recommended maximum impurity limits for CO2 transported in pipelines and by ship.
TABLE H-1 Overview of Impurity Concentrations of CO2 Streams from Different Illustrative Facility Types
| Component | Subcritical Pulverized Bituminous Coal (Illinois #6) Plant with Post-Combustion Capturea | Natural Gas with Carbon Capturec | Oxyfuel Combustion at Supercritical Pulverized Coal Planta,d | Cement Planta | Refinery Stacka | Bioethanol Plante | Direct Air Capturef |
|---|---|---|---|---|---|---|---|
| Gas leaving the carbon capture unit (post-combustion with MEAb) | Gas leaving the carbon capture unit (post-combustion with MEAb) | Gas leaving the boiler unit | Gas leaving the carbon capture unit (post-combustion with MEAb) | Gas leaving the carbon capture unit (post-combustion with MEAb) | Raw CO2 gas from ethanol plant | Gas leaving the capture unit (KOH sorbent) | |
| CO2 | 99.7% | 95% | 96.65% | 99.8% | 99.6% | 90% | 97.11% |
| CO | 750 ppmv | 1.2 ppmv | |||||
| H2O | 640 ppmv | 100 ppmv | 640 ppmv | 640 ppmv | 1–5 ppmv | 0.01% | |
| CH4 | 4% | 0.026 ppmv | 0–3 ppmv | ||||
| SO2 | <1 ppmv | 50 ppmv | <0.1 ppmv | 1.3 ppmv | |||
| SO3 | 20 ppmv | ||||||
| NO2 | 1.5 ppmv | 0.86 ppmv | 2.5 ppmv | ||||
| NOx | 100 ppmv | ||||||
| O2 | 61 ppmv | 0.81 % | 35ppmv | 121 ppmv | 10–100 ppmv | 1.36% | |
| H2S | 200 ppmv | 7.9 ppmv | |||||
| N2 | 0.18% | 0.5% | 1.96% | 893 ppmv | 0.29% | 50–600 ppmv | 1.51% |
| Ar | 22 ppmv | 0.57% | 11 ppmv | 38 ppmv | |||
| Hg | 0.0007 ppmv | 0.011 ppmv | 0.00073 ppmv | ||||
| As | 0.0055 ppmv | 0.026 ppmv | 0.0029 ppmv | ||||
| Se | 0.017 ppmv | 0.08 ppmv | 0.0088 ppmv | ||||
| Cl | 0.85 ppmv | 0.41 ppmv | 0.4 ppmv | ||||
| Ethanol | 25–950 ppmv | ||||||
| Methanol | 1–50 ppmv | ||||||
| Acetaldehyde | 3–75 ppmv | ||||||
| Isoamyl acetate | 0.6–3.0 ppmv | ||||||
| Isobutanol | 0–3 ppmv | ||||||
| Ethylacetate | 2–30 ppmv |
b MEA = monoethanolamine.
c Values from SINTEF (2019).
d Values from Rütters et al. (2015).
e Values from McKaskle et al. (2018).
f Values from Keith et al. (2018).
NOTE: ppmv = parts per million by volume.
SOURCE: Reproduced from NASEM (2023).
TABLE H-2 Overview of Trace Impurities by CO2 Source
| Impurity | CO2 Source | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Combustion | Wells/Geothermal | Fermentation/Bioethanol Anaerobic Digestion (Purely Energy Crops) | Anaerobic Digestion (waste) | Hydrogen or Ammonia | Phosphate Rock | Coal Gasification | Ethylene Oxide | Acid Neutralization | Vinyl Acetate | |
| Aldehydes | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Amines | ✓ | ✓ | ||||||||
| Benzene | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |
| Carbon monoxide | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Carbonyl sulfide | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Cyclic aliphatic hydrocarbons | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |||
| Dimethyl sulfide | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||||
| Ethanol | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Ethers | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |||
| Ethyl acetate | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||||
| Ethyl benzene | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||||
| Ethylene oxide | ✓ | ✓ | ||||||||
| Halocarbons | ✓ | ✓ | ✓ | ✓ | ✓ | |||||
| Hydrogen cyanide | ✓ | ✓ | ||||||||
| Hydrogen sulfide | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Ketones | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Mercaptans | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |
| Mercury | ✓ | ✓ | ✓ | |||||||
| Methanol | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Nitrogen oxides | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |||
| Phosphine | ✓ | |||||||||
| Radon | ✓ | ✓ | ✓ | |||||||
| Sulfur dioxide | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Toluene | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |||
| Vinyl chloride | ✓ | ✓ | ✓ | ✓ | ||||||
| Volatile hydrocarbons | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Xylene | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |||
SOURCES: Adapted from EIGA (2016) and NASEM (2023).
TABLE H-3 Overview of Recommended Maximum Impurity Limits for CO2 Transport in Pipelines and Shipping
| Component | Pipelines | Shipping | |||
|---|---|---|---|---|---|
| NETL (United States)a | National Grid Carbon (United Kingdom)b | Northern Light Project (Norway)c | EU CCUS Projects Networkd | ||
| Conceptual Design | Range in Literature | ||||
| CO2 (minimum vol %) | 95 | 90–99.8 | ≥91 (gaseous phase) ≥96 (dense phase) |
99.81 | >99.7 |
| H2O (ppmv) | 500 | 20–650 | 50 | ≤30 | <30 |
| N2 | 4 vol% | 0–7 vol% | ≤50 ppmv | ||
| O2 | 0.001 vol% | 0.001–4 vol% | 0.001 vol% | ≤10 ppmv | <10 ppmv |
| Ar | 4 vol% | 0.01–4 vol% | ≤100 ppmv | ||
| CH4 | 4 vol% | 0.01–4 vol% | ≤100 ppmv | ||
| H2 | 4 vol% | 0–4 vol% | 2 | ≤50 ppmv | <500 ppmv |
| CO ppmv | 35 | 10–5000 | 200 | ≤100 | <12,000 |
| H2S | 0.01 vol% | 0.002–1.3 vol% | 0.002 vol% (for dense-phase 150 barg) 0.008 vol% (for gas-phase 38 barg) |
≤9 ppmv | <5 ppmv |
| SO2 ppmv | 100 | 10–50000 | |||
| SOx ppmv | 100 | ≤10 | <10 | ||
| NOx ppmv | 100 | 20–2500 | 100 | ≤1.5 | <1.5 |
| NH3 ppmv | 50 | 0–50 | ≤10 | <10 | |
| COS ppmv | trace | trace | |||
| C2H6 ppmv | 1 | 0–1 | ≤75 | ||
| C3+ ppmv | <1 | 0–1 | ≤1100 | ||
| Particulates | 1 ppmv | 0–1 ppmv | ≤1 μm | ||
| Hg ppmv | ≤0.0003 | <0.03 | |||
| Glycol ppmv | 46 | 0–174 | ≤0.005e | ||
| Cd, Tl, ppm | ≤0.03 (sum) | <0.03 | |||
a Values from NETL (2019).
b Values from Gibbins and Lucquiaud (2021).
c Values from Northern Lights (2024).
d Values from Aramis (2023).
e Concentration limit is for mono-ethylene glycol; tri-ethylene glycol is not allowed.
NOTES: The data in this table have been corrected to reflect accurate values. Please disregard previous versions of this table published in earlier editions. EU CCUS = European Union carbon capture, utilization, and storage.
SOURCE: Adapted from NASEM (2023).
REFERENCES
Aramis. 2023. “CO2 Specifications for Aramis Transport Infrastructure.” https://www.aramis-ccs.com/news/co2-specifications-foraramis-transport-infrastructure.
EC (European Commission and Directorate-General for Climate Action). 2011. Implementation of Directive 2009/31/EC on the Geological Storage of Carbon Dioxide: Guidance Document 2, Characterisation of the Storage Complex, CO2 Stream Composition, Monitoring and Corrective Measures. Publications Office. https://doi.org/10.2834/98293.
EIGA (European Industrial Gases Association). 2016. “Carbon Dioxide Food and Beverages Grade, Source Qualification, Quality Standards and Verification.” EIGA Doc 70/17, revision of Doc 70/08. https://www.eiga.eu/ct_documents/doc070.pdf.
Gibbins, J., and M. Lucquiaud. 2021. “BAT Review for New-Build and Retrofit Post-Combustion Carbon Dioxide Capture Using Amine-Based Technologies for Power and CHP Plants Fuelled by Gas and Biomass as an Emerging Technology Under the IED for the UK, UKCCSRC Report.” UKCCSRC Report, Ver.1.0. Sheffield, UK: UK CCS Research Centre. https://ukccsrc.ac.uk/wp-content/uploads/2021/06/BAT-for-PCC_V1_0.pdf.
Keith, D.W., G. Holmes, D. St. Angelo, and K. Heidel. 2018. “A Process for Capturing CO2 from the Atmosphere.” Joule 2(8):1573–1594. https://doi.org/10.1016/j.joule.2018.05.006.
McKaskle, R., K. Fisher, P. Selz, and Y. Lu. 2018. “Evaluation of Carbon Dioxide Capture Options from Ethanol Plants.” Circular 595. Champaign, IL: Illinois State Geological Survey Prairie Research Institute. https://library.isgs.illinois.edu/Pubs/pdfs/circulars/c595.pdf.
NASEM (National Academies of Sciences, Engineering, and Medicine). 2023. Carbon Dioxide Utilization Markets and Infrastructure: Status and Opportunities: A First Report. Washington, DC: The National Academies Press. https://doi.org/10.17226/26703.
NETL (National Energy Technology Laboratory). 2019. “CO2 Impurity Design Parameters.” Quality Guidelines for Energy System Studies. Pittsburgh, PA: National Energy Technology Laboratory. https://www.netl.doe.gov/projects/files/QGESSCO2ImpurityDesignParameters_010119.pdf.
Northern Lights. 2024. “Liquid CO2 Quality Specifications.” https://norlights.com/wp-content/uploads/2024/02/NorthernLights-GS-co2-Spec2024.pdf.
Rütters, H., D. Bettge, R. Eggers, A. Kather, C. Lempp, U. Lubenau, and COORAL-Team. 2015. CO2-Reinheit Für Die Abscheidung Und Lagerung (COORAL) – Synthese. Hannover: Bundesanstalt für Geowissenschaften und Rohstoffe. https://www.bgr.bund.de/DE/Themen/Nutzung_tieferer_Untergrund_CO2Speicherung/CO2Speicherung/COORAL/Downloads/Synthesebericht.pdf?__blob=publicationFile&v=6.
SINTEF. 2019. “CO2 Impurities: What Else Is There in CO2 Except CO2?” #SINTEFblog, November 6. https://blog.sintef.com/sintefenergy/energy-efficiency/what-else-is-there-in-co2-except-co2.
