Carbon Dioxide Capture Using a Zeolite Molecular Sieve Sampling System for Isotopic Studies (¹³C and ¹⁴C) of Respiration

Abstract

A method for collecting an isotopically representative sample of CO2 from an air stream using a zeolite molecular sieve is described. A robust sampling system was designed and developed for use in the field that includes reusable molecular sieve cartridges, a lightweight pump, and a portable infrared gas analyzer (IRGA). The system was tested using international isotopic standards (13C and 14C). Results showed that CO2 could be trapped and recovered for both δ13C and 14C analysis by isotope ratio mass spectrometry (IRMS) and accelerator mass spectrometry (AMS), respectively, without any contamination, fractionation, or memory effect. The system was primarily designed for use in carbon isotope studies of ecosystem respiration, with potential for use in other applications that require CO2 collection from air.

A passive sampling method for radiocarbon analysis of atmospheric CO2 using molecular sieve

“…We employed the MSC previously described by Hardie et al (2005) and , and illustrated schematically in Fig. 1 Gut et al, 1998); air was free to pass from the atmosphere through the filter into the MSC, however, the filter prevented entry of liquid water.…”

“…Zeolite molecular sieve is an extremely effective CO 2 absorbent that does not suffer from many of the disadvantages that affect hydroxides. The technique employs exactly the same molecular sieve cartridge (MSC) that was tested by Hardie et al (2005) and found not to suffer from fractionation, contamination or sample carry-over effects when used with a pump-based sampling system. Application of the MSC in passive sampling form has already been successfully tested for trapping samples of soil respired CO 2 for 14 C measurement ).…”

Synthesis of Zeolite-X Supported on Kapok Fiber for CO₂ Capture Material: Variation of Immersion Time during Fiber Activation

“…As a result, zeolite has a high affinity for polar molecules like CO2. CO2 quadrupole moment interacts with the electric field of zeolite, resulting in high adsorption of CO2 into the zeolite structure [10].…”

Do Riparian Plants Fix CO2 Lost by Evasion from Surface Waters? An Investigation Using Carbon Isotopes

“…Collection of evasion CO 2 samples for isotope analysis and measurement of CO 2 flux rate was achieved by linking a molecular sieve sampling system (Hardie et al 2005) to a floating chamber as described by Billett et al (2006). This recently developed method allows direct collection of the evaded CO 2 and is considered preferable to previously used indirect methods (e.g.…”

“…Following sample collection, the molecular sieve cartridges were returned to the NERC Radiocarbon Laboratory and the sample CO 2 recovered by heating and cryogenic trapping (see Hardie et al 2005 for details about the molecular sieve procedures).…”