Biomass Carbon Ratio of Biomass Chemicals Measured by Accelerator Mass Spectrometry

The biomass carbon ratios of various chemical products were studied. The biomass carbon ratios of chemicals such as polymers, their monomers, starches, cellulose, calcium carbonate, charcoal, ethanol, and polymer blends were estimated by the ratios of C-14 to C-12 measured by accelerator mass spectrometry (AMS) based on ASTM D 6866. Preparations of the gaseous and liquid samples for the AMS measurements are described, and the pretreatment for carbonate is also explained. Repeatability and accuracy of the biomass carbon ratio evaluation by AMS are discussed. It was found that a new correction factor is necessary for cellulose other than 0.93, which is regulated as the correction factor for present modem carbon newer than 1950 in ASTM D 6866. The developed sample preparations of gaseous materials and carbonate were confirmed to be applicable for the AMS measurement of the biomass carbon ratio. The repeatability and accuracy of the biomass carbon ratio evaluation by AMS were confirmed for ethanol derived from biomass (bioethanol), a polymer blend of biomass-based poly(lactic acid) (PLA), and petroleum-based poly(butylene succinate) (PBS). Standard deviations of the bioethanol and the blend of PLA and PBS are 0.36 and 0.84%, respectively. The biomass carbon ratio evaluation by AMS has been proposed for the International Standard (ISO).