Carbon footprint of bioplastics using biocarbon content analysis and life-cycle assessment

Abstract

Bio-based plastics, in which the fossil carbon is replaced by bio/renewable-based carbon, offer the intrinsic value proposition of a reduced carbon footprint and are in complete harmony with the rates and time scale of the biological carbon cycle. Identification and quantification of bio-based content is based on the radioactive C-14 signature associated with (new) biocarbon. Using experimentally determined biocarbon content values, one can calculate the intrinsic CO₂ emissions reduction achieved by substituting petrocarbon with biocarbon—the material carbon footprint value proposition. The process carbon footprint arising from the conversion of feedstock to final product is computed using life-cycle assessment methodology. Biodegradability in conjunction with selected disposal systems such as composting and anaerobic digestion offers an end-of-life solution to completely remove the plastic substrate from the environment. Not all bio-based polymer materials are biodegradable, and not all biodegradable polymers are bio-based. Most importantly, complete biodegradability (complete utilization of the polymer by the microorganisms present in the disposal environment) is necessary as per ASTM and ISO standards, otherwise there could be serious health and environmental consequences.