(2025) Journal of Environmental Chemical Engineering_Sustainable production of bioplastic using Halomonas sp.: Enhancing process sustainability by minimizing waste generation

Yoo Y.; Kim J.Y.; Lee D.-J.; Kwon D.Y.; Park J.; Kim J.-J.; Kwon E.E.

(Elsevier Ltd) Journal of Environmental Chemical Engineering ISSN: 22133437 Vol.13 Issue.5 Article No.117566 DOI: 10.1016/j.jece.2025.117566

Biopolymers, such as poly(3-hydroxybutyrate), offer a promising alternative to fossil-derived plastics. Although considerable attention has been paid to bacterial biopolymer production, the management of residual biomass after biopolymer extraction has received limited focus. This study aimed to promote a circular approach to sustainable poly(3-hydroxybutyrate) manufacturing by valorizing residual bacterial biomass, thereby contributing to sustainable biopolymer production. Halomonas sp. (strain halo6) produced poly(3-hydroxybutyrate) at 52wt% under cultivation conditions with 1% NaCl. The residual biomass, representing 48wt% of the bacterial culture, was pyrolyzed to generate syngas. Syngas yields from pyrolysis under N₂ and CO₂ conditions showed no significant differences, despite the potential of CO₂ to facilitate volatile thermal cracking. To improve the effectiveness of CO₂ during pyrolysis, a catalyzed bed was introduced. Under CO₂ conditions, the catalyzed pyrolysis setup produced 148.5mmol of syngas, a 2.6-fold increase compared to N₂ conditions. With CO₂-catalyzed pyrolysis, 80wt% of the residual biomass was converted to syngas, while the remaining fraction was distributed between oil and char. Valorizing residual bacterial biomass from poly(3-hydroxybutyrate) production via CO₂-catalyzed pyrolysis enhances the sustainability of the biopolymer production process, contributing to the circular bioeconomy and waste-to-energy conversion. © 2025 Elsevier Ltd.

This research was supported by the "Development of living shoreline technology based on blue carbon science toward climate change adaptation" of the Korea Institute of Marine Science & Technology Promotion (KIMST), funded by the Ministry of Oceans and Fisheries (KIMST-20220526), and the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education (RS-2024-00453186). This work was also supported by the NRF grant funded by the Korean Government (RS-2025-00522812).