(2013) Environmental Science and Technology_Effect of carbon dioxide on the thermal degradation of lignocellulosic biomass

Kwon E.E., Jeon E.-C., Castaldi M.J., Jeon Y.J.

() Environmental Science and Technology ISSN: 0013936X Vol.47 Issue.18 Article No. DOI: 10.1021/es402250g

Using biomass as a renewable energy source via currently available thermochemical processes (i.e., pyrolysis and gasification) is environmentally advantageous owing to its intrinsic carbon neutrality. Developing methodologies to enhance the thermal efficiency of these proven technologies is therefore imperative. This study aimed to investigate the use of CO₂ as a reaction medium to increase not only thermal efficiency but also environmental benefit. The influence of CO₂ on thermochemical processes at a fundamental level was experimentally validated with the main constituents of biomass (i.e., cellulose and xylan) to avoid complexities arising from the heterogeneous matrix of biomass. For instance, gaseous products including H₂, CH₄, and CO were substantially enhanced in the presence of CO₂ because CO₂ expedited thermal cracking behavior (i.e., 200-1000%). This behavior was then universally observed in our case study with real biomass (i.e., corn stover) during pyrolysis and steam gasification. However, further study is urgently needed to optimize these experimental findings. © 2013 American Chemical Society.