Thermo-chemical upcycling of cellulosic paper packaging waste into furfural and bio-fuel catalyst

Abstract

The extensive use of fossil fuels and chemicals has resulted in substantial emissions of anthropogenic carbon dioxide (CO2), which in turn have triggered global warming. As a proactive response, converting waste into energy and chemicals is a paramount importance. To maximize carbon utilization, implementing a thermo-chemical process for waste valorization is a promising approach owing to its high tolerance for the intrinsic heterogeneity of waste materials. Thus, the development of thermo-chemical processes that exhibit high productivity and selectivity for valorized products should be prioritized. In this study, we focused on the pyrolysis of paper packaging waste (PPW) as a case study to address these challenges. To enhance the production of syngas and furfural, PPW was pretreated with ferrous sulfate (FeSO4) before undergoing pyrolysis. Slow and fast pyrolysis were conducted to characterize the production of syngas and bio-oil, respectively. The pretreatment of PPW with FeSO4 increases syngas production, attributed to the catalytic properties of iron (Fe). Bio-oil derived from FeSO4-treated PPW contained more homogenized chemicals compared with that from untreated PPW. Furfural selectivity reached 51.1 % when PPW pretreated with FeSO4 (10 wt% of Fe relative to PPW) was pyrolyzed at 600 ˚C. Additionally, biochar produced from FeSO4-treated PPW exhibited a porous carbon structure with a high surface area (123.8 m2 g−1) and was rich in minerals, such as Fe and calcium (Ca). This biochar catalytically enhanced the reaction kinetics of thermally induced transesterification of soybean oil, resulting in a biodiesel yield of 88.7 % at 350 ˚C. The findings of this study offer a practical approach to establishing a sustainable and carbon-neutral platform for the conversion of lignocellulosic biomass into value-added products.