Preparation of metal-modified carbon-based catalyst and experimental study on catalytic pyrolysis of distillers dried grains with solubles

Distillers dried grains with solubles (DDGS) offer high calorific value, suited for catalytic rapid pyrolysis for energy and chemical applications, yet tar and coke formation during bio-oil upgrading necessitates exploration of cost-effective, durable biocarbon-based catalysts for tar removal. In this study, a carbon-based catalyst was prepared by metal modification of alkaline biochar for catalytic pyrolysis with Distillers dried grains with solubles (DDGS) biomass. Brunauer-Emmet-Teller (BET), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) were used to characterized the morphology and microstructure of the metal-modified carbon-based catalysts. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was used to analysis the pyrolysis-gas of catalytic pyrolysis. Furthermore, the effects of the loading and metal mass ratio of carbon-based monometallic catalysts (Fe and Co) and carbon-based bimetallic catalysts (Fe-Co) on the distribution of the DDGS pyrolysis products were further investigated. The results showed that the 8 wt% of loading rate of bimetallic catalyst significantly reduced the oxygenated compounds but increased the aromatic hydrocarbons. Compared with pyrolysis without catalyst, when the catalyst was 2Fe6Co (mass ratio of Fe/Co 1:3), the hydrocarbons increased from 36.42 % to 44.53 %, the oxygen-containing compounds decreased from 60.36 % to 52.35 %, and the aromatics increased significantly from 0.73 % to 25.37 %. This study provides a new route of increasing the aromatic hydrocarbon content of catalytic pyrolysis to offer theoretical basis for carbon-based catalysts of biomass conversion.