A comprehensive study on torrefaction of penicillin mycelial residues: Analysis of product characteristics and conversion mechanisms of N

Torrefaction is a promising method for biomass pretreatment, and the analysis of products properties is the essential way to reveal mechanism. In this study, torrefaction of penicillin mycelial residue was carried out at 200–320 °C. The results showed that the gaseous products were mainly CO2, followed by CO, and with the increase in temperature, CH4 and H2 were detected successively. GC–MS results showed that the tar mainly contained ketone, furan, ester, phenolic and N-containing compounds, among which the relative content of N-containing compounds was the highest (23.16–31.91 %). Torrefaction made the TG and DTG curves of solid products move to the upper right upon removal of volatiles, and enhanced the fuel thermal stability. XPS results showed that torrefaction increased the relative content of C-(C, H) and decreased that of OC-OH in solid products. And higher torrefaction temperature promoted the decomposition of protein-N and inorganic quaternary-N and the formation of pyridine-N. Based on the above results, the migration mechanism of N was also summarized. And torrefaction could eliminate the residual antibiotic and achieve safe disposal of AMR.