Fast pyrolysis behaviors of biomass with high contents of ash and nitrogen using TG-FTIR and Py-GC/MS

Abstract

In order to examine the effective exploitation of high ash and high nitrogen content biomass, the fast pyrolysis behavior of mushroom bran (MB) and corn straw (CS) was studied utilizing high heating rate TG-FTIR and Py-GC/MS. TG was used to study the pyrolysis behavior of MB and CS under low and high heating rates followed by a seven-stage pyrolysis studies using Py-GC/MS. The results showed that at higher heating rates, there is an overlap of the decomposition of starch and hemicellulose, potentially leading to synergistic effects that would promote the formation of furan and furfural. At heating rates greater than 200 °C/min, nitrogen has a tendency to migrate from hydrogen cyanide to NH3 before 450 °C. Deoxidation and denitrification mainly occurred between the pyrolysis temperature range of 300 °C to 350 °C, which merits further research. Staged pyrolysis interrupts the oil's continuous deoxidation process in comparison to direct pyrolysis, and it reduces the selectivity of aldehydes and ketones in MB and CS pyrolysis by 12.57% and 12.25%, respectively. More importantly, the study of staged pyrolysis in this work provides detailed pyrolysis characteristics for high nitrogen and ash content biomass, allowing for a better understanding of the pyrolysis behavior of such biomass.