Fast Pyrolysis Behavior of High Ash and Nitrogen Content Biomass Using Tg-Ftir and Py-Gc/Ms

Abstract

Fast pyrolysis behavior of mushroom bran (MB) and corn straw (CS) was investigated using high heating rate TG-FTIR and Py-GC/MS in order to explore the efficient utilization of high ash and high nitrogen content biomass. Firstly, the pyrolysis behavior of MB and CS was investigated by TG under low heating rates and high heating rates. Then, the seven-stage pyrolysis experiments of MB and CS was carried out by Py-GC/MS. The results showed that increasing the heating rates can widen the temperature range of pyrolysis, causing the decomposition of starch and hemicellulose to overlap and potentially creating synergistic effects that would promote the synthesis of furan and furfural. High temperature sensitive components such as nitrogenous aromatic compounds have the potential for autocatalytic reactions at heating rates above 200°C/min, and nitrogen has a tendency to migrate from hydrogen cyanide to NH3 before 450°C. The pyrolysis temperature range from 300°C to 350°C is the main deoxidation and nitrogen removal range for MB and CS, which is worthy of further research. Compared with direct pyrolysis, the continuous deoxidation of oil is interrupted by staged pyrolysis, the selectivity of aldehydes and ketones in MB and CS pyrolysis is reduced by 12.57% and 12.25%, respectively, and the deoxidation capacity is increased by 14.95% and 15.55%, respectively. More importantly, the study of staged pyrolysis in this work provides more detailed pyrolysis characteristics for high nitrogen and ash content biomass, allowing for a better understanding of the pyrolysis behavior of such biomass.

Keywords: Fast Pyrolysis, Staged Pyrolysis, High Ash, High Nitrogen, Py-GC/MS, TG-FTIR