Study on the Correlation between Functional Group Structural Parameters and Prediction of Biomass Combustion Characteristics

Abstract

In this work, the aim is to predict biomass combustion characteristics based on the semiquantitative analysis of biomass functional group structural parameters. The structural parameters of biomass were calculated by Fourier transform infrared (FT-IR) spectroscopy. Then, a chemical percolation devolatilization model suitable for biomass was used to predict the pyrolysis process of biomass, and the influence of functional group structural parameters on the pyrolysis behavior was analyzed. The combustion characteristics of biomass were investigated by using a thermogravimetric analyzer and visual drop tube furnace. Finally, correlations between functional group structural parameters and combustion characteristics were established. The results show that biomass with a high content of hydroxyl groups (Ia1) preferentially generates H2O at 150 °C, leading to a delay in ignition time. Long-chain aliphatic hydrocarbons (Ib1) exhibit lower thermal stability, and CH4 and tar are released in 200–400 °C. This accelerates the reaction combustion rate and increases the likelihood of homogeneous ignition. The release rates of CO and CO2 are related to the types of carbon–oxygen functional groups. The content of difficult-to-decompose ether bonds in corn stalks is as high as 33.97%, which does not easily decompose at low temperatures, leading to a long ignition delay time and a reduced probability of homogeneous ignition.