Use of FTIR combined with forms of water to study the changes in hydrogen bonds during low-temperature heating of lignite

摘要

The changes in the hydrogen bonds (HBs) of three types of Indonesian lignite during low-temperature heating were investigated. The amount of water loss was determined by weighing the samples before and after heating in an oven. The changes in the number of the different types of HBs were determined using Fourier transform infrared spectroscopy coupled with types of water in lignite. The number of peak positions and absorption bands in each spectrum was determined by curve-fitting analysis with a Gaussian function. The quantified integrated area of aromatic hydrogen atoms was used to accurately investigate the changes in the HBs. The results show that at low temperatures (T50 degrees C), free water is mainly removed, and the HBs broken are those between free water molecules. However, at medium temperatures (50