Chemistry

Char

Pyrolysis

Physics

Mineralogy

Molecule

Diffuse reflection

Optics

Aromaticity

Vitrinite

Organic chemistry

Chemical engineering

Coal

Fourier transform infrared spectroscopy

Analytical Chemistry (journal)

Engineering

Fuel

The functional groups and coalification jumps were studied by the Fourier Transform Infrared spectroscopy (FTIR), characterized along with the increasing temperature. The raw coal sample with high coal rank (Ro,max = 1.82%) was used to further form some high rank samples using improved microscale sealed vessel (MSSV) pyrolysis method for the FTIR analyses. The MSSV pyrolysis simulates coalification process under different temperatures by heating the raw coal from 350 °C to 550 °C at a heating rate of 10 °C/h, producing the high rank coal samples that can be used for characterization of the functional groups and coalification jumps. Combined with proximate and ultimate analyses, FTIR provides new insight to the chemical structure of the coal samples. The results show that the typical vibration of function groups includes CH aromatic out-of-plane deformation at 877 cm−1, 812 cm−1 and 784 cm−1; carbonyl/carboxyl CO stretching at 1712 cm−1; OH stretching at 3422 cm−1 and aromatic CH stretching at 3040 cm−1. The s...

Characterization of coalification jumps during high rank coal chemical structure evolution