Modification with formaldehyde on the thermal reactivity of >300°C distillation fraction from low-temperature coal tar

A >300°C distillation fraction (300F) from low-temperature coal tar was reacted with formaldehyde. Residual oil (RO) and residual solid (RS) were collected. RO was detected by gas chromatography-mass spectroscopy (GC-MS) and shows that it mainly contains alkanes and polycyclic aromatic hydrocarbons. The degradations under a nitrogen atmosphere of 300F and RO were investigated by Fourier transform infrared spectrometer. The result shows that 300F and RO consist of two degradation stages and five stages, respectively. CO has significant absorbency in the pyrolysis process of RO, not in 300DF. Modification of formaldehyde and compounds with carboxyl, short-chain fatty, and ester group in 300F generates polymers and fixes these compounds.