Online study on the co-pyrolysis of coal and corn with vacuum ultraviolet photoionization mass spectrometry (Englisch)

Highlights•Coal and corn pyrolysis have been studied with photoionization mass spectrometry.•The mass spectra and time-evolved profiles of selected species were obtained.•Coal can promote the reaction temperature of cellulose in corn.•Coal affects pyrolysis rate of cellulose, hemicellulose, and lignin from corn.•Pyrolysis behaviour revealed in this work allows to optimize the pilot-scale plant.

AbstractWith the aim to support the experimental tests in a circulating fluidized bed pilot plant, the pyrolysis processes of coal, corn, and coal-corn blend have been studied with an online pyrolysis photoionization time-of-flight mass spectrometry (Py–PI–TOFMS). The mass spectra at different temperatures (300–800°C) as well as time-evolved profiles of selected species were measured. The pyrolysis products such as alkanes, alkenes, phenols, aromatics, as well as nitrogen- and sulfur-containing species were detected. As temperature rises, the relative ion intensities of high molecular weight products tend to decrease, while those of aromatics increase significantly. During the co-pyrolysis, coal can promote the reaction temperature of cellulose in corn. Time-evolved profiles demonstrate that coal can affect pyrolysis rate of cellulose, hemicellulose, and lignin of corn in blend. This work shows that Py–PI–TOFMS is a powerful approach to permit a better understanding of the mechanisms underlying the co-pyrolysis of coal and biomass.