On-line photoionization mass spectrometric study of lignin and lignite co-pyrolysis: Insight into the synergetic effect

Co-pyrolysis behavior of kraft lignin (KL) and lignite (LI) was studied by thermogravimetry (TG) combined with on-line photoionization time-of-flight mass spectrometry (PI-TOF-MS) to get insights into the synergetic effect on the total yield and detailed composition of volatile. Significant synergetic effect was observed between KL and LI during co-pyrolysis processes, especially near the temperature with maximum weight loss rate. The interactions of typical co-pyrolysis products were figured out via the real-time and online mass spectrometry and was evaluated by comparing the experimental value with the calculated theoretical value. The results showed that the synergetic effect was beneficial to enhance the production of volatile and decrease the total yield of char. The interaction on typical co-pyrolysis products was further discussed. The result may provide useful guidance for the practical co-conversion of biomass and low-rank coal.