Translating analytical pyrolysis fingerprints to Thermal Stability Indices (TSI) to improve biochar characterization by pyrolysis-GC-MS

How to trace back an unknown production temperature of biochar from chemical characterization methods in a feedstock independent way

“…In this study as well, the B/T ratio of biochars showed a good positive correlation with the biochar HTT (R 2 = 0.78). However, it is not that much stronger as previously reported [20,27,29,30]. This may be due to the diversity of the biochar feedstock material used in this study.…”

“…J o u r n a l P r e -p r o o f Therefore, the B/T ratio derived from Py-GC/MS analysis was used as an indicator to assess carbonization level of biochar in several studies and showed a good correlation with the biochar HTT [20,27,29,30]. In this study as well, the B/T ratio of biochars showed a good positive correlation with the biochar HTT (R 2 = 0.78).…”

“…Micro-pyrolysis experiments of biochar were performed using a micro-pyrolysis unit (Multishot pyrolyser EGA/PY-3030D, Frontier Laboratories Ltd.) coupled to a gas chromatograph (Thermo Fisher Scientific Trace GC) -mass spectrometer (Thermo ISQ MS). Samples were analysed according to the procedure described in Suarez-Abelenda et al [20]. In brief, ca.…”

“…Therefore, these compounds and their homologues with alkyl side chains can be transformed into ratios. Next, they can be used as an indicator of the degree of thermal alteration and dealkylation in the pyrolysis products [20,27]. Due to the significant thermal stability of the char produced at high HTT, their pyrograms are characterized with fewer pyrolysis products out of which benzene is the predominant one [28,31,32].…”

“…This may be due to the diversity of the biochar feedstock material used in this study. Suarez-Abelenda et al [20] reported that biochars from N rich, hence protein-rich feedstocks produced at low temperatures are able to introduce bias into the measured B/T ratio via the addition of toluene derived from incompletely converted protein, especially the amino acid phenylalanine produces toluene upon pyrolysis. Moreover, in this J o u r n a l P r e -p r o o f study Ph/B, B/EtB, EtB/Ph ratios were used to examine their correlation with biochar HTT.…”