Investigation on co-pyrolysis of lignocellulosic biomass and amino acids using TG-FTIR and Py-GC/MS

Co-pyrolysis of lignocellulosic biomass and microalgae could greatly improve bio-oil quality. In order to understand the interaction, nitrogen transformation mechanism, and better use lignocellulosic biomass and microalgae, co-pyrolysis of lignocellulosic biomass (bamboo waste (Ba)) and amino acids (glutamic acid (Glu) and aspartic acid (Asp)) was performed by TG-FTIR and Py-GC/MS technique. Results showed that individual pyrolysis of Glu and Asp formed 52% pyrrolidinone and 75% maleimide through intramolecular dehydration reactions, respectively, with the releasing of CO2, C=O and NH3. Besides, co-pyrolysis of Ba with Glu and Asp decreased the biomass decomposition temperature largely. Furthermore, co-pyrolysis greatly increased the yield of CO2 and NH3, and promoted the formation of phenols, O-containing species (but oxygen yield decreased), while inhibited the generation of N-species (decreased about 50%) in bio-oil, through strong Maillard reaction, ketonization, deamination, and decarboxylation reactions. At last, the possible reaction pathways of co-pyrolysis of lignocellulosic biomass and amino acids were proposed. In conclusion, co-pyrolysis of lignocellulosic biomass and amino acids could significantly improve the quality of bio-oil, and effectively control the nitrogen transformation into bio-oil.