Biochar catalyzing polymerization of the volatiles from pyrolysis of poplar wood

Abstract

In this study, the pyrolysis of poplar wood chips with biochar catalyst produced from gasification of the same poplar wood chips was conducted, aiming to probe its influence on the evolution of the pyrolysis products. From the results, it was concluded that the biochar catalyst enhanced the polymerization of the volatiles produced from the pyrolysis, and thus reduced the yields of the gaseous compounds while increased the yield of char. The carbonaceous deposit on surface of the char was oxygen-rich and more aliphatic, which decreased the thermal stability and crystallinity of the char, while made the char prone to oxidation. The biochar catalyst also promoted the formation of methoxy phenols at the expense of alkyl phenols, and the formation of the phenolics with bigger π-conjugated structures. In addition, the volatile-biochar interaction removed the defective structures in the large aromatic structures in the biochar catalyst. Highlights• Biochar catalyzed polymerization, but not cracking, of volatiles in pyrolysis.• Biochar catalyst enhances char formation while reduces gas formation in pyrolysis.• Char in catalytic pyrolysis is more O-rich and aliphatic and low thermal stability.• Biochar catalyzed condensation of volatiles to form bigger fused ring structures.• Biochar-volatiles interaction removes defective structure in fused ring of biochar. K E Y W O R D Sbiochar catalyst, catalytic pyrolysis, coke formation, poplar wood, product properties | INTRODUCTIONBiomass is an abundantly available and renewable resource, which can be used to produce fuels via thermochemical processes such as pyrolysis. 1,2 Via pyrolysis, biooil, char, and gaseous compounds were obtained from biomass. 3,4 Bio-oil is the major products with the yield ranging from 45 to 75%, depending on the process conditions such as temperature, reactor design, heating rate, particle size of biomass, etc. [4][5][6][7] In general, bio-oil has a high amount of oxygen, leading to its high acidity, low thermal stability, and low heating value, which makes it

Leucaena leucocephala and montmorillonite co-pyrolysis biochar: A Study on physicochemical properties and stability

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Using the Conditional Process Analysis Model to Characterize the Evolution of Carbon Structure in Taxodium ascendens Biochar with Varied Pyrolysis Temperature and Holding Time

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