title: Understanding the stability of pyrolysis tars from biomass in a view point of free radicals.
abstract: Fast pyrolysis of biomass has attracted increasing attention worldwide to produce bio-tars that can be upgraded into liquid fuels and chemicals. However, the bio-tars are usually poor in quality and stability and are difficult to be upgraded. To better understand the nature of the bio-tars, this work reveals radical concentration of tars derived from pyrolysis of two kinds of biomass. The tars were obtained by condensing the pyrolysis volatiles in 3s. It shows that the tars contain large amounts of radicals, at a level of 10(16)spins/g, and are able to generate more radicals at temperatures of 573K or higher, reaching a level of 10(19)spins/g at 673K in less than 30min. The radical generation in the tar samples is attributed to the formation of THF insoluble matters (coke), which also contain radicals. The radical concentrations of the aqueous liquids obtained in pyrolysis are also studied.
authors: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors: Wenjing
authors: W
authors: He
authors: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors: Qingya
authors: Q
authors: Liu
authors: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors: Lei
authors: L
authors: Shi
authors: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: liuzy@mail.buct.edu.cn.
authors: Zhenyu
authors: Z
authors: Liu
authors: Coal Upgrading Center, National Institute of Clean-and-Low-Carbon Energy, Beijing 102209, China.
authors: Donghui
authors: D
authors: Ci
authors: Coal Upgrading Center, National Institute of Clean-and-Low-Carbon Energy, Beijing 102209, China.
authors: Caroline
authors: C
authors: Lievens
authors: Coal Upgrading Center, National Institute of Clean-and-Low-Carbon Energy, Beijing 102209, China.
authors: Xiaofen
authors: X
authors: Guo
authors: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Shanxi 030001, China.
authors: Muxin
authors: M
authors: Liu
mesh_terms: D018533:Biomass; D003077:Coke / Q000032:analysis; D005609:Free Radicals / Q000737:chemistry*; D006358:Hot Temperature; D031324:Juglans / Q000737:chemistry; D013638:Tars / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry
chemical_list: D003077:Coke; D005609:Free Radicals; D013638:Tars
keywords: Bio-tars; Biomass; Pyrolysis; Radicals