title: Value-added organonitrogen chemicals evolution from the pyrolysis of chitin and chitosan.
abstract: Thermogravimetric characteristics of chitin and chitosan and their potentials to produce value-added organonitrogen chemicals were separately evaluated via TG/DSC-FTIR and Py-GC/MS. Results shown that chitin had the better thermal stability and higher activation energy than chitosan because of the abundant acetamido group. Furthermore, the dominated volatilization in active pyrolysis of chitin contributed to its endothermic property, whereas the charring in chitosan led to the exothermal. During fast pyrolysis, the acetamido group in chitin and chitosan was converted into acetic acid or acetamide. Typical products from chitosan pyrolysis were aza-heterocyclic chemicals, i.e. pyridines, pyrazines, and pyrroles, with the total selectivity of 50.50% at 600°C. Herein, selectivity of pyrazine compounds was up to 22.99%. These aza-heterocyclic chemicals came from the nucleophilic addition reaction of primary amine and carbonyl. However, main reaction during chitin pyrolysis was ring-opening degradation, which led to the formation of acetamido chemicals, especially acetamido acetaldehyde with the highest selectivity of 27.27% at 450°C. In summary, chitosan had the potential to produce aza-heterocyclic chemicals, and chitin to acetamido chemicals.
authors.affiliation: Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, PR China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.affiliation: Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, PR China.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, PR China. Electronic address: ruixiao@seu.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, PR China. Electronic address: shubinwu@scut.edu.cn.
authors.forename: Shubin
authors.initials: S
authors.lastname: Wu
mesh_terms: D002686:Chitin / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature; D011719:Pyrazines; D011725:Pyridines; D011758:Pyrroles; D013818:Thermogravimetry; D014835:Volatilization
chemical_list: D011719:Pyrazines; D011725:Pyridines; D011758:Pyrroles; D002686:Chitin; D048271:Chitosan
keywords: Chitin; Chitosan; Organonitrogen chemicals; Py-GC/MS; Pyrolysis; TG/DSC-FTIR