title: Key intermediates in nitrogen transformation during microwave pyrolysis of sewage sludge: a protein model compound study.
abstract: The nitrogen transformations with attention to NH3 and HCN were investigated at temperatures of 300-800°C during microwave pyrolysis of a protein model compound. The evolution of nitrogenated compounds in the char, tar and gas products were conducted. The amine-N, heterocyclic-N and nitrile-N compounds were identified as three important intermediates during the pyrolysis. NH3 and HCN were formed with comparable activation energies competed to consume the same reactive substances at temperatures of 300-800°C. The deamination and dehydrogenation of amine-N compounds from protein cracking contributed to the formation of NH3 (about 8.9% of Soy-N) and HCN (6.6%) from 300 to 500°C. The cracking of nitrile-N and heterocyclic-N compounds from the dehydrogenation and polymerization of amine-N generated HCN (13.4%) and NH3 (31.3%) between 500 and 800°C. It might be able to reduce the HCN and NH3 emissions through controlling the intermediates production at temperatures of 500-800°C.
authors: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
authors: Jun
authors: J
authors: Zhang
authors: Yu
authors: Y
authors: Tian
authors: Yanni
authors: Y
authors: Cui
authors: Wei
authors: W
authors: Zuo
authors: Tao
authors: T
authors: Tan
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature; D006856:Hydrogen Cyanide / Q000737:chemistry; D008872:Microwaves; D008956:Models, Chemical; D009584:Nitrogen / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011506:Proteins / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D011506:Proteins; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D006856:Hydrogen Cyanide; D009584:Nitrogen