Key intermediates in nitrogen transformation during microwave pyrolysis of sewage sludge: A protein model compound study

► A novel Microwave Heating Reactor was designed to introduce microwave heating in the pyrolysis. ► The evolution of nitrogenated compounds in the char, tar and gas fractions were investigated. ► Three key intermediate compounds was identified in the pyrolysis tars during the pyrolysis. ► The gas products were formed with comparable activation energies from the same reactive species. ► The nitrogen transformation pathways in relation to NH3 and HCN formation were proposed.