Elucidation Of Mechanism Of Catalyst And Migration Of The Nitrogen And Chlorine During Pyrolysis Of Organic Solid Waste

Pyrolysis is an effective method for the disposal of organic solid waste (OSW), which can largely reduce the waste volume, and recycle the resources in the waste, with great environment and science significances. On the one hand, OSW mainly consists of sewage sludge, biomass, synthetic polymer, and so on. Different pollution is contained in these wastes, which may transform into other pollutants during the pyrolysis and then release into the environment. Make it clear that the transformation and transport of pollutants during pyrolysis is overwhelming. On the other hand, we synthesized functional materials from biomass, which exhibit a good performance in catalysis and environment, and propose a new road in the disposal and recycling of organic solid waste. The main contents of this thesis are as follows:1. Sewage sludge contains a lot of nitrogen, which can converts into variety of N-containing pollutants during pyrolysis. The temperature and heating rate are key influence factors during the pyrolysis process. There are pyrrolic-N, protein-N, amine-N, and pyridinic-N in the sludge; and there are mainly converted into heterocyclic-N, amine-N, and nitrile-N during pyrolysis, simultaneously release the NOx precursor (NH3, HCN, HNCO, and NO). And also the release of N-containing pollutants will increased along with the heating rate. We found that higher heating rate (200 K min-1) and medium pyrolysis temperature (400-550℃) can result in the conductive in liquid products.2. We use a online TG-FTIR-MS technique to explore the transformation of Cl in PVC waste. We study the kinetics of PVC pyrolysis and expound the kinetics mechanism. We found that most of the Cl in PVC was converted into the HCl and then released into the air. The remaining is transferred into the Cl-containing organic compounds. And we explore the fate of the Cl-containing compounds during pyrolysis of PVC waste.3. We use copper and silver pre-loaded biomass to prepare a Cu-Ag bimetallic nanoparticles carbon materials (Cu-Ag/C) by pyrolysis, "one pot" process. The metal particls are monodispersed on the biochar. It has an excellent performance in direct catalytic hydroxylation of benzene to phenol. The reaction temperature is mild, only 50℃, more significant is that the conversation of benzene is 34.9%, and the selectivity of phenol is 96%.4. Synthesis of Ag nanoparticls by the reduction of plant waste liquid extract (Squeezed out liquid, SOL), and then loaded onto the C3N4. Comparative research on the photocatalytic performance and mechanism of the biogenic and chemosythetic Ag/C3N4 (reduction of sodium borohydride). The biogenic Ag/C3N4 has better photocatalytic performance than chemosythetic ones. And B-Ag4g/C3N4 has the best photoreactivity when Ag nanoparticls load is 0.048%, the reaction rate constants is seven times higher than the chemosythetic Ag/C3N4 complexes. It is mainly result of the high dispersion of Ag nanoparticles on the surface by the effect of organic compounds in the SOLs.