Microwave Enhanced Pyrolysis of Gumwood

摘要

Microwave pyrolysis of biomass has gained increasing interests due to the fact that microwave heating provides a volumetric heating and instant heating at improved heating efficiencies compared with conventional heating techniques.Microwave-enhanced heating has become one of the research focuses attracting widespread concerns.In this study,microwave-enhanced pyrolysis of gumwood was carried out at 500°C with silicon carbide as a microwave absorber.Conventional pyrolysis of gumwood was also studied under the same conditions of microwaveenhanced pyrolysis.The yields of pyrolytic products,morphology of bio-char,and composition of bio-oil and biogas are analyzed by using Scanning Electron Microscope,Gas Chromatograph / Mass Spectrum and Gas Chromatograph respectively.According to the Table 1,the yields of pyrolytic bio-oil and bio-gas under microwave heating are 8.52 wt.％ and 73.26 wt.％ respectively,which are higher than the products obtained via conventional methods.In microwave enhanced pyrolysis,numerous carbon nano tubes (CNTs) are formed on the surface of the bio-char,as shown in Figure 1.These CNTs are grown from pyrolysed round particles without the use of specific catalysts,substrates and source gases.The bio-oil obtained by microwave pyrolysis has simpler constituents compared with conventional pyrolytic bio-oil.The proportions of syngas (H2+CO) and methane (CH4) in microwave pyrolytic gas product are 62.52 vol.％ and 22.41vol.％ respectively,whose high heating value are 30％ higher than that of conventional pyrolytic gas.It is clear that microwave enhanced pyrolysis has shown its potential as an alternative method for biomass conversion.