future outlook of microwave pyrolysis
Author: langfeng Time: 2018-09-30
Bio‐oils from microwave‐assisted pyrolysis of biomass have lower oxy‐ gen content and higher HHV than those from conventional biomass pyrolysis. The dielec‐ tric properties of biomass play a large role in microwave‐assisted pyrolysis as they affect the microwave absorbance of biomass. Utilizing the superior microwave absorbance of exog‐ enous microwave absorbents and reaction catalysts, we can achieve very high heating rates, high pyrolysis temperatures, and catalytic cracking of large molecules, resulting in higher yield and better quality of bio‐oils. However, too high a pyrolysis temperature can adversely affect the bio‐oil yield by inducing secondary reactions that break down the volatiles to incon‐ densable gases. Nonetheless, microwave‐assisted pyrolysis has a bright future as it offers many advantages over conventional pyrolysis processes. Particularly, microwave heating is a mature technology which can be easily implemented and precisely controlled. Future work in the areas of catalyst screening and applications, co‐pyrolysis of feedstocks with complemen‐ tary microwave heating characteristics, pilot study, and equipment development is necessary in order to cost‐effectively produce high quality bio‐oils and commercialize the technology.