Microwave-assisted pyrolysis of cashew nut shell

Abstract

This research examines the characteristics of microwave assisted pyrolysis products of cashew nutshell waste (CNS). The pyrolysis process of CNS conducted with microwave heating of 400 W for 60 minutes. Pyrolysis product such as bio-gas, bio-oil and bio-char were identified using proximate and ultimate analysis, scanning electron microscope (SEM), thermogravimetric analysis (TGA/DTG), gas chromatograph-mass spectrometer (GC-MS) and Fourier Transform InfraRed (FTIR) Method. There is a significant increasing in volatile matter and fixed carbon of derived bio-char and the porous structure was observed in a range of macropore after pyrolysis. The TGA profile reveals CNS sample lost about 71.25% of mass before reached 750℃. The highest decomposition rate on the DTG profile was 0.57 mg/min and 0.56 mg/min as observed at about 261.2℃ and 340.3℃. Bio-oil yield has density of 1.036 gr/ml, viscosity of 19.5 cst after water removing, flash point of 138℃ and HHV of 21.7 MJ/kg. The GC-MS of the bio-oil shows about 53% phenol, 19% palmitic and oleic acid, 11% cyclobutene, 14% ethyl and methyl ester, and cyclopentene and cyclohexane in small amounts in accordance with FT-IR results.