Production of Bio Char and Bio Oils from Botswana Marula Shells through Torrefaction and Pyrolysis

Abstract

The pyrolysis and mild pyrolysis (torrefaction) of marula shells were studied. The objectives were to optimize torrefaction conditions and production of bio-oil from marula shells. A pyrolysis plant with nitrogen purging with varying temperatures from 200°C to 600 °c was used in this work. The results show that mass yield decreased with increase in temperature while weight loss increases with increase in temperature. The products obtained were characterized with Fourier transform infra-red spectroscopy (FTIR) and thermogravimetric analyzer (TGA). FTIR results indicated the presence of alcohols, alkanes, alkenes, ketones and nitrogenous compounds. TGA results show that the fixed carbon increases with increase in temperature, the ash and moisture content were recorded to be very low at average of 2.1% and 3.7% respectively compared to that of raw biomass which were 3.46 % and 6.91% for ash and moisture content respectively.