PYROLYSIS OF SHEA BUTTER SHELL TO PRODUCE BIO-BASED PRODUCTS

Abstract

ABSTRACT

This research work focused on the production of bio-based products and response optimization of bio-oil yield operating parameters from shea butter shell. The Thermogravimetry Analysis (TGA) was used to determine the thermal stability of the shea butter shell and found to be stable at temperature 400 °C. Also, for the bio-char produced, it was found to be stable at temperature 700 °C. Design of Experiment (DOE) was applied to establish optimal pyrolysis conditions for the biomass (shea butter shell) using 23 factorial design module of Response Surface Methodology (RSM) available in Design Expert® Software version 7.0.0. Furthermore, the effect of temperature (300-600 °C), residence time (10-60 min), and heating rate (10-30 °C/min) at constant feedstock mass of 100g per run was studied. The results of operating variable effects shows that bio-oil yield depends on significant variables of the process. Temperature and heating rate were found to be significant to obtain optimum bio-oil yield experimentally. Optimum yield of the study was 51.50 %wt. against 71.00 %wt. of the predicted model. Physicochemical analysis shows that the bio-oil has pH 3.14 and Heating values of 26.03 MJ/kg. The Gas Chromatogram revealed phenolic and carboxyl compounds are dominant in the bio-oil with alcohol, ketones, aldehydes and aliphatic hydrocarbons were equally present. Characterization of the bio-based products using Fourier-Transform Infra-Red (FTIR) revealed that bio-oil contains predominantly the organic functional groups of alkanes, alcohol, acids, aldehydes, ketones, some phenolic compounds and water impurities from the studies. Bio-char was characterized to determine the external surface area and BET surface area, following values were obtained 196.022 m2/g and 170.025 m2/g. Moreover, the values obtained for the pore volume and pore size of the bio-char were 0.0055cm3/g and 1.410 nm respectively. Bio-char from shea butter shell pyrolysis can be upgraded as potential adsorbent in waste water treatment as bio-adsorbent.