Lagerstroemia speciosa (Banaba) seed as a new and prospective bioenergy resource

Abstract

Bio-oil, a highly valuable product obtained from biomass pyrolysis after proper up-gradation and refining, can be utilised in a variety of downstream applications which is gaining attention to the researcher from last few decades. Extraction and fractionation are two viable techniques to upgrade bio-oil those divide the complex mixture of bio-oil compounds into distinct fine chemicals and fractions enriched classes of chemical compounds. In the current investigation, a new biomass plant (Lagerstroemia speciosa) seed, commonly known as Banaba underwent thermo-chemical conversion at four terminal temperatures viz., 350 ⁰C, 450 ⁰C, 550 ⁰C and 650 ⁰C with a rate of heating 10 ⁰C/min. The highest bio-oil yield (59.36 % out of that 41.68 % is of oil phase) was attained at pyrolysis temperature of 550 °C. The optimum condensable liquid (bio-oil) was collected and analysed. Properties of Banaba were investigated by physico-chemical, biochemical, ultimate analysis, TGA/DTG and FTIR analysis. Characterization of condensable liquid (bio-oil) was investigated by FTIR, NMR and GC-MS. Fuel property of the condensable liquid was further analysed through flash point, pour point, viscosity, Calorific value, and ultimate analysis. The Hydrogen/Carbon molar ratio (1.49) of the bio-oil was determined to be on a level with petroleum-based diesel. The oil derived from Banaba is found to have considerable fuel properties and may be substituted for commercial fuel with chemical modification or through blending with conventional diesel for utilization in IC engine which need to be addressed further.