Abstract:
Selective extraction of hexose and pentoses from guinea (Sorghum bicolor L.) moench and maize
corn (Zea mays L.) chaffs as platform materials for bio-products were investigated. Guinea and
maize corn chaffs were subjected to different pretreatment methods (screening and ultrasonication)
and hydrolysed with dilute sulphuric acid in a percolation reactor under various
experimental conditions such as acid concentration, particle size and temperature. The monomeric
sugars such as glucose, xylose and arabinose as well as degradation products present in the
hydrolysate were identified and quantified with two instrumental techniques (HPLC and UVVisible).
The hydrolysate were fermented with baker’s yeast as well as Saccharomyces cerevisiae
generated from waste fruits to obtain bioethanol. The crude bioethanol was purified using both
conventional and bio-CaO (unconventional) from calcined cow bone, which was further analysed
to determine its fuel properties and used in the synthesis of industrial chemicals such as acetic acid
and ethyl benzoate. Thereafter, characterised with FTIR and (GC-MS).
Pretreatment result in fractional increase of the fiber content of 74.96 and 76.34%. The result of
the optimal conditions of the hydrolysis investigated were established at 120 oC, 4%w/v H2SO4,
120 min and 1.21 um for the release of glucose, xylose and arabinose. HPLC techniques gave a
better yield of the monomeric sugars. Brewer’s yeast and the one generated from waste fruits have
proven to be effective in the fermentation of ethanol from hydrolysate. However, the result also
confirmed that crude bioethanol produced can be purified with both conventional and bio-CaO.
The fuel properties of the bioethanol produced conformed to standard values. The result of FTIR
and GC-MS have confirmed the production of industrial chemicals such as acetic acid and ethyl
benzoate. Therefore with the research findings, the results show that the chaff can be used as
platform material for synthesis of biochemicals.
