Bioconversion potential of sorghum crude grains to ethanol: A case study Muhammad Nasidi PhD research student School of Contemporary Sciences University of Abertay Dundee Principal Supervisor: Prof. G Walker
Dec 16, 2015
Bioconversion potential of sorghum crude grains to ethanol: A case study
Muhammad NasidiPhD research student
School of Contemporary SciencesUniversity of Abertay Dundee
Principal Supervisor: Prof. G Walker
Introduction
Sorghum bicolor (L.) Moench is a C-4 cereal crop that grows well under varied temp and rainfall regimes.
It is the 2nd most important cereal crop in Africa and the 5th world wide (FAO 2008).
The grains come in different shapes and sizes and may contain condensed tannin (ICRISAT 2004).
The crude grains comprised husks, awn, spikelet, rachis and pubescence materials (USAID, 2009)
Courtesy: CIAD, Nigeria
.....background contd.
Pests/diseases attack accounts for over 10% of annual sorghum production loss in Nigeria (USAID, 2009; Codex, 2012).
Quelea birds invaded farmSorghum grain head
Courtesy: www.google.com
In Africa & Asia, over $130 million loss in income is recorded by farmers annually due to sorghum head smut attack (Yago et. al., 2011).
An estimated 200,000t of post-harvest sorghum grains are loss to smut/fungi infection annually in Nigeria; due to poor storage facilities (USAID, 2009; Ismail, et. al., 2010).
Examples of sorghum production loss sources;
Why bioethanol in this study?
Bioethanol is a petrol additive/substitute for use as automotive fuel (Defra, 2006).
Nigeria sets a voluntary target of achieving self-sufficiency in domestic E-10 fuel supply by 2020 (NBPI, 2007).
This represents a potential demand of 1.3billion litres of bio-ethanol for transport, in addition to the 3.75 billion litres ethanol gel demand for cooking (NBPI, 2007; FMARD
2011).
Currently over 90% of ethanol consumed in Nigeria is imported (NNPC, 2010)
Source: googleimage.com
Research background The SSV2, KSV8 and KSV3 sorghum cultivars are among the most favourable cultivated varieties in Nigeria, because of their suitability as food, animal feeds, and malting/brewing feedstock source (USAID, 2009; Ofor, et. al., 2009; Hussein et. al., 2009; FMARD, 2011).
(Galadima et al 2011; Imam and Capareda 2011; Nasidi et al 2010; FMARD, 2012).
Degraded and/or spoilt sorghum grains are usually fed to livestock in Nigeria. This practice is considered to have serious health consequences to livestock and possibly humans wellbeing in Nigeria (NAERLS, 2008; Hussaini et al 2009; Etuk, et. al., 2012).
Research Aim & Objectives
AIMThis work aimed to investigate the potential for bioconversion of crude/degraded sorghum grains to ethanol.
OBJECTIVES To investigate possible potential for utilisation of degraded/spoilt sorghum grains as fuel alcohol feedstock.
To specifically investigate saccharification and fermentation performance of SSV2, KSV8 and KSV3 sorghum crude grains.
SSV2 head
KSV3 head
KSV8 head
Results discussions
S/no Item SSV2 KSV8 KSV3
1 Ash 2.81 ±0.10 1.31 ±0.03 2.25 ±0.07
2 Lignin 15.10 ±0.13 11.58 ±0.04 13.96 ±0.13
3 Starch 63.64 ±1.67 66.87 ±1.34 72.42 ±1.86
4 Crude protein 15.57 ±0.52 14.31 ±0.41 16.38 ±0.47
Table 1: Composition of SSV2, KSV8 & KSV3 sorghum cultivars (g/100g db)
.... Fermentation results.
ANKOMRF CPU
ANKOMRF module
ANKOMRF monitor
Keyboard
Shaking incubator
Fermentation progress was monitored through cumulative CO2 gas pressure (psi) measurements by ANKOM® system.
ANKOMRF module
ANKOMRF SYSTEM
ANKOMRF glass bottle
Conclusions.
Final ethanol yield obtained for the crude grains of SSV2, KSV8 and KSV3 sorghum cultivars in this study were 401l/t, 423l/t and 443l/t respectively.
These results compared well with the 460-480l/t alcohol yields reported for de-husked and malted sound grains of SSV2, KSV8 and KSV3 sorghum cultivars (Agu, 1995; Agu, et. al., 2006; Ogbonna, 2011; Okolo, et. al., 2012; Aregbesola, et. al,. 2012).
These results suggest residual/degraded sorghum grains from fields invaded by pests or post-harvest grain storage facilities attacked by rodents may be considered potential feedstock source for bioethanol production.
Future Work Sorghum grains severely infected by smut/mold diseases could be investigated to evaluate their fermentation performance potentials.
Acknowledgement
I would like to express my sincere appreciation to; My generous sponsor, PTDF (Nigeria).
My supervisory team: Prof. G Walker, Dr Y Deeni and Dr D Blackwood.
Mall Idris (NIHORT, Kano, Nigeria).
Dr A Reg (SWRI, Edinburgh).