Bio-Butanol Production from Napier Grass Hydrolysis Using Clostridium Acetobutylicum
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Date
2022-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Napier grass is a potential biomass for biofuel production due to its high adaptability and
widespread availability in tropical areas such as Ethiopia. A compositional analysis of Napier
grass collected from the Menagesha Mushroom farm in an Addis Ababa city suburb was
performed, and microbes and enzymes were purchased from France. An alkaline pretreatment
(2.5wt% NaOH, 1.5wt% urea, and 8wt% sample biomass) was mixed for 40 minutes at 121°C,
followed by enzymatic hydrolysis (2ml Novozymes Cellic glucadase enzyme and 5gram pretreated
biomass) shaken at 50rpm for 40 minutes at 50°C, and separated by centrifuge at 8500rpm to
hydrolyze Napier grass. Carbohydrates make up 52.1 % of the Napier grass composition, making
it an excellent carbon source. Acetone-Butanol-Ethanol fermentation (ABE) was carried out in a
continuous fermentation process using co-cultured C. acetobutylicum bacteria. After optimizing
the operating parameters pH, Temperature, substrate concentration, and fermentation time, the
productivity of butanol was found to be 0.077 g lt
-1
hr
-1
with a 29.5 % efficiency. The yield of ABE
was 0.0833 g lt
-1
hr
-1
when compared to the semi–Simultaneous Saccharification fermentation
(sSSF) process, which combined alkaline pretreated biomass with enzymatic hydrolysis and cocultured
bacteria
after
24
hours
of
hydrolysis
followed
by
96hrs
of
fermentation.
Butanol
efficiency
at
the
s-SSF
process
is
33.6
%.
When
compared
to
previous
studies,
ABE
fermentation
of
Napier
grass
yields
a competitive
yield.
Description
Keywords
Napier grass, Alkali-pretreatmentl, Enzymatic hydrolysis, Acetone-Butanol-Ethanol (ABE) fermentationl, semi-Simultaneous Saccharification fermentation (sSSF), Bio-Butanol