TITLE:
Comparative Analysis of Hydrodynamics Behavior of Microalgae Suspension Flow in Circular, Square and Hexagonal Shape Photo Bioreactors
AUTHORS:
Mushfique Shahriar, Mohammad Iftekhar Monir, Ujjwal Kumar Deb
KEYWORDS:
CFD, Microalgae, Biofuel, Photo Bioreactor, Simulation
JOURNAL NAME:
American Journal of Computational Mathematics,
Vol.6 No.4,
December
21,
2016
ABSTRACT: Microalgae
based biofuel is an emerging natural source of energy alternative to the fossil
fuel. As microalgae are photosynthetic microorganisms, light is one of the limiting
factors for its culture. Though many researches have been carried out for
findings behind suitable culture system for the proper growth of microalgae,
those are confined only to tubular Photo-bioreactor (PBR). This paper aims to
make comparison among the horizontal loop photo bioreactors with different
cross sections based on the analysis of hydrodynamics behavior. Three different
geometrical shapes having vertical cross sections of circular, square and
hexagonal PBR, have been proposed taking into account light intensity for
microalgae culture. In this study, we simulate the flow dynamics of three types
of PBRs and discuss the velocity, pressure and shear stress properties as
microalgae endurance capacity depends on them. For the dimension of the three
PBRs we considered here, each of them have radius of about 0.05 m while the
length together with bending portion is approximately 20.5 m for a single loop.
From the study, the hydrodynamic behaviors are observed to be quite dissimilar
in case of three PBR’s. In the straight portion the velocity profile is quite
parabolic in tubular but distorted minimally in case of square and hexagonal
PBRs. In the middle of the U-loop, a haphazard fluid distribution is noticed.
The velocity magnitude and agitation of microalgae cells are higher in
hexagonal than in square and tubular. The shear rate is less in case of tubular
compared to square and hexagonal. A linear pressure drop is found from the
inlet to the outlet for three PBR’s. From this comparison, it can be said that
the tubular one would be the best option for microalgae culture in case of
industrial purposes.