Abstract
This paper reports on the growth condition of Nannochloropsis sp. in an annular column-type photobioreactor (PBR) using light-emitting diode as an internal illumination. The microalgae growth in the 20-L batch culture mode under mixed blue (450 nm) and red (660 nm) light-emitting diode (LED) in various conditions such as photoperiod and light intensity (controlled by supplied current) was monitored. Compact-type 5-W LED module with narrow beam angle (radiation pattern) was installed in the PBR so as to obtain higher intensity and deeper penetration to the culture. Based on the PBR dimension with optical path length 120 mm, the minimum light intensity required at the PBR tank inner surface at initial stage of cultivation was approximately 350–370 mol m−2s−1, while mean light intensity derived was 140–160 mol m−2s−1. Photoperiod ratio of light:dark at 18:6 h provided better results compared to 12:12 in terms of final cell density achieved. Efficiency of light utilization was calculated to be 9.0 × 109 cell/mol photon (0.49 g/mol photon), while biomass volumetric productivity was 0.04 g L−1day−1. The usage of narrow beam angle LED was feasible to be used but with further improvement is necessary.
Highlights
This paper reports on the growth condition of Nannochloropsis sp. in an annular column-type photobioreactor (PBR) using light-emitting diode as an internal illumination
The trend of mass cultivating microalgae has shifted from open pond system to closed photobioreactor (PBR) system
Light intensity (PPFD) inside the PBR By using high power 5 W lightemitting diode (LED) package, the light intensity at IS achieved more than 2000 μmol m−2s−1, which is approximately equal to incidental sunlight intensity during sunny day in Malaysia
Summary
This paper reports on the growth condition of Nannochloropsis sp. in an annular column-type photobioreactor (PBR) using light-emitting diode as an internal illumination. In an annular column-type photobioreactor (PBR) using light-emitting diode as an internal illumination. One of its potential is to be used as biomass source for biodiesel production (Chisti 2007). Open pond cultivation method which generates low density culture is faced with a tough situation to meet the low price requirement of biodiesel. The trend of mass cultivating microalgae has shifted from open pond system to closed photobioreactor (PBR) system. In regards to light parameters, indoor PBR using artificial lights may offer some solutions to overcome the problems in the outdoor PBR which depends to sunlight. With rapid development of highly energy efficient LEDs which are increasingly cheaper and consume less energy than ordinary lamps, the potential of using artificial lights in PBR and its economic feasibility need to be reviewed (Fu et al 2012). The cost and energy consumption are factors that need to be seriously considered
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
