Bioreactors, Photo

Recovery of microalgal biomass and metabolites: process options and economics

“…Closed photobioreactors may be located indoors or outdoors (Sánchez Mirón et al, 1999;Pulz, 2001), but outdoor location is more common because it can make use of free sunlight. Design and operation of the microalgal biomass production systems have been discussed extensively (Terry and Raymond, 1985;Borowitzka, 1996;Pulz and Scheinbenbogen, 1998;Pulz, 2001;Pulz et al, 2001;Sánchez Mirón et al, 1999;Tredici, 1999). Here, we focus exclusively on issues relating with the harvest of the biomass and its downstream processing to recover intracellular metabolites.…”

“…Production of 0734-9750/02/$ -see front matter D 2002 Elsevier Science Inc. All rights reserved. PII: S 0 7 3 4 -9 7 5 0 ( 0 2 ) 0 0 0 5 0 -2 microalgae-derived metabolites requires processes for culturing the alga (Ben-Amotz and Avron, 1987;Sánchez Mirón et al, 1999;Tredici, 1999;Borowitzka, 1999;Pulz, 2001;Pulz et al, 2001), recovery of the biomass, and further downstream processing to purify the metabolite from the biomass. As with many microbial processes for producing bioactives, the downstream recovery of algal products can be substantially more expensive than the culturing of the alga.…”

Photofermentative Hydrogen Production in Outdoor Conditions

“…They are generally classified according to their: (i) Design -flat or tubular, horizontal, inclined, vertical or spiral and manifold or serpentine [30] (ii) Mode of operation batch, fed-batch and continuous [29]. In order to achieve sustainable photofermentative hydrogen production in outdoor conditions, the development of an optimized photobioreactor system that has the following properties is targeted: (i) a simply designed enclosed system that is impermeable to hydrogen (ii) a transparent system that allows maximum light penetration, preferably at high visible light or near red-infrared transmissions (iii) a system with high surface-tovolume ratio for better/wide distribution of light (iv) a system made from an unreactive material that is durable, easy to clean and sterilize [29,[31][32][33].…”

An Overview of Algae Biofuel Production and Potential Environmental Impact

“…The average biomass energy production reported was 4542.5 L (1,200 gal) of biodiesel per acreyear, which is greater than conventional oil-bearing crops such as soybeans, which yield an average of 227 L (60 gal) of oil (or approximately 151 L (40 gal) of biodiesel) per acre-year. 39,65,66 An example methodology is illustrated with Neochloris oleabundans, a freshwater microalga, which was grown in continuously stirred PBRs at 30°C, with CO 2 supplementation and illuminated by six fluorescent lamps (Philips TL-DM36W/ 54-765). 17 The lipid biomass concentration reached 56% (DW) after 5 days of nitrogen starvation.…”

“…69 Once the product is separated from the organism, it is then further separated from the culture mix by other techniques such as distillation for ethanol or oil−water separation. 66,68 7. Heterotrophic Algae Respiration and Fermentation.…”