Photobioreactor biomass productivity

P. Carlozzi, A. Sacchi (2001) Biomass production and studies on Rhodopseudomonas palustris grown in an outdoor, temperature controlled, underwater tubular photobioreactor. Journal of Biotechnology, 239-249... 

Photobioreactor engineering addresses optimization of the volumetric rate of biomass production, the surface rate of biomass production (with respect to the solar-energy collecting surface), and thermodynamic efficiency of the process as well as biomass composition (ie, the biomass quality). Hereafter, we mainly focus on construction of a predictive model for the volumetric rate (eg, expressed in kg, or moles of dry biomass per second and per m of the reaction volume). This is the main difficulty with assessing performance of a photobioreactor because most of the other parameters of interest can be deduced only from the value of < >, in a... 

Cx = biomass concentration in photobioreactor (moix m Cx,in/Cx,out = biomass concentration in inflow or outflow (moix rx = volumetric biomass production rate (moix m s )... 

With respect to the design and operation of photobioreactors the production term tx is of major importance. Parameter represents the volumetric biomass production rate of a cultivation system and it is the product of the biomass concentration in the system and the average specific growth rate of the microalgae ... 

Hindersin S, Leupold M, Kemer M, Hanelt D Key parameters for outdoor biomass production of Scenedesmus obliquus in solar tracked photobioreactors, J Appl Phycol 26 2315-2325, 2014. 

Lee Y-K, Low C-S Effect of photobioreactor inclination on the biomass productivity of an outdoor algal culture, Biotechnol Bioeng 38(9) 995—1000, 1991. 

PruvostJ, CornetJF, Goetz V, LegrandJ Theoretical investigation of biomass productivities achievable in solar rectangular photobioreactors for the cyanobacterium Arthrospira platensis, Biotechnol Prog 28(3) 699—714, 2012. 

Jorquera, O. Kiperstok, A. Sales, E. A. Embirucu, M. Ghirardi, M. L. Comparative energy life-cycle analyses of microalgal biomass production in open ponds and photobioreactors. Bioresour. Technol. 2010,101, 1406-1413. 

Figure 22.7 Illustrative costs of algal biomass production in idealized raceway pond and photobioreactor systems. The assumed operating days are 360 days. In the base case, CO2 is assumed to be purchased from the market. In the projected case, municipal wastewater is assumed to be the source of all water and nutrient input and that the source of CO2 is a nearby power plant and assumed to be free.

The specific volumetric rate of hydrogen photoproduction depends on the rate of hydrogen production by one unit of biomass and on the concentration of the biomass in a photobioreactor. The improvement of a biomass activity is the basic problem for strain selection or construction. The specific volumetric rate might be increased technologically by increase of biomass concentration. 

The rate of H2 production by one unit of illuminated surface (Fs) depends on the specific activity of cells, on biomass concentration and on the surface-to-volume ratio of photobioreactor ... 

By increasing Xb we can expect an increase of Fs. Experiments with Rb. capsulatus showed a complicated dependence of Fs on Xb (Table 2). Specific H2 production rate (measured in small vials) depended on Xb and was lower at high concentrations of biomass. The potential H2 production (as recalculated from data measured in small vials) increased at higher biomass concentrations. However, the actual H2 production by photobioreactor (with surface-to-volume ratio 69 m2 m 3) increased up to 1.05 g I 1 of biomass. The actual H2 production in the photobioreactor was lower than the potential activity of this culture at any concentration of biomass. 

At any biomass concentration the culture was ammonium-limited (data not shown). The increase in incident light intensity (Table 2) affected neither the hydrogen production by the photobioreactor nor the specific activity of the cells. Thus, the culture was not limited by light even at high biomass concentrations. Measurements of residual lactate concentration showed that only at the highest biomass content it was quite low (100 pM), possibly limiting the culture. 

In conelusion, green algae with a truneated Chi antenna size are indispensable in efforts to substantially inerease solar eonversion efifieieneies and the yield of biomass and H2 production in photobioreactors under mass eulture conditions. 

Finally, if necessary, the mean volumetric biomass growth rate in the photobioreactor < R > is easily obtained by means of a spatial integral of the specific rate of net oxygen production < J02 > and again by means of... 

Pmvost J, Cornet JF, Pilon L Large scale production of algal biomass photobioreactors. In Chisti Y, Bux F, editors Algae biotechnology products and processes, UK, 2014, Springer. 

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