Photobioreactor performance

Umitation by Hght (luminostat y = 1, or photo-limitation y < 1, see Comet, 2010) are presented in Table 2. They are compared with the predictive model calculations presented in this chapter, where the radiative transfer equation was solved using the one-dimensional two-flux approximation for all the simple geometric stmctures of photobioreactors except for reactor PBR 2 (as indicated in Table 2), for which we used the three-dimensional finite element method developed by Comet et al. (1994). As shown in the table, the mean deviation between the experimental results and the model calculation is less than 5% (ie, within the range of the experimental standard deviation), thus confirming the ability of the proposed predictive approach to quantify photobioreactor performance under many conditions of operation. 

Engineering design of full-scale photobioreactors and the balance of the facility for photobiological hydrogen production has not been considered beyond very general concepts. Consequently, there has been little effort to identify construction material and establish boundaries for specifying materials performance and properties. In... 

Photosynthetic CO2 fixation performance by a helical tubular photobioreactor incorporating Chlorella sp. under outdoor culture conditions... 

For optimal production of hydrogen by photosynthetic bacteria, to be economically attractive, one has to take into account several parameters from an overall point of view, such as the productivity rate, the light efficiency and the yield from the carbon source. An efficient parameter to evaluate the performance of photobioreactors, in order to maximize hydrogen production is still missing. With this parameter one should also be able to forecast the consequences of scaling-up. 

Pulz, O. and Scheibenbogen, K. (1998). Photobioreactors design and performance with respect to light energy input. Advances in Biochemical Engineering/Biotechnology 59, 123-152. 

Cultivation of the cyanobacterium was performed in a 4.35 L automated helical photobioreactor (PhBR) described by Tsygankov et al. (1998a). A. variabilis PK 84 was cultivated autotrophically in the PhBR under sterile air containing 2% C02 (500 ml-min 1). Growth conditions in the PhBR were monitored by a computer system connected to built-in pH, temperature, optical density, pO, and sunlight intensity sensors. When necessary 1 or 2 polyurethane foam balls were circulated along with the culture in the PhBR to clean the inner surface of the PVC tubing. 

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... 

In case of an interaction with the non-emitting surface TZ of the photobioreactor, the Bemoulh test is performed a random number, rj, is uniformly sampled across the unit of interval and... 

The whole theoretical approach relies now on the abihty to calculate, for any condition of radiation field in the photobioreactor, the variables q, x, and x in a predictive manner. This calculation can be performed in two steps. First, it can be demonstrated (Dussap, 1988) that there are two non-adaptive conditions (ie, fixed conditions arising at the early stage of a cell s Hfe cycle), allowing us to obtain constant values for q and X- The first condition hnks the stoichiometric coefficient for the phosphorylation to the phenomenological stoichiometric coefficient in non-ideal coupling ... 

It has been previously demonstrated in both cases that these thermodynamic-efficiency levels strongly decrease with the increasing incident PFD ( n this effect forms the basis of the light dilution concept for improvement of thermodynamic performance of photobioreactors (Comet, 2010 Pmvost and Comet, 2012). For example, in the DiCoFluV concept (for which simulations of the complete model are shown in Fig. 29 at the end of this section), the sunlight capture surface can be 50-fold smaller than the light distribution surface inside the photobioreactor (see chapter Industrial Photobioreactors and Scale-up Concepts by Pmvost et al.). 

A cultivation system specially adapted to screening microalgae in reliable conditions was recently developed (Fig. 2). This system, named efficient overproducing screening system—photobioreactor (EOSS-PBR), was used to evaluate cell growth and productivity to compare strain performances... 

Aden Fernandez FG, SevillaJM, Sanchez Pdez JA, Mohna Grima E, Chisti Y Airlift-driven external-loop tubular photobioreactors for outdoor production of microalgae assessment of design and performance, Chem Eng Sci 56(8) 2721—2732, 2001. 

Pulz, 0., Scheibenbogen, K. Photobioreactors Design and Performance with Respect to Light Energy Input. Vol. 59, p. 123... 

Masojidek, J., Papdcek, ., Sergejevova, M., Jirka, V., Cerveny, J., Kune, J., et al., 2003. A closed solar photobioreactor for cultivation of microalgae under supra-high irradiance basic design and performance. Journal of Applied Phycology 15 (2-3), 239-248. 

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