A tubular bioreactor for photosynthetic production of biomass from carbon dioxide: Design and performance

Abstract

A theory of photobioreactor design is developed. A photobioreactor was constructed in the form of a loop made from 52 m of glass tubing of 1 cm bore; the loop covered about 0.5 m2. The culture was illuminated with mercury halide lamps to reproduce sunlight. Computer control was used to maintain constant biomass concentration. The influence of radiation on the reactor temperature is quantitatively predicted. An air lift system was preferred to a liquid pump for culture recycle. The energy required for culture recycle in the loop with Reynolds number 2000 was 0.6 W m-2. The COZ gas/liquid transfer rate achieved was sufficient to meet the maximum possible demand with solar irradiation. The 0 2 gas/liquid transfer rate was sufficient to meet the maximum respiration demand at night. The maximum algal biomass concentration achieved exceeded 20 g dry weight litre-l. A biomass concentration of 8 g dry weight litre-1 was found to be convenient for normal operation. The maximum uptake of light in the available wavelength range (400-700 nm) was 38 W m-2, this corresponds to utilisation of solar irradiation up to 89 W m-2. Below the maximum light uptake rate the efficiency of storage of light energy in the biomass corresponded to 16.6% of solar energy.

Nutritional Value and Uses of Microalgae in Aquaculture

“…Note, however, that the costs of closed systems are substantially higher than their open pond counterparts [54]. A variety of closed photobioreactors have been tested (or at least proposed) for industrial microalgal biomass production [64,65], but engineering and economic analyses of such reactors still lag behind the open ponds [66][67][68][69][70].…”

Appraisal of a horizontal two-phase flow photobioreactor for industrial production of delicate microalgae species

“…With respect to this key problem, several steps marked the evolution of the horizontal tubular PBRs since this design appeared in the late 1970s (e.g. Jüttner 1977;Pirt et al 1983). Typically, movement and mass transfers took place in a gas lift in which the culture passed every 10 min in order to limit the dissolved oxygen concentration at peak sunlight.…”

Short-term evaluation of the photosynthetic activity of an alkaliphilic microalgae consortium in a novel tubular closed photobioreactor

“…Pirt et al (1983) suggested that ratios around 129 m 2 m −3 are desirable for optimizing the light utilization efficiency in microalgae. Torzillo (1997) reported that suitable photosynthetic rates would be achieved in tubular photobioreactors with a diameter of 2.6 cm operated at a linear velocity of around 30 cm s −1 with air stripping cycle every 6 min.…”