套管式新型光生物反应器的性能初步实验

Preliminary experiment on performance of concentric-tube photobioreactor

针对管式光生物反应器藻液中溶解氧及pH限制进一步规模扩大等因素,设计了一种套管新型内曝气式光生物反应器。以Chlorella vulgaris为培养对象,BG-11为培养基,以细胞干重为检测指标,同时检测藻液的溶氧量和pH,比较了小规模实验条件(锥形瓶,500 mL)和套管式新型光生物反应器(36 L)对微藻生物质积累的影响。结果表明,新型反应器和小规模实验条件相比,培养体积扩大了72倍,培养10 d时微藻的比生长率下降了33.2%,单位体积产率下降了69.8%。在整个培养过程中,藻液溶氧量为6.2～7.0 mg/L,未超过限值7.5 mg/L。通入气体为空气,藻液pH由7.5上升至9.0,处于微藻可适应范围(4.5～10.6),尚可通过在空气中混入CO2进行调节。

Gradient of dissolved oxygen and pH along the tube limit scale-up of the tubular photobioreactor. To solve the problems above, a new concentric-tube photobioreactor is introduced and preliminaryly tested by Chlorella vulgaris in BG-11 medium. The influence of small culture scale （500 mL conical flask） and concentric-tube （36 L） photobioreactor on the biomass concentration is studied by detecting the biomass concentration, dissolved oxygen and pH. The results show that after 72 times larger scale than the conical flask, the specific growth rate is decreased by 33.2% and the biomass productivity is decreased by 69. 8% in the concentric-tube photobioreactor. In the process of cultivation, the concentration of dissolved oxygen in the medium is ranging in 6. 2 - 7.0 mg/L, which is steady below 7. 5 mg/L that microalgae can stand with. Compressing air into the photobioreactor,pH is rising from 7.5 to 9.0 during 10 days which is suitable （4. 5 - 10. 6） for microalgae,but it can be controlled by CO2 which can be mixed into the air before compressed into the photobioreactor.