120ℓ 급 미세조류 대량생산용 평판형 광생물 반응기 케이스 열성형 금형 개발에 관한 연구

Abstract

The interest in bio-fuels has steadily increased to cope with the global warming and the resource depletion. The volume of bio-fuels is in proportion to an amount of the biomass. Microalgae have begun to receive attention as the third generation biomass. Recently, the development of the effective photobioreactor (PBR) to mass-produce microalgae is one of hot research issues. The objective of this thesis is to investigate into the development of thermoforming mould of a 120 ℓ flat panel photobioreactor (FP PBR) case with characteristic shapes for the mass cultivation of microalgae. A proper design of 120 ℓ FP PBR case has been obtained via the fundamental formability investigation as well as the structural and rigidity analyses. Considering the anti-fouling and transparency characteristics of the FP PBR case, the polycarbonate plate has been chosen as the material of the FP PBR case. The structural and rigidity analyses have been performed using a commercial software ABAQUS V11. Using the proper design of 120 ℓ FP PBR case, the surface design of the thermoforming mould for 120 ℓ FP PBR case has been deduced. The thermoforming process has been established to manufacture a plastic 120 ℓ FP PBR case. The material of thermoforming mould has been selected as an AC2B aluminum alloy. Thermoforming analysis has been carried out to investigate the formability of the designed FP PBR case using a commercial software PAM-FORM 2G. In order to obtain stress-strain relationships considering the temperature and the strain rate, tensile tests of the polycarbonate with the thickness of 4.5 mm have been performed in the elevated temperature. From the results of the thermoforming analysis, a proper thermoforming conditions has been obtained. Thermoforming mould of a 120 ℓ FP PBR case with characteristic shapes has been fabricated from casting, machining and drilling processes. The plastic 120 ℓ FP PBR case has been produced from the thermoforming process. The fabricated thermoforming mould and the estimated thermoforming condition have been applied to manufacture the plastic 120 ℓ FP PBR case. Left and right sides of the plastic 120 ℓ FP PBR case with characteristic shapes have been joined with adhesives. In order to evaluate the safety and the cultivation characteristics of the fabricated 120 ℓ FP PBR case, durability and culture experiments has been performed. From the results of the durability and culture experiments, it has been shown that the fabricated 120 ℓ FP PBR case has sufficient rigidity to cultivate the microalgae and the designed FP PBR case with characteristic shapes can conspicuously improve productivity of the microalgae as compared to a FP PBR case without characteristic shapes.