A Study on New Conceptual Design Formula for Offshore Seaweed Biomass Cultivation System

Abstract

An attention and attempting utilize seaweed biomass as an energy resource is increasing in many countries over the world. The idea of using marine biomass for energy was first conceived by Howard Wilcox in 1968 (Chynoweth, 2002). According to the increase in demand of this eco-friendly energy, the mass seaweed cultivation in offshore was considered. Many researchers have studied the effects of physical and biological in seaweed cultivation system (Neushul, 1992; Choi et al., 2006). However, there is still lack of both design plans for installation and construction of seaweed biomass cultivation in offshore. This study aims to make conceptual design for seaweed cultivation system by using the results of existing research and designing new formula for cultivation system in offshore together with using hydrodynamic and biological factors. Firstly, the research of offshore seaweed cultivation system and environmental condition in global and Korea were reviewed to understand several designs and methods of seaweed cultivation system in different conditions. Then the relationship of environmental factors and the analysis of physical conditions in Korea sea area, using filed observation and numerical simulation, were investigated. The result of environmental factors showed that water temperature was between 6.5°C-25.0°C in Wando station, in Gijang station was between 12-27°C. The result of salinity was ranged between 31-35‰ in Wando station which is smaller than in Gijang station. The results of temperature and salinity in both of station were corresponding with an existing research on growth of seaweed. In addition, field observation results in Gijang station presented the range of maximum wave height(Hmax), mean wave period(Tmean), maximum current velocity(Vmax) is 8~9 m, 6~8 sec, 55 cm/sec and in Wando station is 4~5 m, 4~8 sec, 40 cm/sec, respectively. These results were consistent with the results from numerical simulation on wave and current. Finally, our study estimated schematic form of conceptual design and a new formula for seaweed cultivation system.