Energy Analysis of Hydrotreated Vegetable Oil as Renewable Fuel Using Chlorella Vulgaris Using Aspen Energy Analyzer

Due to limited literature on hydrotreated vegetable oil (HVO) production using third-generation feedstock, the study was proposed to investigate the energy analysis using microalgae Chlorella Vulgaris. The plant simulation was performed using ASPEN HYSYS, while heat integration was performed using ASPEN Energy Analyzer. Utilizing the problem algorithm table (PTA), hot and cold pinch was determined to be 173.1°C and 163.1°C, respectively. Two cases were proposed, i.e. (1) heat exchanger network (HEN) Grassroot case and (2) heat exchanger network (HEN) retrofit case. For the first case, a new heat exchanger (E-107) is implemented in exchange for one reduction on the cooler unit (E-103). In contrast, the second case introduces two new heat exchangers (E-107 and E-108) with one cooler unit (E-103) reduction but lowered heating duty by around 7.08%, while cooling duty was reduced by 14.78% compared to the grassroots design. Although retrofits have more heat exchangers, the operating cost was saved up to 7.200$\times 10^{-3}$ ${\$}$/s. This indicates both flaws and benefits to retrofit design; hence, the implementation should consider the trade-off between the plant’s capital and operating costs and be justified once the additional cost was offset throughout the operating plant life after a payback period of 0.5846 years.