Use of a cheap, non-edible feedstock would reduce the biodiesel production cost and make the process economically viable. This study investigated the production of fatty acid methyl ester (FAME) using both acid (sulfuric acid, H2SO4) and base (sodium hydroxide, NaOH) catalysts. Techno-economic analysis was performed to assess the commercial feasibilities of acidcatalysed biodiesel production from waste shark liver oil (WSLO) and alkali-catalysed biodiesel production from refined vegetable oil in Oman. Historically, the discarded WSLO was used to proof wooden boats, but now these applications are no longer required as modern boats are made of fiberglass. Hence,the excess WSLO derived from these discarded shark livers in the fishing industry could instead be utilised for biodiesel production. This would be environmentally beneficial as it converts a waste into a product. Aspen HYSYS-V9 was used to simulate both production types at plant capacity of 12,000 te/y and lifespan of 20 years. Net present values (NPVs) of US $34.8 and US $4.9 million were obtained for the acidcatalysed process using WSLO and the alkali-catalysed process using refined vegetable oil, respectively. The internal rate of return (IRR) was calculated to be 260% for the acid-catalysed process and 56% for the alkalicatalysed process. Sensitivity analysis was also conducted to show the effect of certain variables on the NPV of both biodiesel production types. It was concluded that the biodiesel selling price has more effect on the NPV than the glycerol variation price, whereas the triglyceride feedstock purchase prices have the largest influence on the NPV of the two processes.
Keywords biodiesel, process simulation, technoeconomic analysis, sensitivity analysis, homogeneous acid and base catalysis