Simulação, projeto e análise de viabilidade econômica da produção de biodiesel de óleo de dendê em rota de transesterificação catalítica heterogênea

Abstract

A continuous biodiesel production plant with an 8000 kg.h-1 inlet of palm oil and methanol, using the heterogeneous transesterification route was simulated, designed and economically assessed with the software Aspen HYSYS 7.3 and spreadsheets. The thermodynamic fluid package NRTL was selected in order to represent all properties of the fluids through the simulation. Packed-bed reactors were designed using numerical simulation to achieve an oil conversion of 97.3% in the process. The reactors were operated isothermally at 64.8°C and with an alcohol/oil ratio of 17.5. A vacuum distillation column was designed to recovery 99% of the methanol in excess. A decanter to separate the biodiesel and glycerin phases was designed through the calculation of residence time t. A second vacuum distillation column was designed to purify the biodiesel phase until a 99.97 wt%, in accordance with the ANP specifications. The glycerin phase was purified in a vacuum flash distillation column until a 99.53 wt%. The Total Capital Invested ITOTAL on the plant was estimated using the Detailed Factorial Method presenting the amount of US$ 5,798,469 was found. The Variable Costs of Production (VCOP) were estimated using the prices of raw materials, catalysts and utilities, whereas the annual revenues were calculated using the prices of biodiesel and glycerin. The Fixed Costs of Production (FCOP) were calculated using the operating labor costs, supervision, maintenance, corporate overheads and insurance. In order to calculate the cash flow of the project, the current tax regime in Brazil was used, including PIS/COFINS with a rate following the general rule and the reduction of 69% on it to companies with the social stamp, 25% of IRPJ and 9% of CSLL on the Net Profit before Income Taxes (NPIT). A Net Profit after Taxes (NP) of US$ 2,340,889 was obtained, a positive figure if compared to conventional processes using virgin soybean oil. The economic viability of the project was analyzed by calculating the Net Present Value (NVP) and Internal Rate of Return (IRR). A NVP of US $ 21.36 million and IRR of 39.0% were obtained, showing the economic viability of the project. The raw material price sensitivity analysis also showed that the process is feasible as long as palm oil prices do not increase or biodiesel do not decrease more than 3%