Simulação de processos catalíticos para a produção de biodiesel sem glicerol - uma análise técnica, econômica e energética

Abstract

Although the use of biodiesel presents many economic, social and environmental advantages, the biodiesel production still has a high cost. Most production processes use alcohol as acyl receptor, producing glycerol as a byproduct, which is surplus in the market. Besides that, the step of removing glycerol from biodiesel makes the process expensive. Therefore, alternatives of glycerol-free biodiesel production have been investigated. This paper aims to compare three processes in order to define the most advantageous. For this purpose, three studies of biodiesel glycerol-free production were chosen, each one with a different catalyst (homogeneous, heterogeneous and enzymatic). The processes flow diagrams were proposed and simulated using the UniSim Design software on an industrial scale, providing a database to technical, economic and energy feasibility analysis. Thermodynamic and kinetic reaction models used were validated based on experimental data from the literature. Results indicated that the three technologies perform well, that is, they are capable of producing biodiesel. Route 1, which used macaw oil, methyl acetate and γ-alumina (Al2O3) as an heterogeneous catalyst, demonstrated to be not economically viable, this may be linked to the type of raw material used, that was only 65% esterifiable. Route 1 was also the process that presents the highest energy consumption per mass of biodiesel produced. Route 2, which used cotton oil, methyl acetate and homogeneous catalyst CH3OK, has the biggest project value at the end of its life. Route 3, which used palm oil, dimethyl carbonate and Novozyme 435 as enzymatic catalyst has the lowest equipment cost and the lowest energy consumption. Routes 2 and 3 proved to be economically viable.