Simulação do processo de desacidificação de misturas de hidrocarbonetos, em colunas de absorção em contracorrente, usando co2 supercrítico como solvente no simulador aspen hysys

Abstract

In this work, the deacidification of organic liquid products (OLP) obtained by thermal catalytic cracking of palm oil at 450 C, 1.0 atmosphere, with 10% (wt.) Na2CO3 as catalyst, in multistage countercurrent absorber columns using supercritical carbon dioxide (SC-CO2) as solvent, with Aspen HYSYS® process simulator was systematically investigated. In a previous study, the thermodynamic database and the modeling of equations of state necessary to simulate the deacidification of OLP were presented [Molecules 2021, 26, 4382. https://doi.org/10.3390/molecules26144382 ]. This work addresses a new flowsheet, consisting of 03 absorber columns, 10 expansions valves, 10 flash drums, 08 heat exchanges, 01 high pressure pump, and 02 make-up of CO2, aiming to improve the deacidification of OLP. The simulation was performed at 333 K, 140 bar, and (S/F) = 17; 350 K, 140 bar, and (S/F) = 38; 333 K, 140 bar, and (S/F) = 25. The simulation shows that 81.49% of OLP could be recovered and the concentrations of hydrocarbons in the extracts of absorber-01 and absorber-02 were 96.95% and 92.78% (wt.) in solvent-free basis, while the bottom stream of absorber-03 was enriched in oxygenates compounds with concentrations up to 32.66% (wt.) in solvent-free basis, showing that SC-CO2 was able to deacidify liquid organic products, obtaining fractions with lower olefin content. The best deacidifying conditions was obtained at 333 K, 140 bar, and (S/F) = 17.