Adsorption isotherm and kinetic study of gas-solid system of formaldehyde on oil palm mesocarp bio-char: Pyrolysis effect

The kinetic and isotherm studies of gas-solid system were represented by oil palm mesocarp bio-char as adsorbent and formaldehyde as adsorbate. Three kinetic model; i.e pseudo-first-order, pseudo-second-order and Elovich model and three isotherm model; i.e.Langmuir, Freundlich and Temkin isotherm were applied to evaluate the applicability of the equilibrium experimental data and the pyrolysis effect was studied. As a result, oil palm fiber carbonized at 500 °C and 700 °C was best presented by the Langmuir isotherm and oil palm mesocarp carbonized at 600 °C and 800 °C followed Temkin and Freundlich model, respectively. The formaldehyde adsorption was found favorable to happen at 25 °C with initial concentration of 0.5 ppm, 0.9 ppm, 0.75 ppm and 2.1 ppm as the Langmuir dimensionless constant, RLgave the value of 0 < RL < 1. Carbonization temperature of 500 °C, 600 °C, and 700 °C was kinetically presented by pseudo-first-order kinetic equation and carbonization temperature of 800 °C followed Elovich equation. As a conclusion, the pyrolysis of oil palm mesocarp does affect the isotherm and kinetic behavior of formaldehyde adsorption on oil palm char.