Adsorption behavior of methyl palmitate onto silica particle surface

Abstract

Adsorption behavior of methyl palmitate (MP), as a model substance of biodiesel fuel, onto silica surface in the presence of methanol and toluene was investigated, assuming the dry washing purification of biodiesel production process. Methanol and toluene affected amount absorbed of MP, especially methanol greatly affected amount absorbed of MP. The adsorption model was proposed based on the Langmuir type adsorption and two assumptions for competitive adsorption. The equilibrium adsorption constant, K, and the maximum number of the adsorption sites, XS, were determined by fitting the data to the proposed model. The proposed model agreed well experimental data. The magnitude of K correlated with the dielectric constant of each substance. The occupied surface area of silanol group estimated from XS was mostly the same as the reported values. These adsorption parameters were verified experimentally with other conditions.