Propyl-Sulfonic Acid Functionalized Nanoparticles as Catalyst for Pretreatment of Corn Stover

Abstract

Propyl-sulfonic (PS) acid-functionalized nanoparticles were synthesized, characterized and evaluated as catalysts for pretreatment of corn stover. Silica coated nanoparticles were functionalized with 0.5% mercaptopropyltrimethoxysilane (MPTMS) at neutral pH in a mixture of water and ethanol. Sulfur contents of the acid functionalized nanoparticles, measured in a CHNS analyzer, varied from 6% - 10%, and the acid load ranged from 0.040 to 0.066 mmol H+/g. A Box-Behnken design was employed to calculate the minimum number experiments required to obtain an estimate of the surface response for temperature, catalyst load, and %S content of the catalyst. Pretreatment of corn stover was carried out at three temperature levels 160, 180, and 200˚C for 1 h. Three levels of catalyst load were used 0.1, 0.2, and 0.3 g of catalyst per gram of biomass. Hydro-thermolysis controls were carried at each temperature level.