Search

Adsorption is one of the methods used to reduce free fatty acid in feedstock oils with high acid content that are used for the production of biodiesel. This work investigated MCM-41 synthesized from rice husk silica for the adsorption of oleic acid in isooctane. The adsorption conformed to the Langmuir isotherm model and equilibrium adsorption capacities at 25.0°C were 277.8 mg/g for as- synthesized MCM-41 and 270.3 mg/g for template- removed MCM-41. The determined free energy and enthalpy of adsorption showed that the adsorption was spontaneous and exothermic. Adsorption of oleic acid in soy bean oil was also demonstrated. Results showed that as-synthesized MCM-41 was a better adsorbent than template-removed MCM-41 for oleic acid removal from soybean oil. [ABSTRACT FROM AUTHOR]

Sugarcane is widely grown in the Northeastern region of Thailand. The sugarcane leaves are usually eliminated before harvesting by burning, producing PM 2.5 as air pollutant. Here, we explore an approach to produce high-purity silica from the sugarcane leaves by leaching with hydrochloric acid (2.0 M) and subsequent calcination at 500°C for 4 h. The obtained silica is in an amorphous phase. The silica purity is 83.4 ± 0.9 wt.%, better than the product without acid leaching (18.5 ± 0.2 wt.%). Then, the silica was used in the synthesis of zeolite by hydrothermal method. The obtained zeolite has LTA as a major phase, zeolite NaX and SOD as minor phases. The zeolite has a high ethyleneadsorbed volume of 5.26 cm3/g, comparable to the reported value in the literature. Consequently, the zeolite synthesized from the sugarcane leaves silica is a promising adsorbent to preserve fresh fruit. [ABSTRACT FROM AUTHOR]