Synthesis and Testing of Zeolite from Industrial-Waste Coal Fly Ash as Sorbent For Water Adsorption from Ethanol Solution

In the present work, zeolite was prepared from industrial-waste coal fired ash (CFA) by fusion technique with and without acid-washing pretreatment under various conditions. The synthesized materials were then tested for water adsorption from bioethanol solution with an aim to produce a high purity ethanol (> 99.5%) for later utilization in gasohol production manufacturing. From our studies, it was found that the impurities (i.e., Fe2O3, TiO2, MgO, CaO, K2O and SO3) in CFA could be efficiently removed by acid-washing pretreatment. Among three different acids studied (i.e. HCl, HNO3, and H2SO4), HCl exhibited the highest pretreatment performance, while the most suitable pretreatment conditions to enhance high purity raw material (up to 85% purity) were by using 20% HCl with the acid to CFA ratio of 25 mlHCl/gCFA at 80°C for 3 h. After fusion at 550ºC with NaOH/CFA mass ratio of 2.25 and further crystallization at 90ºC for 4 h, the pretreated CFA was converted to zeolite; from which the main phases were sodium aluminum silicate hydrate (1.08Na2O•Al2O3•1.68SiO2•1.8H2O) and faujasite-Na (Na2Al2Si2.4O8.8•6.7H2O). Regarding water adsorption testing, the synthesized zeolite provided comparable adsorption performance with the commercial grade molecular sieve. Under three adsorption cycles testing at 85ºC, high ethanol purity (99.8%) could be achieved without deactivation being observed

Bacterial Cellulose-Alginate Membrane for Dehydration of Biodiesel-Methanol Mixtures

Pervaporation, a membrane-based technique, is taken into consideration in order to separate water from biodiesel-methanol mixtures. Several operational conditions in biodiesel production could cause water contamination into the reaction mixture, which can affect biodiesel production and quality. In this study, bacterial cellulose-alginate (BCA) nanocomposite film was applied as a selective membrane in order to separate water from biodiesel-methanol mixtures using pervaporation. For effective operation, factors that affected the performance in the pervaporation, such as concentration of water in the biodiesel-methanol mixtures and temperature of the process were investigated. It was demonstrated that, the BCA membrane has good potential for removing water from the biodiesel-methanol mixtures. Under a permeate pressure of 10 mmHg and 30°C, the BCA membrane could separate water from the mixture containing methyl ester (C10:0): methanol: water at a weight ratio of 42.3:52.7:5 with a total permeate flux of 148 g/(m2h) and a water selectivity of 332. The permeate was contained 94.5% w/w water and methyl ester was completely rejected by the BCA membrane. The increase of water concentration in biodiesel-methanol mixtures and the temperature rise resulted in an increase in the permeate flux but lowered the selectivity