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  • Küçük Resim
    Öğe
    Potential utilization of fusel oil: A kinetic approach for production of fusel oil esters through chemical reaction
    (Turkish Journal of Chemistry, 1998) Küçük, Zeki; Ceylan, Kadim
    Abstract: Fusel oil is a by-product of the distillation of ethyl alcohol from the fermentation of molasses and contains mainly C3-C5 alcohols. Acetic acid and butyric acid esters of its major alcohol components have economic value as chemicals for flavor and fragrance manufacturing. This study presents some data regarding the uncatalyzed esterification of fusel oil with acetic acid, propionic acid and butyric acid. The reactions were carried out at two temperatures, i.e., 45° C and under the reflux conditions (80 — 85° C). The composition of raw fusel oil and the reaction mixtures were determined by gas chromatography. The reaction rate constants for the formation the esters were estimated based on the concentration-time relationships. The results indicated that esterification rate of fusel oil is very slow and, under identical conditions, the rate depends on the reacting acid. The formation rates of butyric acid esters were found to be higher than the those of acetic acid and propionic acid esters. After approximately 6.5 hours of the reaction at 45° C, the estimated maximum production yield of the mixed acedic acid esters was around 19%, propionic acid esters 24% and butyric acid esters 35%. Increasing reaction temperature increased the conversion ratios.
  • Küçük Resim Yok
    Öğe
    Reductive leaching of pyrolusite ore by using sawdust for production of manganese sulfate
    (Pleiades Publishing Inc, 2012) Ekmekyapar, Ahmet; Asin, Celal; Demirkiran, Nizamettin; Kunkul, Asim; Baysar, Ahmet; Ceylan, Kadim
    Manganese compounds, such as manganese sulfate, can be obtained from pyrolusite, a manganese ore. Low-grade manganese ores is usually treated by hydrometallurgical methods. In this study, the leaching and recovery of manganese from pyrolusite ore in sulfuric acid solutions containing sawdust as reducing agent was investigated. The effects of experimental parameters, such as sulfuric acid concentration, sawdust amount, solid-to-liquid ratio, stirring speed, particle size, reaction temperature, and leaching time, on the manganese extraction from ore were examined. The results showed that the leaching rate of pyrolusite ore increased with an increasing sulfuric acid concentration, sawdust amount, stirring speed, reaction temperature and leaching time, and decreasing in solid to liquid ratio and particle size. The kinetic analysis of leaching process was carried out, and it was determined that the reaction rate was controlled by diffusion through the product layer under the experimental conditions in this work. The activation energy was found to be 22.35 kJ mol(-1). Manganese can be recovered as manganese sulfate by the evaporative crystallization of the purified leach liquor.