An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in a tert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel....

Heat and mass transfer problem in a fixed-bed tubular reactor is one of the major concerns in the chemical engineering. The two dimensional axial plug flow model was used for a water gas shift reactor to compare heat conduction or mass diffusion with convective effect. In the case of fast fluid flow in highly permeable catalyst-bed, convective heat transfer was dominant compared to heat conduct...

In this study, an innovative aerobic/anoxic sludge bed bioreactor with two feeding regimes, continuous-fed (an up-flow sludge bed reactor (USBR)) and batch fed (sequencing batch reactor (SBR)), was evaluated for the treatment of an industrial estate wastewater with low BOD(5)/COD ratio. The process performance in the two regimes was compared. Two numerical independent variables (retention/react...

a model describing the main processes occurring in the uasb reactor was developed; in orderto maintain simplicity and applicability of the model, only the fundamental aspects were considered. in themodel, the reactor is divided in several well-stirred reactors coupled in series and it comprises substratedegradation, biomass growth and the reactions that take place within the granules. the impor...

Due to its structure, hexamethylenetetramine (HMT) is a slowly biodegradable substance, hydrolysing in acid environment to ammonium and formaldehyde. Formaldehyde is toxic under normal conditions for biological treatment processes. Following an adaptation, a formaldehyde concentration of 1000 mg·l may become biodegradable both in aerobic and anaerobic conditions. Acidic conditions for hydrolysi...

The production of methane by reacting CO2 with H2 (CO2 methanation) has the potential for producing synthetic natural gas, which could be exported using the existing infrastructure for the distribution of natural gas. The methanation of CO2 was investigated over a wide range of partial pressures of products and reactants using (i) a gradientless, spinning-basket reactor operated in batch mode a...

in this study, a pellet scale model was developed for trickle bed reactor utilizing cfd techniques. drag coefficients were calculated numerically at different velocities and bulk porosities in the case of single phase flow through the dry bed. the simulation results were then compared with the prediction of kozeny-carman (k-c) equation. the results indicated that drag coefficients calculated fr...

In this study, characterization and anaerobic treatability of leachate from Komurcuoda Sanitary Landfill located on the Asian part of Istanbul were investigated. Time based fluctuations in characteristics of leachate were monitored for an 8 month period. Samples were taken from a 200 m3 holding tank located at the lowest elevation of the landfill. COD concentrations have ranged between 18,800 a...

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L-Glutamine amidohydrolase (L-glutaminase, EC 3.5.1.2) is a therapeutically and industrially important enzyme. Because it is a potent antileukemic agent and a flavor-enhancing agent used in the food industry, many researchers have focused their attention on L-glutaminase. In this article, we report the continuous production of extracellular L-glutaminase by the marine fungus Beauveria bassiana ...