This work studied the influence of effluent recirculation upon the kinetics of anaerobic degradation of dairy wastewater in the feedless phase of intermittent upflow anaerobic sludge bed (UASB) reactors. Several laboratory-scale tests were performed with different organic loads in closed circuit UASB reactors inoculated with adapted flocculent sludge. The data obtained were used for determinati...

Trickle bed reactors are governed by equations of flow in porous media such as Darcy’s law and the conservation of mass. Our numerical method for solving these equations is based on a total-velocity splitting, sequential formulation which leads to an implicit pressure equation and a semi-implicit mass conservation equation. We use high-resolution finite-difference methods to discretize these eq...

Ethylbenzene is primarily produced by the alkylation of benzene with ethylene in liquid-phase slurry reactors promoted with aluminum chloride catalysts or by vapor-phase reaction of benzene with dilute ethylene-containing feedstock with a boron trifluoride catalyst supported on alumina (Cannella 2007; Clayton and Clayton 1981; HSDB 2009; Welch et al. 2005; Ransley 1984). Newer versions of the m...

MIT has been developing a conceptual design for pebble bed reactors since approximately 1998, when a student design project concluded that in order to resurrect the nuclear power industry a new, innovative approach was needed, not only in reactor design but also in construction and operation. In their quest to identify the appropriate technology several key conclusions were reached. First was t...

A concise review of relevant experimental observations and modeling of high-pressure tricklebed reactors, based on recent studies, is presented. The following topics are considered: flow regime transitions, pressure drop, liquid holdup, gas-liquid interfacial area and mass-transfer coefficient, catalyst wetting efficiency, catalyst dilution with inert fines, and evaluation of tricklebed models ...

Since its discovery in the 1920s, the Fischer-Tropsch Synthesis (FTS) has undergone periods of rapid development and periods of inaction. Within ten years of the discovery, German companies were building commercial plants. The construction of these plants stopped about 1940 but existing plants continued to operate during WWII. Two types of reactors were used in the German commercial plants: the...

Dechlorination of 2,4,6-trichlorophenol was performed within a magnetically stabilized fluidized bed (MSFB), containing a palladized iron (Pd/Fe) catalyst entrapped within alginate beads. Kinetic parameters of this multistep reaction yielding phenol as a final product were preliminarily defined in a batch system using four different intermediates as substrates for Pd/Fe catalyzed dechlorination...

The kinetics of cellulose hydrolysis under extremely low acid (ELA) conditions (0.07 wt%) and at temperatures >200°C was investigated using batch reactors and bed-shrinking flow-through (BSFT) reactors. The maximum yield of glucose obtained from batch reactor experiments was about 60% for α-cellulose, which occurred at 205 and 220°C. The maximum glucose yields from yellow poplar feedstocks were...