In a recent paper, Vortmcycr and Haidegger (1881) prcsented a comparison of thm models to evaluate heat iluxes fur wall-cooled fixed-bed chemical rtaEtvrs. We have the following comments about this mper. Vortmeya and Haidegger used the fast exothermic oxidation of etbane to test three (quasi-) homogeneous m&Is. They concluded that the wall ks c~tducri~~mcdel WBS the best thaw of kttcr agreement...

-Anaerobic biodegradation and inhibitory effects of nonionic and anionic surfactants on methanogenic fermentation were tested in incubation experiments with anoxic sediment samples and sewage sludge. Alkylsulfonates and alkylbenzenesulfonates were not degraded but inhibited methanogenesis from sludge constituents at concentrations 1> 10 mg l-k Sodium dodecylsulfate was at least partly degraded ...

The objective of this work was to establish fixed bed sorption enhanced reactors (SER) and simulated moving bed reactors (SMBR) for the production of high purity biodiesel (fatty acid methyl ester, FAME) using esterification reactions between fatty acids (FA) in used oils and methanol. This study has demonstrated that these processes have tremendous potential in terms of overcoming the low conv...

Sulfur-based autotrophic denitrification processes utilize autotrophic denitrifiers, such as Thiobacillus denitrificans and Thiomicrospira denitrificans, to reduce nitrate to nitrogen gas. Bench-scale experiments were conducted to evaluate the sulfur-based autotrophic denitrification process. This paper addresses three issues: (1) start-up and operation of a CSTR to provide an adequate seed sou...

The study aims to compare three sewage biological treatment methods- activated sludge, moving bed biofilm reactor (MBBR), and fixed reactor. sludge method is the most used in ship treatment. However, carrier methods, such as MBBR reactors, have improved their effectiveness with industrial wastewater, being considered industrial. An experiment was carried out untreated samples, chemical oxygen d...

Pebble Bed Reactors could allow nuclear plants to support the goal of reducing global climate change in an energy hungry world. They are small, modular, inherently safe, use a demonstrated nuclear technology and can be competitive with fossil fuels. Pebble bed reactors are helium cooled reactors that use small tennis ball size fuel balls consisting of only 9 grams of uranium per pebble to provi...

ethyl benzene used increasingly each year is the raw material of producing styrene monomer. this substanceis produced from benzene alkylation with ethylene or ethanol, depending on the availability and cost of rawmaterials. in this study benzene alkylation in the presence of ethanol in a catalytic fixed bed reactor inthree states of isotherm, adiabatic and non-isotherm-non-adiabatic is mathemat...

the potential of six economically cheap agricultural waste materials, viz. rice husk, betel nutpeels, sugarcane molasses, tea waste, mustard oil cake and saw dust, was investigated for copper and leadremoval from aqueous solutions under batch and continuous conditions. the effect of ph, contact time,sorbent dose and initial metal ion concentration on the uptake of copper and lead was first exam...

The work studied the characteristics of membrane catalysts in reaction methane carbonate conversion as a model reaction. This process produces synthesis gas (a 1:1 mixture Н 2 and СО), which can be used to make many products, including synthetic fuels (in FischerTropsch process). One serious problems is presence side reactions that prevent production with required ratio products (H :CO=1:1).Mem...