Production of optically pure products can be based on simple unselective synthesis of racemic mixtures combined with a subsequent separation of the enantiomers. However, this approach suffers from a 50% yield limitation which can be overcome by racemization of the undesired enantiomer and recycling. Application of biocatalyst for the racemization steps offers an attractive option for high-yield...

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 ...

A linearized non-isothermal general rate model is formulated and analytically solved to quantify the effects of temperature variations in fixed-bed chromatographic columns. The contains a set four coupled PDE accounting for energy transfer resistances, inner outer particle-pore diffusions, interfacial mass axial dispersion. Laplace transform, eigenvalue-decomposition technique, conventional tec...

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...