Trapped materials alumina

Continuous analysis of highly fluorinated materials can present problems, primarily caused by the corrosiveness of hydrogen fluoride which is liberated from all of them during combustion. Hydrogen fluoride will react with the permanently bound hydroxy groups on the surface of the cooler parts of combustion tube walls and catalysts. The effect can lead to erratic hydrogen values and so the installation of some type of oxide [magnesium oxide, alumina, or cerium (IV) oxide] trap in the combustion tube to prevent its escape is recommended. 11... 

Coaxial (or assimilation) traps utilize an adsorbing material drawn out to a fine fiber to provide as much surface area as possible. The various different materials available provide varying capabilities. For example, copper provides the best absorption capabilities (particularly to hydrocarbon oils), but is not very durable and needs to be replaced often. Stainless steel (particularly good for acid environments) and bronze will survive better in tougher environments, and activated alumina is great when organics or pump oils need to be trapped. Like molecular sieves, these traps work at room temperature. Unlike molecular sieves, not all can be baked out for regeneration and typically must be replaced with the old one discarded in an environmentally safe manner because it is likely to contain a variety of harmful materials. 

Materials for selective vapor-phase trapping have been considered by various workers (6,7). Traps used in the present study included molecular sieve 5A for subtraction of straight chain hydrocarbons, sodium bisulfate and phosphoric acid for subtraction of shale oil bases, and alumina for subtraction of acidic components. 

Solid-phase extraction columns contain either nonpolar reversed-phase Cig sorbents, or polar sorbents such as alumina, aminopropyl, and propylsulfonic acidJ Matrix solid-phase dispersion cleanup, using reversed-phase Cig material, has also been employed for the determination of oxolinic acid in catfish muscleJ On-line dialysis and subsequent trace enrichment have been further described for the extraction/cleanup of flumequine residues from fish muscle,or oxolinic acid and flumequine from chicken liver and salmon muscleJ This process involves on-line use of a diphasic dialysis membrane, trapping of the analytes onto a preconcentration column filled with reversed-phase Cig or polymeric material, rinsing of the coextracted interfering compounds to waste, and, finally, flushing of the concentrated analytes onto the analytical column. 

Zeolites are used as the primary builder in areas where phosphates cannot be used. Zeolite A is the most common type. This material is a synthetic aluminosilicate, made from alumina and alkaline sodium silicate. Zeolite A has a cage-like structure, which is of the right size to trap calcium ions from the wash water. Sodium ions are released from the cage in an ion exchange process. 

The reformate left the reformer with a temperature of 814 °C and entered a zinc oxide trap. However, this would he not feasible in a practical system, because zinc oxide adsorbent materials cannot tolerate temperatures exceeding 450 °C. The reformate, which was cooled to 440 °C in heat-exchanger E-2 was then passed to the water-gas shift reactor. This reactor was cooled by steam generation at 15-bar pressure and a temperature of200 °C in a counternoble metal based rhenium/alumina catalyst at the inlet section followed by a copper/zinc oxide catalyst at the outlet section. Despite the fact that a water-gas shift catalyst of fairly low activity had been chosen for the... 

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