Hydrogen separation alternatives

A similar but somewhat less ambitious approach is to carry out dehydrogenation of ethylbenzene and oxidation of the hydrogen product alternately in separate reactors containing different catalysts ... 

Hydrochloric acid digestion takes place at elevated temperatures and produces a solution of the mixed chlorides of cesium, aluminum, and other alkah metals separated from the sUiceous residue by filtration. The impure cesium chloride can be purified as cesium chloride double salts such as cesium antimony chloride [14590-08-0] 4CsCl SbCl, cesium iodine chloride [15605 2-2], CS2CI2I, or cesium hexachlorocerate [19153 4-7] Cs2[CeClg] (26). Such salts are recrystaUized and the purified double salts decomposed to cesium chloride by hydrolysis, or precipitated with hydrogen sulfide. Alternatively, solvent extraction of cesium chloride direct from the hydrochloric acid leach Hquor can be used. 

If the sample of nitrocymene is impure, or if the catalyst is of poor quality, the hydrogenation may not proceed to completion and a solution of the product in hydrochloric acid will be turbid. In this event, the mixture of products (after separation of the spent catalyst) may again be submitted to hydrogenation. An alternative procedure involves removal. of the non-basic material by steam distillation of a mixture of the product with 350 cc. of water and 90 cc. of concentrated hydrochloric acid. The amine is then liberated from its salt by the addition of 45 g. of sodium hydroxide and is extracted with 500 cc. of ether. The ether layer may be siphoned from the water layer. The ether is removed by distillation, and the residue is fractionated as described in the procedure. For steam distillations, the submitters employ the adapter shown in Fig. 1. With this adapter the... 

Although the Clean Fuels PEPS design is intended to produce syngas for F-T synthesis of liquid fuels, it should be noted that the system, with minor modifications, could be used to produce hydrogen as the primary product. The water gas shift reactor could be modified to drive the gas composition to primarily H2 and CO2. The addition of a hydrogen separation unit downstream of the shift reactor would permit recovery of hydrogen as an alternate product stream. 

The chapter begins with a description of reference processes that are currently used industrially for hydrogen production and power generation from natural gas and coal. Alternative plant designs that employ membranes are discussed next. Only oxygen and hydrogen separation membranes are... 

A. Sanmcci, S. Tosti, A. Basile, Alternatives to paUadium in membranes for hydrogen separation Nickel, niobium and vanadium alloys, ceramic supports for metal alloys and porous glass membranes, in Handbook of Membrane Reactors, volume 1, A. Basile, ed., ComwaU Woodhead Publishing Series in Energy, 2013, pp. 183-217. 

Alternatives to palladium in membranes for hydrogen separation nickel, niobium and vanadium alloys, ceramic supports for metal alloys and porous glass membranes... 

Key words hydrogen separation, metal membranes, metal alternatives to Pd alloys. 

Alternatives to Pd in membranes for hydrogen separation 197 Table 4.6 H2 permeability data for some recent alloys reported in literature... 

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