la mise en contact, dans une zone réactionnelle (4) dans laquelle est présent un catalyseur de type acide et où règnent des conditions convenant à une réaction d'éthérification, d'au moins un alcool et d'une charge d'hydrocarbures riche en oléfines légères, mais contenant des composés azotés susceptibles de désactiver le catalyseur ; la séparation des effluents de la zone réactionnelle (4) de manière à obtenir au moins une première coupe riche en éther et une seconde coupe contenant la majeure partie de l'alcool résiduel et des composés azotés ; et le recyclage de la seconde coupe à l'entrée de la zone réactionnelle.
Selon l'invention, préalablement à son recyclage dans la zone réactionnelle, la seconde coupe est traitée (en 40) de manière à abaisser d'au moins 50 % sa concentration en lesdits composés azotés.
摘要:
Dimethyl ether (18) is produced from synthesis gas (10) in a single step by contact with a bifunctional catalyst system having a methanol synthesis functionality and a methanol dehydration functionality while maintaining (12) a methanol concentration greater than 1.0 mole %, preferably 4 to 8 mole %. The presence of the methanol increases the stability of the bifunctional catalyst system, particularly when the process is conducted in the liquid phase. The methanol can be provided by recycling (12a) byproduct methanol.
摘要:
PCT No. PCT/GB94/02722 Sec. 371 Date Dec. 22, 1995 Sec. 102(e) Date Dec. 22, 1995 PCT Filed Dec. 13, 1994 PCT Pub. No. WO95/17461 PCT Pub. Date Jun. 29, 1995This invention relates to aqueous resin formulations comprising as cosolvent an alkoxy ethoxyethanol which (i) has 4-8 carbon atoms in the alkoxy group, (ii) has a boiling point at atmospheric pressure within the range from 200 DEG to 350 DEG C. and (iii) in mixtures with n-heptane in the ratio of 30:70 by weight respectively has specific miscibility characteristics. The cosolvent acts either as a solvent or coalescing aid in aqueous formulations used as coatings and paints.
摘要:
Light olefins (72, 74, 76) are produced from a hydrocarbon gas stream (50) by a combination of steam reforming (54), oxygenate production (58), and oxygenate conversion (66) to olefin wherein a crude methanol steam (60) - produced in the production of oxygenates and comprising methanol, light ends, and heavier alcohols - is passed directly to the oxygenate conversion zone (66) for the production of light olefins. Furthermore, the combination provides the synergy for increased catalyst life and reduced water treatment costs by recycling by-product water (71) produced in the oxygenate conversion zone to provide water to the steam reforming zone (54). The advantage of this integration is the elimination of costly methanol separation and purification steps which result in the overall reduction in the costs of producing the light olefins. In addition, a portion of the by-product water can be combined with a propylene stream to provide a high octane blending component for gasoline. The propylene and butylene fractions produced by the above integrated scheme are further converted to high octane ether and other high value products.