Stamicarbon B.v.

Unie Van Kunstmestfabrieken B.v.

Johannes D Verstegen

Petrus J Kaasenbrood

Jacobus Jansen

Dirk Knol

Christiaan Groeneveld

A process for the preparation of methyl tertiary butyl ether (MTBE) in two stages:

Process for the preparation of methyl tertiary butyl ether

A process for recovering maximum amounts of styrene from hydrocarbon fractions produced by thermal cracking of hydrocarbons. The cracked products are subjected to quench cooling and in a separating column separated into a bottom fraction comprised predominantly of hydrocarbons with 9 and more carbon atoms and into a top fraction comprised predominantly of hydrocarbons having less than 9 carbon atoms. The top fraction is fed to a cooling and separating device wherein a cracked gasoline fraction is recovered from which fraction styrene is recovered by fractionation. The cracked gasoline fraction from the separating device can be combined with the hydrocarbon condensates from the first and second compressor stages of a multistage compressor in which the vaporous fraction from the cooling and separating device is compressed.

Recovery of styrene from cracked hydrocarbon fractions

The invention is directed to a process for preparing cyanic acid from urea, comprising atomizing urea in a tubular reactor in the presence of a stream of a carrier gas to obviate the formation and deposition of by-products on the inner walls of the tubular reactor, thereby increasing the efficiency and production yields of the process.

Process for preparing cyanic acid

An improved urea synthesis process is disclosed in which carbon dioxide and ammonia are reacted at 210.degree. to 245.degree.C under pressures of 250 to 600 atm., the gross molar NH.sub.3 /CO.sub.2 ratio in the liquid phase in the synthesis zone of the order of 2.5 and 8, the carbon dioxide and ammonia being reacted together in a synthesis zone then the resulting urea synthesis solution being stripped in a stripping zone which is in heat exchange relation with the synthesis zone through a wall, and the gas mixture resulting from the stripping is partially recycled to the synthesis zone.

Process for preparing urea from ammonia and carbon dioxide

Cyanates of alkali and alkaline-earth metals are prepared by reacting a salt such as the hydroxide, carbamate or carbonate of the metal in aqueous solution or slurry with cracked urea gas which is a gaseous mixture of ammonia and (iso)cyanic acid.

Process for preparing alkali metal and alkaline-earth metal cyanates

Ammonium carbamate is decomposed and removed in the form of its gaseous components by contacting a urea synthesis solution comprising the carbamate with a stripping gas, such as carbon dioxide, the countercurrent stripping conducted at adiabatic conditions in the stripper unit. Urea synthesis solution to be treated is supplied at higher pressures and temperatures, at least 205.degree.C and at a pressure of at least 225 atm. Conveniently, the decomposition of the ammonium carbamate and the removal of the liberated gases are carried out at these temperatures and pressures so that the stripper is operative under the same conditions as well.

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Sittard, Netherlands

Johannes D Verstegen