The invention concerns a process for the production of butadiene from an ethanol feed comprising at least 80% by weight of ethanol, comprising a step for conversion of ethanol to acetaldehyde, a step for the extraction of butadiene, a step for scrubbing gaseous by-products with water, a step for eliminating impurities and brown oils, a step for treating effluents, a first butadiene purification step, and a subsequent butadiene purification step, said ethanol feed being supplied to said butadiene extraction step, the arrangement of the steps and recycles allowing the recycles to be maximized and allowing the water and energy consumption to be minimized.

The present invention relates to a process for efficiently synthesizing highly optically active 1,3-disubstituted allenes, i.e., a one-step process for preparing highly optically active 1,3-disubstituted allenes by using a functionalized terminal alkyne, an aldehyde and a chiral ,-diphenyl prolinol as reactants under the catalysis of a divalent copper salt. The operation of the process is simple, and the raw materials and reagents are readily available. The process has a broad-spectrum of substrates and a good compatibility for a wide variety of functional groups such as glycosidic units, primary alcohols, secondary alcohols, tertiary alcohols, amides, malonates, etc., and does not require the protection for the functional groups. The obtained axially chiral allene has a moderate to high yield and a good diastereoselectivity or enantioselectivity.

The present invention relates to a process for efficiently synthesizing highly optically active 1,3-disubstituted allenes, i.e., a one-step process for preparing highly optically active 1,3-disubstituted allenes by using a functionalized terminal alkyne, an aldehyde and a chiral ,-diphenyl prolinol as reactants under the catalysis of a divalent copper salt. The operation of the process is simple, and the raw materials and reagents are readily available. The process has a broad-spectrum of substrates and a good compatibility for a wide variety of functional groups such as glycosidic units, primary alcohols, secondary alcohols, tertiary alcohols, amides, malonates, etc., and does not require the protection for the functional groups. The obtained axially chiral allene has a moderate to high yield and a good diastereoselectivity or enantioselectivity.

Disclosed are a preparation method for a 1,3-disubstituted allene compound at room temperature based on a metal carbene catalyst, comprising: reacting terminal alkynes, aldehydes and amines in an organic solvent under the action of a gold catalyst and a molecular sieve, and then synthesizing a 1,3-disubstituted allene compound at room temperature. The method of the present invention is simple to operate, raw materials and reagents are easily obtained, reaction conditions are mild, substrate universality is wide, functional group compatibility is good, yield is high (36-93%), the method is scalable (11 g), and practicability is strong. The 1,3-disubstituted allene compound obtained in the present invention may be used as an important intermediate to construct -caprolactone, trans-allyl alcohol, other allene-derived compounds and natural product molecules and the like.

A silicon-aluminum zeolite SCM-36, a manufacturing method therefor and an application thereof are provided. The zeolite has a silicon/aluminum ratio n5, and has a distinctive XRD diffraction spectrum. The SCM-36 zeolite can be used as an adsorbent, a catalyst, or a catalyst carrier.

In a process for producing cumene, a C.sub.3 feed stream is contacted with an aromatic stream comprising benzene to produce an alkylation effluent comprising cumene. A portion of the alkylation effluent and at least one three-carbon alkylating agent is supplied to a treatment zone to remove impurities to form a treated feedstock. The C.sub.3 feed stream comprises a portion of the treated feedstock.

The present invention relates to an improved process for the preparation of metallocenes of the general formula (A) CR.sub.2L.sub.2MX.sub.2 as well as to intermediates useful in the synthesis of said metallocene and the use thereof as a catalyst in a polymerization of an olefin.

The present invention relates to an improved process for the preparation of metallocenes of the general formula (A) CR.sub.2L.sub.2MX.sub.2 as well as to intermediates useful in the synthesis of said metallocene and the use thereof as a catalyst in a polymerization of an olefin.