摘要:
A process for olefin metathesis is disclosed. The process involves contacting a feedstock comprising a first olefin and a second olefin having a carbon number at least two greater than that of the first olefin with a catalyst comprising a tungsten component on a refractory oxide support, e.g. silica at metathesis conditions to provide a product olefin having an intermediate carbon number between that of the first and second olefin. The catalyst is characterized in that it is first pretreated with hydrogen followed by treatment with ethylene.
摘要:
The present invention relates to a process for carrying out a chemical reaction in the presence of a ruthenium-carbene complex supported on silicon dioxide in a continuously operated reactor and also the use of corresponding supported catalysts in continuously operated reactors.
摘要:
Systems and methods for processing one or more hydrocarbons are provided. In one or more embodiments, the method can include thermally converting a hydrocarbon comprising methane to produce a first product comprising acetylene. The method can also include hydrogenating the first product to produce a second product comprising ethylene. The method can further include catalytically reacting the second product with one or more butene products to produce a third product comprising propylene.
摘要:
The present invention provides metal-free abnormal N-heterocyclic carbenes, also known as imidazol-5-ylidenes and metal complexes of abnormal N-heterocyclic carbenes. The present invention also provides methods of making metal-free abnormal N-heterocyclic carbenes and metal complexes of abnormal N-heterocyclic carbenes. The present invention also provides methods of using metal-free abnormal N-heterocyclic carbenes and metal complexes of abnormal N-heterocyclic carbenes in catalytic reactions.
摘要:
The invention relates to a complex of ruthenium of the structural formula I, where X1 and X2 are identical or different and are each an anionic ligand, R1 and R2 are identical or different and can also contain a ring, and R1 and R2 are each hydrogen or/and a hydrocarbon group, the ligand L1 is an N-heterocyclic carbene and the ligand L2 is an uncharged electron donor, in particular an N-heterocyclic carbene or an amine, imine, phosphine, phosphate, stibine, arsine, carbonyl compound, carboxyl compound, nitrile, alcohol, ether, thiol or thioether, where R1, R2, R3 and R4 are hydrogen or/and hydrocarbon groups. The invention further relates to a process for preparing acyclic olefins having two or more carbon atoms or/and cyclic olefins having four or more carbon atoms from acyclic olefins having two or more carbon atoms or/and from cyclic olefins having four or more carbon atoms by an olefin metathesis reaction in the presence of at least one catalyst, wherein a complex is used as catalyst and R1, R′2, R′3 and R′4 are hydrogen or/and hydrocarbon groups.
摘要:
This invention relates generally to olefin metathesis, more particularly, to tri- or tetra-substituted imidazolinium salts which are precursors to N-heterocyclic carbene (NHC) ligands with tri- or tetra-substituted imidazolinium rings, organometallic ruthenium complexes comprising gem di-substituted imidazolinium NHC ligands, organometallic ruthenium complexes comprising tri- or tetra-substituted imidazolinium NHC ligands, and to olefin metathesis methods using them. The catalysts and methods of the invention have utility in the fields of catalysis, organic synthesis, and industrial chemistry.
摘要:
Novel group 6 organometallic compounds, supported on anions by means of at least one covalent metal-oxygen bond, are obtained by reaction of at least one borate or aluminate comprising at least one hydroxy group with at least one compound of a group 6 transition metal. These compounds are used in a catalytic composition utilized in an olefin metathesis method.
摘要:
In a process for producing olefins by a metathesis reaction comprising feeding an olefin gas to pass the olefin through a catalyst bed in the presence of hydrogen gas to convert the olefin into another kind of olefin, the catalyst bed having a catalyst including at least one metal selected from the group consisting of tungsten, molybdenum, rhenium, niobium, tantalum and vanadium, and a co-catalyst including a basic compound having at least one metal selected from the group consisting of Group Ia (alkali metals), Group IIa (alkaline earth metals), Group IIb and Group IIIa of the periodic table, the improvement lies in controlling the superficial velocity of the gas passing through the catalyst bed to 0.01 to 2.0 m/sec. According to the present invention, the presence of hydrogen gas dramatically increases the durability of the metathesis catalytic activity and the by-production of paraffins is suppressed.
摘要:
A processing scheme and system for enhanced light olefin production, particularly for increased relative yield of propylene, involves oxygenate conversion to olefins and subsequent oxygenate conversion effluent stream treatment including cross-metathesis of 1-butene with 2-butene, metathesis of 2-butene with ethylene, conversion or removal of at least a portion of the isobutene, and/or isomerization of at least a portion of 1-butene to 2-butene to produce additional propylene. The processing scheme and system may further involve a reaction with distillation column for the metathesis of butenes with ethylene to produce propylene and/or a reaction with distillation column for the conversion of isobutenes with an oxygenate-containing material to produce a tertiary ether or alcohol.