A process for the oligomerization of C.sub.3- to C.sub.5-olefins proceeds in the presence of a catalyst, wherein the oligomerization is carried out in at least one reaction stage which includes at least one reactor and at least one distillation column. The content of oligomers in the feed stream to the at least one reaction stage after removal of the oligomers in the at least one distillation column is less than 0.4% by weight.

A process for the oligomerization of C.sub.3- to C.sub.5-olefins proceeds in the presence of a catalyst, wherein the oligomerization is carried out in at least one reaction stage which includes at least one reactor and at least one distillation column. The content of oligomers in the feed stream to the at least one reaction stage after removal of the oligomers in the at least one distillation column is less than 0.4% by weight.

A process for the oligomerization of C.sub.3- to C.sub.5-olefins proceeds in the presence of a catalyst, wherein the oligomerization is carried out in at least one reaction stage which includes at least one reactor and at least one distillation column. The content of oligomers in the feed stream to the at least one reaction stage after removal of the oligomers in the at least one distillation column is less than 0.4% by weight.

The present invention relates to catalysts, more particularly to a cobalt-containing catalyst composition. The present invention further relates to a process for preparing a cobalt-containing catalyst precursor, a process for preparing a cobalt-containing catalyst, and a hydrocarbon synthesis process wherein such a catalyst is used. According to a first aspect of the invention, there is provided a cobalt-containing catalyst composition comprising cobalt and/or a cobalt compound supported on and/or in a silica (SiO.sub.2) catalyst support wherein the average pore diameter of the catalyst support is more than 20 nm but less than 50 nm; the catalyst composition also including a titanium compound on and/or in the catalyst support, and a manganese compound on and/or in the catalyst support.

The present invention relates to catalysts, more particularly to a cobalt-containing catalyst composition. The present invention further relates to a process for preparing a cobalt-containing catalyst precursor, a process for preparing a cobalt-containing catalyst, and a hydrocarbon synthesis process wherein such a catalyst is used. According to a first aspect of the invention, there is provided a cobalt-containing catalyst composition comprising cobalt and/or a cobalt compound supported on and/or in a silica (SiO.sub.2) catalyst support wherein the average pore diameter of the catalyst support is more than 20 nm but less than 50 nm; the catalyst composition also including a titanium compound on and/or in the catalyst support, and a manganese compound on and/or in the catalyst support.

An aromatization catalyst and preparation process and use thereof is set forth. The catalyst comprises an inorganic oxide and a modified Ga-ZSM-5 zeolite, which comprises a modified ZSM-5 zeolite with a hierarchical macro-meso-microporosity and gallium deposited in channels of and/or on surfaces of the modified ZSM-5 zeolite. The hierarchical porosity of the modified ZSM-5 zeolite in the catalyst can reduce diffusion resistance of products during the aromatization reaction, thereby retarding carbon depositing rate and substantially improving catalytic activity, aromatic hydrocarbon selectivity, stability and lifetime of the catalyst. When being used in aromatization of propane, the catalyst exhibits a high stability, a lifetime of more than 320 hours, and a selectivity to aromatic hydrocarbons of up to 73.3 wt. %.

An aromatization catalyst and preparation process and use thereof is set forth. The catalyst comprises an inorganic oxide and a modified Ga-ZSM-5 zeolite, which comprises a modified ZSM-5 zeolite with a hierarchical macro-meso-microporosity and gallium deposited in channels of and/or on surfaces of the modified ZSM-5 zeolite. The hierarchical porosity of the modified ZSM-5 zeolite in the catalyst can reduce diffusion resistance of products during the aromatization reaction, thereby retarding carbon depositing rate and substantially improving catalytic activity, aromatic hydrocarbon selectivity, stability and lifetime of the catalyst. When being used in aromatization of propane, the catalyst exhibits a high stability, a lifetime of more than 320 hours, and a selectivity to aromatic hydrocarbons of up to 73.3 wt. %.

The present invention relates to catalysts, more particularly to a cobalt-containing catalyst composition. The present invention further relates to a process for preparing a cobalt-containing catalyst precursor, a process for preparing a cobalt-containing catalyst, and a hydrocarbon synthesis process wherein such a catalyst is used. According to a first aspect of the invention, there is provided a cobalt-containing catalyst composition comprising cobalt and/or a cobalt compound supported on and/or in a silica (SiO.sub.2) catalyst support wherein the average pore diameter of the catalyst support is more than 20 nm but less than 50 nm; the catalyst composition also including a titanium compound on and/or in the catalyst support, and a manganese compound on and/or in the catalyst support.

The present invention relates to catalysts, more particularly to a cobalt-containing catalyst composition. The present invention further relates to a process for preparing a cobalt-containing catalyst precursor, a process for preparing a cobalt-containing catalyst, and a hydrocarbon synthesis process wherein such a catalyst is used. According to a first aspect of the invention, there is provided a cobalt-containing catalyst composition comprising cobalt and/or a cobalt compound supported on and/or in a silica (SiO.sub.2) catalyst support wherein the average pore diameter of the catalyst support is more than 20 nm but less than 50 nm; the catalyst composition also including a titanium compound on and/or in the catalyst support, and a manganese compound on and/or in the catalyst support.

The present disclosure provides methods and materials for oligomerization of lower olefins (e.g., C.sub.2-C.sub.8) to transportations fuels including diesel and/or jet fuel. The oligomerization employs, in certain embodiments, tungstated zirconium catalysts. Surprisingly, the oligomerizations proceed smoothly in high yields and exhibit little to no sensitivity to the presence of significant amounts of oxygenates (e.g., water, lower alcohols such as C.sub.2-C.sub.8 alcohols) in the feed stream. Accordingly, the present disclosure is uniquely suited to the production of fuels derived from bio-based alcohols, wherein olefins produced from such bio-based alcohols typically contain high levels of oxygenates.