Basf Se Corporation

Thomas Roussiere

Stephan Andreas Schunk

Andrian Milanov

Guido Wasserschaff

Gerrit Waters

Hans-Guenter Wagner

Suman Thotla

Andreas Strasser

Markus Neudert

Michael Huebner

Ekkehard Schwab

Randolf Hugo

Randolph Hugo

Gerhard Cox

Claudia Querner

Bernd Hinrichsen

Ulrich Floerchinger

Robert MÜLLER

The invention relates to a process for obtaining isobutene from an isobutene containing C4-hydrocarbon mixture () in a plant comprising an etherification unit (), a first distillation unit (), an ether cleavage unit () and a second distillation unit (), the process comprising: (a) contacting the C4-hydrocarbon mixture () with a primary alcohol () and reacting the mixture with the primary alcohol in the presence of an acidic catalyst to form the corresponding alkyl tert-butyl ether in the etherification unit (); (b) distilling the reaction mixture () from the etherification unit () in the first distillation unit (), a C4-hydrocarbon raffinate being withdrawn as the overhead product (), and the alkyl tert-butyl ether being withdrawn as the bottom product (); (c) vaporizing the bottom product from the first distillation unit () in an evaporator () obtaining a vapor stream (); (d) reacting the vapor stream () of step (c) in the presence of an acidic catalyst obtaining isobutene and the primary alcohol as reaction products in the ether cleavage unit (); (e) distilling the reaction mixture () from the ether cleavage unit () in the second distillation unit (), isobutene being withdrawn as the overhead product (), the primary alcohol and diisobutene being withdrawn as the bottom product () and being recycled to the etherification unit (); wherein a purge stream () containing high boiling components with a normal boiling point higher than that of the alkyl tert-butyl ether is withdrawn from the evaporator () in step (c).

Process for obtaining isobutene from a C4-hydrocarbon mixture

The invention relates to a process for obtaining isobutene from an isobutene containing C4-hydrocarbon mixture () in a plant comprising an etherification unit (), a first distillation unit (), an ether cleavage unit () and a second distillation unit (), the process comprising: (a) contacting the C4-hydrocarbon mixture () with a primary alcohol () and reacting the mixture with the primary alcohol in the presence of an acidic catalyst to form the corresponding alkyl tert-butyl ether as an intermediate product and diisobutene as a by-product in the etherification unit (); (b) distilling the reaction mixture () from the etherification unit () in the first distillation unit (), a C4-hydrocarbon raffinate being withdrawn as the overhead product (), the alkyl tert-butyl ether and diisobutene being withdrawn as the liquid or vaporous bottom product (), and vaporizing the bottom product () if it is withdrawn as a liquid; (c) reacting the vaporous bottom product () in the presence of an acidic catalyst obtaining isobutene and the primary alcohol as reaction products in the ether cleavage unit (); (d) distilling the reaction mixture () from the ether cleavage unit () in the second distillation unit (), isobutene being withdrawn as the overhead product (), the primary alcohol and diisobutene being withdrawn as the bottom product () and being recycled to the etherification unit (); the plant further comprising a byproduct separation unit () being fed by a bottom purge stream () of the first distillation unit () and/or by a part of the bottom product of the second distillation unit (), this feed stream () being split up in at least three byproduct streams wherein a first byproduct stream () is rich in diisobutene, a second byproduct stream () is rich in the primary alcohol, and a third byproduct stream () is rich in components with a normal boiling point higher than 110° C.

The invention relates to a process for obtaining isobutene from an isobutene containing C4-hydrocarbon mixture () in a plant comprising an etherification unit (), a first distillation unit (), an ether cleavage unit () and a second distillation unit (), the process comprising: (a) contacting the C4-hydrocarbon mixture () with a primary alcohol () and reacting the mixture with the primary alcohol in the presence of an acidic catalyst to form the corresponding alkyl tert-butyl ether as an intermediate product and diisobutene as a by-product in the etherification unit (): (b) distilling the reaction mixture () from the etherification unit () in the first distillation unit (), a C4-hydrocarbon raffinate being withdrawn as the overhead product (), the alkyl tert-butyl ether and diisobutene being withdrawn as the liquid or vaporous bottom product (), and vaporizing the bottom product () if it is withdrawn as a liquid: (c) reacting the vaporous bottom product () in the presence of an acidic catalyst obtaining isobutene and the primary alcohol as reaction products in the ether cleavage unit (): (d) distilling the reaction mixture () from the ether cleavage unit () in the second distillation unit (), isobutene being withdrawn as the overhead product (), the primary alcohol and diisobutene being withdrawn as the bottom product () and being recycled to the etherification unit (); the plant further comprising a byproduct separation unit () being fed by a bottom purge stream () of the first distillation unit () and/or by a part of the bottom product of the second distillation unit (), wherein a diisobutene product stream rich in diisobutene is separated from this feed stream ().

The invention relates to a process for starting up a plant for removing isobutene from an isobutene-containing C4-hydrocarbon mixture, the plant comprising an etherification unit containing moist acidic ion exchange resin, a first distillation unit, an ether cleavage unit, and a second distillation unit. The invention further relates to a process for shutting down the plant from a stationary operation mode.

Process for starting up and shutting down a plant for removing isobutene from a C4-hydrocarbon mixture

A hexaaluminate-containing catalyst containing a hexaaluminate-containing phase which includes cobalt and at least one further element of La, Ba or Sr. The catalyst contains 2 to 15 mol % Co, 70 to 90 mol % Al, and 2 to 25 mol % of the further element of La, Ba or Sr. In addition to the hexaaluminate-containing phase, the catalyst can include 0 to 50% by weight of an oxidic secondary phase. The process of preparing the catalyst includes contacting an aluminum oxide source with cobalt species and at least with an element from the group of La, Ba and Sr. The molded and dried material is preferably calcined at a temperature greater than or equal to 800&#xb0; C. In the reforming process for reacting hydrocarbons in the presence of CO, the catalyst is used at a process temperature of greater than 700&#xb0; C., with the process pressure being greater than 5 bar.

Hexaaluminate-comprising catalyst for the reforming of hydrocarbons and a reforming process

A hexaaluminate-containing catalyst for reforming hydrocarbons. The catalyst consists of a hexaaluminate-containing phase, which consists of cobalt and at least one further element from the group consisting of La, Ba, and Sr, and an oxidic secondary phase. To prepare the catalyst, an aluminum source is brought into contact with a cobalt-containing metal salt solution, dried, and calcined. The metal salt solution additionally contains the at least one further element. The reforming of methane and carbon dioxide is great economic interest since synthesis gas produced during this process can form a raw material for the preparation of basic chemicals. In addition, the use of carbon dioxide as a starting material is important in the chemical syntheses in order to bind carbon dioxide obtained as waste product in numerous processes by a chemical route and thereby avoid emission into the atmosphere.

The invention relates to a nickel hexaaluminate-comprising catalyst for reforming hydrocarbons, preferably methane, in the presence of carbon dioxide, which comprises hexaaluminate in a proportion in the range from 65 to 95% by weight, preferably from 70 to 90% by weight, and a crystalline, oxidic secondary phase selected from the group consisting of LaAlO, SrAlOand BaAlOin the range from 5 to 35% by weight, preferably from 10 to 30% by weight. The BET surface area of the catalyst is &#x2267;5 m/g, preferably &#x2267;10 m/g. The molar nickel content of the catalyst is &#x2266;3 mol %, preferably &#x2266;2.5 mol % and more preferably &#x2266;2 mol %. The interlayer cations are preferably Ba and/or Sr. The process for producing the catalyst comprises the steps: (i) production of a mixture of metal salts, preferably nitrate salts of Ni and also Sr and/or La, and a nanoparticulate aluminum source, (ii) molding and (iii) calcination. The catalyst of the invention is brought into contact with hydrocarbons, preferably methane, and COin a reforming process, preferably at a temperature of &#x3e;800&#xb0; C. The catalyst is also distinguished by structural and preferred properties of the nickel, namely that the nickel particles mostly have a tetragonal form and the particles have a size of &#x2266;50 nm, preferably &#x2266;40 nm and particularly preferably &#x2266;30 nm, and are present finely dispersed as grown-on hexaaluminate particles. The catalyst has only a very low tendency for carbonaceous deposits to be formed.

Nickel hexaaluminate-containing catalyst for reforming hydrocarbons in the presence of carbon dioxide

The present invention relates to a process for producing a catalyst for the reforming of hydrocarbons, preferably methane, in the presence of CO, water and/or hydrogen. The production of the catalyst is based on contacting of a hydrotalcite-comprising starting material with a fusible metal salt. The compounds which have been brought into contact with one another are intimately mixed and treated thermally, resulting in the fusible metal salt forming a melt. After molding, the material is subjected to a high-temperature calcination step. The metal salt melt comprises at least one metal selected from the group consisting of K, La, Fe, Co, Ni, Cu and Ce, preferably Ni. The metal salt melt more preferably comprises nickel nitrate hexahydrate. In addition, the invention relates to the use of the catalyst of the invention for the reforming of hydrocarbons, preferably methane, in the presence of CO, water and/or hydrogen at elevated pressures which are greater than 5 bar, preferably greater than 10 bar, particularly preferably greater than 20 bar. The catalyst according to the invention is distinguished from the prior art by particular, preferred physicochemical properties.

Process for producing a reforming catalyst and the reforming of methane

The present invention relates to a process for producing a catalyst for carrying out methanation reactions. The production of the catalyst is based on contacting of a hydrotalcite-comprising starting material with a fusible metal salt. The compounds brought into contact with one another are intimately mixed, thermally treated so that the metal salt fraction melts and subsequently subjected to a low-temperature calcination step and a high-temperature calcination step. The metal salt melt comprises at least one metal selected from the group consisting of K, La, Fe, Co, Ni, Cu and Ce, preferably Ni. The metal salt melt more preferably comprises/contains nickel nitrate hexahydrate. The hydrotalcite-comprising starting material is preferably hydrotalcite or a hydrotalcite-like compound as starting material, and the hydrotalcite-comprising starting material preferably comprises magnesium and aluminum as metal species. The catalyst of the invention is preferably used for carrying out methanation reactions at elevated pressures (from 10 to 50 bar) and elevated temperatures.

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Mannheim, Germany

Thomas Roussiere