초록 ▼

The invention relates to a method for producing unsaturated hydrocarbons. According to said method, in a first step, a hydrocarbon, especially a mixture which contains alkanes, essentially no water, and can contain water vapour, is continuously guided through a first catalyst bed provided with stand

The invention relates to a method for producing unsaturated hydrocarbons. According to said method, in a first step, a hydrocarbon, especially a mixture which contains alkanes, essentially no water, and can contain water vapour, is continuously guided through a first catalyst bed provided with standard dehydration conditions. Liquid water, water vapour and a gas containing oxygen are then added to the reaction mixture obtained in the first step and, in a second step, the reaction mixture obtained is then continuously guided through another catalyst bed for oxidising hydrogen and for further dehydrating hydrocarbons. The first catalyst bed can be heated and the heating in the first step is then preferably regulated in such a way that an essentially isothermic operating mode is created.

대표청구항 ▼

The invention claimed is: 1. A process for the production of unsaturated hydrocarbons, with the following layout: In a first step a hydrocarbon comprising paraffins, which may have a water vapor content but which is essentially free from oxygen, penetrates in a continuous stream through a first cat

The invention claimed is: 1. A process for the production of unsaturated hydrocarbons, with the following layout: In a first step a hydrocarbon comprising paraffins, which may have a water vapor content but which is essentially free from oxygen, penetrates in a continuous stream through a first catalyst bed, the latter exhibiting the standard dehydration conditions; subsequently the reaction mixture obtained in the first step is mixed with liquid phase water and water vapor as well as with an oxygen-bearing gas; and then the reaction mixture is fed in a continuous stream to a further catalyst bed as a second step in which hydrogen oxidation and further dehydration of the hydrocarbons take place. 2. The process according to claim 1, wherein the first catalyst bed is heated and the heating of the first step is preferably adjusted in such a manner that an essentially isothermal operating mode is obtained. 3. The process according to claim 1, wherein oxygen-bearing gas is added to the reaction mixture produced in the second step and the reaction mixture thus obtained flows in a continuous stream through a further catalyst bed in at least a third step. 4. The process according to claim 1, wherein the reaction mixture is cooled in a cooling unit downstream of the second step prior to entering a further catalyst bed in a third process step. 5. The process according to claim 1, wherein the catalyst bed of the first step uses any standard commercial dehydration catalyst and the second and any further catalyst bed are provided with dehydration catalysts that exhibit not only dehydration activity but also SHC activity. 6. The process according to claim 2, comprising a catalyst that contains Pt and Sn applied to a carrier element essentially containing aluminate. 7. The process according to claim 2, comprising a specialist catalyst for water oxidation, hence a catalyst that improves the selectivity compared to that of standard dehydration catalysts when it comes to hydrogen oxidation, the said specialist catalysts being employed in combination with standard dehydration catalysts. 8. The process according to claim 1, wherein the oxygen-bearing gas is oxygen-rich air. 9. The process according to claim 1, wherein the quantity of oxygen-bearing gas added in the second and further steps is controlled via the temperature measured at the outlet of the respective upstream catalyst bed or via the outlet temperature of the last catalyst bed. 10. The process according to claim 1, wherein the hydrocarbon comprises a mixture containing alkanes. 11. The process according to claim 6, wherein the aluminate comprises zinc aluminate. 12. A process for the production of unsaturated hydrocarbons, with the following layout: In a first step a hydrocarbon comprising paraffins, which may have a water vapor content but which is essentially free from oxygen, penetrates in a continuous stream through a first catalyst bed, the latter exhibiting the standard dehydration conditions; subsequently the reaction mixture obtained in the first step is mixed with liquid phase water and water vapor as well as with an oxygen-bearing gas, wherein the water and water vapor introduction decreases the reaction temperature; and then the reaction mixture is fed in a continuous stream to a further catalyst bed as a second step in which hydrogen oxidation and further dehydration of the hydrocarbons take place.