Abstract: A process for producing sulfuric acid and cement clinker may use calcium sulfate that is formed as a solid by-product and separated off in phosphoric acid production in a reaction of raw phosphate with sulfuric acid to form phosphoric acid. The process comprises treating calcium sulfate separated from the phosphoric acid with an acid to obtain a suspension comprising purified calcium sulfate, separating the purified calcium sulfate in solid form from the liquid phase of the suspension, mixing the purified calcium sulfate with admixtures and reducing agents to obtain a raw meal mixture for cement clinker production, burning the raw meal mixture to obtain the cement clinker, with formation of sulfur dioxide as offgas, and subjecting the sulfur dioxide formed to offgas purification and feeding the sulfur dioxide as raw material to sulfuric acid production to produce the sulfuric acid. The sulfuric acid produced may be used as starting material in phosphoric acid production.

Abstract: A process for producing sulfuric acid and cement clinker may use calcium sulfate that is formed as a solid by-product and separated off in phosphoric acid production in a reaction of raw phosphate with sulfuric acid to form phosphoric acid. The process comprises treating calcium sulfate separated from the phosphoric acid with an acid to obtain a suspension comprising purified calcium sulfate, separating the purified calcium sulfate in solid form from the liquid phase of the suspension, mixing the purified calcium sulfate with admixtures and reducing agents to obtain a raw meal mixture for cement clinker production, burning the raw meal mixture to obtain the cement clinker, with formation of sulfur dioxide as offgas, and subjecting the sulfur dioxide formed to offgas purification and feeding the sulfur dioxide as raw material to sulfuric acid production to produce the sulfuric acid. The sulfuric acid produced may be used as starting material in phosphoric acid production.

Abstract: A process for preparing sulfuric acid may involve oxidizing sulfur to sulfur dioxide by way of dried air in a first oxidation stage. The sulfur dioxide may then be oxidized to sulfur trioxide in a second oxidation stage. The sulfur trioxide may be absorbed by sulfuric acid in at least one absorption stage. Further, heated sulfuric acid may be drawn off from the absorption stage and used for generating steam. Process gas from an intermediate absorption stage may be recycled to the second oxidation stage and, in some cases, a final absorption stage after the process gas flows through the second oxidation stage.

Abstract: A process for preparing sulfuric acid may involve oxidizing sulfur to sulfur dioxide by way of dried air in a first oxidation stage. The sulfur dioxide may then be oxidized to sulfur trioxide in a second oxidation stage. The sulfur trioxide may be absorbed by sulfuric acid in at least one absorption stage. Further, heated sulfuric acid may be drawn off from the absorption stage and used for generating steam. Process gas from an intermediate absorption stage may be recycled to the second oxidation stage and, in some cases, a final absorption stage after the process gas flows through the second oxidation stage.

Abstract: In a production mode a process for preparing sulfuric acid may involve oxidizing sulfur to sulfur dioxide in a first oxidation stage, and catalytically oxidizing the sulfur dioxide to sulfur trioxide in a second oxidation stage. The sulfur trioxide may be absorbed in at least one absorption stage. In the production mode, process gases from a last of the at least one absorption stage with respect to a flow direction are discharged. In a standby mode of the process, at least one heating stage for heating the process gases is connected. The process gases exiting from the at least one absorption stage are conveyed to the heating stage, and the process gases are circulated via the heating stage, the second oxidation stage, and the absorption stage.

Abstract: A process for preparing sulfuric acid may involve melting elemental sulfur in a melting stage to give molten sulfur. Sulfuric acid is subsequently produced from the molten sulfur. Further, sulfur-containing offgases formed in the melting stage may be subjected to oxidation in a supplementary oxidation stage in which sulfur-containing components of the offgases are oxidized to sulfur dioxide. The process may further involve processing the sulfur dioxide to give at least one reaction product. The melting stage may be operated without emissions by processing all of the offgases from the melting stage. An apparatus may be employed for carrying out such a process.

Abstract: A catalytic reactor may have at least one reactor module and a shell that extends about a reactor center axis. The reactor module may include a gas distribution chamber, a gas collection chamber, and a catalyst. The gas distribution chamber may be connected to a shell-side gas feed. The gas collection chamber may be connected to a shell-side gas discharge. A catalyst bed between the distribution and collection chambers may extend transversely to the reactor center axis. The gas distribution and collection chambers are bounded by the catalyst bed and reactor walls. The gas feed either opens into the gas distribution chamber on the shell side or is connected to a pipe length that extends towards the reactor center axis and opens into the gas distribution chamber in the region of the reactor center axis. A height parallel to the reactor center axis of the gas distribution chamber reduces towards the reactor center axis starting from a mouth of the gas feed in the case of a shell-side connection.

Abstract: A catalytic reactor may have at least one reactor module and a shell that extends about a reactor center axis. The reactor module may include a gas distribution chamber, a gas collection chamber, and a catalyst. The gas distribution chamber may be connected to a shell-side gas feed. The gas collection chamber may be connected to a shell-side gas discharge. A catalyst bed between the distribution and collection chambers may extend transversely to the reactor center axis. The gas distribution and collection chambers are bounded by the catalyst bed and reactor walls. The gas feed either opens into the gas distribution chamber on the shell side or is connected to a pipe length that extends towards the reactor center axis and opens into the gas distribution chamber in the region of the reactor center axis. A height parallel to the reactor center axis of the gas distribution chamber reduces towards the reactor center axis starting from a mouth of the gas feed in the case of a shell-side connection.

Abstract: In a production mode a process for preparing sulfuric acid may involve oxidizing sulfur to sulfur dioxide in a first oxidation stage, and catalytically oxidizing the sulfur dioxide to sulfur trioxide in a second oxidation stage. The sulfur trioxide may be absorbed in at least one absorption stage. In the production mode, process gases from a last of the at least one absorption stage with respect to a flow direction are discharged. In a standby mode of the process, at least one heating stage for heating the process gases is connected. The process gases exiting from the at least one absorption stage are conveyed to the heating stage, and the process gases are circulated via the heating stage, the second oxidation stage, and the absorption stage.

Abstract: A process for preparing sulfuric acid may involve melting elemental sulfur in a melting stage to give molten sulfur. Sulfuric acid is subsequently produced from the molten sulfur. Further, sulfur-containing offgases formed in the melting stage may be subjected to oxidation in a supplementary oxidation stage in which sulfur-containing components of the offgases are oxidized to sulfur dioxide. The process may further involve processing the sulfur dioxide to give at least one reaction product. The melting stage may be operated without emissions by processing all of the offgases from the melting stage. An apparatus may be employed for carrying out such a process.