Abstract: The invention relates to a method and an apparatus for comminuting grinding stock with a roller mill, wherein a grinding plate cooperates with at least two grinding rollers and the grinding stock supplied in the mass flow is comminuted between grinding plate and grinding roller. At least two grinding rollers are driven via dedicated drives, wherein a power compensation control is carried out for the drives of the grinding rollers, such that the power of the drives is controlled in a predefined ratio to one another. The power control is then effected by changing the mass flow of the grinding stock supplied to at least one of the grinding rollers.

Abstract: A process for preparing ammonia or ammonia and urea in a facility may involve compressing a crude synthesis gas stream that includes hydrogen, nitrogen, and carbon dioxide, washing a substream of the crude synthesis gas with ammonia to form a purified synthesis gas stream depleted of carbon dioxide and a condensate, synthesizing ammonia from the purified synthesis gas stream, and synthesizing urea from the condensate to form an aqueous urea composition. In the preparation of ammonia and urea, the crude synthesis gas stream may be, after being compressed, divided into a first synthesis gas substream and a second synthesis gas substream. In some instances, only the first synthesis gas substream is scrubbed with liquid ammonia.

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: In a process for the epoxidation of an olefin by continuously reacting the olefin with hydrogen peroxide in a methanol solvent on a fixed bed epoxidation catalyst comprising a titanium zeolite, the hydrogen peroxide is used as an aqueous hydrogen peroxide solution made by an anthraquinone process, the aqueous hydrogen peroxide solution is mixed with methanol to give a feed mixture and this feed mixture is filtered before being contacted with the fixed bed epoxidation catalyst.

Abstract: A conveyor system for conveying material may include a conveyor belt, a feeding mechanism for feeding materials to be conveyed onto the conveyor belt, and a belt system in which the conveyor belt is guided. The belt system may include a first belt-shaping device with which the conveyor belt can be shaped into a U shape. Thus the material to be conveyed may be brought from a substantially flat shape into the U shape. A second belt-shaping device of the belt system may shape the conveyor belt downstream of the feeding mechanism in the conveying direction to form a closed tube. The feeding mechanism may include a catching region configured such that material to be conveyed accumulates therein and forms an impact surface onto which the material to be conveyed can be fed.

Abstract: In a process for the epoxidation of propene, comprising the steps of reacting propene with hydrogen peroxide, separating propene oxide and a recovered propene stream from the reaction mixture, separating propane from all or a part of the recovered propene stream in a C3 splitter column, and passing the overhead product stream of the C3 splitter column to the epoxidation step, a propane starting material with a propane fraction of from 0.002 to 0.10 is used, the epoxidation is operated to provide a propane fraction in the reaction mixture of from 0.05 to 0.20 and the C3 splitter column is operated to provide an overhead product stream which comprises a propane fraction of at least 0.04 in order to reduce the size and the energy consumption of the C3 splitter column.

Abstract: A system suitable for oxidizing ammonia with oxygen in the presence of catalysts is described. The system includes a reactor equipped with at least one supply line for a reactant gas mixture and at least one discharge line for a process gas; a catalyst comprising at least one transition metal oxide that is not an oxide of a platinum metal; and a device for adjusting a molar ratio of oxygen to ammonia of less than or equal to 1.75 mol/mol in the reactant gas mixture by mixing an oxygen-containing gas stream having an O2 content of <20% by volume with a chosen amount of ammonia. The oxygen-containing gas stream is produced by a device for: diluting an air stream with a gas stream comprising less than 20% by volume oxygen; or depleting oxygen from an oxygen-containing gas mixture, preferably from air; or by a combination thereof.

Abstract: The integrated process comprises a step a) of dehydrogenating propane providing a stream S1 comprising propane and propene; a step b) of separating stream S1 in at least one rectification column, providing an overhead product stream S2 comprising more than 99% by weight propene, a side stream S3 comprising from 90 to 98% by weight propene and a bottoms product stream S4 enriched in propane; a step c) of reacting propene with hydrogen peroxide in the presence of an epoxidation catalyst using propene in molar excess; and a step d) of separating non-reacted propene and propene oxide from the reaction mixture of step c) providing a propene oxide product and a stream S5 comprising propene and propane; wherein stream S3 is passed to step c), stream S5 is recycled to step b) and stream S4 is recycled to step a).

Abstract: During start-up of a continuous epoxidation of propene with hydrogen peroxide in a methanol solvent with a shaped titanium silicalite catalyst in a tube bundle reactor with a cooling jacket, cooling medium is fed at the rate for full load of the reactor with a constant entry temperature of from 20° C. to 50° C., methanol solvent is fed at a rate of from 50 to 100% for full load of the reactor, hydrogen peroxide is fed at a rate that starts with no more than 10% of the rate for full load and is increased continuously or stepwise to maintain a maximum temperature in the fixed bed of no more than 60° C. and a difference between the maximum temperature in the fixed bed and the cooling medium entry temperature of no more than 20° C., and propene is fed at a rate of from 20 to 100% of the rate for full load, increasing the feeding rate when the molar ratio of propene to hydrogen peroxide reaches the molar ratio for full load.

Abstract: A method for determining a charge state of a vanadium redox flow cell may comprise indirectly determining concentrations of V4+ and V5+ in a positive electrolyte by mixing positive and negative electrolytes with one another in particular proportions to reduce V5+ present in the positive electrolyte. In this way, CT complexes of V4+/V5+ may be avoided, the concentration of which is not determinable directly owing to the strong UV/vis absorption. Furthermore, the method enables determination of the concentrations of the negative electrolyte and positive electrolyte via UV/vis absorptions, which enables simple monitoring of the charge state of a vanadium redox flow battery.

Abstract: A coke oven may comprise an upper oven and a lower oven beneath the upper oven. Crude gas produced in a coking chamber of the upper oven during a coking process is incompletely combusted in the upper oven and may subsequently be conducted into the lower oven via downwardly directed downcomer channels. The crude gas may flow through an outer sole flue, may be deflected in a transition region, may flow through an inner sole flue, and may exit the lower oven via an exhaust gas collecting channel. The outer and inner sole flues may be supplied with secondary air such that the gas initially partially combusted in the upper oven by means of primary combustion is completely combusted in the lower oven by means of secondary combustion. The transition region in which the gas is deflected in the lower oven may be divided into a plurality of flow channels.

Abstract: An ammonium-sulphate-containing fertiliser granulate including at least one metal salt as a granulation additive, which is a trace element and/or a granulation aid, and a sulphate of a metal selected from the group including Cu, Co, and Mo. A method is disclosed for the production of a fertiliser granulate in which the fertiliser granulate is produced by granulation in a fluidised-bed granulator, in which an aqueous composition containing at least the ammonium sulphate and at least one granulation additive is sprayed onto a fluidised bed of fluidised ammonium-sulphate-containing nuclei. Moreover, the granulation aid can contain at least one metal sulphate selected from the group comprising zinc sulphate, magnesium sulphate, manganese sulphate, iron sulphate or aluminium sulphate.

Abstract: A method for the thermal treatment of dispersible raw material may involve introducing raw material into a riser tube that is perfused by hot gases and thermally treating the raw material with the hot gases. Furthermore, the method may involve feeding a fuel to the riser tube. The fuel may initially dwell in a fuel-conditioning region on a bearing face, where the fuel comes into contact with a part of the hot gas that is mixed with the raw material. Consequently, the fuel is dried and/or at least partially de-gassed and/or at least partially reacted and subsequently transferred into the riser tube.

Abstract: Processes for separating carbon dioxide from CO2-containing gases and an apparatus for providing carbon dioxide for the synthesis of urea.

Abstract: An apparatus for producing and analyzing sample materials may comprise a milling device for milling material components, a first metering device for metering a material component into the milling device, a second metering device for metering an activator liquid into the milled material component, a homogenization device for homogenizing the material components and the activator liquid to produce a sample material, a control device that is connected to the milling device and is configured to vary a parameter characteristic for milling intensity of the milling device so that particle size of the material components is altered, and a measuring device for determining a reactivity of the sample material. The present disclosure further concerns a process for producing and analyzing a plurality of sample materials. The process may involve varying at least one parameter characteristic for milling intensity for each sample material produced.

Abstract: The invention relates to a gyratory crusher for comminuting material to be crushed, comprising a crusher housing, in which a crusher shaft is arranged, said shaft being held in the crusher housing so that it can tumble about a vertical axis. To accommodate the crusher shaft, the crusher is provided with a cross member which extends diametrically across the crusher housing and the cross member ends of which are connected to the crusher housing. According to the invention, the connection of the cross member ends to the crusher housing has at least one hydraulic tensioning device.

Abstract: A synthesis device may include a pressure vessel with an inlet and an outlet for fluid, a catalyst bed that is disposed within the pressure vessel, a plate heat exchanger that is disposed in a flow path of fluid between the inlet of the pressure vessel and the catalyst bed such that fluid flowing into the catalyst bed is heated by fluid flowing out of the catalyst bed. The plate heat exchanger may be disposed outside a reactor volume occupied by the catalyst bed in the pressure vessel. The catalyst bed may be one of a plurality of catalyst beds disposed axially over one another in the pressure vessel.

Abstract: A process for preparing methanol by a methanol synthesis reaction of carbon dioxide with hydrogen may involve a distillation step and a condensation step following the synthesis of a crude methanol. A volatile component and water may be separated off from a methanol-containing product stream, and a gas stream containing a volatile component that has been separated off may be discharged at least partially as offgas. At least part of the gas stream that has been separated off may be recirculated into the methanol synthesis reaction. A plant for preparing methanol can store or utilize electric power generated from renewable energy sources and provide facilities for discharging the offgas stream, which can be purified by catalytic after-combustion. Alternatively, the plant can be configured without discharge of an offgas substream, or the offgas streams are so small that they can be released without treatment into the environment at a suitable position.

Abstract: A burner basket for an ammonia oxidation burner includes a gas-permeable bottom plate, with a side wall that is spaced apart from the bottom plate by a gap, and a retaining device covering the bottom plate and the gap for retaining particles of a bulk material that can be arranged in the burner basket. A fastening element is arranged on the bottom plate, by which the retaining device is fixed in place. An ammonia oxidation burner comprises a burner for oxidizing ammonia and a burner basket.

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.