Abstract: Methods for producing pozzolanic or latent hydraulic cement clinker substitutes may involve calcining clay with a fuel comprising a mineral substance at temperatures in the range from 500 to 1250° C., preferably from 550 to 1150° C., most preferably from 700 to 900° C. A resulting mixture of mineral substance from the fuel and the calcined clay forms a pozzolanic or latent hydraulic cement clinker substitute, in which a fraction of the mineral substance incorporated into the pozzolanic or latent hydraulic cement clinker substitute by the fuel is 1-60% by weight.

Abstract: A process for preparing nitric acid may involve vaporizing ammonia in at least one first ammonia vaporizer to produce an ammonia gas, oxidizing this ammonia gas to nitrogen dioxide in a plant section of a nitric acid plant, and absorbing the nitrogen dioxide in water to produce nitric acid. A residual gas containing nitrous gases may be taken off from the plant section of the nitric acid plant and conveyed to a residual-gas cleaning apparatus. The residual gas containing nitrous gases may be reduced by means of ammonia in the residual-gas cleaning apparatus, wherein ammonia-containing wastewater obtained in the at least one first ammonia vaporizer may be conveyed to the residual-gas cleaning apparatus. Such a process may eliminate or at least substantially reduce ammonia-containing wastewater. Furthermore, a plant can be used in this process for preparing nitric acid.

Abstract: A process and a plant for decreasing the concentration of NOx nitrogen oxides in the residual gas in the preparation of nitric acid, where the temperature of the residual gas is regulated by means of a temperature regulating apparatus during shutdown and/or start-up of the plant, with the residual gas being conveyed in a circuit and here flowing through the temperature regulating apparatus and the residual gas purification plant so that colorless shutdown and/or start-up of the plant is made possible.

Abstract: A method and device for producing ammonia from a syngas in a heterogeneous gas catalysis process in at least two reaction devices connected in series. Each reaction device includes at least two catalyst beds through which the syngas is conducted and in which an at least partial conversion of the syngas into the product gas is carried out. At least one first heat exchanger is provided in the first reaction device, and the fresh syngas is pre-heated in the first heat exchanger. The syngas exiting the first catalyst bed and which includes the product and non-converted reactants is cooled before entering the second catalyst bed. According to an embodiment of the invention, the pre-heating process is carried out in a first heat exchanger arranged between the first and the second catalyst bed. Thus, synthesis conversion can be increased without substantially increasing the process gas quantity.

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: The invention relates to a process for utilizing a hydrocarbon-comprising and/or carbon dioxide-comprising coproduct gas, accompanying gas and/or biogas, wherein hydrocarbon-comprising and/or carbon dioxide-comprising coproduct gas, accompanying gas and/or biogas is introduced into a reaction space and the multicomponent mixture comprised in the coproduct gas, accompanying gas and/or biogas is converted in a high-temperature zone at temperatures of more than 1000° C. and in the presence of a carrier into a product gas mixture which comprises more than 95% by volume of CO, CO2, H2, H2O, CH4 and N2 and optionally into a carbon-comprising solid which is deposited to an extent of at least 75% by weight, based on the total mass of the carbon-comprising solid, on the carrier where the flow velocity of the gas mixture of coproduct gas, accompanying gas and/or biogas in the reaction zone is less than 20 m/s.

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: Propene is continuously reacted with hydrogen peroxide in a tube bundle reactor comprising a multitude of parallel reaction tubes in the presence of a titanium silicalite catalyst arranged as a fixed bed in the reaction tubes. A cooling jacket encloses the reaction tubes, which has a feed point for cooling medium near the entry of the reaction tubes, a withdrawal point for cooling medium near the end of the reaction tubes and at least one additional withdrawal point upstream of the withdrawal point near the end of the reaction tubes. Cooling medium is fed to the feed point for cooling medium, a part of the cooling medium is withdrawn at the at least one additional withdrawal point and the remainder exits at the withdrawal point near the end of the reaction tubes.

Abstract: In a process for the epoxidation of an olefin with hydrogen peroxide in the presence of a solvent, where a mixture comprising olefin, an aqueous hydrogen peroxide solution and a solvent is continuously passed through a fixed bed of an epoxidation catalyst comprising a titanium zeolite, addition of a chelating agent to the aqueous hydrogen peroxide solution before mixing it with solvent reduces or prevents formation of deposits on the catalyst and blocking of orifices of a liquid distributor.

Abstract: A wear-resistant element for partial insertion into a recess on the surface of a wear area of a comminuting device. The wear-resistant element includes particles made of a highly wear-resistant material which are embedded in a matrix material.

Abstract: The invention relates to a comminuting machine such as a crusher, a mill, or the like, wherein the material to be comminuted is guided through a gap which is formed between at least one wear layer attached to a component of the comminuting machine and a counter surface and the extension of which varies as the wear of the at least one wear layer progresses. The invention is characterized in that in order to determine the wear occurring on the wear layer and/or in order to determine the effective extension of the gap between the wear layer and the counter surface, a radar antenna is provided which is oriented towards the corresponding counter surface. The radar antenna comprises an antenna region and a wear part which is paired at least with the wear layer region provided for a permissible wear and which shortens as the wear layer wears down.

Abstract: An apparatus and a process for reducing the concentration of NOx nitrogen oxides in residual gas may be employed during shutdown and/or startup of apparatuses for preparing nitric acid. An example apparatus for reducing NOx nitrogen oxides may include a reactor that produces NOx nitrogen oxides, an absorption apparatus that absorbs at least part of the NOx nitrogen oxides produced in an aqueous composition, a residual gas purification plant that decomposes and/or reduces unabsorbed NOx nitrogen oxides, feed means for feeding the NOx nitrogen oxides to the absorption apparatus, discharge means for discharging the unabsorbed NOx nitrogen oxides from the absorption apparatus to the residual gas purification plant, and a bypass that transfers a gas mixture from the reactor to the residual gas purification plant while bypassing the absorption apparatus during startup and/or shutdown of the apparatus for preparing nitric acid.

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 classifier for classifying granular feedstock has a rotary cage rotating about a rotor axis and an air-guiding system arranged around the rotary cage, wherein a classifying zone is formed between the rotary cage and the air-guiding system. In the classifying zone one or more baffles are arranged such that the torque acting on the rotary cage is increased—for the same rotational speed—by at least 20% with respect to an embodiment without baffles and/or the separation between the air-guiding system and the rotary cage is chosen such that the torque acting on the rotary cage is increased—for the same rotational speed—by at least 20% with respect to an embodiment wherein the separation of the air-guiding system is without influence on the torque of the rotary cage.

Abstract: A screen bar for a bar screen may comprise a steel composite sheet having at least three steel layers: a top layer, a core layer, and a bottom layer. The top, core, and bottom steel layers may be interconnected by roll cladding in a non-releasable manner. In some examples, the core steel layer may have a higher deformability than the top steel layer and the bottom steel layer. Likewise, the top steel layer and the bottom steel layer may have higher hardnesses than the core steel layer. Such screen bars have extended service life and can be manufactured more cost effectively, amongst other benefits. Methods for manufacturing such screen bars may involve a variety of steps including hot rolling and/or heat-treating.

Abstract: The invention relates to a process for purifying synthesis gas, comprising at least one stage for separating the crude synthesis gas to be treated into at least two effluents, namely a first part and a complementary part, in which the said first part is subjected to a carbon monoxide conversion stage with steam and the said complementary part is subjected to a COS and HCN catalytic hydrolysis stage, the two gas flows, namely the first part and complementary part, are then each treated separately in two stages intended to remove acid gases such as CO2 and H2S, by washing with aqueous solutions of specific amines, before a recombination stage of the two treated effluents.

Abstract: A method for decreasing an amount of a harmful substance of a chlorine-containing off-gas stream formed or used in a thermal treatment of a material may comprise dividing the chlorine-containing off-gas stream into a main stream and a substream, separating at least some chlorine from the main stream, lowering an amount of the harmful substance in the main stream by introducing a chlorine-containing additive into the main stream to enhance separation of the harmful substance, and filtering the substream such that a filter cake separated from the substream comprises at least part of the chlorine-containing additive.

Abstract: A separator may include a housing with a separation space in which a ventilation base is disposed and in which separation stock is perfusable by separation gas so as to separate fine stock from coarse stock. A separation-gas inlet and a separation-stock inlet may open into the separation space, and a fine-stock outlet and a coarse-stock outlet may lead out of the separation space. A bypass duct may be integrated in the housing for bypassing the separation space. The bypass duct may lead out of the separation-gas inlet and open out downstream of the separation space.

Abstract: In a process for the epoxidation of an olefin, where a mixture comprising olefin, hydrogen peroxide, water and methanol with a weight ratio of water to methanol of less than 1 is passed through a catalyst fixed bed comprising a shaped titanium silicalite catalyst, catalyst breakage is reduced by conditioning the dry catalyst with at least one conditioning liquid comprising water and from 25 to 45% by weight methanol.

Abstract: A plant and a process may be utilized to isolate a carboxylic acid from a fermentation broth. The process may involve separating a biomass from the fermentation broth containing a salt of the carboxylic acid to produce a low-biomass solution. The separation of the biomass may be performed in a first step by centrifugation, separation, precoat filtration, or microfiltration, and in a second step by ultrafiltration. The process may further involve concentrating the salt of the carboxylic acid in the low-biomass solution. The concentrated solution may then be acidified. Further, precipitation of the carboxylic acid may be obtained by acidification.