Abstract: The present invention relates to a process for the production of melamine and the production plant including an off-gas condensation step carried out at a pressure of 70 to 220 bar by feeding gaseous and liquid streams at the same pressure, converting the liquid stream from the off-gas condensation step to a first stream, followed in succession by a high pressure decomposition step, a medium pressure decomposition step, a low pressure decomposition step, and urea concentration step.

Abstract: A method for revamping existing plants as well as a plant for the production of melamine with zero environmental impact and the relative process.

Abstract: A heating group for melamine production plants and a melamine production plant using the heating group. The heating group for melamine plants comprises a molten salt circuit for supplying the reaction heat to the plant and a superheated ammonia supply unit comprising at least an evaporation exchanger and a superheating exchanger, the superheating exchanger comprising at least one separate heat source with respect to the molten salt circuit, the separate heat source being superheated steam. The superheating exchanger is a jacketed tube of two concentric tubes wherein the inner tube is suitable for a flow of ammonia to be superheated and the sealed outer tube or jacket is suitable for a flow of superheated steam, the inner tube having an internal diameter which ranges from 20 mm to 85 mm, corresponding to a length of the jacketed tube ranging from 30 to 20 m.

Abstract: The present invention relates to an apparatus for the production of melamine from urea at high pressure and the relative process.

Abstract: A process for converting an anhydrous off-gas stream from melamine synthesis plants to urea and the relative plant for the direct conversion of an anhydrous off-gas stream from melamine synthesis plants into urea, are described.

Abstract: A centrifugal pump (100) for processing molten urea having: an inlet (102) adapted to receive molten urea at a suction pressure; a delivery outlet (104) adapted to allow an output of molten urea at a delivery pressure greater than the suction pressure; and an intermediate outlet (103) adapted to allow an output of molten urea at an intermediate pressure greater than the suction pressure and lower than the delivery pressure.

Abstract: A fuel emulsion has a liquid hydrocarbon fuel, water, at least one emulsifier and at least one oxygen-containing water soluble organic compound. In the fuel emulsion, water is present in an amount not greater than 15% by weight, and the emulsifier is selected from a product obtained by reacting (a1) a polyolefin oligomer functionalized with at least one group deriving from a dicarboxylic acid, or a derivative thereof, with (a2) a polyoxyalkylene comprising linear oxyalkylene units. In the fuel emulsion, the oxygen-containing water soluble organic compound is present in a predetermined amount so as to obtain an amount of water soluble organic oxygen of from 0.1 to 5% by weight. A considerable reduction of particulate emissions is obtained by using this fuel emulsion while maintaining or even further reducing the NOx level which is already reduced by the engine itself.

Abstract: Method for reducing emission of pollutants from an internal combustion engine including at least one combustion chamber. A fuel emulsion is injected into a combustion chamber; the fuel emulsion is ignited in the combustion chamber in the presence of air; and the internal combustion engine is operated so as to reduce peak combustion temperature in the combustion chamber. The fuel emulsion has a liquid hydrocarbon fuel, water, at least one emulsifier and at least one oxygen-containing water soluble organic compound. A considerable reduction of particulate emissions is obtained by using this fuel emulsion while maintaining or even further reducing the NOx level which is already reduced by the engine itself.

Abstract: The present invention relates to a tank for the containment of a liquid, preferably a molten salt, said tank being associable to an aspiration pump of said liquid, wherein said tank comprises a bottom from which a lateral wall raises and wherein said aspiration pump requires a minimum level of liquid in said tank for operating, characterized in that it comprises at least an element occupying a volume and placeable inside said tank with at least a portion of said volume arranged at a height, with respect to said bottom, which is lower than said minimum level. The improved tanks of the present invention are suitable as storage tanks for liquids at elevated temperature such as molten salts to be used in heat storage systems in connection with solar power plants.

Abstract: A low-energy-consumption process is described for the production of high-purity melamine, through the pyrolysis of urea, by the collection and purification of the melamine in aqueous solution produced in the pyrolysis reactor, and its separation by crystallization. The present invention also relates to the equipment for effecting the above process.

Abstract: The present invention relates to a tank for the containment of a liquid, preferably a molten salt, said tank being associable to an aspiration pump of said liquid, wherein said tank comprises a bottom from which a lateral wall raises and wherein said aspiration pump requires a minimum level of liquid in said tank for operating, characterized in that it comprises at least an element occupying a volume and placeable inside said tank with at least a portion of said volume arranged at a height, with respect to said bottom, which is lower than said minimum level. The improved tanks of the present invention are suitable as storage tanks for liquids at elevated temperature such as molten salts to be used in heat storage systems in connection with solar power plants.

Abstract: Fuel for motor vehicles comprising an emulsion between water and a liquid hydrocarbon, and an anti-cavitation additive comprising a copolymer including 20-80% in moles, preferably 35-70% in moles, of units containing at least one carboxylic group and 80-20% in moles, preferably 65-30% in moles, of units deriving from at least one monomer having an ethylene unsaturation, and wherein at least 20% in moles of the carboxylic groups, preferably 30-90% in moles, is in the form of at least one derivative selected from carboxylate salt, ester, amide and imide.

Abstract: Fuel made from an emulsion between water and a liquid hydrocarbon and polymeric surfactant, used to stabilize the emulsion, obtainable by (a) reacting (i) at least one polyolefin oligomer functionalized with at least one group deriving from a dicarboxylic acid, or a derivative thereof; and (ii) at least one polyoxylalkylene having linear oxyalkylene units, the polyoxyalkylene being linked to a long-chain alkyl group optionally containing at least one ethylenic unsaturation; and (b) reacting the product of step (a) with (ii) at least one nitrogen compound selected from monoamines, polyamines and quaternary ammonium hydroxides. The fuel has high stability over time, without forming carbonaceous deposits adhering to metal surfaces.

Abstract: Method for reducing emission of pollutants from an internal combustion engine including at least one combustion chamber. A fuel emulsion is injected into a combustion chamber; the fuel emulsion is ignited in the combustion chamber in the presence of air; and the internal combustion engine is operated so as to reduce peak combustion temperature in the combustion chamber. The fuel emulsion has a liquid hydrocarbon fuel, water, at least one emulsifier and at least one oxygen-containing water soluble organic compound. A considerable reduction of particulate emissions is obtained by using this fuel emulsion while maintaining or even further reducing the NOx level which is already reduced by the engine itself.

Abstract: Fuel made from an emulsion between water and a liquid hydrocarbon and polymeric surfactant, used to stabilize the emulsion, obtainable by (a) reacting (i) at least one polyolefin oligomer functionalized with at least one group deriving from a dicarboxylic acid, or a derivative thereof; and (ii) at least one polyoxylalkylene having linear oxyalkylene units, the polyoxyalkylene being linked to a long-chain alkyl group optionally containing at least one ethylenic unsaturation; and (b) reacting the product of step (a) with (ii) at least one nitrogen compound selected from monoamines, polyamines and quaternary ammonium hydroxides. The fuel has high stability over time, without forming carbonaceous deposits adhering to metal surfaces.

Abstract: A static mixer (1)to emulsify water and/or other additives in gas oil comprises a hollow structure (2) within which two mixing units (23,27) are disposed, each comprising a first and a second mixing bodies (24, 25, 28, 29) each carrying a frusto-conical boundary surface (24a, 25a, 28a, 29a). The boundary surfaces (24a, 25a, 28a, 29a) are disposed mutually opposite in parallel and facing each other so as to define a narrow mixing gap (26, 30) of truncated conical form at which the mixture runs in a condition of substantially laminar flow and is submitted to shear forces causing emulsification. Also proposed is a process for producing a dispersion, which process can be carried out by said mixer (1).