Abstract: A process for the production of biuret from urea wherein: a urea aqueous solution (24) withdrawn from the recovery section of a urea plant is processed to remove water and obtain a concentrated urea melt (25); said urea melt is processed under biuret-forming conditions to decompose urea into biuret and ammonia and obtain a high-biuret urea melt (26); said high-biuret urea melt (26) is diluted with water or with an aqueous stream obtaining a solution (28); the solution (28) is subject to crystallization and precipitation of a solid phase containing biuret which is separated from the aqueous phase.

Abstract: A multi-bed catalytic converter comprising: a plurality of catalytic beds which are traversed in series by a process gas, sequentially from a first catalytic bed to a last catalytic bed of said plurality, and at least one inter-bed heat exchanger (7) positioned between a first catalytic bed and a second catalytic bed of said plurality, wherein at least the last catalytic bed of said plurality is adiabatic and is made of fine catalyst with a particle size not greater than 2 mm.

Abstract: A process for producing nitric acid comprising: catalytic oxidation of ammonia in the presence of oxygen to form a nitrous gas containing NO, O2, N2O and water vapor; a catalytic abatement of N2O which is performed over a first catalyst; a catalytic conversion of NO into NO2 which is performed over a second catalyst; the so obtained nitrous gas is then subject to absorption in water to produce nitric acid.

Abstract: A process of reducing the content of nitrogen oxides in a gas, comprising passing the gas over a catalyst suitable for selective catalytic reduction of nitrogen oxides and in the presence of a reducing agent, wherein the catalyst is a FER-zeolite obtainable with a process which does not include a step of iron loading and does not include a step of loading with any transition metal so that said FER-zeolite does not contain ion-exchanged iron and is not loaded with iron or any transition metal.

Abstract: Reactor for catalytic chemical reactions comprising a catalyst bed with an annular-cylindrical form crossed by a radial flow or mixed axial-radial flow, wherein the bed is delimited by cylindrical walls made gas-permeable by means of slits and the catalyst bed is formed by particles of catalyst with a nominal minimum size such that: the ratio between a transverse dimension of the slits and the nominal minimum size of the particles of catalyst is smaller than or equal to 0.6; the catalyst bed contains no more than 3% by weight of particles with an actual size smaller than said nominal size.

Abstract: Integrated process for the synthesis of ammonia and nitric acid, comprising a synthesis of nitric acid including the following steps: a) subjecting a stream of ammonia (10) to catalytic oxidation, obtaining a gaseous stream containing nitrogen oxides (13); b) subjecting said gaseous stream to a process of absorption of nitrogen oxides, providing nitric acid (16) and a tail gas (17) containing nitrogen and residual nitrogen oxides; c) subjecting at least a portion of said first tail gas (17) to a process of removal of nitrogen oxides, providing a nitrogen oxides-depleted tail gas (18), and comprising a synthesis of ammonia by catalytic conversion of a make-up gas (126, 226) comprising hydrogen and nitrogen in an ammonia synthesis loop, wherein at least a portion (18b, 18d, 21) of said second tail gas is used as nitrogen source for obtaining said make-up gas (126, 226).

Abstract: A multi-bed catalytic converter comprising: a plurality of catalytic beds which are traversed in series by a process gas, sequentially from a first catalytic bed to a last catalytic bed of said plurality, and at least one inter-bed heat exchanger (7) positioned between a first catalytic bed and a second catalytic bed of said plurality, wherein at least the last catalytic bed of said plurality is adiabatic and is made of fine catalyst with a particle size not greater than 2 mm.

Abstract: Integrated process for the synthesis of ammonia and nitric acid, comprising a synthesis of nitric acid including the following steps: a) subjecting a stream of ammonia (10) to catalytic oxidation, obtaining a gaseous stream containing nitrogen oxides (13); b) subjecting said gaseous stream to a process of absorption of nitrogen oxides, providing nitric acid (16) and a tail gas (17) containing nitrogen and residual nitrogen oxides; c) subjecting at least a portion of said first tail gas (17) to a process of removal of nitrogen oxides, providing a nitrogen oxides-depleted tail gas (18), and comprising a synthesis of ammonia by catalytic conversion of a make-up gas (126, 226) comprising hydrogen and nitrogen in an ammonia synthesis loop, wherein at least a portion (18b, 18d, 21) of said second tail gas is used as nitrogen source for obtaining said make-up gas (126, 226).