A fluidized bed granulator for granulation with urea or urea-containing liquids is described, wherein the granulation liquid is supplied via a supply manifold comprising a header and risers. The risers are at least in part provided inside channels for secondary gas.

Disclosed is a method for the removal of urea dust from the off-gas of a finishing section of a urea production plant. the method comprises subjecting the off-gas to quenching with water so as to produce quenched off-gas. The quenched off-gas is subjected to humidification by mixing said quenched gas stream with a humidification fluid selected from (a) saturated steam and (b) superheated steam mixed with a second aqueous stream, so as to produce a humidified gas stream, subjecting said humidified gas stream to particle separation (i.e., dust removal) by means of a scrubbing liquid in which at least part of the particles in the gas stream are soluble.

Disclosed is a method for the removal of urea dust from the off-gas of a finishing section of a urea production plant. the method comprises subjecting the off-gas to quenching with water so as to produce quenched off-gas. The quenched off-gas is subjected to humidification by mixing said quenched gas stream with a humidification fluid selected from (a) saturated steam and (b) superheated steam mixed with a second aqueous stream, so as to produce a humidified gas stream, subjecting said humidified gas stream to particle separation (i.e., dust removal) by means of a scrubbing liquid in which at least part of the particles in the gas stream are soluble.

A production system for a product selected from a nitrogen-containing product and a fermented and cultured product that does not involve (or can minimize) the transport of liquid ammonia can include: an ammonia synthesis apparatus in which an ammonia-containing gas is synthesized by reaction of a source gas containing hydrogen and nitrogen in the presence of a supported metal catalyst containing as a support one or more selected from the group consisting of: i) a conductive mayenite compound; ii) a two-dimensional electride compound or a precursor thereof; and iii) a complex formed of a support base containing at least one metal oxide selected from ZrO.sub.2, TiO.sub.2, CeO.sub.2, and MgO and a metal amide represented by a formula M(NH.sub.2).sub.x (where M represents one or more selected from Li, Na, K, Be, Mg, Ca, Sr, Ba, and Eu; and x represents a valence number of M) supported by the support base.

A production system for a product selected from a nitrogen-containing product and a fermented and cultured product that does not involve (or can minimize) the transport of liquid ammonia can include: an ammonia synthesis apparatus in which an ammonia-containing gas is synthesized by reaction of a source gas containing hydrogen and nitrogen in the presence of a supported metal catalyst containing as a support one or more selected from the group consisting of: i) a conductive mayenite compound; ii) a two-dimensional electride compound or a precursor thereof; and iii) a complex formed of a support base containing at least one metal oxide selected from ZrO.sub.2, TiO.sub.2, CeO.sub.2, and MgO and a metal amide represented by a formula M(NH.sub.2).sub.x (where M represents one or more selected from Li, Na, K, Be, Mg, Ca, Sr, Ba, and Eu; and x represents a valence number of M) supported by the support base.

A duplex stainless steel for use in a urea production plant and/or in a urea production process, containing in weight percentage (% w): C 0.03 or less; Si 0.5 or less; Mn 2.5 or less; Cr from more than 30.0 to 35.0; Ni from 5.5 to 8.0; Co from 0.01 to 0.8; Mo from 2.0 to 2.5; W 2.5 or less; N from 0.3 to 0.6; Cu 1.0 or less; and having one or more of: Ca 0.0040 or less; Mg 0.0040 or less; one or more rare-earth elements in a total amount of 0.1 or less; the balance being Fe and impurities; and satisfying the relationship: Z=1.062 (Ni+Co)+4.185 Mo is between 14.95 and 19.80.

A duplex stainless steel for use in a urea production plant and/or in a urea production process, containing in weight percentage (% w): C 0.03 or less; Si 0.5 or less; Mn 2.5 or less; Cr from more than 30.0 to 35.0; Ni from 5.5 to 8.0; Co from 0.01 to 0.8; Mo from 2.0 to 2.5; W 2.5 or less; N from 0.3 to 0.6; Cu 1.0 or less; and having one or more of: Ca 0.0040 or less; Mg 0.0040 or less; one or more rare-earth elements in a total amount of 0.1 or less; the balance being Fe and impurities; and satisfying the relationship: Z=1.062 (Ni+Co)+4.185 Mo is between 14.95 and 19.80.

A process of prilling of a urea melt comprising the use of calcium lignosulfonate or carboxymethyl starch as additive to obtain a formaldehyde-free urea product.

A process of prilling of a urea melt comprising the use of calcium lignosulfonate or carboxymethyl starch as additive to obtain a formaldehyde-free urea product.

A fluidized bed granulator for granulation with urea or urea-containing liquids is described, wherein the granulation liquid is supplied via a supply manifold comprising a header and risers. The risers are at least in part provided inside channels for secondary gas.