The present invention relates to a method for the production of an urea ammonium sulphate (UAS) composition, wherein said UAS composition comprises 1 to 40 weight % of ammonium sulphate (AS) relative to the total weight of the UAS composition, from sulphuric acid, ammonia and/or ammonium carbamate, and urea, in a pipe reactor comprising at least a reactor section wherein feeds of sulphuric acid and/or ammonium bisulphate, ammonia and/or ammonium carbamate, and urea are combined to obtain said urea ammonium sulphate (UAS) composition, comprising the step of including a viscosity-reducing agent, selected from the group of water soluble aluminium salts, into one or more of said feeds. Preferably, said agent is an aluminium sulphate (AluS). The present invention also relates to a pipe reactor for the production of a urea ammonium sulphate (UAS) composition from sulphuric acid, ammonia and/or ammonium carbamate, and urea, the pipe reactor comprising at least a reactor section wherein continuous feeds of sulphuric acid and/or ammonium bisulphate, ammonia and/or ammonium carbamate and urea are combined to obtain said urea ammonium sulphate (UAS) composition, wherein the pipe reactor further comprises means for supplying an aqueous solution of a viscosity-reducing agent to the urea solution upstream of said pipe reactor section, which agent reduces the viscosity of said UAS solution or slurry. The present invention also relates to the use of aluminium sulphate as viscosity-reducing agent in in a method for the production of urea ammonium sulphate (UAS) composition, wherein said UAS composition comprises 1 to 40 weight % of ammonium sulphate (AS) relative to the total weight of the UAS composition, from sulphuric acid, ammonia and/or ammonium carbamate, and urea, in a pipe reactor comprising at least a reactor section wherein continuous feeds of sulphuric acid and/or ammonium bisulphate, ammonia and/or ammonium carbamate and urea are combined to obtain said urea ammonium sulphate (UAS) composition.

[Problem to be solved] To provide a urea manufacturing method capable of inhibiting corrosion of a urea plant and enhancing a reaction yield.

[Solution] In a urea manufacturing plant, a method for manufacturing urea from manufacturing raw materials including NH.sub.3 and CO.sub.2, wherein the urea manufacturing plant includes a plurality of processing units including a reactor, a stripper and a condenser, and a plurality of lines, and the inner wall surfaces of the plurality of processing units and the plurality of lines are made of a stainless steel and at least some of the plurality of lines is made of an austenitic stainless steel, the urea manufacturing method including: forming a passivation film on the inner wall surfaces of the plurality of processing units and the plurality of lines by supplying CO.sub.2 of the manufacturing raw material with added oxygen; continuously measuring a wall thickness of the line made of the austenitic stainless steel; and adjusting a supply amount of the oxygen in response to a measurement value of the wall thickness to control a corrosion rate and a reaction yield of urea.

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.

Use of a non-ionic deep eutectic mixture consisting of A and B, A being R1R2NCONR3R4 and B being selected from the group consisting of R5R6NCOCH3 and R7R8NCONR9R10, and wherein each of R1-R10 is independently H, CH3 or alkyl, as a solvent or dispersant in chemical synthesis, material synthesis or fabrication, chemical or enzymatic catalysis, food, cosmetic or pharmaceutical formulation, separation or partitioning, heat transfer, and as detergents or cleaners, as well as such mixtures, is disclosed.

The present invention provides solvent-limited processes for the preparation of an existing crystalline solid form of an active pharmaceutical ingredient comprising mixing, in the presence of solvent vapour, of a solid active pharmaceutical ingredient and a pharmaceutically acceptable entity that is either a high-boiling liquid or a solid. Also provided is the use of a standard rotary apparatus, such as a rotary cone dryer, for application of the processes herein.

The present invention provides solvent-limited processes for the preparation of an existing crystalline solid form of an active pharmaceutical ingredient comprising mixing, in the presence of solvent vapour, of a solid active pharmaceutical ingredient and a pharmaceutically acceptable entity that is either a high-boiling liquid or a solid. Also provided is the use of a standard rotary apparatus, such as a rotary cone dryer, for application of the processes herein.

A urea co-crystal form A of apixaban, and a preparation method therefor. The urea co-crystal form A has high physical and chemical stability, crystal form stability and drug forming stability, better solubility, and higher bioavailability. The preparation process is good in repeatability, high in yield, green and environment-friendly, and easy to operate, facilitates large-scale production, and allows for preparation of products in different particle size ranges by means of adjustment of parameters, thereby meeting different requirements for formulations.

A urea co-crystal form A of apixaban, and a preparation method therefor. The urea co-crystal form A has high physical and chemical stability, crystal form stability and drug forming stability, better solubility, and higher bioavailability. The preparation process is good in repeatability, high in yield, green and environment-friendly, and easy to operate, facilitates large-scale production, and allows for preparation of products in different particle size ranges by means of adjustment of parameters, thereby meeting different requirements for formulations.

Disclosed is a novel method of controlling the formation of biuret in urea production, and particularly reducing, preventing or reversing such formation. This is accomplished by adding liquid ammonia to a urea aqueous stream. This addition is done at one or more positions downstream of a recovery section in a urea plant. The addition of liquid ammonia serves to shift the equilibrium of biuret formation from urea, to the side of the formation of urea from biuret and ammonia. The invention can be accomplished also in pre-existing urea plant, by the simple measure of providing an appropriate inlet for liquid ammonia, in fluid communication with a source of such liquid ammonia.

Disclosed is a novel method of controlling the formation of biuret in urea production, and particularly reducing, preventing or reversing such formation. This is accomplished by adding liquid ammonia to a urea aqueous stream. This addition is done at one or more positions downstream of a recovery section in a urea plant. The addition of liquid ammonia serves to shift the equilibrium of biuret formation from urea, to the side of the formation of urea from biuret and ammonia. The invention can be accomplished also in pre-existing urea plant, by the simple measure of providing an appropriate inlet for liquid ammonia, in fluid communication with a source of such liquid ammonia.