Processes and plants for the production of purified urea solution are described. In a described urea production process, urea is produced in a synthesis section without a high pressure stripper and the urea solution is subjected to purification after the recovery section, to give purified urea solution and off-gas. The purification comprises e.g. steam stripping.

A gas injection element (10) for a system for distributing a gas inside a chamber of a fluid catalytic cracking unit. This injection member comprises a passage (14) extending entirely therethrough, andan inner ceramic member (20) having an inner surface (22) that entirely delimits the through-passage (14); anda hollow metal sleeve (30), inside which at least a portion of the inner member (20) is received, the sleeve (30) and the inner member (20) respectively having an inner surface (32) and an outer surface (24) with matching shapes allowing the inner member (20) to move relative to the sleeve (30) in a direction parallel to an axis (X) of the passage (14), the outer (32) and inner surfaces (24) being provided with fastening elements (26, 36) that engage to reversibly fasten the sleeve and the inner member.

An object of the present invention is to prevent stress-corrosion cracking of a header (40) of a reactor. A reactor for producing trichlorosilane by causing metal silicon powder and a hydrogen chloride gas to react with each other includes a cooler (70), the cooler including a plurality of heat transfer medium pipes (30) and a header (40), the plurality of heat transfer medium pipes being provided in a fluid bed (60) inside the reactor, the header being provided in a freeboard section (50) inside the reactor, the header being comprised of a corrosion-resistant material.

Processes and plants for the production of purified urea solution are described. In a described urea production process, urea is produced in a synthesis section without a high pressure stripper and the urea solution is subjected to purification after the recovery section, to give purified urea solution and off-gas. The purification comprises e.g. steam stripping.

Disclosed is a Hot Isostatic Pressed ferritic-austenitic steel alloy, as well objects thereof. The elementary composition of the alloy comprises, in percentages by weight:

TABLE-US-00001 C 0-0.05; Si 0-0.8; Mn 0-4.0; Cr more than 29-35; Ni 3.0-10; Mo 0-4.0; N 0.30-0.55; Cu 0-0.8; W 0-3.0; S 0-0.03; Ce 0-0.2;
the balance being Fe and unavoidable impurities. The objects can be particularly useful in making components for a urea production plant that require processing such as machining or drilling. A preferred use is in making, or replacing, liquid distributors as used in a stripper as is typically present in the high-pressure synthesis section of a urea plant.

A plant for the manufacture of tetrafluoropropene comprises three reactors for reaction in the gas phase comprising a catalyst bed. The first and second reactor are each configured in order to be fed in turn by a device for feeding with a reaction stream comprising a compound B and hydrofluoric acid; and a device for feeding with a regeneration stream configured in order to feed the reactor with a regeneration stream comprising an oxidizing agent. The third reactor is configured in order to be fed in turn by a device for feeding with a reaction stream comprising a compound A and hydrofluoric acid; said compound A being different from said compound B; and a device for feeding with a regeneration stream configured in order to feed the reactor with a regeneration stream comprising an oxidizing agent.

Disclosed is a Hot Isostatic Pressed ferritic-austenitic steel alloy, as well objects thereof. The elementary composition of the alloy comprises, in percentages by weight: TABLE-US-00001 C 0-0.05; Si 0-0.8; Mn 0-4.0; Cr more than 29-35; Ni 3.0-10; Mo 0-4.0; N 0.30-0.55:.sup. Cu 0-0.8; W 0-3.0; S 0-0.03; Ce 0-0.2; the balance being Fe and unavoidable impurities. The objects can be particularly useful in making components for a urea production plant that require processing such as machining or drilling. A preferred use is in making, or replacing, liquid distributors as used in a stripper as is typically present in the high-pressure synthesis section of a urea plant.

The present invention relates to a process for modifying the fluorine distribution in a hydrocarbon compound, comprising a step of placing in contact between a hydrocarbon compound and a catalytic composition comprising a chromium-based catalyst, said process being performed in a reactor made of a material comprising a base layer made of a material M1 and an inner layer made of a material M2, said base layer and said inner layer being laid against each other, characterized in that the material M2 comprises at least 80% by weight of nickel on the basis of the total weight of the material M2, advantageously at least 90% by weight, preferably at least 95% by weight, in particular at least 99% by weight of nickel on the basis of the total weight of the material M2.

The present invention concerns a method for preparing tetrafluoropropene utilising three reactors and comprising the steps of (a) implementing, in the first and second reactors, at least one step of reacting, in the gas phase, a compound B in the presence of hydrofluoric acid and a catalyst, in alternation with a step of regenerating the catalyst by bringing it into contact with a regeneration flow comprising an oxidising agent, (b) implementing, in the third reactor, a preliminary step of producing the compound B, in alternation with a step of regenerating the preliminary catalyst with a regeneration flow comprising an oxidising agent. The step of regenerating the preliminary catalyst in the third reactor is implemented in the absence of a step of reacting the compound B in the presence of hydrofluoric acid in said first and second reactors. The present invention also concerns a facility configured to implement the present method.

A low cost and versatile plate reactor is capable of producing exothermic reactions under a wide variety of conditions using a wide variety of materials. The reactor design can be used to test various combinations of materials and triggers for exothermic reactions quickly. The reactor design can be used for solid-state materials, wet-cells/electrolytic materials, plasmas, and gases. The design will work with nanoparticles, solid materials, materials plated to a reactor wall, heavy water, or other liquid materials, and gases.