In an FCC apparatus and process structured packing should be located at the very top of the stripping section in an upper region. The lower region below the structural packing may be equipped with fluidization equipment such as stripping media distributors and one or more gratings. This arrangement enables stripping of entrained hydrocarbons off the incoming catalyst immediately upon entry into the stripping section allowing the entrained hydrocarbon to exit the stripping section with minimized residence time to minimize post-riser cracking. Revamp of stripping sections with tall stripping sections should conducted in this way to improve performance and reduce down-time for equipment installation.

A catalytic reactor comprises a load distributor assembly to evenly transfer a load from equipment (internals) to a reactor support ring or support structure fixed within the reactor shell, thereby maximizing the possible load to be applied to the support ring or support structure without any hot-work modifications and without exceeding the allowable tensions/stress.

The disclosure pertains to a urea production plant and process using a high-pressure CO.sub.2 stripper, downstream medium-pressure treatment unit and a medium-pressure dissociator receiving urea synthesis solution from the reactor, wherein gas from the treatment unit and dissociator are condensed in a first condenser and off-gas from the synthesis section is condensed separately in a second condenser. A revamping method is also described.

Methods for scale-up from a pilot plant to a larger production facility of a bimodal polymer product having a density, a melt index and melt index ratio are provided herein.

A dual-pressure plant for the synthesis of nitric acid comprising: a reactor (4) providing a gaseous effluent (15) containing nitrogen oxides; an absorption tower (6) nitrogen oxides react with water providing raw nitric acid and, said absorption tower operating at a pressure greater than the pressure of the reactor; a compressor (5) elevating the pressure of the reactor effluent (15) to the absorption pressure; said plant also comprising a first bleacher (37) and a second bleacher (7), said first bleacher (37) stripping with air (39) nitrogen oxides from the output stream (27) of the absorption tower (6) providing a partially stripped nitric acid stream (40) and a nitrogen oxides-loaded air stream (41), the former being fed to the second bleacher (7) and the latter being recycled to the delivery-side of said compressor (5).

A dual-pressure plant for the synthesis of nitric acid comprising: a reactor (4) providing a gaseous effluent (15) containing nitrogen oxides; an absorption tower (6) nitrogen oxides react with water providing raw nitric acid and, said absorption tower operating at a pressure greater than the pressure of the reactor; a compressor (5) elevating the pressure of the reactor effluent (15) to the absorption pressure; said plant also comprising a first bleacher (37) and a second bleacher (7), said first bleacher (37) stripping with air (39) nitrogen oxides from the output stream (27) of the absorption tower (6) providing a partially stripped nitric acid stream (40) and a nitrogen oxides-loaded air stream (41), the former being fed to the second bleacher (7) and the latter being recycled to the delivery-side of said compressor (5).

A dual-pressure plant for the synthesis of nitric acid comprising: a reactor (4) providing a gaseous effluent (15) containing nitrogen oxides; an absorption tower (6) nitrogen oxides react with water providing raw nitric acid and, said absorption tower operating at a pressure greater than the pressure of the reactor; a compressor (5) elevating the pressure of the reactor effluent (15) to the absorption pressure; said plant also comprising a first bleacher (37) and a second bleacher (7), said first bleacher (37) stripping with air (39) nitrogen oxides from the output stream (27) of the absorption tower (6) providing a partially stripped nitric acid stream (40) and a nitrogen oxides-loaded air stream (41), the former being fed to the second bleacher (7) and the latter being recycled to the delivery-side of said compressor (5).

A method for revamping a catalytic converter wherein: said catalytic converter comprises a pressure vessel and a catalytic cartridge containing at least one catalyst bed, the pressure vessel includes a cylindrical shell with a full aperture and includes a removable cover of said aperture, and the catalytic cartridge is removable through said upper aperture, and the method includes: installing an additional shell over the aperture of the original shell, thus obtaining an axially extended shell of the pressure vessel; providing an axially extended catalytic cartridge having an axially extended room for holding catalyst in the so obtained axially extended shell.

This disclosure relates to SA alkylation reactor systems. The reactor system involves a closed reactor vessel comprising a shell, a vapor outlet, and an emulsion outlet. The reactor system also involves a distributor located at the lower portion of the reactor vessel, a mixer fluidly connected with the distributor, and an emulsion pump fluidly connected with the mixer and the emulsion outlet, wherein the emulsion pump is located outside the reactor vessel. This disclosure also relates to a split SA alkylation reactor system wherein a single horizontal reactor vessel is divided to accommodate two reactor systems. This disclosure also relates to alkylation processes using the reactor systems. This disclosure also relates to methods of converting an HF alkylation unit to a SA alkylation unit. This disclosure also relates to converted SA alkylation units and alkylation processes performed in the converted SA alkylation units.

Process for manufacturing a hydrogen-containing synthesis gas from a natural gas feedstock, comprising the conversion of said natural gas into a raw product gas and purification of said product gas, the process having a heat input provided by combustion of a fuel; said process comprises a step of conversion of a carbonaceous feedstock, and at least a portion of said fuel is a gaseous fuel obtained by said step of conversion of said carbonaceous feedstock.