Saipem S.p.a.

Lorenzo Bruno

Lino Carlessi

Alessandro Gianazza

Rosario Galati

Matteo Berra

A plant for recovering metals and/or metal oxides from industrial process waste, in particular oil product refining waste, comprises a furnace; a feed line connected to a main inlet of the furnace and configured to feed the furnace with a solid waste containing metals, in particular in oxide form; an outlet line, connected to a solid phase outlet of the furnace and configured to draw a metal-enriched solid phase out of the furnace; the furnace is a belt conveyor furnace having a belt conveyor closed in a loop with a substantially horizontal configuration and having a top face, which receives the waste to treat and conveys it between two longitudinal opposite ends of the belt conveyor furnace respectively provided with the main inlet and the solid phase outlet.

Plant and method for recovering metals and/or metal oxides from industrial process waste, in particular refinery waste

A counter-current cross-flow heat exchanger for heating a first gas and cooling a second gas, includes modules in fluid communication with one another, each module being positioned on a plane, the planes mutually overlapping. Conduits allow entry and exit of the first and second gases into and out of the exchanger. Each module has heat exchange plates, with heating and cooling faces. The plates are orthogonal to the module plane and parallel to define alternating heating and cooling spaces. The first gas crosses each heating space with a direction substantially parallel to the plane of each module and the second gas crosses each cooling space with a direction substantially orthogonal to the plane of each module. The cooling spaces between adjacent modules are in direct fluid communication. The heating spaces between adjacent modules are in fluid communication with one another by conduits/conveyors, creating a serpentine path.

Cross-flow heat exchanger

An integrated process for production of urea and urea-ammonium sulphate ('UAS') comprises: a urea synthesis step carried out in a urea synthesis reactor; a recovery and concentration step, wherein a urea solution produced in the urea synthesis step is progressively concentrated in at least one recovery section and in a concentration section, recovering unreacted ammonia and carbon dioxide and water from said urea solution; a step of producing ammonium sulphate by reaction of sulphuric acid and ammonia in an ammonium sulphate production apparatus; a step of mixing said ammonium sulphate with concentrated urea coming from the concentration section to produce a UAS mixture; in the ammonium sulphate production step, at least a part of the ammonia is provided by at least one off-gas containing ammonia and recovered from the recovery and concentration step.

Integrated process and plant for production of urea and UAS (urea-ammonium sulphate) mixtures

A method of removing ammonia from a continuous vent gas stream of a urea plant, in particular of a medium-pressure section of a urea plant, includes a step of removing ammonia from the continuous vent gas stream of the urea plant using a controlled-combustion process including at least a first lean, oxygen-poor combustion step performed in the presence of an understoichiometric amount of oxygen acting as the sole comburent, and in a reducing atmosphere of hydrogen.

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San Donato Milanese, Italy

Lorenzo Bruno