AESA (A-Evangelista S.A.) completed turnkey construction of the new naphtha hydrotreating unit in La Plata industrial base, in Buenos Aires, Argentina, for RepsolYPF.

The plant is designed to produce 60 m3/h of low-sulfur naphtha; since sulfur is one of the main naphtha pollutants, it definitely entails an environmental step ahead, as well as compliance with stricter global environmental requirements. The process consists in hydrogenating gasoline cuts, reducing sulfur content to less than 50 ppm and optimizing the octane rating, among other properties.

The core of the unit is a catalytic reactor where naphtha is processed with refinery hydrogen. The reactor has two beds where hydrodesulfurization reactions will take place, and the resulting products will later be treated in heat exchangers and liquid/ vapor separators. Then, vapors will be sweetened in an amine contactor for reuse in the process, and liquid will be routed through the stripper distillation tower to obtain the final product: naphtha with sulfur content below 50 ppm.

The above equipment is supplemented by all auxiliary systems and machines required for proper operation of the unit as a whole, among others: separation and preheating of initial load, recycle gas recompression, reboilers, ovens, condensers, pumps, electric power supply to machines as needed; instruments and distributed control system of the unit, buildings and civil works, etc.

The project included detail engineering, partial supply of equipment and materials, precast, construction and assembly, precommissioning, commissioning and start up of the unit.

Outstanding project data follow:

• Construction: 3 buildings (control, substation and satellite room)
• Foundation piles: 300
• Concrete: 1000 M3
• Process modules: 9
• Provision and assembly of pipes and metallic structures: 300 tn
• Electrical and instruments assembly: 70000 Man-hours

Eng. Francisco Deas Project Manager AESA