We have recently realized an interesting application for the cooling of soda caustic solution employed in the separation and purification process in oil & gas facilities. The system employs a plate heat exchanger served by a chiller, that produces nonfreezing solution at the temperature of 0° C employed for the cooling of a caustic soda solution at 4%. The soda solution comes from the depuration process of the condensations of the petrochemical plant, with an inlet temperature in the plate heat exchanger of approx 45° C and outlet temperature of 25° C.
The treatment of condensations in an oil & gas plant is achieved using a bipolar cation and anion-exchange resins membrane process, that removes the ions present in the condensations cooled down at 45° C, in order to avoid possibile pollution by hydrocarbons. The exhaust resins are then regenerated with solutions of sulphuric acid and soda at 4%.
The heat exchangers has titanium plates, ensuring corrosion resistance due to possible presence of chlorides concentrations. The thermal power capacity is 500 KW, and all the connecting pipes are mixed rigid and flexible, in order to allow easy installation operations on-site.
The chiller provides the heat dissipation of the thermal energy removed from the soda solution, and must ensure 365/24 operations. The system is thus equipped with redundancy, with multi-compressor and multi-circuit, avoiding interruptions of the depuration process even in case of partial fault. In addition, the chiller has been sized for the most challenging summer design conditions, to guarantee the maximum efficiency in all variable weather conditions in winter/summer. A step regulation allows to adjust the power capacity to the season and to the effective thermal need required.