Evaluation of litiferous brines in an evaporitic process by using simulation in Aspen Plus

JUAN RAMIRO LEZAMA; JUAN PABLO GUTIERREZ; LAURA GIMÉNEZ; ELEONORA ERDMANN

Buenos Aires

Congreso; WCCE11 - 11th WORLD CONGRESS OF CHEMICAL ENGINEERING IACCHE - XXX INTERAMERICAN CONGRESS OF CHEMICAL ENGINEERING CAIQ2023 - XI ARGENTINIAN CONGRESS OF CHEMICAL ENGINEERING CIBIQ2023 - II IBEROAMERICAN CONGRESS OF CHEMICAL ENGINEERING; 2023

Asociación Argentina de Ingenieros Químicos

In this work, authors study the process of concentration of brines, through evaporation in a system of solar ponds. To carry out the study, various brines with different compositions are used. Data from different salars in Argentinian Puna region are considered. The processes of evaporation, concentration, and precipitation of salts are analyzed by using the simulator Aspen Plus. The list of components is composed of basic ionic species (Na, K, Li, Ca, Mg, B, Cl and SO4) and the main salts usually precipitating in this type of operation (halite, sylvite, sylvinite, gypsum, schoenite, cainite, carnallite and bischofite). The ENRTL-RK method is applied to calculate properties. A scheme of five ponds is proposed, in each of which an evaporation rate of 30% of the inlet water is eliminated. In addition, each pond is simulated based on the work of Riveros et al. [1] and a 30% loss due to impregnation is considered.The precipitation sequence of the salts in each pond is evaluated. Then the mass flow rate and the composition of the precipitate are monitored. It is observed that in all of them NaCl, CaSO4·2H2O and KCl precipitate as main salts, which are explained by the ionic concentrations present in the supersaturated brine. Obtained results are compared with data from real plants to validate the model. A good performance of the proposed configuration is obtained. The applied evaporation performance indicator is the Brine/Halite ratio of the set of ponds. For an evaporation rate of 87% of the brine, the obtained value for this indicator is 7.05. This is close to the data for projects/plants operating in the Puna region (between 6.27 and 38.5). Hence, this simulation could be used as a model to evaluate different types of brines, coming from different salars and to be transfer to developing companies located in the studied region.