Viability of using chemical speciation software in the study of the removal of Ca2+ and Mg2+ in industrial waters.

Abstract

In this project the prediction of the removal of dissolved calcium and magnesium from the industrial waters that they feed some processes such reverse osmosis (RO) system, boilers, coolers or heat exchangers has been study. The removal or hardness is necessary to avoid scaling problems in the equipment or in the pipes. The scaling may reduce the efficiency of the processes increasing costs and energy consumption. The main objective of the project is to study the viability of a chemical speciation software, OLI Analyzer Studio®. The software is used to predict the reduction of dissolved calcium and magnesium. The removal method used in the simulations is the lime and soda ash softening (among others, chemical precipitation is one of the most used methods for water softening). Different simulations have been done with OLI based in different water characteristics obtained from two sources: scientific articles and laboratory Jar Tests. From the waters composition extracted from scientific articles, some simulations are realized to obtain water with minimum content in calcium and magnesium (under 5 ppm). These results are compared with the results obtained from stoichiometric calculations. Furthermore, if the removal values of the article are available, these are compared with the results obtained from OLI. From the waters composition extracted from the laboratory Jar Tests, some simulations are realized with the same chemical doses to see if the remaining amounts are similar. The obtained values show that OLI is an effective estimation software that allows to predict the consumptions of the products necessary in the chemical precipitation. It is very important to dispose of a well-defined water composition. OLI is a tool that allows us to save time and costs in the laboratory.