Avaliação da Carboximetilcelulose como inibidor de Incrustação de Sulfato de Cálcio

Inorganic scales are quite recurrent in the oil industry, such as calcium sulfate scale, which is generated by the chemical incompatibility of water, causing several operational problems. Scale inhibitors are chemical substances capable of minimizing or solving this problem, however, some classes of inhibitors have elements in their composition that are harmful to the environment. In view of this, many studies are being developed in order to evaluate the inhibition efficiency of biodegradable and non-toxic species. Biopolymers have emerged as good substitutes for conventional inhibitors, including carboxymethylcellulose, an anionic polysaccharide derived from cellulose. Therefore, in this work, the inhibition rate and the mechanism of action of carboxymethylcellulose against calcium sulfate dihydrate incrustation were observed through analytical methods. For this, brines (anionic and cationic) and a CMC solution, with a degree of substitution of 0.7, were prepared to carry out complexometric titrations with the following concentrations of the inhibitor: 2, 4, 6, 8, 10, 20, 40 , 80, 100 and 125 mg/L. Subsequently, the characterizations of the solid part were carried out without the presence of the inhibitor and with 6 mg/L of inhibitor, using optical microscopy, Fourier transform infrared and X-ray diffraction. It was found that from 10 mg/L the inhibitor showed an efficiency of 80%, with 87.33% being the highest percentage of inhibition achieved with 80 mg/L concentration. With the results of the characterizations, it was possible to conclude that the method of action of the CMC under the conditions of the study was the complexation of Ca2+ ions. The study carried out for the elaboration of this work made it possible to understand the analysis carried out, the results obtained provided important information to conclude the mechanism of inhibition of carboxymethylcellulose and its inhibition potential, serving as a basis for future discussions. ; As incrustações inorgânicas são bastante recorrentes na indústria ...