BR-102024017558-A2 - PROCESS FOR DETERMINING PHOSPHONATE IN SALINE WATERS

Abstract

The present invention discloses a process that determines the presence of phosphonate in saline waters without specific equipment and can be used with simple resources if necessary. The process is carried out in two parts: 1) Conversion of phosphonate by a thermal method and 2) determination of phosphate using the analytical method based on digital imaging (MABID). Furthermore, the process for detecting phosphonates was developed with the concept of a portable analytical method capable of being performed even by analysts without training in chemical operations.

Inventors

• MARCO ANTÔNIO GOMES TEIXEIRA
• MARIANA DIAS MARTINS
• Helida Vasques Peixoto Vieira
• RENATO MALBAR MUSIELLO BARCELLOS
• Aline Machado De Azevedo Novaes
• Rogerio Mesquita De Carvalho
• Rafaella Magliano Balbi De Faria
• RENATA RECKER SOUSA DE SÁ
• Caroline Dos Santos Silva
• AMANDA FERREIRA DA SILVA
• ANA MEHL

Assignees

• Petróleo Brasileiro S.A. - Petrobras
• UNIVERSIDADE FEDERAL DO RIO DE JANEIRO - UFRJ

Dates

Publication Date

20260310

Application Date

20240827

Claims (6)

1. 1. PROCESS FOR DETERMINING PHOSPHONATE IN SALINE WATERS, characterized in that it comprises the steps of: (a) converting phosphonate by a thermal method; (a.1) transferring 2 ml of the sample to be analyzed to a crucible with a lid; (a.2) heating the sample from step (a.1) in the crucible with the lid ajar in a muffle furnace; (a.3) transferring the closed crucible to a desiccator; (a.4) recovering the cold residue from the conversion with 5 ml of pure water; and (b) determining phosphate by applying the analytical method based on digital images.
2. 2. PROCESS, according to claim 1, characterized in that in step (a.1) the concentration of NaCl is equal to 5 mol.L-1.
3. 3. PROCESS, according to claim 1, characterized in that in step (a.2) the crucible and crucible lid are made of porcelain.
4. 4. PROCESS, according to claim 1, characterized in that in step (a.2) the crucible is 50 ml.
5. 5. PROCESS, according to claim 1, characterized in that in step (a.3) a muffle furnace with internal dimensions of 12cm W x 9.5cm H x 15cm D is used.
6. 6. PROCESS, according to claim 1, characterized in that in step (a.3) the muffle furnace is heated at a rate of 10°C min-1 to a temperature of 450°C for 30 minutes.

Description

FIELD OF APPLICATION [001] The present invention discloses a process for detecting residual phosphonates in waters where oil extraction is carried out, which use anti-scaling agents with phosphonates in their composition to control saline fouling, including on board offshore production facilities. FUNDAMENTALS OF THE INVENTION [002] Phosphonates are widely used as anti-scalants in a variety of applications, including for oil formation waters. They prevent salt deposits, including during oil production, thus avoiding clogging problems in the lines and equipment of the processes in which they are used. Detecting the presence and efficiently controlling the concentration of these compounds so that it does not fall below the ideal level for anti-scaling action and, similarly, that it is not being added in excess in nature, is a technological solution that offers advantages in these processes. [003] The control of phosphonates usually involves (normally after some reaction) the application of sophisticated, high-cost equipment such as, for example, ion chromatography. Based on chromatographic separation, several detection methods have been developed, such as indirect photometric detection and mass spectrometry detection (Shamsi S.A., Danielson N.D., Ion chromatography of polyphosphates and polycarboxylates using a naphthalenetrisulfonate eluent with indirect photometric and conductivity detection, J. Chromatogr. A 653 (1993) 153-160; Nowack B., Determination of phosphonates in natural waters by ion-pair high-performance liquid chromatography, J. Chromatogr. A 773 (1997) 139-146; Carsten K. Schmidt, Brigitte Raue, Heinz-Jürgen Brauch & Frank Sacher, Trace-level analysis of phosphonates. Environmental waters by ion chromatography and inductively coupled plasma mass spectrometry. Intern. J. Environ. Anal. Chem., 2014 Vol. 94, No. 4, 385-398). Indirect detection methods combined with capillary electrophoresis are also used (Shamsi S.A., Danielson N.D., Ribonucleotide electrolytes for capillary electrophoresis of polyphosphates and polyphosphonates with indirect photometric detection, Anal. Chem. 67 (1995) 1845-1852). All these methodologies require sample collection and transport to laboratories that possess the sophisticated techniques they utilize. Particularly for the case of oil production in offshore environments and other remote processes, this is not a possibility for detection on board production facilities. [004] A simpler protocol would be ideal due to its ease of implementation in the field. It would then be necessary to perform a phosphonate reaction that would promote a mode of easy subsequent detection. Possibly a specific color formation, for example, by direct reaction of the phosphonate present in saline matrices, but such a reaction is not known. [005] However, since the presence of phosphate anion precursor groups is the main chemical characteristic to be observed in the evaluation of the chemical structure of phosphonates, methodologies found in the literature transform them into orthophosphate through a conversion process. Phosphate is an anion whose concentration in various aqueous media is of interest, including for the evaluation of natural waters, for example, so it is possible to use methods for this anion and, once the phosphonates are converted into phosphate, methodologies with varied principles can be executed, including color generation, using different reactions already presented in the literature (for example, in SM-4500-P, precisely for natural waters). Color generation has characteristics of methodologies that can be easily adapted for field use. Therefore, the question of conversion remains. [006] The literature presents types of phosphonate conversion using oxidants that, together with catalysts, break down phosphonate molecules, transforming them into orthophosphate (Rott E, Minke, Bali U, Steinmetz H. Removal of phosphonates from industrial wastewater with UV/FeII, Fenton and UV/Fenton treatment. Water Research 122 (2017) 345e354; Assalim M R., Moraes S G., Queiroz S. C.N., Ferracini V. L and Duran N. Studies on degradation of glyphosate by several oxidative chemical processes: Ozonation, photolysis and heterogeneous photocatalysis. Journal of Environmental Science and Health Part B (2010) 45, 89-94). The trend observed from the literature review is towards methods that apply advanced oxidation processes (AOPs), in which the oxidation accelerator is ultraviolet light that promotes the breakdown of the complex molecule into orthophosphate (Zhanga X, Guoa W, Zhenga Y, Chengb Z, Qib X, and Gaoa C. Rapid determination of aminotris (methylenephosphonic acid) in water by ultraviolet photooxidation. Instrumentation science and technology, 2017, vol. 45, no. 4, 459-468; Wang Z, Chen G, Patton S, Ren C., Liu J, Liu H. Degradation of nitrilotris-methylenephosphonic acid (NTMP) antiscalant via persulfate photolysis: Implications on desalination concentrate treatment. WaterResearch 159 (20