Method for obtaining an Anti-foaming additive and Anti-foaming additive obtained in this way

Abstract

The present invention relates to a method for obtaining an anti-foaming additive and to an anti-foaming additive obtained in this way by using polymers that destabilize foams. The field of use of the present invention is the chemical industry, more specifically the petroleum industry. The anti-foaming additive of the present invention has an efficiency of 32%.

Description

METHOD FOR OBTAINING ANTI-FOAMING ADDITIVE AND ANTI-FOAMING ADDITIVE THUS OBTAINED Field of the invention

[0001] The present invention relates to a method for obtaining an antifoaming additive and an antifoaming additive thus obtained using microparticulate polymers that act to destabilize foams.

[0002] The area of ​​application of the present invention is the chemical industry, more specifically in the petroleum industry. Fundamentals of the invention

[0003] Some physical and chemical methods are found in the literature for controlling and mitigating petroleum foams, such as surface whipping, thermal shock, removal of surfactants and injection of chemical additives, the latter being an inexpensive method, usually the most effective (among the others) and most widely used in the petroleum industry. The chemical additives are stored in tanks connected to the production line; thus, their injection occurs before the oil reaches the separator vessels located in the surface treatment units (Pape, GP Journal of Petroleum Thechnology, v. 35, n.7, p.1197-1204, 1983; Shaban, HI, Gas Separation & Purification. Kuwait, p. 81-86. 1995). Polydimethylsiloxane (PDMS) is the most widely used foam control agent (FCA) in the field due to its low cost and better efficiency in compared to physical methods. However, low efficiency of PDMS-based antifoams is observed in foams produced with oils of different API densities (American Petroleum Institute), compared to the efficiency of the same additive in aqueous foams. Another problem with the application of PDMS-based additives is that during the oil refining process, PDMS is deposited on the surface of the catalysts, causing their poisoning (Pape, GP Journal of Petroleum Technology, v. 35, n.7, p.1197-1204, 1983). Other antifoams have been proposed in the literature, such as jojoba oil, which is obtained from the nuts of the jojoba plant. These compounds have monoester chains, generally with twenty carbons, and are non-volatile. The positive point of jojoba oil is that it does not undergo chemical changes after heating or cooling, as does PDMS (Cevada, E. et al., Thermal Analyses Calorimetry, Budapest, p. 357-367, 2017).Along the same lines, high molecular weight polyethers (>15000 g / mol) form the basis of another class of defoamers (Cevada, E. et al. Fuel. Mexico City, p. 447-454, 2018). However, although they do not cause damage to catalysts during the refining process, jojoba oil and polyethers have high commercial value for large-scale applications, such as that demanded by field production (Cevada, E. et al. Fuel. Mexico City, p. 447-454, 2018). Thus, the additiveization of commercial PDMS-based defoamers with microparticles. Polyethylene oxide (PEG) constitutes a simpler and more economically viable solution for large-scale field application.

[0004] Mendes' (2017) master's dissertation entitled "Influence of the hydrophilicity of polymeric surfactants and the solvent medium on the breaking of foam formed in petroleum" (Universidade Federal do Rio de Janeiro, 2017) describes the use of different ethylene oxide contents as anti-foaming agents. However, the lack of statistical parameters to evaluate the experimental error made it difficult to evaluate the performance of the formulations presented as foam inhibitors and the results indicate that the formulations presented by the authors are inefficient compared to the reference standards, products already used in the field.Differently, the present invention aims to combine the action of two types of foam control agents, one liquid and one solid, in obtaining a product that acts as a foam inhibitor, reducing by up to 32% the volume of petroleum foam produced by decompression of a petroleum sample containing dissolved gas, a methodology that reproduces, on a laboratory scale, the process of producing petroleum foams during field production. Furthermore, in the present invention, the suspension of solid PEG microparticles is significantly efficient on petroleum foams generated in the production lines and accumulated in the separators.

[0005] In Yuka Imanisi's (2022) final paper entitled "Preformulation and development studies of cosmetics: celestial line", the author presented the chemical definition of Dimethicone Copolyol with the two components (PDMS and PEG) soluble in water for use as a hair conditioner. In the document, there is a description of a product that is a copolymer of PDMS and polyethylene oxide, which is used as a hair conditioner, therefore, soluble in the aqueous phase. The referred "Dimethicone Copolyol" is a copolymer of PDMS and PEG, this means that PDMS and PEG monomers are intercalated in the polymer chain, that is, PDMS and PEG are chemically linked by covalent bonds, resulting in a new product from a chemical point of view.

[0006] Patent application US20120061877 describes a surfactant for use in the method for manufacturing a hydrophilic polysiloxane elastomer and the use of PEO-PDMS as a block copolymer for the purpose of increasing the hydrophilicity of PDMS (highly hydrophobic). The copolymer formed from PDMS and PEG blocks intercalated and chemically linked (covalent bond) forms a polymer with characteristics different from PEG and PDMS.

[0007] Unlike the aforementioned documents, the present invention is the result of the dispersion of PEG microparticles in a PDMS solution, in which both components preserve their chemical identities by not being chemically linked, acting as a product of independent and complementary form. Furthermore, the formulation comprises a suspension of PEO microparticles in oil phase, containing solubilized PDMS.

[0008] US Patent 8,088,218 B2 refers to a foamed slurry and a construction panel made from it. The gypsum slurry described comprises a defoamer containing PEO and PDMS and the use of some structural hydrophobic elements and their mixtures. It also presents formulations for the production of "expanded" gypsum panels for civil construction, aiming at the distribution of bubbles in the panels to ensure desirable mechanical characteristics. To ensure the desired bubble distribution, the author includes in the formulation surfactants (to generate bubbles) and a defoamer to promote the distribution / uniformization of bubble size. In the formulation, PDMS, PEO and PPO (polypropylene oxide) act as a defoamer, accelerating the collapse of bubbles in the foam produced, favoring the uniformization of bubble sizes.Differently, in the present invention, the product acts by preventing the formation of oily matrix foam (petroleum) and is a suspension, in which PEO acts as a potentiator of the effect of PDMS as an inhibitor of petroleum foams.

[0009] WO2022 / 106815 describes the use of a foaming cleansing composition containing PEO and PDMS components and discloses the use of silicon surfactants for the optimization of cleansing foams, a cosmetic used for cleaning / sanitizing the skin. The objective of the formulation proposed by the author is to optimize the product, making it more effective in sanitizing, reducing the negative effect of alcohol and forming stable foams. To achieve this, the inventor uses a polymeric surfactant made of PDMS and PEO, as surfactants stabilize foams and do not inhibit or accelerate their breakdown. PEO and PDMS are chemically bonded, where PDMS is the backbone and PEO chains are bonded as side groups. Again, PDMS is chemically bonded to PEO generating, through chemical reaction, a new product, a soluble polymer. In contrast, the present invention inhibits foam formation using a mixed liquid-solid system, with PEO microparticles dispersed in a PDMS solution. Brief description of the invention

[0010] The present invention relates to a method for obtaining an antifoam additive and an antifoam additive thus obtained using polymers that act to destabilize foams.

[0011] The method for obtaining an antifoam additive comprises the following steps: a. solubilize 27.5% by mass of polymethyl siloxane (PDMS) and 72.5% by mass of polyalphaolefin oil (PAO) at 25 °C, until a homogeneous solution is obtained; b. add microparticulate polyethylene oxide (PEO) with a molecular mass of 100,000 or of 8,000,000 g / mol in the solution of step (a) at a mass fraction of 0.01 or 0.1%; c. homogenize the solution obtained in step (b) for 5 to 10 minutes, preferably 5 minutes, at 25 to 30 °C, preferably 25 °C by mechanical dispersion at 1800 to 2200 rpm, preferably 2000 rpm; and d. obtain an antifoam additive.

[0012] The antifoam additive obtained by the method comprises: - PDMS and PAO solution with 27.5% by mass of PDMS and 72.5% by mass of polyalphaolefin oil (PAO); and - Microparticulate PEO in a fraction of 0.01 or 0.1% by mass in relation to the mass of the PDMS + PEO solution. Brief description of the figures

[0013] Figure 1 is the representation of the values ​​of Hi (height H at the initial time) and Hf for calculating the foam height, based on the binary image generated in the treatment of the videos to record the foam generation and decay process.

[0014] Figure 2 shows the comparison of the efficiency of the antifoam additive at 35 °C: A) as a function of the concentration of PEO in the foam control agent (ACE); B) as a function of the molecular mass of PEO.

[0015] Figure 3 shows the comparison of the efficiency of the antifoam additive at 55 °C: A) as a function of the PEO concentration in the ACE; B) as a function of the molecular mass of the PEO. Detailed description of the invention

[0016] The present invention relates to a method for obtaining an antifoam additive and an antifoam additive thus obtained using polymers that act to destabilize foams.

[0017] The method for obtaining an antifoam additive comprises the following steps: a. solubilize 27.5% by mass of polymethyl siloxane (PDMS) and 72.5% by mass of polyalphaolefin oil (PAO) at 25 °C, until a homogeneous solution is obtained; b. add microparticulate polyethylene oxide (PEO) with a molecular mass of 100,000 or 8,000,000 g / mol to the solution from step (a) at a mass fraction of 0.01 or 0.1%; c. homogenize the solution obtained in step (b) for 5 to 10 minutes, preferably 5 minutes, at 25 °C to 30 °C, preferably 25 °C by mechanical dispersion at 1800 to 2200 rpm, preferably 2000 rpm; and d. obtain an antifoam additive.

[0018] The antifoam additive comprises: - PDMS + PAO solution: 27.5% by mass of PDMS and 72.5% by mass of polyalphaolefin oil (PAO); and - Microparticulate PEO in a fraction of 0.01 or 0.1% by mass in relation to the mass of the PDMS + PEO solution.

[0019] Microparticulate polyethylene oxide (PEO) comprises a molecular mass of 100,000 or 8,000,000 g / mol.

[0020] Tests with the additive of the present invention were carried out at 35 and 55 °C for inhibition of API 20 density petroleum foams.

[0021] Foam decay kinetics tests involve generating oil foam by decompressing an oil sample with dissolved gas and monitoring the height of the foam column over time until complete collapse. These tests were performed using the foam generating apparatus designed and built in partnership with Petrobras (2018-2022), disclosed in protection BR 10 2019 027158 2, entitled "Foam Generating Apparatus".

[0022] For the tests, a sample of approximately 400 mL of oil was added to the pressure cell and pressurized with N2 at 10 bar. The cell was then placed in a rotating oven (FANN, 704ES) for aging for one hour. The tests were performed at temperatures of 35 and 55 °C. During the aging period, the pressure was checked and, if necessary, readjusted to 10 bar.

[0023] After the aging period, the cell containing the pressurized oil sample was fixed upside down on a support and the cell outlet valve was connected to the valve installed at the inlet of the decompression chamber of the foam generating apparatus. At this point, video recording began to record the foam generation and decay process.

[0024] To generate the foam, the cell valve was initially opened and then the valve at the decompression chamber inlet. The height of the foam column inside the decompression chamber was manually controlled by closing the valve. The temperature of the decompression chamber was maintained by circulating thermostated water at the same temperature as the aging process.

[0025] After the test was completed, the filming was completed. The videos were processed using a Matlab® algorithm, from which images were obtained at defined time points, in which the foam height was measured. The final height of the liquid was assumed as a reference value, as shown in Figure 1. The foam fraction (Fp) in the decompression chamber at each time point was calculated according to Equation 1. Fp= (H-Hf ) / Hf Equation 1

[0026] Where, H is the height of the foam column and Hf is the final height.

[0027] The kinetic decay curves of the foams were obtained by constructing graphs of Fp vs. time.

[0028] The results presented refer to tests to evaluate the potential of using polymeric microparticles to increase the efficiency of PDMS-based foam control agents (ACE), usually applied in the field.

[0029] Three experimental parameters were defined that are usually relevant to the activity as an antifoam / defoamer. The chosen parameters were: temperature, PEO concentration in ACE and PEO molecular mass. For each of these parameters, 2 levels were tested: 25 and 35 °C; 0.01 and 1% PEO in ACE; PEO of 100,000 and 8,000,000 g / mol. Since the idea was, in addition to verifying the impact of PEO on ACE efficiency, whether the variables PEO concentration and PEO molecular mass are important for efficiency, the effect of concentration was tested only with 100,000 g / mol PEO and the effect of molecular mass only at a concentration of 1% by mass. All tests were performed with 25 ppm of pure ACE or ACE+PEO.

[0030] The kinetic curves of foam breakdown are shown in Figures 2 and 3.

[0031] The efficiency analysis was performed comparatively with the system called "reference", that is, ACE without PEO. Thus, in Figure 2A it can be observed that, although the test results presented a high standard deviation (error bars), a reduction in the initial foam height (Hi) of 9% was observed with ACE containing 0.01% PEO 100,000 g / mol, but increasing the concentration to 1% promoted a reduction in Hi of 23%, indicating that PEO is capable of enhancing the effect of ACE as an inhibitor of petroleum foams at 35 °C and that the PEO concentration is an important parameter in the inhibition efficiency.

[0032] Figure 2B shows a comparison of the effect of PEO of different molecular weights. The results indicate that PEO of 8,000,000 g / mol presented a slightly superior foam inhibitory effect than PEO of 100,000 g / mol, reducing the Hi value by 32%. This result suggests that molecular weight is another parameter that controls the efficiency of PEO as the main factor of ACE activity at 35 °C.

[0033] However, when analyzing the effect of PEO on the bubble collapse kinetics, known as the defoaming effect, the results shown in Figure 2A and 2B indicate a considerable increase in the total foam collapse time (tc) in the presence of PEO compared to pure ACE (reference). The tc is the time required for all the foam to collapse, leaving only the liquid phase. The increase in tc relative to the reference was 67% and 96% for 0.01 and 1% PEO in ACE, respectively. On the other hand, for PEO of 8,000,000 g / mol, an increase in tc of 52% was observed, a significant increase, however, smaller than that observed for the system with PEO of 100,000 g / mol.

[0034] Figures 3A and 3B show the results of tests performed at 55 °C. In the same way as observed for the tests at 35 °C, the presence of PEO presented a potentiating effect on the efficiency of ACE as an inhibitor of petroleum foams, however, with a considerably lower response than that observed at 35 °C. The results indicated a reduction in Hi from 8% and 7% to 0.01% and 1% PEO in ACE, respectively. However, unlike the observations in the tests at 35 °C, with PEO of 8,000,000 g / mol, the reduction in Hi was only 1%, that is, a worsening in efficiency was observed with the increase in the molecular mass of PEO.

[0035] Analyzing the effect on the foam breaking kinetics, in Figure 3A a significant increase in tc is noted in the presence of PEO, with a trend similar to that observed at 35 °C. The increase in tc was 89% and 73% for PEO concentrations of 0.01 and 1% in ACE, respectively. For PEO of 8,000,000 g / mol, an increase in tc of 107% was observed, as shown in Table 1. Table 1: Experimental data of initial foam height (Hi) and total foam collapse time (tc) at 35 and 55 °C. reference system: ACE without PEO particles. # percentage of variation of the referred foam parameter with ACE + PEO in relation to the reference system.

[0036] The test results indicate that the presence of microparticulate PEO in PDMS-based ACE is capable of enhancing the inhibitory effect of petroleum foams. However, the time to total collapse was significantly increased. The test results indicated that both the PEO concentration in ACE and the molecular mass are important parameters, as they affect both Hi and tc. The tests indicated the potential of the antifoam additive, as a reduction of up to 32% in the initial foam height was observed. The main property of particulate material for good efficiency lies in the interface properties between the particle, the oil and the gas phase.

Claims

CLAIMS 1. Method for obtaining an antifoam additive characterized by comprising the following steps: a. solubilizing 27.5% by mass of polymethyl siloxane (PDMS) and 72.5% by mass of polyalphaolefin oil (PAO), at 25 °C, until obtaining a homogeneous solution; b. adding microparticulate polyethylene oxide (PEO) with a molecular mass of 100,000 or 8,000,000 g / mol to the solution of step (a) in a mass fraction of 0.01 or 0.1%; c. homogenizing the solution obtained in step (b) for 5 to 10 minutes, preferably 5 minutes, at 25 to 30 °C, preferably 25 °C by mechanical dispersion at 1800 to 2200 rpm, preferably 2000 rpm; and d. obtaining an antifoam additive.

2. Antifoam additive characterized by being obtained by the method of claim 1 and comprising: - PDMS and PAO solution with 27.5% by mass of PDMS and 72.5% by mass of polyalphaolefin oil (PAO); and - Microparticulate PEO in a fraction of 0.01 or 0.1% by mass in relation to the mass of the PDMS + PEO solution.

3. Additive according to claim 2, characterized in that it comprises microparticulate polyethylene oxide (PEO) with a molecular mass of 100,000 or 8,000,000 g / mol.

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