Patent Application
20230166989
The disclosure of the present patent application relates to separating water from oil or other viscous fluids and, more particularly, to a method and system for liquid separation using magnetite.
Export standards for exporting crude oil and transferring crude oil to refineries and vessels requires low water and sediment (Bs&W) content in crude oil. Separating oil and other viscous fluids from water is of extreme importance, both economically and environmentally. The amount of Bs&W percentage in crude oil is directly proportional to salt content. The higher the amount of Bs&W, the lower the quality of the crude oil and the higher risk of corrosion to facility and pipelines.
Conventional methods to purify crude oil predominately involve chemicals.
Chemical methods to purify crude oil are associated with high cost and damage to the environment. Chemicals commonly used include stabilizers which adjust the color, pH, corrosion, and enhance the stability of hard water. Solvents minimize the viscosity of the surfactants, depress the freezing point of the dispersant, dilute the dispersant compound and maximize the dispersant concentrations. Surfactants minimize the formation of oil in the water emulsion, to increase and spread the microbial decomposition surface area.
Thus, a method and system for separating oil from water solving the aforementioned problems is desired.
A method for separating water from oil can include the steps of adding magnetite powder to a mixture of oil and water and subjecting the resulting mixture to a magnetic field, such that the magnetite powder and the oil are drawn out of the mixture.
A system for separating oil from water includes a closed chamber with an inlet pipe, a crude oil outlet pipe and a water outlet pipe extending into the chamber. The inlet pipe and the crude oil outlet pipe are at a higher level in the chamber than the water outlet pipe. The magnetite powder, oil, and water can be fed into the chamber via the inlet pipe. The magnetite powder combines with or binds to the oil in the mixture. A plurality of magnetic field generating elements extend into the chamber and generate a magnetic field when activated. The magnetic field generating elements can separate the oil and magnetite powder combination from the water by raising the oil and magnetite powder combination such that the water sinks to the bottom of the chamber. The water can be removed via the water outlet pipe. A lower valve of the chamber can be opened to drain the water until the crude oil and magnetite powder combination is lowered to a predetermined level, at which point the valve can be closed. A sensor at a lower portion of the chamber can be configured to detect crude oil proximate to the valve. In an embodiment, the chamber cavity can provide a magnetic field of about 12,000 gauss.
These and other features of the present subject matter will become readily apparent upon further review of the following specification.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
A method for separating water from oil can include the steps of adding magnetite powder to a mixture of oil and water and directing the resulting oil, water, and magnetite mixture to a magnetic chamber including magnetic field generating elements. The magnetic field generating elements can provide a magnetic field of about 12,000 gauss, for example. As the magnetite powder is hydrophobic, the magnetite powder can coalesce with the oil inside the chamber, such that the oil and magnetite powder are elevated and the water sinks to the bottom of the chamber. A valve at a lower portion of the chamber can be opened to drain the water collected at the bottom of the chamber. After the water is drained, the fluid remaining in the chamber includes magnetite and crude oil.
In an embodiment, the magnetite powder includes magnetite nanoparticles. The nanoparticles can range in size from about 15 nm to about 35 μm, for example from about 15 nm to about 5 μm. In an embodiment, the oil is selected from crude oil, diesel fuel, and cooking oil. Although separation of oil from water is described herein, it should be understood that the present method can be used to separate water from other viscous fluids in a similar manner.
A system 100 for separating water from oil is shown in
The removeable lid 104 includes a centrally located magnetic element support plate 110 with a handle 106 for manipulating the lid 104 attached to a top surface. A plurality of magnetic field generating elements 212 extend downwardly from the bottom surface of the magnetic element support plate 110. The magnetic field generating elements 212 are electrically connected to a power supply (not shown) and produce a magnetic field in the chamber's cavity 200 when activated. The lid 104 can include a plurality of pivoting and tightening latches 108 for securing the lid 104 to the top of the chamber 102. The latches 108 include threaded shafts 206 that extend through the latch slots 204 in the radially extending flange 202, and latch slots 204 in the lid 104, when the latches are in their locked position. An O-ring seal 214 between the lid 104 and the flange 202, seals the chamber's interior 200.
The operation of the system 100 is illustrated in
The efficiency of different sized magnetite particles (powder) sizes for removing crude oil (30° API) (SAE-30), diesel fuel and cooking oil from water was determined using the standard test method for water and sediment in crude oil by the centrifuge method (ASTM D4007—11(2016)e1). Samples with magnetite particles having the following mean particle sizes were tested: 35 μm (Sample A), 5 μm (Sample B), and 15 nm (Sample C)). with a temperature range of 60° C. (+−3). As described herein, Sample A showed a lower removing efficiency compared to both Sample B and Sample C because the surface area of the magnetite particles in this sample was smaller than that of the particles of Sample B and C. Increased surface area of the particles facilitates combining with more oil droplets in the sample. In other words, as particle size is reduced, more oil droplet can be collected from the sample.
It should be noted that the results were rounded to the closest 0.025% of Bs&W.
The graph 800 and Table 2 indicate that as the amount of 35 μm magnetite powder is increased from 0.333 g to 1 g, the efficiency (Eff.) increases steadily from 62.87% to 67.62%.
The results show a slight increase in efficiency of removing the crude oil from the seawater as the amount of 5 μm magnetite is increased. The graph 900 and Table 3 indicate that as the amount of 5 μm magnetite powder is increased from 0.333 g to 1 g, the efficiency (Eff.) increases steadily from 83.95% to 88.29%.
The results show a slight increase in efficiency of removing the crude oil from the seawater as the amount of 15 nm magnetite is increased. The graph 1000 and Table 4 indicate that as the amount of 15 nm magnetite powder is increased from 0.333 g to 1 g, the efficiency (Eff.) increases steadily from 93.62% to 98.1%.
The graph 1100 and Table 5 indicate that as the amount of 35μ magnetite powder is increased from 0.333 g to 1 g, the efficiency (Eff.) increases steadily from 18.5% to 26.59%.
The graph 1200 and Table 6 indicate that as the amount of 5 μm magnetite powder is increased from 0.333 g to 1 g, the efficiency (Eff.) increases steadily from 33.79% to 45.74%, substantially higher than the 35 μm magnetite powder efficiency.
The graph 1300 and Table 7 indicate that as the amount of 15 nm magnetite powder is increased from 0.333 g to 1 g, the efficiency (Eff.) increases steadily from 37.83% to 51.35%, Accordingly, the magnetite powder can be used both diesel fuel and crude oil removal from water.
The graph 1400 and Table 8 indicate that as the amount of 35 μm magnetite powder is increased from 0.333 g to 0.5 g, the efficiency (Eff.) increases only slightly from 56.65% to 58.77%. The efficiency also increases only slightly as the amount of 5 μm magnetite powder is increased from 0.333 g to 0.5 g, from 63.98% to 64.92%. As the amount of 15 nm magnetite powder is increased from 0.333 g to 0.5 g, the efficiency increases substantially when compared to the larger powders, from 72.64% to 79.07%. While the efficiency of the magnetite powder when used with cooking oil is less than its efficiency when used with crude oil, it is substantially more efficient at removing/recovering cooking oil when compared with diesel fuel.
It is to be understood that the method of and system for separating water from oil is not limited to the specific embodiments described above but encompasses any and all embodiments within the scope of the generic language of the following claims enabled by the embodiments described herein, or otherwise shown in the drawings or described above in terms sufficient to enable one of ordinary skill in the art to make and use the claimed subject matter.
