Method for producing bio-based dielectric fluids

Abstract

The process for processing the bio-feedstock to produce the bio-feedstock dielectric fluid comprises a process for treating the bio-feedstock to produce a bio-feedstock dielectric fluid. 2 It can be carried out using equipment mounted on a mobile transportation platform system having a total footprint of: The process achieves production under low energy and pressure conditions using the described array of pumps, heaters, filters, degassers and high vacuum systems, and additive metering / mixing valve systems.

Description

[Technical field]

[0001] The present invention relates to the processing of bio-feedstocks to provide bio-feedstock dielectric fluids. [Background technology]

[0002] Dielectric (or insulating) fluids used in electrical distribution and power equipment, including transformers, switching gear and electrical cables, perform two important functions: they act as an electrical insulating medium, i.e., they exhibit dielectric strength, and they carry away generated heat from the equipment, i.e., they act as a cooling medium. For example, when used in transformers, dielectric fluids carry heat from the windings and core of the transformer or connected circuits to a cooling surface. Apart from having dielectric strength and cooling capabilities, an ideal dielectric fluid for electronic equipment would also exhibit little or no adverse effects on the environment, be compatible with the materials used to construct the equipment, and be relatively non-flammable.

[0003] There are several specific functional properties that are characteristic of dielectric oils. The dielectric breakdown, or dielectric strength, of an oil provides an indication of the oil's ability to resist electrical breakdown and is measured as the minimum voltage required to cause an arc discharge between two electrodes at a specific gap submerged in the oil. The impulse breakdown voltage provides an indication of the oil's ability to resist electrical breakdown under transient power stresses such as lightning and power surges. The dissipation factor of an oil is a measure of the dielectric loss in the oil, with a low dissipation factor indicating low dielectric loss and low concentrations of soluble polar contaminants. The gassing tendency of an oil measures the tendency of the oil to generate or absorb gas under conditions in which partial discharges are present. Similarly, stray gassing can occur as a result of thermal stress in dielectric oils (e.g., transformer oils) and can cause the release of hydrogen, methane, ethane, ethylene, and the like.

[0004] Since one of the functions of a dielectric fluid is to transport and dissipate heat, factors that significantly affect a fluid's relative ability to function as a dielectric coolant include viscosity, specific heat, thermal conductivity, low temperature properties, and coefficient of expansion. In selecting the appropriate dielectric fluid for a particular application, the values ​​of these properties must be weighed for the equipment at all ratings, particularly over the range of operating temperatures.

[0005] In addition to the aforementioned properties that affect heat transfer, the dielectric fluid should have a relatively high dielectric strength, a low dissipation factor, a dielectric constant that is compatible with solid dielectrics, low gassing tendency, and must be compatible with the electronic equipment materials to which it will be exposed. Control of stray gassing prevents the accumulation of explosive gases in the headspace of electronic equipment.

[0006] Dielectric fluids for use in electronic devices comprising vegetable oils or vegetable oil blends and containing one or more antioxidant compounds are described in US Pat. No. 7,651,641 to Corkran, et al.

[0007] U.S. Patent Publication No. 2018 / 0294068 describes a method for insulating and cooling transformers using enzymatically degummed vegetable oils, as well as a method for adding enzymatically degummed vegetable oils to the housings of electronic devices. The application also discloses a process for making a dielectric fluid using enzymatic degumming of vegetable oils, or using enzymatically degummed vegetable oils as a starting material for the process. Summary of the Invention

[0008] Mobile systems have been developed for conditioning, or particularly reconditioning, mineral oil for use as a dielectric fluid in transformers. These systems provide the ability to recondition the mineral oil at the transformer site, thereby avoiding transportation of the mineral oil from the point of use to a central processing facility and vice versa.

[0009] For example, systems for conditioning transformer oil, such as the model SES320(R)-3000 Insulating Oil Purifier by Sesco, Inc., are described at https: / / www.sesco-inc.com / 37-products / transformer-service-equipment / insulating-oil-purifiers / ses320-insulating-oil-conditioning / ses320-r / 90-ses320-3000.html. These systems are designed for single-pass conditioning of new and in-use (Group I and II) insulating fluids, increasing voltage values ​​(dielectric strength) by removing dissolved water, dissolved gases, oxidation by-products, and solid material contamination. This model is also described as useful for "natural ester fluids" if process specifications are met by reducing the flow capacity of the system by up to 25% when treating natural or synthetic ester dielectric fluids, and it is further recommended to perform at least two passes of the fluid through the system.

[0010] Similarly, transformer oil purification systems have been marketed by Enervac international ULC, as described at http: / / www.enervac.com / transformer-oil-purification-systems. For example, the E865A product is described as performing a very high vacuum process for the dehydration and degassing of electrical insulating liquids, including transformer oils, polybutenes and silicone fluids, to increase and maintain their dielectric strength. Processing includes the removal of free and soluble water, dissolved air and gases, and particulate matter.

[0011] An apparatus for drying and degassing oil is described in U.S. Patent No. 4,121,352. The apparatus includes a treatment tank, an oil circulation circuit with a pumping set, heating means, and spraying means, and a high vacuum pump for applying a partial high vacuum to the oil in the tank. The apparatus is shown disposed on a wheeled carriage.

[0012] In contrast to the inventive system for processing biofeedstock to provide a biofeedstock dielectric fluid, a typical process design of a prior art mobile system 100 for reconditioning mineral oil is shown in FIG. 1 as a schematic process flow diagram. In this system, used mineral oil is provided to a mineral oil source tank 110. The mineral oil is pumped from the mineral oil source tank 110 by a pump 120 and heated, for example, by a heater 130 to a temperature of about 60° C. The mineral oil can be pumped through the mobile system 100 at a flow rate of, for example, about 9000 l / hr (9 M3 / H). The heated oil is then filtered through an absorbent medium, for example, a clay filter 140 that decolorizes and / or removes polar and / or acidic components from the oil. The oil then flows through a paper filter 150 to capture particles that may escape from the clay filter. The oil is then degassed in a degasser / high vacuum system array 160, which includes a degasser 162 and a high vacuum system 164. The degassed oil then passes through a final paper polishing filter 170 before being sent to the final product tank 180. Mineral oil is relatively easy to process compared to bio-based feedstocks because it is non-polar. Thus, in one pass through conventional filtration equipment, the used mineral oil can generally be decolorized and acidic materials can be removed from the used mineral oil. Because it is relatively easy to remove water and other polar species from the mineral oil, inexpensive paper filters can be used after the clay treatment step because the paper is not exposed to polar species and water and will not deform or stretch. In addition, mineral oil exhibits a relatively low viscosity and does not retain fines that tend to damage downstream filtration media. In addition, it should be noted that care must be taken when heating the mineral oil. If the mineral oil is heated to too high a temperature, it can be adversely affected and some components can volatilize and be removed during the degassing step.

[0013] In contrast, bio-based fluids are much more difficult to process compared to mineral oils, especially when the bio-based fluids are processed in a mobile system environment where there is limited space for equipment and power available to perform the processing. Those familiar with the processes and systems for reprocessing mineral oils and synthetic esters in a mobile system environment are not aware of issues that can complicate the production of bio-based dielectric fluids. First, bio-based fluids contain more polar functional groups than mineral oils. The main challenge in processing bio-based fluids to provide bio-based dielectric fluids is that the bio-based fluids contain water or readily pick up water. As discussed above, bio-based dielectric fluids (e.g., vegetable oils) are polar and therefore more likely to carry undesirable polar impurities (e.g., moisture, contaminants, or oxidation by-products) than mineral oils. The impurities in the bio-based fluids are less likely to be captured by conventional filtration equipment and processing conditions typically used for mineral oils. Additionally, the bio-based fluids can strip the treated clay of additional water. This can lead to unforeseen problems in both the production and use of bio-based dielectric fluids, such as swelling and weakening of filter paper and increased degassing times.

[0014] In addition, biofeedstocks contain polar impurities that are not typically present in mineral oils. These polar impurities are difficult to remove from the desired biofeedstock. Examples of such polar impurities include impurities from the oil refining process, such as phospholipids, and components formed by the breakdown of triacylglycerides, such as monoacylglycerides, diacylglycerides, aldehydes, ketones, acids, soaps, etc. The presence of water and such polar impurities is problematic for the use of biofeedstocks as dielectric fluids, and proper and economical processing of biofeedstocks for use as dielectric fluids is difficult.

[0015] It has been discovered that bio-feedstock derived dielectric fluids can be efficiently and effectively processed in a mobile environment, provided the design of the mobile system differs from that of systems configured for the reprocessing of mineral oils or synthetic esters.

[0016] Additionally, it has been discovered that the methods for producing dielectric fluids derived from bio-feedstocks using the mobile equipment described herein provide certain advantages in providing benefits in certain applications and markets. As smaller, less industrialized countries increase the growth of their industrial sectors, the use of smaller and / or more geographically remote equipment using dielectric fluids is required. The increased demand for smaller quantities of dielectric fluids for use at various work sites is generated by both the increased development of local industries and satellite production networks by international companies. In addition, the economies and import obligations of developing countries do not provide a price structure to support long-term imports of fluids, and in many cases, governments require the use of locally produced oils to support growth in their economic zones. It is not usually cost-effective to build large-scale production facilities to produce dielectric fluids for transformers in order to produce under the umbrella of local production. The mobile equipment described herein can be made at a cost that fits the economics of the market and may be co-located with the facility that uses the dielectric fluid to provide on-site processing, thereby allowing for "on-demand" delivery of the product at a reasonable price. In some aspects, multiple mobile units described herein are distributed within an area co-located at or near a facility that uses dielectric fluid to provide on-site processing, thereby providing a network of biofeedstock processing capabilities for localized "on-demand" delivery of product.

[0017] A method and mobile device for processing bio-feedstocks is described to produce bio-feedstock dielectric fluids that allow for low capitalization for market entry into newly emerging markets by processing the bio-feedstock fluids (i.e., vegetable oils) into highly refined base oils, which are then formulated and processed to provide dielectric fluid compositions to the specifications required for performance in electronic devices.

[0018] In an aspect, a method for processing a biofeedstock to provide a biofeedstock dielectric fluid includes: Providing a biofeedstock starting material; heating the biofeedstock to a temperature of at least about 60°; circulating the heated biofeedstock through an adsorbent media array comprised of clay media in an adsorbent media column, the adsorbent media removing polar impurities from the biofeedstock; circulating the heated oil through one or more filter arrays, the filter arrays collectively retaining particles 0.5 microns or larger having a beta rating of at least 200; circulating the heated oil through a degasser and high vacuum system array; adding additives in liquid form, including antioxidants, optional pour point depressants, and optional colorants, to the biofeedstock by use of an additive metering / mixing valve system to provide a biofeedstock dielectric fluid; and collecting the bio-feedstock dielectric fluid; Where: i) the biofeedstock is maintained at a temperature of at least about 60°C throughout the process; ii) the mobile device is configured such that a pressure differential of the biofeedstock does not exceed about 300 kPa when flowing through the adsorbent media array or the one or more filter arrays; iii) the mobile device is configured to be able to operate with a power supply of about 100 kW to about 2000 kW; iv) The mobile device is approximately 30 m2 Mounted on a mobile transportation platform system having a total footprint of: wherein the bio-based dielectric fluid is (a) a dielectric loss coefficient of less than about 0.2% at 25°C; (b) an acid value (AV) of less than about 0.06 milligrams KOH / gram oil; (c) a water content of about 25 ppm or less; and (d) exhibiting a pour point of less than about -5°C.

[0019] In one aspect, a mobile apparatus for processing a bio-feedstock to provide a bio-feedstock dielectric fluid comprises: a pump and heater array; an adsorbent media array, the adsorbent media removing polar impurities from the biofeed; and one or more filter arrays downstream from the adsorbent media array, the filter arrays collectively retaining particles 0.5 microns or larger having a beta value of at least 200; a degasser and high vacuum system array; Additive metering / mixing valve system; a piping system fluidly interconnecting the pump and heater array, the adsorbent media array, the one or more filter arrays, the degasser and high vacuum system array, and the additive metering / mixing valve system; Where: i) the mobile apparatus is configured with a control unit for maintaining the biofeedstock at a temperature of at least about 60° throughout a process carried out in the apparatus; ii) the mobile apparatus is configured with controls to prevent the biofeedstock from being exposed to a pressure differential of more than 300 kPa throughout a process carried out in the apparatus; iii) The mobile device is configured with a control unit that enables the mobile device to be operated with a power supply of about 100 kW to about 2000 kW; iv) The pump and heater array, the adsorbent media array, one or more filter arrays, the degasser and high vacuum system array, the additive metering / mixing valve system, and the piping system are approximately 30 m 2 It is mounted on a mobile transportation platform system having a total footprint of:

[0020] The mobile apparatus described herein is particularly advantageous because it provides a specialized manufacturing facility that does not require the capital investment of building a full-scale manufacturing plant. The need to provide high quality, low cost, locally supplied dielectric fluids can be economically met by assembling the mobile apparatus of the present invention at production scale in a controlled manufacturing facility such as a manufacturing plant. The mobile apparatus itself can be prepared using standard procedures and equipment to provide a turnkey mobile apparatus that can be operated as a production facility that can be used anywhere in the world. The mobile apparatus is mobile in the sense that it can be easily transported from the assembly location to the use location. In some embodiments, the mobile apparatus may be permanently located at its initial use location. In some embodiments, the mobile apparatus may be moved from one location to another multiple times during its operation time. [Brief description of the drawings]

[0021] The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate several aspects of the invention and, together with the description of the embodiments, serve to explain the principles of the invention. In the drawings, like reference numerals represent like parts. A brief description of the drawings is as follows: [Figure 1] FIG. 1 is a schematic process flow diagram of an example of a prior art mobile system for reconditioning mineral oil. [Diagram 2] FIG. 1 is a schematic process flow diagram of one embodiment of a mobile apparatus for processing a biofeedstock to provide a biofeedstock dielectric fluid. [Diagram 3] FIG. 1 is a schematic process flow diagram of an alternative embodiment of a mobile apparatus for processing a biofeedstock to provide a biofeedstock dielectric fluid. [Figure 4]FIG. 2 is a schematic process flow diagram of one embodiment of a sorbent media array that may be used in one embodiment of a mobile device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description, but rather the purpose of the embodiments selected and described is to facilitate a deeper appreciation and understanding by those skilled in the art of the principles and practice of the present invention.

[0023] The suitability of bio-based dielectric fluids for use in electronic devices can be determined by quantitative tests such as the Dielectric Dissipation Factor (DDF) test. Other tests, such as the Interfacial Tension of Oil Against Water by the Ring Method test ("IFT") and the DDF test, can indicate the presence of small amounts of soluble polar molecular contaminants that may be undesirable in electronic devices and may cause degradation of the electrical performance of the dielectric fluid in electronic devices. It will be understood that other such tests may be used as alternatives to the DDF test, while the method of the present invention is conveniently performed in situ to show that the material being treated meets the suitability standard as indicated by the DDF test described herein.

[0024] The dielectric loss factor is a measure of the dielectric loss caused by a liquid and is determined according to ASTM D924-08 at 25°C, with the test being performed using an average voltage gradient of 500 volts / mil and an applied voltage frequency of 60 Hz. High dielectric loss factor values ​​can indicate contamination of the liquid with moisture, particulate or soluble polar contaminants, or poor purification quality.

[0025] Bio-based feedstocks are particularly desirable for preparing the dielectric fluids of the present invention because they are derived from renewable resources and are generally readily biodegradable. In some embodiments, bio-based feedstocks have the additional property of increasing paper stability in transformer applications. Unlike mineral oils, bio-based feedstocks offer the advantages of high flash and fire point properties, low ignition potential, and low flame spread. The flash, fire, and ignition potential of synthetic esters are highly composition dependent. Bio-based feedstocks containing unsaturation provide beneficial flow properties, and a decrease in oil viscosity correlates with an increase in unsaturation.

[0026] In some aspects, the oil is a natural biosource oil, which means that it includes triacylglycerides obtained from a plant or animal source that have not been modified by reaction chemistry (e.g., by transesterification or the formation of an oil derivative product). For clarity, it is understood that a plant or animal oil that is modified by transesterification (i.e., the redistribution of fatty acid moieties present in a triglyceride oil to its glycerol moiety) is considered to be a natural biosource oil. In addition, it is understood that a plant or animal oil obtained by extraction is considered to be a natural biosource oil.

[0027] In some embodiments, the oil used in the preparation of the dielectric fluid is a vegetable oil. In some embodiments, the bio-based feedstock comprises a vegetable oil selected from the group consisting of castor oil, coconut oil, corn oil, cottonseed oil, crambie oil, flaxseed oil, jojoba oil, kukui nut oil, lesquerella oil, linseed oil, olive oil, palm oil, peanut oil, pine nut oil, rapeseed oil, safflower oil, sunflower oil, soybean oil, and veronica oil, and mixtures thereof. In some embodiments, the only oil in the dielectric fluid is a vegetable oil. In one embodiment, the only oil in the dielectric fluid is a vegetable oil selected from the group consisting of castor oil, coconut oil, corn oil, cottonseed oil, cramby oil, flaxseed oil, jojoba oil, kukui nut oil, lesquerella oil, linseed oil, olive oil, palm oil, peanut oil, pine nut oil, rapeseed oil, safflower oil, sunflower oil, soybean oil, and veronica oil, and mixtures thereof.

[0028] In one embodiment, the vegetable oil is selected from soybean oil and rapeseed oil.

[0029] In some embodiments, the biofeedstock is obtained from organic sources such as microorganisms, seaweed, and the like.

[0030] In an embodiment, a raw biofeedstock may be provided for use as a biofeedstock starting material having an unacceptably high acid value, which in an embodiment may be reduced before the biofeedstock is used as a biofeedstock starting material. For example, the raw biofeedstock may have an acid value of about 5 to about 0.1 milligrams KOH / gram oil, or about 3 to about 0.01 milligrams KOH / gram oil, or about 1 to about 0.01 milligrams KOH / gram oil. The acid value of the biofeedstock starting material may advantageously be reduced by any suitable pretreatment before being used as a biofeedstock starting material, i.e., before being processed in the apparatus of the present invention, before being processed in the mobile apparatus of the present invention. In an embodiment, the raw biofeedstock is pretreated by a deodorization treatment before being used as a biofeedstock starting material. In an embodiment, the raw biofeedstock is pretreated with an adsorbent comprising magnesium silicate to reduce the acid value before being used as a biofeedstock starting material. Examples of commercially available filter aids that can be used for this purpose include Britesorb™, Hubersorb™, Frypowder™, and Magnesol™. In some embodiments, the acid value of the raw biofeedstock is reduced prior to introduction into the mobile unit to provide a biofeedstock starting material having an acid value close to or within the desired acid value range for use as a dielectric fluid. If the acid value is close to or within the desired acid value range for use as a dielectric fluid, the acid value of the biofeedstock can be further reduced to the desired acid value level during processing in the mobile unit of the present invention. In some embodiments, the acid value of the raw biofeedstock is reduced prior to introduction into the mobile unit described herein to provide a biofeedstock starting material having an acid value of about 2 to about 0.01 milligrams KOH / gram of oil. In some embodiments, the biofeedstock starting material has an acid value of about 1 to about 0.01 milligrams KOH / gram of oil. In one embodiment, the biofeedstock starting material has an acid value of about 0.5 to about 0.01 milligrams KOH / gram oil.

[0031] In some embodiments, the biofeedstock starting material has an acid value of about 0.09 milligrams KOH / gram oil or less. In some embodiments, the biofeedstock starting material has an acid value of about 0.6 milligrams KOH / gram oil or less. In some embodiments, the biofeedstock starting material has an acid value of about 0.09 to about 0.005 milligrams KOH / gram oil. In some embodiments, the biofeedstock starting material has an acid value of about 0.09 to about 0.01 milligrams KOH / gram oil. In some embodiments, the biofeedstock starting material has an acid value of about 0.06 to about 0.005 milligrams KOH / gram oil. In some embodiments, the biofeedstock starting material has an acid value of about 0.06 to about 0.001 milligrams KOH / gram oil.

[0032] The raw biofeedstock provided for use as a biofeedstock starting material typically has a higher water content than a suitable mineral oil dielectric fluid. The water content of the raw biofeedstock is typically not reduced prior to use as a biofeedstock starting material. In some embodiments, the biofeedstock starting material has an initial water content of greater than about 100 ppm. In some embodiments, the biofeedstock starting material has an initial water content of about 100 ppm to about 400 ppm.

[0033] In some embodiments, a raw biofeedstock may be provided for use as a biofeedstock starting material that has an unacceptably high dielectric loss factor. In some embodiments, the dielectric loss factor of the raw biofeedstock is reduced prior to use as a biofeedstock starting material. The dielectric loss factor of the raw biofeedstock may be advantageously reduced prior to processing in the present apparatus by pretreatment prior to processing in the present apparatus. It has been found that pretreatment of the biofeedstock to reduce the initial dielectric loss factor prior to processing in the present apparatus is advantageous, as such pretreatment can substantially increase the useful life of the adsorbent media in the apparatus.

[0034] In some embodiments, the raw biofeedstock is pretreated with an adsorbent medium that removes polar impurities from the biofeedstock to reduce its dielectric loss factor for use as a biofeedstock starting material. In some embodiments, the raw biofeedstock may have a dielectric loss factor of about 1-10% at 25° C., which in some embodiments is reduced prior to introduction into an apparatus described herein as a biofeedstock starting material. In some embodiments, the raw biofeedstock may have a dielectric loss factor of about 2-10% at 25° C., which in some embodiments is reduced prior to introduction into an apparatus described herein as a biofeedstock starting material. In some embodiments, the raw biofeedstock may have a dielectric loss factor of about 3-10% at 25° C., which in some embodiments is reduced prior to introduction into an apparatus described herein as a biofeedstock starting material.

[0035] In some embodiments, the bio-feedstock starting material has a dielectric loss factor of at least 0.5% at 25° C. In some embodiments, the bio-feedstock starting material has a dielectric loss factor of at least 0.7% at 25° C. In some embodiments, the bio-feedstock starting material has a dielectric loss factor of at least 0.8% at 25° C. In some embodiments, the bio-feedstock starting material has a dielectric loss factor of at least 0.9% at 25° C. In some embodiments, the bio-feedstock starting material has a dielectric loss factor of at least 1% at 25° C.

[0036] In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.5% to about 3% at 25°C. In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.5% to about 2% at 25°C. In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.5% to about 1.5% at 25°C. In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.5% to about .8% at 25°C. In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.08% to about 0.5% at 25°C. In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.08% to about 0.4% at 25°C. In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.08% to about 0.3% at 25°C. In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.08% to about 0.2% at 25° C. In some embodiments, the biofeedstock starting material has a dielectric loss factor of about 0.1% to about 1% at 25° C.

[0037] The biofeedstock starting material is heated to a temperature greater than about 60° C. using any suitable heating system, such as a heat exchanger. In certain embodiments, the biofeedstock starting material is heated to a temperature of about 60° C. to about 80° C. using any suitable heating system, such as a heat exchanger. In certain embodiments, the temperature of the biofeedstock is maintained at a temperature greater than about 60° C. throughout the method (i.e., after the initial heating step until the optional circulation of the heated oil through the polishing filter). In certain embodiments, the temperature of the biofeedstock is maintained at a temperature of about 60° C. to about 80° C. throughout the method (i.e., after the initial heating step until the optional circulation of the heated oil through the polishing filter).

[0038] The biofeedstock is pumped by one or more suitable pumps located in a location in the apparatus appropriate for circulating the biofeedstock at a flow rate and hydraulically (e.g., a location described herein).

[0039] The heated biofeedstock is circulated through at least one sorbent media array, where the sorbent media in the sorbent media array removes polar impurities from the biofeedstock to obtain a biofeedstock dielectric fluid having a desired dielectric loss factor. Advantageously, the sorbent media arrays described herein are space efficient and effectively remove polar impurities under relatively low pressure conditions. This is in contrast to oil processing methods typically used in large-scale plant conditions that use large, heavy industrial equipment (such as filter presses operating at high pressures) to perform certain filtration steps.

[0040] In one aspect, the heated biofeedstock is circulated through an array of adsorbent media selected to reduce the polar components present in the biofeedstock such that the final biofeedstock dielectric fluid exhibits a desired dielectric loss factor.

[0041] In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.20% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.18% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.12% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.1% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.09% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.08% or less at 25° C.

[0042] In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.005 to 0.2% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.005 to 0.18% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.005 to 0.15% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.005 to 0.12% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01 to 0.2% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01 to 0.18% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01 to 0.15% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01 to 0.12% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03 to 0.2% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03 to 0.18% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03 to 0.15% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03 to 0.12% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.05 to 0.2% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.05 to 0.18% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.05 to 0.15% at 25° C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.05 to 0.12% at 25° C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.07 to 0.15% at 25° C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.08 to 0.15% at 25° C.

[0043] The sorbent media array includes several sorbent media columns packed with sorbent media. The sorbent media columns are connected in parallel to facilitate the desired low flow rates in each individual sorbent media column for efficient removal of polar impurities while maintaining an average overall flow rate to achieve acceptable productivity of the mobile device. Multiple combinations or single use of these sorbent media columns can be utilized as desired. Various configurations of sorbent filter arrays are described below with reference to the drawings.

[0044] The adsorbent media of the adsorbent media array are selected from materials that remove polar impurities. In one embodiment, the adsorbent media used in the adsorbent media array are selected for removal of polar impurities by screening tests, whereby a sample of biofeedstock to be processed at the point of use (e.g., soybean oil, corn oil) is loaded with 0.25 wt% of the proposed solid adsorbent media and heated at 80° C. for 2 hours under 10 mm high vacuum, and the dielectric loss factor is measured before and after to confirm the effectiveness of the adsorption of polar impurities for the expected end-use specifications of the biofeedstock dielectric fluid.

[0045] In one embodiment, the sorbent media used in the sorbent media array is selected for removal of polar impurities such that a biofeedstock sample having a dielectric loss factor of 1% or less at 25° C., when loaded with 0.25 wt % of the proposed solid sorbent media and heated at 80° C. for 2 hours under 10 mm high vacuum, has a final dielectric loss factor of 0.2% or less at 25° C.

[0046] In some embodiments, the adsorbent medium comprises a clay medium selected from silicates, aluminates, etc., for removing polar impurities. In some embodiments, the adsorbent medium comprises a clay selected from phyllosilicates. In some embodiments, the adsorbent medium comprises a phyllosilicic acid clay material selected from halloysite, kaolinite, illite, montmorillonite, vermiculite, talc, sepiolite, attapulgite, and pyrophyllite.

[0047] In one embodiment, the adsorbent medium comprises an adsorbent medium selected from attapulgite clays, bauxite clays, bentonite clays, modified silicates, aluminates, magnesium silicates, modified diatomaceous earth, fuller's earth, bleaching earth, resins, other such adsorbent materials modified to remove polar impurities, and mixtures thereof.

[0048] Additionally, it has been discovered that adsorbent media, such as clay media, may be particularly susceptible to degradation over time when exposed to biofeedstocks, as compared to mineral oils. Without wishing to be bound by theory, it is believed that the more polar nature of the biofeedstocks may act to break down the adsorbent media, producing smaller fines that may pass through to subsequent operations of the process. For this reason, the adsorbent media should be selected to have a particle size large enough to avoid generating harmful fines loads downstream. In some embodiments, the adsorbent media columns are each provided with a suitable filtration or screen component to avoid loss of fines from the adsorbent media columns. In some embodiments, the adsorbent media columns are each provided with a filtration or screen component of about 300 to about 250 mesh. In some embodiments, the adsorbent media columns are each provided with a filtration or screen component of about 450 to about 300 mesh. In some embodiments, the adsorbent media columns are each provided with a filtration or screen component of about 625 to 450 mesh.

[0049] In one embodiment, the sorbent media column comprises solid sorbent media having a particle size of 30-90 mesh packed into a canister fitted with a bottom retention screen. It has been found that sorbent media traditionally used in mineral oil reconditioning systems can have much smaller particle sizes, on the order of 90-200 mesh, and therefore require high pressure pumping that can adversely affect the process and / or performance of the final biofeedstock. Additionally, it has been found that the use of solid sorbent media having a particle size larger than about 30 mesh results in undesirably low efficiencies.

[0050] In one embodiment, the adsorbent medium contains magnesium silicate having a particle size of 30 to 90 mesh.

[0051] In one embodiment, the adsorbent media array comprises a column containing thermally activated granular attapulgite adsorbent, such as Microsorb 30 / 60 LVM. In one embodiment, the adsorbent media array comprises a column containing activated bauxite, such as Purocel R1 PSD adsorbent.

[0052] In some embodiments, the heated biofeedstock is further circulated through an array of adsorbent media selected to reduce acids in the biofeedstock.

[0053] In some embodiments, the heated biofeedstock is circulated through a sorbent media array selected to reduce the acids in the biofeedstock to an acid number (AV) of 0.06 milligrams KOH / gram oil or less. In some embodiments, the heated biofeedstock is circulated through a sorbent media array selected to reduce the acids in the biofeedstock to an acid number (AV) of 0.03 milligrams KOH / gram oil or less. In some embodiments, the heated biofeedstock is circulated through a sorbent media array selected to reduce the acids in the biofeedstock to an acid number (AV) of about 0.06 milligrams KOH / gram oil to about 0.01 milligrams KOH / gram oil.

[0054] In one embodiment, the sorbent media used in the sorbent media array are selected for acid number reduction by a screening test whereby a sample of biofeedstock to be processed at the point of use (e.g., soybean oil, corn oil) is loaded with 0.25 wt% of the proposed solid sorbent media and heated at 80° C. for 2 hours under 10 mm high vacuum and the acid number is measured before and after to confirm the effectiveness of the acid number reduction for the expected end use specifications of the biofeedstock dielectric fluid.

[0055] In one embodiment, the sorbent media used in the sorbent media array is selected for reduction of acid value such that a biofeedstock sample having an acid value of about 0.08 milligrams KOH / gram oil, when loaded with 0.25 wt% of the proposed solid sorbent media and heated at 80° C. under 10 mm high vacuum for 2 hours, has a final acid value (AV) of 0.06 milligrams KOH / gram oil or less.

[0056] In one embodiment, a mobile device is provided comprising a plurality of adsorbent media arrays in series, a first adsorbent media array comprising a media selected to reduce acid value, and a second adsorbent media array comprising a media selected to remove polar impurities.

[0057] In certain aspects, certain adsorbent media used in the media arrays described herein have been found to be effective in both removing polar impurities and reducing acid number in biofeedstocks. Such media can be identified by performing both the polar impurity adsorption screening test and the acid number reduction screening test, as described above.

[0058] In one aspect, a mobile device is provided with a single set of sorbent media arrays, the sorbent media arrays including media selected to reduce acid number and remove polar impurities.

[0059] In one embodiment, it has been found that an adsorbent medium comprising magnesium silicate can be effective in reducing both the dielectric loss factor and acid number of bio-feedstocks.

[0060] It has been found to be advantageous to practice the invention such that the biofeedstock pressure differential does not exceed about 300 kPa as it flows through the mobile unit. In certain embodiments, the methods of the invention are practiced such that the biofeedstock pressure differential is between about 100 kPa and about 300 kPa as it flows through either the adsorbent media array or the filter array. In certain embodiments, the methods of the invention are practiced such that the biofeedstock pressure differential is between about 100 kPa and about 250 kPa as it flows through either the adsorbent media array or the filter array. The biofeedstock pressure differential may be different in different components of the mobile unit depending on the relative location of any given component from the pump and the operation of a given component or components upstream from the given component.

[0061] It has been found that operating at too low a pressure reduces the productivity of the mobile system, while operating at too high a pressure can cause damage to either the adsorbent media array or the filter array. In addition, high pressure differentials have been found to cause processing and potential quality issues in the resulting biofeedstock dielectric fluid.

[0062] It has been found to be advantageous to carry out the process of the invention such that the flow rate of the biofeedstock through the adsorbent media arrays and filters used in the process of the invention is relatively low for effective removal and filtration of polar components from the biofeedstock, this beneficial effect being much more pronounced when processing biofeedstocks as compared to mineral oils.

[0063] In certain embodiments, it has been found to be advantageous to carry out the methods of the invention such that the flow rate of the biofeedstock through the adsorbent media array does not exceed about 10 cubic meters per square meter of media per hour (M3 / H / M2). It has been found that processing the biofeedstock through the adsorbent media array at flow rates greater than about 10 M3 / H / M2 can result in detrimental pressure release and acetylene production. In certain embodiments, the methods of the invention are carried out such that the flow rate of the biofeedstock through the adsorbent media array is between about 3 and about 10 M3 / H / M2. In certain embodiments, the methods of the invention are carried out such that the flow rate of the biofeedstock through the adsorbent media array is between about 6 and about 10 M3 / H / M2.

[0064] In one aspect, the sorbent media arrays and filters used in the methods of the invention are monitored for filtration efficiency, rotated during downtime, and replenished as needed.

[0065] After the heated biofeedstock is circulated through the sorbent media array, the oil is circulated through one or more filter arrays to remove fines from the biofeedstock. Polar, highly viscous biofeedstocks have been found to carry large fines loads to the filter array, necessitating a filter to remove the fines load from the system before secondary processing through a degasser to remove excess water introduced into the system. Paper filters typically used for mineral oils stretch and allow fines to pass through to downstream processes, causing blockages and negatively impacting the properties of the biofeedstock transformer fluid.

[0066] In addition, filters typically used in prior art mineral oil reconditioning processes have been found to be ineffective at capturing fines generated during the process from obtaining biofeedstock dielectric fluids. Without wishing to be bound by theory, it is believed that the biofeedstock retains large amounts of water and polar components that adversely affect the aggregation of the absorbent media (e.g., clays) and generate very small fines that leak, damage, or are not captured by conventional filters used in mineral oil processes. Alternatively, or in addition, it is believed that the polarity of the biofeedstock itself adversely affects the performance of conventional filters used in mineral oil processes when the use of such conventional filters is attempted in the method of the present invention.

[0067] In one embodiment, filters used in the mobile devices of the present invention are selected to show no loss of particle retention or beta performance due to distortion or degradation of the filter material in a screening test in which the filter is exposed to a flow of water through the filter at a pressure differential of 300 kPa for 4 hours at a temperature of 80° C. Typical failure modes of filters in this screening test are swelling of the filter media, creation of large pores or voids, or distortion of the filter structure.

[0068] In some embodiments, the filters used in the ambulatory devices of the present invention comprise a non-water-swellable filter medium, hi some embodiments, the filter medium comprises a material selected from polypropylene, HDPE, and the like.

[0069] In one embodiment, multiple filter arrays located downstream from the adsorbent media array are used to retain particles in a graded manner, with a first filter array sized to retain larger particles and a second filter array sized to retain smaller particles, with the final filter array in the mobile device selected to retain particles of the largest size allowed in the biofeedstock dielectric fluid.

[0070] In some embodiments, the filters of the first filter array are selected to retain particles of 10 microns or larger. In some embodiments, the filters of the first filter array are selected to retain particles of 5 microns or larger. In some embodiments, the filters of the first filter array have a beta value of at least 200. In some embodiments, the filters of the first filter array have a beta value of at least 500. In some embodiments, the filters of the first filter array have a beta value of at least 800. In some embodiments, the filters of the first filter array have a beta value of at least 1000.

[0071] After the oil has been circulated through the first filter array, the oil is optionally circulated through a second filter array if the desired specifications of impurity and / or particulate removal are not achieved in circulating the oil through the first filter array.

[0072] In some embodiments, the filters of the second filter array are selected to retain particles of 5 microns or larger. In some embodiments, the filters of the second filter array are selected to retain particles of 1 micron or larger. In some embodiments, the filters of the second filter array are selected to retain particles of 0.5 microns or larger. In some embodiments, the filters of the second filter array have a beta value of at least 800. In some embodiments, the filters of the second filter array have a beta value of at least 1000. It has been found that using filters having a beta value of at least about 800 provides excellent protection of the degasser from particulate contamination.

[0073] In certain embodiments, the flow rate of the biofeedstock through any filter array of the method does not exceed about 100 M3 / H / M2. In certain embodiments, the methods of the invention are practiced such that the flow rate of the biofeedstock through any filter array of the method is between about 30 and about 100 M3 / H / M2. In certain embodiments, the methods of the invention are practiced such that the flow rate of the biofeedstock through any filter array of the method is between about 60 and about 100 M3 / H / M2. The filters used in the methods and apparatus of the invention are in contrast to filters used in mineral oil processing, where filters having a nominal filter pore size of 75 microns are used.

[0074] As described above, the biofeedstock is heated to a temperature of at least about 60° as it passes through the sorbent media array and all filter arrays, which is advantageous for reducing the viscosity of the oil during filtration, thereby increasing filtration efficiency. In some embodiments, the biofeedstock is heated to a temperature of about 60° to about 80° C. as it passes through the sorbent media array and all filter arrays. Limiting the temperature of the biofeedstock to a temperature of 80° C. or less is advantageous when the sorbent media array and filter array are prepared using materials that are adversely affected by higher temperatures. In some embodiments, the biofeedstock may be heated to a temperature of 80° C. when the sorbent media array and filter array are prepared using high temperature resistant materials, such as sintered metal filters and non-plastic containers.

[0075] In one embodiment, the biofeedstock is maintained at a temperature of about 60° C. to about 80° C. throughout the process.

[0076] In one embodiment, the kinetic viscosity of the biofeedstock as it passes through the filter array is about 1-50 mm at 60° C. 2 In one embodiment, the kinetic viscosity of the biofeedstock as it passes through the filter array is about 1-35 mm / s at 60° C. 2 In one embodiment, the kinetic viscosity of the biofeedstock as it passes through the filter array is about 1-20 mm / s at 60° C. 2In one embodiment, the kinetic viscosity of the biofeedstock as it passes through the filter array is about 1-50 mm / s at 60° C. 2 / s.

[0077] The heated oil is then circulated through a degasser and high vacuum system array comprising a high vacuum system that generates a high vacuum sufficient to degas the fluid and remove water and dissolved gases from the biofeedstock. In an embodiment, the biofeedstock starting material has an initial water content of greater than 100 ppm, or the biofeedstock starting material has an initial water content of between 100 ppm and 400 ppm. The presence of high levels of water in the biofeedstock starting material can be effectively managed and removed, as needed, by repeatedly circulating the biofeedstock through the degasser and high vacuum system array. Recirculation of the biofeedstock through the degasser and high vacuum system array has been found to increase processing time, but is not detrimental to the final outcome of the method. It is noted that unconditioned sorbent media may contain water, e.g., captured from the atmosphere. As the biofeedstock is processed through such sorbent media, water is eluted by the oil, potentially necessitating further recirculation of the biofeedstock through the degasser and high vacuum system array during system start-up.

[0078] In some embodiments, the biofeedstock is heated to a temperature of about 70° C. or higher prior to circulation through the degasser and high vacuum system array. In some embodiments, the degasser and high vacuum system array are configured to apply a high vacuum of less than about 15 mmHg, and the degasser is preferably configured to have a surface area sufficient to be designed to reduce the water present in the biofeedstock to about 40 ppm or less within three or fewer passes through the degasser and high vacuum system array. In some embodiments, the degasser and high vacuum system array are configured to apply a high vacuum of less than about 15 mmHg, and the degasser is preferably configured to have a surface area sufficient to be designed to reduce the water present in the biofeedstock to about 25 ppm or less within three or fewer passes through the degasser and high vacuum system array. In some embodiments, the degasser and high vacuum system array are configured to apply a high vacuum of less than about 12 mmHg. In some embodiments, the degasser and high vacuum system array are configured to apply a high vacuum of less than about 10 mmHg. In some embodiments, the degasser is configured to apply a high vacuum of less than about 8 to about 25 m 2 In one embodiment, the degasser has a surface area of ​​about 10 to about 20 m. 2 In one embodiment, the degasser has a surface area of ​​about 12 to about 18 m. 2 has a surface area of

[0079] It should be noted that due to the relatively low boiling point of mineral oil, it is not possible to degas mineral oil at the temperatures required by the process of the present invention.

[0080] In one embodiment, the pressure differential of the biofeedstock while in the degasser and high vacuum system array is typically about 100 kPa.

[0081] As discussed above, the biofeedstock starting material typically has an initial water content of greater than 100 ppm, or in some embodiments, the biofeedstock has an initial water content of between 100 ppm and 400 ppm. In some embodiments, the degasser and high vacuum system array reduces the water content of the biofeedstock starting material from greater than 100 ppm to a biofeedstock dielectric fluid water content of about 40 ppm or less. In some embodiments, the degasser and high vacuum system array reduces the water content of the biofeedstock starting material from greater than 100 ppm to a biofeedstock dielectric fluid water content of about 25 ppm or less. In some embodiments, the degasser and high vacuum system array reduces the water content of the biofeedstock starting material from between 100 ppm and 400 ppm to a biofeedstock dielectric fluid water content of about 25 ppm or less. In some embodiments, low final water content is achieved by passing the biofeedstock through the degasser and high vacuum system array multiple times, either by direct recirculation through the degasser and high vacuum system array, or by recirculation through the apparatus starting at any component upstream from the degasser and high vacuum system array (e.g., the pump and heater array, the adsorbent media array, the first filter array, or the second filter array).

[0082] At least one characteristic of the biofeedstock is tested after the biofeedstock is treated with the degasser and high vacuum system array to determine whether the biofeedstock meets the required performance specifications. In an embodiment, if the biofeedstock does not meet the required dielectric loss factor specifications, the biofeedstock may be redirected through a recycle loop to the adsorbent media array and / or one or more filter arrays and the degasser and high vacuum system array. If the biofeedstock meets the required dielectric loss factor specifications (e.g., 0.2% at 25°C), the biofeedstock may be redirected through a recycle loop, bypassing the adsorbent media array recycle, directly to one or more filter arrays and / or the degasser and high vacuum system array. It is noted that the measured dielectric loss factor continues to decrease to some extent even when the adsorbent media is bypassed by the moisture removal in the degasser and high vacuum system array.

[0083] In certain embodiments, if the biofeedstock does not meet the required water content specifications after being processed in the degasser and high vacuum system array, the biofeedstock may be diverted through a recycle loop to the adsorbent media array and / or one or more filter arrays and the degasser and high vacuum system array, or alternatively to one or more filter arrays and the degasser and high vacuum system array, or alternatively to the degasser and high vacuum system array.

[0084] After degassing, additives are added in liquid form as needed to provide a biofeedstock dielectric fluid that meets the required performance specifications. Adding these additives in liquid form is advantageous because it conveniently avoids the need to handle solids in mobile equipment, thereby greatly simplifying the process. Additionally, additives are added in-line in the process, providing for accurate and efficient addition with a high degree of control over the concentration of the additive.

[0085] In some embodiments, the developer is added using a flow or metering valve to regulate the introduction of the additive. The additive is generally metered into the biofeedstock as a concentrated solution. The additive may be metered into the biofeedstock by volume, weight, or flow rate to achieve the appropriate level of final concentration of the additive in the biofeedstock dielectric fluid.

[0086] In an embodiment, the additives added include an antioxidant, an optional pour point depressant, and an optional colorant.

[0087] The incorporation of antioxidant additives has been found to be beneficial as it retards the oxidation of esters, retarding the formation of gels and acidity. One such antioxidant is 2,6-di-tert-butyl-p-cresol (DBPC), also known as BHT, although others are also used. Detection and measurement of the specified antioxidant additives shall be in accordance with IEC 60666 or other appropriate methods.

[0088] In some embodiments, the additive may include a phosphite additive. In some embodiments, the phosphite component is present in an amount sufficient to reduce hydrogen (H2) gassing of the dielectric fluid by at least 60% as determined by dissolved gas analysis (ASTM D3612-02, Method C) as compared to a similar dielectric fluid composition not containing the phosphite component. In some embodiments, the phosphite component is present in an amount sufficient to reduce H2 gassing of the dielectric fluid by at least 70 percent as determined by dissolved gas analysis as compared to a similar dielectric fluid composition not containing the phosphite component. In some embodiments, the phosphite component is present in an amount sufficient to reduce H2 gassing of the dielectric fluid by at least 80 percent as determined by dissolved gas analysis as compared to a similar dielectric fluid composition not containing the phosphite component. Certain phosphite components added are described, for example, in WO 2019 / 183214(A1), the disclosure of which is incorporated herein by reference.

[0089] In some embodiments, the additive may include a metal passivator. The incorporation of a metal passivator has been found to be useful in dielectric fluids, particularly those containing synthetic ester oils. Without wishing to be bound by theory, it is believed that the metal passivator acts to reduce the catalysis of oxidative decomposition by dissolved metals and metal surfaces in the dielectric fluid's operating environment. In addition, the dielectric fluid compositions described herein that further include a metal passivator have been found to exhibit low fluid dielectric loss factors (and therefore reduced charging tendency) even under prolonged oxidative stress conditions.

[0090] In some embodiments, the metal passivator is selected from benzotriazole or its derivatives. In some embodiments, the metal passivator is selected from N,N-bis(2-ethylhexyl)-al-methyl-1H-benzotriazole-1-methanamine (e.g., commercially available as Irgamet 39), N,N-bis(2-ethylhexyl)-1H-1,2,4-triazole-1-methanamine (e.g., commercially available as Irgamet 30), 1H-benzotriazole (e.g., commercially available as Irgamet BTZ), methyl-1H-benzotriazole (e.g., commercially available as Irgamet TTZ), butyl-1H-benzotriazole, and 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]imino]bis-ethanol (e.g., commercially available as Irgamet 42).

[0091] In certain embodiments, a metal passivator is optionally present, typically in an amount less than 100 ppm.

[0092] In some embodiments, the total concentration of the additives is less than 5% by weight of the bio-sourced dielectric fluid.

[0093] After addition of additives, the biofeedstock is optionally cycled through an array of polishing filters to ensure that the desired specifications of impurity and / or particulate removal are achieved.

[0094] The polishing filter array has the same performance requirements as described above in the context of the filter downstream from the sorbent media array. By definition, when a polishing filter is used, it is the last filter array in the mobile device and is therefore selected to retain particles of the maximum size allowed in the biofeedstock dielectric fluid. In some embodiments, the filters of the polishing filter array are selected to retain particles of 0.5 microns or larger. In some embodiments, the filters of the polishing filter array have a beta value of at least 800. In some embodiments, the filters of the polishing filter array have a beta value of at least 1000.

[0095] The resulting biofeedstock dielectric fluid is collected in a convenient container, which may be, for example, a drum, tank, or tank trailer, or similar mobile storage vessel.

[0096] In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.20% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.18% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.12% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.1% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.09% or less at 25° C. In some embodiments, the bio-feedstock dielectric fluid has a dielectric loss factor of about 0.08% or less at 25° C.

[0097] In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.005 to 0.2% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.005 to 0.18% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.005 to 0.15% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.005 to 0.12% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01 to 0.2% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01 to 0.18% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01 to 0.15% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01 to 0.12% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03 to 0.2% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03 to 0.18% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03 to 0.15% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03 to 0.12% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.05 to 0.2% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.05 to 0.18% at 25°C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.05 to 0.15% at 25° C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.05 to 0.12% at 25° C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.07 to 0.15% at 25° C. In one embodiment, the bio-feedstock dielectric fluid has a dielectric loss factor of 0.08 to 0.15% at 25° C.

[0098] The bio-based dielectric fluid exhibits an acid number (AV) of 0.06 milligrams KOH / gram oil or less. In some embodiments, the bio-based dielectric fluid exhibits an acid number (AV) of 0.03 milligrams KOH / gram oil or less. In some embodiments, the bio-based dielectric fluid exhibits an acid number (AV) of about 0.06 milligrams KOH / gram oil to about 0.01 milligrams KOH / gram oil. Acid number is determined as described in ASTM 0974-12, "Standard Test Method for Acid Base Number by Color-Indicator Titration."

[0099] The bio-based dielectric fluid exhibits a dielectric breakdown voltage of at least about 35 kilovolts (kV) measured at 25° C. In some embodiments, the bio-based dielectric fluid has a breakdown voltage of 50 kV to 100 kV measured at 25° C. In some embodiments, the bio-based starting material has a breakdown voltage of 60 kV to 100 kV measured at 25° C. Dielectric breakdown is determined according to ASTM D1816-12, “Standard Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using VDE Electrodes.”

[0100] The bio-based dielectric fluid exhibits a water content of less than about 25 ppm. In some embodiments, the bio-based dielectric fluid has a water content of about 25 ppm to about 5 ppm. In some embodiments, the bio-based dielectric fluid has a water content of about 20 ppm to about 5 ppm. The water content is determined according to IEC 60814.

[0101] The bio-feed dielectric fluid has a pour point of about -5°C or less as determined by ISO 3016. In some embodiments, the bio-feed dielectric fluid has a pour point of -10°C or less. In some embodiments, the bio-feed dielectric fluid has a pour point of -20°C or less. In some embodiments, the bio-feed dielectric fluid has a pour point of -25°C or less. In some embodiments, the bio-feed dielectric fluid has a pour point of -30°C or less. In some embodiments, the bio-feed dielectric fluid has a pour point of -45°C or less.

[0102] In some embodiments, the bio-sourced dielectric fluid exhibits an IFT of at least about 20 dynes / cm at 25° C. In some embodiments, the bio-sourced dielectric fluid exhibits an IFT of at least about 22 dynes / cm at 25° C. IFT values ​​are determined at 25° C. using Standard Test Method D971-99a.

[0103] In some embodiments, the bio-sourced dielectric fluid has a fire point of at least 300° C. as determined by ISO 2592. In some embodiments, the dielectric fluid has a fire point of at least 310° C. as determined by ISO 2592.

[0104] In some embodiments, the bio-sourced dielectric fluid has a flash point, as determined by ISO 2719, of at least 250° C. In some embodiments, when the oil of the dielectric fluid is bio-sourced, the dielectric fluid has a flash point, as determined by ISO 2719, of at least 270° C.

[0105] In an embodiment, the bio-sourced dielectric fluid has a Gardner color number of 1 or less.

[0106] In one embodiment, the bio-sourced dielectric fluid has a dielectric constant of about 0.96 kg / m at 15° C. as determined by ASTM D1298. 3 It has the following relative density:

[0107] In one embodiment, the bio-based dielectric fluid has a dielectric constant of about 1-15 mm at 100° C. as determined by ISO 3104. 2 / s or at 40°C, about 1 to 35 mm 2 / s or about 20 to 35 mm at 40°C 2 / s or about 100 to 3000 mm at -20°C 2 In one embodiment, the bio-based dielectric fluid has a kinematic viscosity of about 9-50 mm / s at 40° C. 2 In one embodiment, the bio-based dielectric fluid has a kinematic viscosity of about 9-50 mm / s at 40° C. 2 / s. Kinematic viscosity is determined by the ISO 3104 test method.

[0108] In an embodiment, the bio-feedstock dielectric fluid has a peroxide value of about 0.01 to 5, or has a peroxide value of about 0.01 to 3, or has a peroxide value of about 0.01 to 2, or has a peroxide value of about 0.01 to 1, or has a peroxide value of about 0.1 to 1.2. For purposes of this disclosure, "peroxide value" is determined by AOCS Method Cd 8b-90.

[0109] In certain embodiments, the bio-based dielectric fluid is free of silicone compounds, and / or free of phospholipids, and / or free of pigments, and / or free of lecithin, and / or free of fatty acids, and / or free of mono- and diglycerides, and / or free of mineral acids, and / or free of mineral oils, and / or free of alcohols, and / or free of color impurities (e.g., non-bio-based materials that are not intentionally added to the fluid for the primary purpose of imparting a desired color), and / or free of sulfur compounds, and / or free of cresols, and / or free of polyaromatic hydrocarbons, and / or free of halogenated compounds, and / or free of amines. For purposes of this discussion, a bio-based dielectric fluid is considered free of a given substance if 1 ppm or less of the substance can be detected.

[0110] The methods of the invention described above are carried out using a unique mobile apparatus with special features that allow for the processing of a biofeedstock to provide a dielectric fluid in a geographically convenient location and economically. In particular, the mobile apparatus is configured such that the pressure differential of the biofeedstock does not exceed about 300 kPa as it flows through the adsorbent media array or one or more filter arrays.

[0111] Additionally, the methods of the present invention described above are carried out using a unique mobile device configured to be capable of operating with a power supply of about 100 kW to about 2000 kW of power. In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 1200 kW of power. In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 500 kW of power. In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 300 kW of power. In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 250 kW of power. One example of a generator suitable for operating the mobile devices of the present invention is a 135 kW 50 Hz 240 / 380V power supply generator.

[0112] In one embodiment, the method of the present invention described above comprises the step of: 2 The process is carried out using a unique mobile device mounted on a mobile transportation platform system having a total footprint of approximately 30 m. In one embodiment, the mobile device (not including the source and final product tanks) is approximately 30 m. 2 This means that a standard treatment facility will have a footprint of 225 m 2In some embodiments, the mobile equipment described herein has a footprint that can fit into a standard 40 ft shipping container (i.e., a container having an exterior length of 40 ft (12.18 m) and an interior width of 7 ft 8 in (2.31 m). In some embodiments, the mobile equipment described herein (not including the source tanks and the final product tanks) has a footprint that can fit into a standard 40 ft shipping container (i.e., a container having an exterior length of 40 ft (12.18 m) and an interior width of 7 ft 8 in (2.31 m). In some embodiments, the mobile equipment described herein has a footprint that can fit into a standard 20 ft High-Cube shipping container (i.e., a container having an exterior length of 5.89 M (12.18 m) and an interior width of 2.69 M (37 m). 3 The three-dimensional size (not including the source tank and the final product tank) can be accommodated in a container having a total volume of 1000 cubic meters.

[0113] FIG. 2 illustrates one embodiment of a mobile apparatus 200 for processing a biofeedstock to provide a biofeedstock dielectric fluid as a schematic process flow diagram. In this apparatus, the biofeedstock is provided to a biofeedstock tank 210. A pump and heater array 220, including a pump 222 and a heater 224, is fluidly connected to receive the oil from the biofeedstock tank. The pump and heater array 220 heats the biofeedstock to a temperature of at least about 60° C., or to a temperature of about 60° C. to about 80° C. for subsequent processing. The temperature of the biofeedstock during the process carried out by the apparatus of the present invention is higher than the temperature of biofeedstock processing in conventional large-scale plants. In one embodiment, the temperature of the biofeedstock is about 60° C. to about 80° C. during the filtration step in the method of the present invention, which is higher than the typical filtration temperature of about 4° C. to about 60° C. in conventional biofeedstock processing plants. In one embodiment, the temperature of the biofeedstock is about 70° C. to about 80° C. during the degassing step in the methods of the invention, which is higher, and in most cases much higher, than typical degassing temperatures in conventional biofeedstock processing plants.

[0114] In one embodiment, the oil is heated to a temperature range of about 60° C. to about 80° C. throughout the mobile device to provide a viscosity that is favorable for processing and general handling of the oil in the filter.

[0115] In an embodiment, the temperature of the biofeedstock leaving the pump and heater array 220 is measured at a temperature test station 272, and if the temperature is not high enough, the biofeedstock is redirected by the heat recycle valve 273 through the heat recycle loop 270 to the biofeedstock tank 210. In this manner, staged heating of the biofeedstock is facilitated. Staged heating is advantageous in that the oil does not heat up too quickly, in the event of potential decomposition or reaction of components in the oil. In addition, staged heating is advantageous in reducing the energy demand at any given time by distributing the energy load over a longer period of time. Staged heating is particularly advantageous for use of the mobile apparatus of the present invention in locations with limited power capacity. In an embodiment, the pump and heater array is designed to heat the biofeedstock from a starting temperature of 20° C. to a temperature of at least about 60° C., or from about 60° C. to about 80° C., when the maximum power demand is 110 kW. In one embodiment, the pump and heater array is designed to heat the biofeedstock from a starting temperature of 20° C. to a temperature of at least about 60° C., or from about 60° C. to about 80° C., when the maximum power demand is 90 kW. In one embodiment, the pump and heater array is designed to heat the biofeedstock from a starting temperature of 20° C. to a temperature of at least about 60° C., or from about 60° C. to about 80° C., when the maximum power demand is 80 kW.

[0116] In one embodiment, the test station is a sampling port where an aliquot of oil is withdrawn for testing to measure oil characteristics of interest such as temperature, dielectric loss factor, acid number (AV), water content, pour point, breakdown voltage, IFT, fire point, flash point, Gardner color, density, kinematic viscosity, and peroxide number, etc. In one embodiment, the test station is a sampling device such as an in-line sensor to measure oil characteristics of interest such as those listed above.

[0117] In one embodiment, the mobile unit 200 is configured to provide a biofeedstock temperature of about 60° C. to about 80° C. during the degassing and additive steps described below. In one embodiment, the mobile unit 200 is configured to provide a desired temperature profile by incorporating multiple heaters upstream from different components in the unit.

[0118] In some aspects, the pump and heater array may include multiple pumps arranged in series or parallel. In some aspects, the pump and heater array may include multiple heaters arranged in series or parallel. In some aspects, the pump and heater array may include a combination of multiple pumps and heaters arranged in series or parallel.

[0119] The sorbent media array 230 is fluidly connected to receive oil from the pump and heater array 220. In some embodiments, the sorbent media array 230 includes multiple sorbent media columns connected in parallel or in series. In some embodiments, the sorbent media array includes 2-8 sorbent media columns connected in parallel. In some embodiments, the sorbent media array includes 3-6 sorbent media columns connected in parallel. In some embodiments, the sorbent media array includes 1-5 sorbent media columns connected in parallel. In some embodiments, the sorbent media array includes 2-8 sorbent media columns connected in parallel with control capability to hold one or more columns in a standby mode while one or more columns are in a use mode at any given time.

[0120] One embodiment of a sorbent media array that may be used in one embodiment of a mobile apparatus is shown in the schematic process flow diagram of Figure 4, where heated biofeedstock flows through fluid line 431 into sorbent media array 430 and is then distributed to individual sorbent media columns 433 via fluid line 437. The flow of the biofeedstock is controlled by individually operable upstream valves 432 and individually operable downstream valves 434. After processing of the biofeedstock through the individual sorbent media columns 433, the separate streams of biofeedstock are directed by fluid line 435 and combined in fluid line 436 for subsequent processing steps.

[0121] In some embodiments, the adsorbent media columns of the adsorbent media array are connected in parallel to facilitate an average production flow rate in each of the individual adsorbent media columns not exceeding about 3 M3 / H. In some embodiments, the average production flow rate in each of the individual adsorbent media columns is not exceeding about 2 M3 / H. In some embodiments, the average production flow rate in each of the individual adsorbent media columns is about 0.2 M3 / H to about 3 M3 / H. In some embodiments, the average production flow rate in each of the individual adsorbent media columns is about 0.5 M3 / H to about 3 M3 / H. In some embodiments, the average production flow rate in each of the individual adsorbent media columns is about 1 M3 / H to about 3 M3 / H. In some embodiments, the average production flow rate in each of the individual adsorbent media columns is about 0.2 M3 / H to about 2 M3 / H. In some embodiments, the average production flow rate in each of the individual adsorbent media columns is about 0.5 M3 / H to about 2 M3 / H. In one embodiment, the average production flow rate in each individual adsorbent media column is from about 1 M3 / H to about 2 M3 / H.

[0122] In some embodiments, the sorbent media columns are connected in parallel to facilitate an overall production flow rate through the sorbent media array 230 of about 4 M3 / H to about 10 M3 / H. In some embodiments, the sorbent media columns are connected in parallel to facilitate an overall production flow rate through the sorbent media array 230 of about 6 M3 / H to about 10 M3 / H. In some embodiments, the sorbent media columns are connected in parallel to facilitate an overall production flow rate through the sorbent media array 230 of about 6 M3 / H to about 9 M3 / H.

[0123] In some aspects, the sorbent media column is a reusable sorbent media canister. For purposes of this discussion, a reusable canister is a canister that has at least a bottom retention screen attached, contains a sorbent media, and is configured so that the sorbent media can be removed from the canister and replaced with new sorbent media. In some aspects, the reusable canister is removable from the device to facilitate removal of the sorbent media from the device, and is configured to be reinstalled on the device after replacing the sorbent media with new sorbent media. In some aspects, the sorbent media column is a modular cartridge that is filled with the sorbent media. For purposes of this discussion, a modular cartridge is a pre-assembled cartridge that has at least a bottom retention screen attached, contains a sorbent media, and is configured to be removed from the device and replaced with a replacement modular cartridge.

[0124] It has been found to be advantageous to practice the invention such that the pressure differential of the biofeedstock does not exceed about 300 kPa as it flows through the mobile device. In certain embodiments, the methods of the invention are practiced such that the pressure differential of the biofeedstock is from about 100 kPa to about 300 kPa as it flows through either the adsorbent media array or the filter array. In certain embodiments, the methods of the invention are practiced such that the pressure differential of the biofeedstock is from about 100 kPa to about 250 kPa as it flows through either the adsorbent media array or the filter array.

[0125] The sorbent media of the sorbent media array 230 include solid sorbent media selected from materials that remove polar impurities from the biofeedstock. In certain embodiments, the sorbent media for removal of polar impurities used in the sorbent media columns of the sorbent media array 230 may be selected by the screening tests described above. Similarly, specific sorbent media embodiments may be selected as described above.

[0126] In some embodiments, the heated biofeedstock may be further circulated through an acid-reducing sorbent media array (not shown), where the sorbent media is selected to reduce the acids in the biofeedstock as described above. In some embodiments, the acid-reducing sorbent media array is located between the pump and heater array 220 and the sorbent media array 230. In some embodiments, the acid-reducing sorbent media array is located between the sorbent media array 230 and the first filter array 232, described below.

[0127] The first filter array 232 is fluidly connected to receive the oil from the sorbent media array 230, where the first filter array removes fines from the oil. The filters of the first filter array 232 are prepared from filter media and have the performance characteristics described above. In some embodiments, the filters of the first filter array are selected to retain particles of 10 microns or larger. In some embodiments, the filters of the first filter array are selected to retain particles of 5 microns or larger. In some embodiments, the filters of the first filter array have a beta value of at least 200. In some embodiments, the filters of the first filter array have a beta value of at least 500. In some embodiments, the filters of the first filter array have a beta value of at least 800. In some embodiments, the filters of the first filter array have a beta value of at least 1000.

[0128] The second filter array 234 is fluidly connected to receive the oil from the first filter array 232, and the second filter array 234 removes impurities and / or particles not captured by the first filter array 234. The filters of the second filter array 234 are prepared from filter media and have the performance characteristics described above. In some embodiments, the filters of the second filter array are selected to retain particles of 5 microns or larger. In some embodiments, the filters of the second filter array are selected to retain particles of 1 micron or larger. In some embodiments, the filters of the second filter array are selected to retain particles of 0.5 microns or larger. In some embodiments, the filters of the second filter array have a beta value of at least 800. In some embodiments, the filters of the second filter array have a beta value of at least 1000. It has been found that using filters having a beta value of at least about 800 provides superior protection of the degasser from particulate contamination.

[0129] In certain embodiments, each of the filter arrays described herein (including first filter array 232, second filter array 234, and polishing filter array 260) includes multiple filter columns connected in parallel or in series. In certain embodiments, any given filter array includes 2-8 filter columns connected in parallel. In certain embodiments, any given filter array includes 3-6 filter columns connected in parallel. In certain embodiments, any given filter array includes 3-5 filter columns connected in parallel. In certain embodiments, a filter array includes 2-8 filter columns connected in parallel, with the control capability to hold one or more columns in a standby mode while one or more columns are in a use mode at any given time. In certain embodiments, each of the filter arrays is configured in the same manner as the sorbent media array shown in FIG. 4, as described above.

[0130] The degasser and high vacuum system array 240 is fluidly connected to receive the oil from the second filter array 234. The degasser and high vacuum system array 240 includes a degasser 242 that enables removal of moisture and dissolved gases from the biofeedstock, and a high vacuum system 244 that generates a high vacuum sufficient to degas the fluid and remove moisture from the oil.

[0131] In some embodiments, the degasser and high vacuum system array 240 reduces the water content of the biofeedstock starting material from greater than 100 ppm to a biofeedstock dielectric fluid water content of about 40 ppm or less. In some embodiments, the degasser and high vacuum system array 240 reduces the water content of the biofeedstock starting material from greater than 100 ppm to a biofeedstock dielectric fluid water content of about 25 ppm or less. In some embodiments, the degasser and high vacuum system array 240 reduces the water content of the biofeedstock starting material from 100 ppm to 400 ppm to a biofeedstock dielectric fluid water content of about 25 ppm or less. In some embodiments, the low final water content is achieved by multiple passes of the biofeedstock through the degasser and high vacuum system array, either directly or by recirculation through the apparatus starting at any point, such as, for example, the pump and heater array, the adsorbent media array, the first filter array, or the second filter array.

[0132] In one embodiment, this low water content is achieved by recirculating the biofeedstock directly through the degasser and high vacuum system array 240, or by recirculating through a system starting with the biofeedstock tank 210, the pump and heater array 220, the adsorbent media array 230, the first filter array 232, or the second filter array 234.

[0133] The metering / mixing valve system and additive source array 250 is fluidly connected to receive oil from the degasser and high vacuum system array 240. The metering / mixing valve system and additive source array 250 comprises a metering / mixing valve system 251 and an additive source 256. The additive source 256 may be carried on the mobile transport platform or, alternatively, may be separately provided and positioned adjacent the mobile transport platform and fluidly connected to the metering / mixing valve system 251. The metering / mixing valve system 251 comprises a metering valve 252, a pump 253, and a mixer 254.

[0134] The metering / mixing valve system 250 facilitates and regulates the introduction of the additives. The additives are generally metered into the biofeedstock as a concentrated solution. The additives may be metered into the oil by volume, weight, or flow rate to achieve the appropriate level of final concentration of the additive in the biofeedstock dielectric fluid.

[0135] Additives added in liquid form to the biofeedstock at this stage of the process include suitable chemicals intentionally added to the biofeedstock insulating fluid to improve certain characteristics, such as pour point, viscosity, foaming, oxidation, charge tendency inhibitors, metal passivators or deactivators, antifoam agents, refinery process improvers, and optional colorants. It has been found to be highly advantageous to provide additives only in liquid form to facilitate mixing of the additives with the biofeedstock and provide uniform in-line mixing. Additionally, providing additives in liquid form to the biofeedstock in the mobile apparatus described herein avoids the need to incorporate solids handling equipment in the mobile apparatus, as well as the need to perform complex steps of solids handling in such methods carried out using mobile apparatus.

[0136] The polishing filter array 260 is fluidly connected to receive oil from the metering / mixing valve system and the additive source tank array 250. The filters of the polishing filter array 260 are prepared from filter media and have the performance characteristics described above. In some embodiments, the filters of the polishing filter array are selected to retain particles of 0.5 microns or larger. In some embodiments, the filters of the polishing filter array have a beta value of at least 800. In some embodiments, the filters of the polishing filter array have a beta value of at least 1000.

[0137] A final product tank 265 is fluidly connected to receive the oil from the polishing filter array 260 .

[0138] In an embodiment, at least one characteristic of the biofeedstock exiting pump and heater array 220 is measured at a pre-filter test station 274 depending on whether it meets any of the product requirements at this stage in the process, and the biofeedstock may be redirected through a first bypass loop 275 to the degasser and high vacuum system array 240 to bypass one or more of the sorbent media array 230, the first filter array 232, or the second filter array 234 by operation of a sorbent filter bypass valve 276, first filter bypass valves 233 and 277, and / or second filter bypass valves 235 and 278. In an embodiment, the oil characteristics measured at the pre-filter test station 274 include a measurement of the dielectric loss factor and / or the acid number. In one embodiment, if the dielectric loss factor measured at the pre-filter test station 274 is less than 0.20% at 25° C., the biofeedstock is diverted through a first bypass loop 275 to at least bypass the adsorbent media array 230.

[0139] In some embodiments, at least one characteristic of the bio-feedstock exiting the degasser and high vacuum system array 240 is measured at a post-degasser testing station 280. In some embodiments, the oil characteristics measured at the post-degasser testing station 280 include dielectric loss factor and / or acid number and / or water content.

[0140] If the product requirements at this stage in the process are not met, the biofeedstock is redirected through the first recycle loop 282 by operation of the post-degasser bypass valve 284 to flow again through the pump and heater array 220 and filter system. As shown in Figure 2, the biofeedstock is redirected to the biofeedstock tank 210 for convenience of staging and mixing before heating. Alternatively, the biofeedstock may be redirected to an intermediate staging tank or directly to the pump and heater array 220.

[0141] In an embodiment, if the dielectric loss factor measured at post-degasser testing station 280 is less than 0.20% at 25° C., the biofeedstock is redirected through the first recycle loop 282 by operation of the post-degasser bypass valve 284 to flow again through the pump and heater array 220 and the filter system. In an embodiment, if the water content measured at post-degasser testing station 280 is about 25 ppm, the biofeedstock is redirected through the first recycle loop 282, optionally by operation of the sorbent filter bypass valve 276, directly to the degasser and high vacuum system array 240. In an embodiment, the biofeedstock is repeatedly cycled through the degasser and high vacuum system array 240 until the desired water content specification is achieved.

[0142] In an embodiment, at least one characteristic of the biofeedstock exiting downstream from the metering / mixing valve system and additive source array 250 is measured at a post-metering test station 290, and if it does not meet the desired product requirements at this stage in the process, the biofeedstock is redirected through a second recycle loop 292 by operation of a post-metering bypass valve to flow again through the pump and heater array 220 and the filter system. As shown in FIG. 2, the post-metering test station 290 is located immediately downstream of the polishing filter array 260. Alternatively, the post-metering test station 290 may be located, for example, between the metering / mixing valve system and additive source array 250 and the polishing filter array 260, or optionally inside or adjacent to the final product tank 265. As shown in FIG. 2, the biofeedstock can enter the final product tank 265 and then be redirected through the second recycle loop 292 by operation of a post-metering bypass valve located in the final product tank 265. Alternatively, the post-metering bypass valve may be located immediately downstream of the post-metering test station and then in an alternative location as shown above.

[0143] In an embodiment, the characteristics of the bio-feedstock measured at the post-degasser testing station 290 include at least one of the following: dielectric loss factor, pour point, water content, acid number, Gardner color, density, viscosity, flash point, and fire point.

[0144] 2, the biofeedstock redirected through the second recycle loop 292 is redirected directly to the pump and heater array 220. Alternatively, the biofeedstock may be redirected to the biofeedstock tank 210 or an intermediate staging tank for convenience of staging and mixing before heating.

[0145] Once processing of the biofeedstock is complete such that the oil meets the desired performance specifications, the final product biofeedstock dielectric fluid goes to final product tank 265 for temporary storage and to facilitate transfer to transfer tank 268, which is easily transportable. In one embodiment, transfer tank 268 is a truck or truck trailer tank. In one embodiment, transfer tank 268 is a rail car tank.

[0146] In one embodiment, the final product tank 265 itself is an easily transportable tank, eliminating the need for a separate transfer tank 268.

[0147] In some embodiments, the final product tank 265 is physically located on the mobile transportation platform. Alternatively, in some embodiments, the final product tank 265 is not physically located on the mobile transportation platform. In some embodiments, providing the final product tank 265 as a component that is physically separate from (but fluidly connected to) the components of the mobile transportation platform is advantageous because such storage tanks are readily available, relatively easily replaceable, and serve no specialized function in the methods performed in processing the biofeedstock to provide the biofeedstock dielectric fluid described herein. In this embodiment, the critical components of the mobile transportation platform can be assembled on a relatively small platform at a manufacturing facility and transported to the destination of the intended use, and the final product tank 265 can be economically transported separately or sourced locally.

[0148] Similarly, in some embodiments, the biofeedstock tank 210 is physically located on the mobile transportation platform. Alternatively, in some embodiments, the biofeedstock tank 210 is not physically located on the mobile transportation platform. In some embodiments, providing the biofeedstock tank 210 as a component that is physically separate from (but fluidly connected to) the components of the mobile transportation platform is advantageous because such a storage tank is readily available, relatively easily replaceable, and serves no specialized function in the methods performed in processing the biofeedstock to provide the biofeedstock dielectric fluid described herein. In this embodiment, the critical components of the mobile transportation platform can be assembled on a relatively small platform at a manufacturing facility and transported to the destination of the intended use, and the biofeedstock tank 210 can be economically transported separately or sourced locally.

[0149] 3 illustrates one embodiment of a mobile apparatus 300 for processing a biofeedstock to provide a biofeedstock dielectric fluid as a schematic process flow diagram. In this apparatus, the biofeedstock is provided to a biofeedstock tank 310. A pump and heater array 320, comprising a pump 322 and a heater 324, is fluidly connected to receive oil from the biofeedstock tank. The pump and heater array 320 heats the biofeedstock to a temperature as described above in the context of FIG. 2.

[0150] In one embodiment, the temperature of the biofeedstock exiting pump and heater array 320 is measured at temperature test station 372, and if the temperature is not high enough, the biofeedstock is redirected by heat recycle valve 373 through heat recycle loop 370 to the biofeedstock tank 310. In this manner, staged heating of the biofeedstock is facilitated, as described above in the context of FIG.

[0151] The sorbent media array 330 is fluidly connected to receive oil from the pump and heater array 320. In one embodiment, the sorbent media array 330 includes multiple sorbent media columns connected in parallel or series, as described above in the context of FIG.

[0152] The adsorbent media of the adsorbent media array 330 comprises solid adsorbent media selected from materials that remove polar impurities from the biofeedstock, as described above in the context of FIG.

[0153] In some embodiments, the heated biofeedstock may further be circulated through an acid-reducing sorbent media array (not shown), where the sorbent media is selected to reduce the acids in the biofeedstock as described above. In some embodiments, the acid-reducing sorbent media array is located between the pump and heater array 320 and the sorbent media array 330. In some embodiments, the acid-reducing sorbent media array is located between the sorbent media array 330 and the first filter array 332, described below.

[0154] A first filter array 332 is fluidly connected to receive the oil from the sorbent media array 330, where the first filter array removes fines from the oil. The filters of the first filter array 332 are prepared from a filter media and have performance characteristics as described above in the context of FIG.

[0155] The second filter array 334 is fluidly connected to receive the oil from the first filter array 332, and the second filter array 334 removes impurities and / or particles not captured by the first filter array 334. The filters of the second filter array 334 are prepared from a filter media and have performance characteristics as described above in the context of FIG.

[0156] In certain aspects, each of the filter arrays described herein (including first filter array 332, second filter array 334, and polishing filter array 360) includes multiple filter columns connected in parallel or series as described above in the context of FIG. 2.

[0157] The degasser and high vacuum system array 340 is fluidly connected to receive the oil from the second filter array 334. The degasser and high vacuum system array 340 comprises a degasser 342 that allows for removal of water and dissolved gases from the biofeedstock, as described above in the context of Figure 2, and a high vacuum system 344 that generates a high vacuum sufficient to degas the fluid and remove water from the oil. In an embodiment, low water content is achieved by recirculating the biofeedstock directly through the degasser and high vacuum system array 340, or by recirculation through a system starting with the biofeedstock tank 310, the pump and heater array 320, the sorbent media array 330, the first filter array 332, or the second filter array 334.

[0158] The metering / mixing valve system and additive source array 350 is fluidly connected to receive oil from the degasser and high vacuum system array 340. The metering / mixing valve system and additive source array 350 comprises a metering / mixing valve system 351 and an additive source 356, which may be carried on the mobile transport platform or, alternatively, may be separately provided and positioned adjacent the mobile transport platform and fluidly connected to the metering / mixing valve system 351. The metering / mixing valve system 351 comprises a metering valve 352, a pump 353, and a mixing device 354. The metering / mixing valve system 350 facilitates and regulates the introduction of additives as described above in the context of FIG. 2.

[0159] The polishing filter array 360 is fluidly connected to receive oil from the metering / mixing valve system and additive source tank array 350. The filters of the polishing filter array 360 are prepared from filter media and have the performance characteristics described above.

[0160] In some embodiments, at least one characteristic of the bio-feedstock exiting the degasser and high vacuum system array 340 is measured at a post-degasser testing station 380. In some embodiments, the oil characteristics measured at the post-degasser testing station 380 include dielectric loss factor and / or acid number and / or water content.

[0161] If the product requirements at this stage in the process are not met, the biofeedstock is redirected by operation of post-degasser bypass valve 384 through the first recycle loop 382 directly back to the biofeedstock tank 310 to mix with unprocessed biofeedstock starting material. Biofeedstock is continuously withdrawn from the biofeedstock tank 310 and again flows through the pump and heater array 320, the filter system, and the degasser and high vacuum system array 340. This cycle is repeated until the oil characteristics measured at post-degasser testing station 380 meet specification requirements, indicating that the entire batch of biofeedstock starting material provided initially meets specifications.

[0162] Once the specification requirements are met at the post-degasser testing station 380, the biofeedstock is directed to metering / mixing valve system and additive source array 350, which comprises metering / mixing valve system 351 and additive source 356. Additive source array 350 may be carried on the mobile transport platform, or alternatively may be separately provided and positioned adjacent to the mobile transport platform and fluidly connected to metering / mixing valve system 351. Metering / mixing valve system 351 comprises metering valve 352, pump 353, and mixing device 354. Additives are introduced to the biofeedstock at metering / mixing valve system and additive source array 350, as described above in the context of FIG.

[0163] The polishing filter array 360 is fluidly connected to receive oil from the metering / mixing valve system and additive source tank array 350. The filters of the polishing filter array 360 are prepared from filter media and have performance characteristics as described above in the context of FIG.

[0164] In some embodiments, at least one characteristic of the biofeedstock exiting downstream from the metering / mixing valve system and additive source array 350 is measured at a post-metering testing station 390 to ensure it meets the desired end product biofeedstock dielectric fluid specifications. The biofeedstock dielectric fluid so prepared is returned to the biofeedstock tank 310 for temporary storage and to facilitate transfer to a transfer tank 368 that is easily transportable. In some embodiments, the transfer tank 368 is a truck or truck trailer tank. In some embodiments, the transfer tank 368 is a rail car tank. Further embodiments of the transfer tank 368 are as described above in the context of FIG. 2.

[0165] In some embodiments, the biofeedstock tank 310 itself is an easily transportable tank, eliminating the need for a separate transfer tank 368.

[0166] In an embodiment, at least one characteristic of the biofeedstock exiting pump and heater array 320 is measured at a pre-filter test station 374 depending on whether it meets any of the product requirements at this stage in the process, and the biofeedstock may be redirected through a first bypass loop 375 to the degasser and high vacuum system array 340 to bypass one or more of the sorbent media array 330, the first filter array 332, or the second filter array 334 by operation of the sorbent filter bypass valve 376, the first filter bypass valves 333 and 377, and / or the second filter bypass valves 335 and 378. In an embodiment, the oil characteristics measured at the pre-filter test station 374 include a measurement of the dielectric loss factor and / or the acid number. In one embodiment, if the dielectric loss factor measured at the pre-filter test station 374 is less than 0.20% at 25° C., the biofeedstock is diverted through a first bypass loop 375 to at least bypass the adsorbent media array 330.

[0167] In some embodiments, a mobile unit for processing a biofeedstock to provide a biofeedstock dielectric fluid has a production capacity of about 5 to about 40 MT per 24 hour operation. In some embodiments, the mobile unit has a production capacity of about 10 to about 30 MT per 24 hour operation. In some embodiments, the mobile unit has a production capacity of about 15 to about 30 MT per 24 hour operation. In some embodiments, the mobile unit has a production capacity of about 3 to about 10 M3 / H of dielectric fluid.

[0168] In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 2000 kW of power. In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 1200 kW of power. In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 500 kW of power. In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 300 kW of power. In some embodiments, the mobile devices described herein can be operated with a power supply of about 100 kW to about 250 kW of power. One example of a generator suitable for operating the mobile devices of the present invention is a 135 kW 50 Hz 240 / 380V power supply generator.

[0169] The ability to process biofeedstock to provide a biofeedstock dielectric fluid at this low power level is surprising because typical scheduled operations have much higher power demands to operate the equipment to achieve adequate commercial productivity. The relatively low power supply requirements of the inventive system are a significant advantage because the mobile equipment can be operated economically and virtually anywhere due to its portability and ease of setup to support the system in locations without significant infrastructure.

[0170] In one embodiment, the mobile apparatus, including the pump and heater array, the adsorbent media array, the one or more filter arrays, the degasser and high vacuum system array, the additive metering / mixing valve system, and the piping system (but not including the source tank and the final product tank), is approximately 30 m 2 In one embodiment, the mobile equipment, including the pump and heater array, the adsorbent media array, the one or more filter arrays, the degasser and high vacuum system array, the additive metering / mixing valve system, and the piping system (but not including the source tank and the final product tank), has a footprint of about 30 m. 2 This means that a standard treatment facility will typically have a footprint of 225 m 2 This is in stark contrast to conventional process conditions, which have a footprint of more than 100 mm. In one embodiment, a mobile apparatus including a pump and heater array, an adsorbent media array, one or more filter arrays, a degasser and high vacuum system array, an additive metering / mixing valve system, and a piping system (but not including a source tank and a final product tank) has a footprint that can fit into a standard 40-foot shipping container (i.e., a container having an external length of 40 feet (12.18 m) and an internal width of 7 feet 8 inches (2.31 m). In one embodiment, a mobile apparatus including a pump and heater array, an adsorbent media array, one or more filter arrays, a degasser and high vacuum system array, an additive metering / mixing valve system, and a piping system (but not including a source tank and a final product tank) has a footprint that can fit into a standard 40-foot shipping container (i.e., a container having an external length of 40 feet (12.18 m) and an internal width of 7 feet 8 inches (2.31 m). In one embodiment, the mobile equipment, including the pump and heater array, the adsorbent media array, one or more filter arrays, the degasser and high vacuum system array, the additive metering / mixing valve system, and the piping system (but not including the source tank and the final product tank), is packed into a standard 20 foot High-Cube shipping container (i.e., 5.89 M length, 2.35 M width, and 2.69 M height, i.e., 37 m 3The three-dimensional size of the device can be accommodated in a container having a total volume of 100 mm or less.

[0171] In some aspects, the mobile devices described herein may further include features such as buffer tanks, valves, control systems, etc. to enhance operation and control the process.

[0172] In certain aspects, the mobile devices described herein may further comprise storage and processing tanks, totes, or containers to allow for the feeding of base fluids and concentrated components to the system and to provide for subsequent packaging or storage of the fluids after production of the biofeedstock dielectric fluid.

[0173] In one embodiment, the mobile device is located within a convenient transportation distance of several miles from at least one point of use of the dielectric fluid, which is used in electrical power equipment such as transformers, circuit breakers, and pipe-type cables.

[0174] In some embodiments, the mobile unit is located within a convenient transportation distance of several miles from the source of at least one of the biofeedstock raw materials or starting materials. In some embodiments, the mobile unit is located co-located with the production site of the biofeedstock raw materials or starting materials.

[0175] In some aspects, the mobile devices described herein are conveniently located to serve the dielectric fluid needs of an area, such as an economic zone, a county, a state, a province, or a country.

[0176] In some embodiments, the mobile units described herein are used as part of a production fleet of at least three mobile units to serve the dielectric fluid needs of a region. In some embodiments, the mobile units described herein are used as part of a production fleet of at least five mobile units to serve the dielectric fluid needs of a region.

[0177] All percentages and ratios used herein are weight percentages and ratios unless otherwise indicated. All patents, patent applications (including provisional applications) and publications cited herein are incorporated by reference for all purposes as if individually incorporated. Numerous features and advantages of the present invention, which are intended to be described herein, have been set forth in the foregoing description. However, although specific forms or embodiments of the present invention have been described, it should be understood that various modifications, including modifications in shape and arrangement of parts, can be made without departing from the spirit and scope of the present invention.

Claims

1. 1. A method for processing a bio-feedstock to provide a bio-feedstock dielectric fluid in a mobile unit, comprising: Providing a biofeedstock starting material; heating the bio-feedstock to a temperature of at least about 60° C.; circulating the heated biofeedstock through an adsorbent media array, the adsorbent media array removing polar impurities from the biofeedstock; circulating the heated oil through one or more filter arrays, the filter arrays collectively retaining particles 0.5 microns or larger having a beta value of at least 200; circulating the heated oil through a degasser and high vacuum system array; adding additives in liquid form, including antioxidants, optional pour point depressants, and optional colorants, to said biofeedstock by use of an additive metering / mixing valve system to provide a biofeedstock dielectric fluid; and collecting the bio-feedstock dielectric fluid. Where: i) the biofeedstock is maintained at a temperature of at least about 60° C. throughout the process; ii) the mobile device is configured such that the pressure differential of the biofeedstock when flowing through the adsorbent media array or the one or more filter arrays does not exceed about 300 kPa; iii) the mobile device is configured to be capable of operating on a power supply of about 100 kW to about 2000 kW of power; iv) the mobile device is about 30 m ２ Mounted on a mobile transportation platform system having a total footprint of: wherein the bio-based feedstock dielectric fluid is (a) a dielectric loss factor of less than or equal to about 0.2% at 25° C.; (b) an acid value (AV) of less than about 0.09 milligrams KOH / gram oil; (c) a moisture content of about 25 ppm or less; and (d) exhibiting a pour point of less than about -5°C.

2. 2. The method of claim 1, wherein the biofeedstock is a vegetable oil.

3. 2. The method of claim 1, wherein the bio-feedstock is selected from the group consisting of castor oil, coconut oil, corn oil, cottonseed oil, cramby oil, flaxseed oil, jojoba oil, kukui nut oil, lesquerella oil, linseed oil, olive oil, palm oil, peanut oil, pine nut oil, rapeseed oil, safflower oil, sunflower oil, soybean oil, and veronica oil, and mixtures thereof.

4. 4. The method of any one of claims 1 to 3, wherein the biofeedstock starting material has an acid value of about 0.5 to about 0.01 milligrams KOH / gram oil, or the biofeedstock starting material has an acid value of about 0.06 milligrams KOH / gram oil or less, or the biofeedstock starting material has an acid value of about 0.03 milligrams KOH / gram oil or less.

5. 5. The method of any one of claims 1 to 4, wherein the biofeedstock starting material has a water content greater than about 100 ppm, or the biofeedstock starting material has a water content of from about 100 ppm to about 400 ppm.

6. 6. The method of any one of claims 1 to 5, wherein the bio-feedstock starting material has a dielectric loss factor at 25°C of at least 0.5%, or the bio-feedstock starting material has a dielectric loss factor at 25°C of at least 0.7%, or the bio-feedstock starting material has a dielectric loss factor at 25°C of at least 0.8%, or the bio-feedstock starting material has a dielectric loss factor at 25°C of at least 0.9%, or the bio-feedstock starting material has a dielectric loss factor at 25°C of at least 1%.

7. 7. The method of any one of claims 1 to 6, wherein the adsorbent media array comprises an adsorbent media selected from attapulgite clay, bauxite clay, bentonite clay, silicates, aluminates, magnesium silicate, diatomaceous earth, fuller's earth, bleaching earth, resins, and mixtures thereof.

8. 7. The method of any one of claims 1 to 6, wherein the adsorbent media array comprises an adsorbent media that is a phyllosilicic clay material selected from halloysite, kaolinite, illite, montmorillonite, vermiculite, talc, sepiolite, attapulgite, and pyrophyllite.

9. The method of any one of claims 1 to 8, wherein the sorbent media array comprises solid sorbent media having a particle size of 30 to 90 mesh.

10. 10. The method of any one of claims 1 to 9, wherein the bio-feed dielectric fluid has a dielectric loss factor of about 0.18% or less at 25°C, or the bio-feed dielectric fluid has a dielectric loss factor of about 0.12% or less at 25°C, or the bio-feed dielectric fluid has a dielectric loss factor of about 0.1% or less at 25°C, or the bio-feed dielectric fluid has a dielectric loss factor of about 0.9% or less at 25°C, or the bio-feed dielectric fluid has a dielectric loss factor of about 0.08% or less at 25°C.

11. The bio-feed dielectric fluid has a dielectric loss factor of 0.005-0.2% at 25°C, or the bio-feed dielectric fluid has a dielectric loss factor of 0.005-0.18% at 25°C, or the bio-feed dielectric fluid has a dielectric loss factor of 0.005-0.15% at 25°C, or the bio-feed dielectric fluid has a dielectric loss factor of 0.005-0.12% at 25°C, or the bio-feed dielectric fluid has a dielectric loss factor of 0.01 or the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01-0.18% at 25°C, or the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01-0.15% at 25°C, or the bio-feedstock dielectric fluid has a dielectric loss factor of 0.01-0.12% at 25°C, or the bio-feedstock dielectric fluid has a dielectric loss factor of 0.03-0.2% at 25°C, or or the bio-feed oil dielectric fluid has a dielectric loss factor of 0.03-0.18% at 25°C, or the bio-feed oil dielectric fluid has a dielectric loss factor of 0.03-0.15% at 25°C, or the bio-feed oil dielectric fluid has a dielectric loss factor of 0.03-0.12% at 25°C, or the bio-feed oil dielectric fluid has a dielectric loss factor of 0.05-0.2% at 25°C, or the bio-feed oil dielectric fluid has a dielectric loss factor of 0.05-0.18% at 25°C.

10. The method of any one of claims 1 to 9, wherein the bio-feed dielectric fluid has a dielectric loss factor at 25°C of 0.05 to 0.15%, or the bio-feed dielectric fluid has a dielectric loss factor at 25°C of 0.05 to 0.12%, or the bio-feed dielectric fluid has a dielectric loss factor at 25°C of 0.07 to 0.15%, or the bio-feed dielectric fluid has a dielectric loss factor at 25°C of 0.08 to 0.15%.

12. 12. The method of any one of claims 1 to 11, wherein the mobile apparatus is provided with a plurality of sorbent media arrays in series, a first sorbent media array comprising a media selected to reduce acid number, and a second sorbent media array comprising a media selected to remove polar impurities.

13. The method of any one of claims 1 to 12, wherein the one or more filter arrays comprise a non-water-swellable filter media comprising a material selected from polypropylene and HDPE.

14. the one or more filter arrays a first filter array, the filters of the first filter array being selected to retain particles of 10 microns or larger, or the filters of the first filter array being selected to retain particles of 5 microns or larger; a second filter array, wherein the filters of the second filter array are selected to retain particles of 5 microns or larger, or the filters of the second filter array are selected to retain particles of 1 micron or larger, or the filters of the second filter array are selected to retain particles of 0.5 microns or larger; 14. The method of any one of claims 1 to 13, comprising: a polishing filter array, the filters of which are selected to retain particles of 0.5 microns or larger.

15. the filters of the first filter array have a beta value of at least 200, or the filters of the first filter array have a beta value of at least 500, or the filters of the first filter array have a beta value of at least 800, or the filters of the first filter array have a beta value of at least 1000; the filters in the second filter array have a beta value of at least 800, or the filters in the second filter array have a beta value of at least 1000; 15. The method of claim 14, wherein the filters of the polished filter array have a beta value of at least 800, or the filters of the polished filter array have a beta value of at least 1000.

16. 16. The method of claim 14 or 15, wherein the first filter array and the second filter array are located immediately downstream from the adsorbent media array in the mobile apparatus, and the polishing filter array is located immediately downstream from the additive metering / mixing valve system in the mobile apparatus.

17. 17. The method of any one of claims 1-16, wherein the pressure differential of the biofeedstock through the adsorbent media array is from about 100 kPa to about 300 kPa, or the pressure differential of the biofeedstock through the adsorbent media array is from about 100 kPa to about 250 kPa, or the pressure differential of the biofeedstock through any filter array is from about 100 kPa to about 300 kPa, or the pressure differential of the biofeedstock through any filter array is from about 100 kPa to about 250 kPa.

18. 18. The method of any one of claims 1-17, wherein the flow rate of the biofeedstock through any of the adsorbent media arrays does not exceed about 10 M3 / H / M2, or the flow rate of the biofeedstock through any of the adsorbent media arrays is from about 3 to about 10 M3 / H / M2, or the flow rate of the biofeedstock through any of the adsorbent media arrays is from about 6 to about 10 M3 / H / M2.

19. 19. The method of any one of claims 1-18, wherein the flow rate of the biofeedstock through any filter array does not exceed about 100 M3 / H / M2, or the flow rate of the biofeedstock through any filter array is from about 30 to about 100 M3 / H / M2, or the flow rate of the biofeedstock through any filter array is from about 60 to about 100 M3 / H / M2.

20. 20. The method of any one of claims 1-19, wherein the bio-sourced dielectric fluid has an IFT of at least about 20 dynes / cm at 25°C, or wherein the bio-sourced dielectric fluid has an IFT of at least about 22 dynes / cm at 25°C.

21. 21. The method of any one of claims 1 to 20, wherein the bio-feedstock dielectric fluid has a breakdown voltage of at least about 35 kilovolts (kV) measured at 25°C, or the bio-feedstock dielectric fluid has a breakdown voltage of 50 kV to 100 kV measured at 25°C, or the bio-feedstock starting material has a breakdown voltage of 60 kV to 100 kV measured at 25°C.

22. 22. The method of any one of claims 1 to 21, wherein the bio-feed dielectric fluid has a water content of about 25 ppm to about 5 ppm, or the bio-feed dielectric fluid has a water content of about 20 ppm to about 5 ppm.

23. 23. The method of any one of claims 1 to 22, wherein the water content of the biofeed is reduced from a biofeed starting material water content of greater than 100 ppm to a biofeed dielectric fluid water content of about 40 ppm or less, or the water content of the biofeed is reduced from a biofeed starting material water content of greater than 100 ppm to a biofeed dielectric fluid water content of about 25 ppm or less, or the water content of the biofeed is reduced from a biofeed starting material water content of 100 ppm to 400 ppm to a biofeed dielectric fluid water content of about 25 ppm or less.

24. 24. The method according to any one of claims 1 to 23, wherein said dielectric fluid is free of silicone compounds, and / or free of phospholipids, and / or free of pigments, and / or free of lecithin, and / or free of fatty acids, and / or free of mono- and diglycerides, and / or free of mineral acids, and / or free of mineral oils, and / or free of alcohols, and / or free of colouring impurities, and / or free of sulphur compounds, and / or free of cresols, and / or free of polyaromatic hydrocarbons, and / or free of halogenated compounds, and / or free of amines.

25. 25. The process of any one of claims 1 to 24, wherein the biofeedstock is maintained at a temperature of about 60° to about 80° C. throughout the process.

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